 Advances in Anthropology  2013. Vol.3, No.2, 112-120  Published Online May 2013 in SciRes (http://www.scirp.org/journal/aa)                              http://dx.doi.org/10.4236/aa.2013.32015   Copyright © 2013 SciRes.  112  Integrating Biomarkers into Research with Latino Immigrants    in the United States  Heather H. McClure1,2, J. Josh Snodgrass2, Charles R. Martinez Jr.1, J. Mark Eddy3,  Thomas W. McDade4, Melanie J. Hyers5, Anne Johnstone-Díaz6  1Center for Equity Promotion, College of Education, University of Oregon, Eugene, USA  2Department of Anthropology, University of Oregon, Eugene, USA    3School of Social Work, University of Washington, Seattle, USA  4Department of Anthropology and Institute for Policy Research, Northwestern University,    Evanston, USA  5Department of Romance Languages, University of Oregon, Eugene, USA  6Family Resource Center, Bethel School District, Eugene, USA  Email: hmcclure@uoregon.edu    Received February 5th, 2013; revised March 5th, 2013; accepted March 15th, 2013    Copyright © 2013 Heather H. McClure et al. This is an open access article distributed under the Creative Com-  mons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, pro-  vided the original work is properly cited.  Despite extensive research into the toll of persistent psychosocial stress on individual physiology and  health, little is known about the effects of chronic biosocial stress for immigrant populations. In the pre-  sent paper, the authors review challenges encountered when integrating minimally-invasive stress-related  biomarkers (e.g., blood pressure, Epstein-Barr Virus [EBV] antibodies, C-reactive protein [CRP], and  salivary cortisol), as well as anthropometric (e.g., height, weight, waist circumference) and metabolic  measures (e.g., glucose, cholesterol), into research with Latino immigrant adults and families in Oregon,  USA. Finally, the authors present lessons learned and discuss strategies to support the full engagement of  Latino immigrants as participants in studies that rely on the collection of biological data as a central  component of research into psychosocial stress and its effects.    Keywords: Biomarker; Latino; Immigrant; Psychosocial Stress  Introduction  Despite the size of the Latino population in the United States  (16.7% of the US population [US Census Bureau, 2011]), the  role of stress as a contributor to poor mental and physical health  outcomes among Latinos is little known. This is especially true  for the approximately 40% of Latinos in the United States who  are foreign born (Lopez & Taylor, 2010), and the over 50% of  Latino families in which children are US born of immigrant  parents (The Urban Institute, 2010).  Many immigrant families, particularly if recently arrived to  the US, experience stressors (i.e., exposure to circumstances)  that can contribute to profound psychosocial stress (i.e., the  extent to which an individual is challenged to maintain function  [McEwen, 2000]). Common stressors for immigrant families  include low socioeconomic status (SES), challenges of adapting  to life in the U.S. (acculturation), employment uncertainty, dis-  crimination, and concerns about legal status, among others  (Rumbaut & Portes, 2001; Vega & Kolody, 1985; Vega et al.,  2004). In states with unprecedented recent population growth of  immigrants, such as Oregon and North Carolina, there may be  few formal buffers (e.g., well-established ethnic enclaves, cul-  turally-competent services) against such stressors (Capps et al.,  2002; Smokowski & Bacallao, 2007). Though extensive re-  search has been conducted on the toll of persistent psychosocial  stress on individual physiology and health (e.g., Kiecolt-Glaser  et al., 1994; McDade et al., 2007), little is known about the  effects of chronic biosocial stress for Latino immigrants.  Research with US born populations suggests that chronic  psychosocial stress is a key link between challenging social  contexts and negative health outcomes (Dressler et al., 2005;  William et al., 2003). The measurement of stress among immi-  grant populations, however, may present unique challenges. As  the notion of “stress” is deeply culturally-bound, dominant no-  tions regarding “stress” in the US may be distinct from and  even unrecognizable to immigrants, especially if they are re-  cently arrived. Attempts to measure self-reported Latino immi-  grant stress and its effects using standardized instruments,  which are often validated through studies with second and third  generation Latinos in the US, may fail to resonate with immi-  grant respondents. More sensitive and objective measures of  stress are needed for a clearer understanding of links between  contexts favoring stress and health outcomes among Latino  immigrants (Martinez, 2006).  To begin to fill these knowledge gaps, in 2007, the Latino  Research Team (LRT) at the Oregon Social Learning Center  (OSLC) initiated two pilot research projects to determine the  feasibility of collecting biological data among Latino immi-  grants, and to better “map” the pathways through which psycho-  social stressors related to acculturation, discrimination, and  SES, among others, influence self-report and biological meas-  ures of immigrant stress. Both projects utilized minimally-   
 H. H. MCCLURE    ET    AL.  invasive techniques (i.e., saliva collection and pricking a par-  ticipant’s finger with a lancet for the collection of a few drops  of blood on filter paper cards). Our use of multiple, complemen-  tary biological markers of stress is novel, as most investigations  into stress and health have relied upon measures of self-re-  ported stress, rather than upon physiological measures such as  stress biomarkers (McDade et al., 2007); this is particularly true  for studies involving immigrant populations.  In the present paper, we review challenges encountered when  integrating stress-related biomarkers (e.g., blood pressure, Ep-  stein-Barr Virus [EBV] antibodies, C-reactive protein [CRP],  and cortisol), as well as anthropometric (e.g., height, weight,  waist circumference) and metabolic measures (e.g., glucose, cho-  lesterol), into research with Latino immigrant adults and fami-  lies in Oregon. Finally, we present lessons learned and discuss  strategies to support the full engagement of Latino immigrants  in studies that rely on the collection of biological data as a com-  ponent of research into psychosocial stress and its effects.  Overview of Pilot Studies  Despite the apparent value of incorporating stress biomarkers  into research with Latino immigrants in the US, few previous  studies had done so and many questions regarding feasibility  remain (Ryan et al., 2006; Steffen et al., 2006). To examine  questions relating to participants’ comfort with biomarker me-  thods, in 2007, we began a two-phase Latino stress and health  study (a.k.a. “The Farmworker Study” or TFS) in collaboration  with a highly respected farmworker housing and social service  organization, and with biological anthropologists at the Univer-  sity of Oregon and Northwestern University. This cross-sec-  tional study took place in three geographically distant housing  complexes in Oregon’s northern Willamette Valley; analyses  involved 132 Latino immigrant adults (≥18 years of age; 86  females, 46 males; 96% Mexican origin; 96% were parents).  Approximately 38% of men and 33% of women had a third  grade education or less, with 11% of men and 19% of women  completing high school or receiving post-secondary education.  Ninety-three percent of men and 46% of women were em-  ployed. Heads of household reported an annual median house-  hold income of $15,825 to support an average household of five  people (SD = 1.5).  This project was followed by the 2009-2010 Stress and Ac-  culturation Project (SAP), which focused on links among stress,  health, and parenting in 44 Latina immigrant mothers and their  young children in the 1st to 3rd grades (93% Mexican origin),  and collaboration with the University of Oregon. About a third  of mothers (32%) had a third grade education or less, and 23%  completed high school or received post-secondary education.  Forty-three percent of mothers worked outside the home. Mo-  thers reported an annual median household income of $18,750  to support an average household of five people (SD = 1.5).    Recruitment for Studies  Study samples were drawn from non-probability designs and  recruitment was conducted through trusted social networks, and  by recruiters who share characteristics of the target study popu-  lation (Martinez et al., 2012; Villarruel et al., 2006). TFS took  place during the busiest time of year for agricultural workers.  Despite this, recruitment was completed quickly with staff of  our partner organization recruiting all participants within 10 days.  In the SAP pilot, 24 families in the Eugene/Springfield area  were recruited in one week. Our participation rate for both pilot  studies was 98%.  The Farmworker Study  On a single day, residents participated in a health assessment  and responded to a 20 minute interview. Senior staff from the  LRT and the farmworker organization collaborated on the de-  sign of the interview. Due to its brevity, specific questions were  drawn from a larger assessment battery that had been exten-  sively developed by the LRT for use with the Latino population  in Oregon (see Martinez & Eddy, 2005; Martinez et al., 2009).  A focus group composed of Latino immigrant farmworkers  reviewed the questionnaire, and changes were made per focus  group findings. The SAP interview was modeled after that for  TFS, with items added relating to depression and parenting.  The Institutional Review Boards at OSLC and the University of  Oregon approved all research protocols and all participants  provided written consent prior to the assessment. All respon-  dents were assessed in Spanish.  Assessors for TFS included LRT professional interviewers,  staff from our partner organization, volunteer undergraduate  students, and community members. All assessors received four  hours of intensive training in how to conduct the interview and  collect biological and health data, and between four and eight  hours of on-site supervision. Assessments were scheduled for  Saturday and Sunday mornings (residents were given a choice  of days), and childcare was provided.  Assessments for the first study were conducted in the com-  munity center in each housing complex. The health exam in-  volved measures of blood pressure, height, weight, and waist  circumference (WC). Staff used a lancet to prick the partici-  pant’s finger to collect a drop of blood for the immediate meas-  urement of fasting glucose and total cholesterol (all participants  had fasted [>8 hours]), and two drops of blood to dry onto filter  paper for later laboratory analyses of EBV antibodies and CRP.  Assessors then conducted the interview and provided a one-on-  one saliva collection demonstration (see cortisol measurement  section below for detail). Finally, each participant met with a  health educator to review their health values. Participants with  measures indicating need for follow-up were referred to part- nering public health agencies. During the following week, staff  made reminder calls to participants the evening before and the  day of each saliva collection. A week after the health assess-  ment, a staff member collected participants’ saliva samples and  transported them to the laboratory for later analysis. Partici-  pants received $30 in compensation. Findings from this study  have been reported elsewhere (McClure et al., 2010a, 2010b,  2010c, 2012; Midttveit et al., 2010; Squires et al., 2012).  The Stress & Acculturation Project  The SAP study incorporated similar indicators and involved  only LRT assessors. This study was conducted in the homes of  participating families and involved two visits approximately  one week apart. At the first home visit, data were collected on  mother and children’s height, weight, WC, and blood pressure.  Staff also conducted a 30 - 40 minute interview with mothers  and provided training in the collection of saliva samples.  Though we measured blood pressure for both mothers and chil-  dren, our focus was on mothers’ blood pressure; we measured  children’s blood pressure as part of the health information   Copyright © 2013 SciRes. 113  
 H. H. MCCLURE   ET    AL.  provided to families as an incentive for participation. Mothers  received $15 at the completion of the first home visit, and chil-  dren were given a toy of their choice.  The second home visit occurred upon completion of saliva  collection. A few drops of blood generated through finger stick  were analyzed for separate measures for mother and child.  Mothers’ fingers were pricked first and analyzed for fasting  glucose and lipid levels (i.e., total cholesterol, HDL cholesterol,  triglycerides, and calculated LDL cholesterol; equipment in-  formation below). The assessor then pricked the child’s finger  to test for hemoglobin levels (a test for anemia; equipment in-  formation below). Mothers were given a copy of their own and  their child’s health values, health information in Spanish, and a  list of local clinics for follow-up if indicated. An exit interview  (5 minutes) was administered to the mother regarding her and  her child’s experience in the project. Assessors also picked up  saliva samples and delivered them to a lab for later analysis.  For compensation, mothers received $15 and children chose a  toy.  Measurement of Psychosocial Stress  Our investigation of physiological measures of psychosocial  stress is informed by a large body of research dating back to  Selye (1956), and integrates complementary biomarkers to bet-  ter understand how stress gets “under the skin” to affect health  (McDade, 2007). The following briefly reviews the specific  biomarkers and health measures used in TFS and SAP and  measurement techniques.  Cortisol  The hypothalamic-pituitary-adrenal (HPA) axis has been  recognized for its important role in the stress response and, in  particular, its role in energy mobilization (Sapolsky et al., 2000).  Cortisol, the primary glucocorticoid hormone in humans and a  marker of HPA activity, has a strong diurnal rhythm with high-  est levels typically occurring in the early morning hours and  lowest levels in the late evening (Kirschbaum & Hellhammer,  2000). Over time, everyday negatively perceived experiences  can contribute to atypical cortisol fluctuation with either high or  blunted cortisol levels in the morning, and flatter diurnal curves  over the day. Although increased cortisol release in response to  acute stressors can be adaptive, the prolonged activation of the  HPA axis can lead to HPA dysregulation with downstream  effects including the progression of various diseases, such as  obesity, type 2 diabetes, and cardiovascular disease (McEwen  & Wingfield, 2003). Studies indicate that Latinos have signifi-  cantly flatter diurnal cortisol slopes than Caucasians due per-  haps to greater stress exposure, including perceived discrimina-  tion (DeSantis et al., 2007).  Measurement. In TFS, cortisol was measured from six saliva  samples: each participant collected three samples each day for  two consecutive days. The SAP study involved nine samples per  participant with mothers collecting their own and their child’s  saliva three times a day for three consecutive days. Adult par-  ticipants collected 1.0 mL of saliva in Eppendorf tubes from  themselves (and from any participating child) upon awakening,  within 30 minutes of awakening, and a half-hour before bed-  time. In addition, adult participants were asked to record the  date and time of the collection of each sample. In SAP, mothers  were asked to maintain a saliva diary for themselves and their  child that recorded the exact time and date of sample collection,  substances used in the prior 24 hours that might interfere with  cortisol assay (e.g., medications, tobacco, and alcohol), and  major events during the day. Participants were instructed not to  eat, smoke, brush their teeth, drink alcoholic or caffeinated  beverages, or engage in intense physical activity in the 30 min-  utes prior to each sample due to possible changes in salivary  cortisol concentrations (Pollard & Ice, 2007). To ensure the  stability of salivary cortisol (Kirschbaum & Hellhammer, 2000),  participants were instructed to refrigerate all saliva samples  until a staff member collected them during a follow-up visit and  transported them in an ice chest to the Snodgrass laboratory.  Once in the lab, all samples were stored frozen at −30˚C in a  secure location until analysis. All cortisol samples were ana-  lyzed using enzyme immunoassay with a commercially avail-  able salivary cortisol assay kit (Salimetrics, State College, PA).  Epstein-Barr Virus Antibodies  Over the past two decades, EBV antibody levels have been  applied as a useful biomarker of chronic psychosocial stress  (McDade, 2007). EBV is a ubiquitous herpes virus for which  80 to 90 percent of adults and adolescents in the US test posi-  tive by the age of 40 (Jones & Straus, 1987), though little is  known about EBV prevalence among children. Once infected,  individuals harbor the virus for life in infected cells. Adequate  cell-mediated immune function maintains the virus in a latent  state and most adults infected with EBV are clinically asymp-  tomatic (Henle & Henle, 1982). Stress-induced immunosuppres-  sion, however, allows EBV to reactivate, which may trigger an  antibody response (Glaser et al., 1991). Thus, EBV antibodies  provide a measure of cell-mediated immune function over the  duration of several days or weeks (McDade, 2007). Researchers  have found elevations in EBV antibody levels among adults in  poor quality marriages (Kiecolt-Glaser et al., 1994), children  experiencing family stress (McDade et al., 2000), and Latino  men who report discrimination stress (McClure et al., 2010a,  2010b). Because of EBV’s utility as a marker of chronic psy-  chosocial stress, it has been incorporated into the National  Longitudinal Study of Adolescent Health (Add Health) and the  World Health Organization’s Study on Global Ageing and  Adult Health (SAGE).  Measurement. EBV was measured through the collection of  dried blood spot samples. Following standard procedures  (McDade et al., 2000), each participant had their finger pricked  with a sterile disposable lancet; 2 - 5 drops (approximately 50  µL) of whole blood were then collected on standardized filter  paper (No. 903; Whatman). Blood spot samples were then dried  overnight, and stored at −80˚C until laboratory analysis. Blood  spot EBV antibodies were measured using DiaSorin (Stillwater,  MN) EBV VCA IgG kits according to a high-sensitivity en-  zyme-linked immunosorbent assay (ELISA) protocol described  elsewhere (McDade et al., 2000). In our studies, all participants  were seropositive for EBV antibodies. Protocols in English and  Spanish are available online    (http://www.bonesandbehavior.org/dbsprotocol.pdf).  C-Reactive Protein  CRP is a nonspecific acute phase reactant that rapidly in-  creases in plasma concentration in response to inflammation,  infection, and injury (Pepys & Hirschfeld, 2003). Studies have  Copyright © 2013 SciRes.  114   
 H. H. MCCLURE    ET    AL.  linked minor CRP elevations, previously considered clinically  normal, with increased cardiovascular risk (Ridker et al., 1998).  Elevated levels of CRP are linked to factors such as obesity  (Rexrode et al., 2003), and with several dimensions of psycho-  social stress, including lack of social integration (Ford et al.,  2006) and low SES (Nazmi & Victora, 2007). Few studies in-  volving CRP have been conducted with Latino populations  (Midttveit et al., 2010).  Measurement. CRP was measured through the collection of  dried blood spot samples following the same procedure descry-  bed above for EBV. CRP samples were used for two purposes.  First, CRP was used to identify acute infection or tissue injury,  which could potentially impact EBV antibody levels. Second,  subclinical CRP concentrations were used as indicators of chro-  nic inflammation, and for the examination of whether low-  level elevations CRP concentrations related to psychosocial  stressors. CRP was analyzed using a high-sensitivity enzyme  immunoassay protocol (McDade et al., 2004) that uses Bio-  Design International (Saco, ME) capture and detection anti-  bodies.  Blood Pressure  It is well-established that blood pressure is associated with  diet and physical activity, among other lifestyle factors. In ad-  dition, psychosocial stress related to perceived discrimination  and low SES have been shown to correlate with elevated sys-  tolic blood pressure (SBP) and diastolic blood pressure (DBP;  Dressler et al., 2005). The few studies among Latino adults in  the US reveal important gender differences (Steffen et al.,  2006), with higher discrimination stress relating to higher SBP  among men only (McClure et al., 2010a).  Measurement. For the first pilot study, blood pressure (SBP  and DBP) was measured using an Omron HEM-422CRLC  manual inflation oscillometric blood pressure monitor (Vernon  Hills, IL); for each individual, blood pressure was measured  twice, separated by at least 10 minutes. In a few cases involving  obese participants, blood pressure was measured with a manual  sphygmomanometer by a registered nurse. In the second pilot  study, blood pressure was measured using an Omron HEM-  907XL professional oscillometric instrument (Bannockburn, IL).  In both studies, blood pressure was measured by a trained as-  sessor using standard procedures (Chobanian et al., 2003).  Anthropometric and Metabolic Values  Chronic stressors such as job strain, divorce, and perceived  discrimination have been associated with greater levels of fast-  ing glucose, lipids, and insulin (Vitaliano et al., 2002). Findings  from the British Whitehall studies indicate that the degree to  which individuals were treated unfairly independently predicted  larger waist circumference, higher hypertension, triglycerides,  and fasting glucose, and lower serum HDL cholesterol, even  after controlling for SES, behavioral risk factors, and other  psychosocial factors (DeVogli et al., 2007). Extensive evidence  also illustrates links between chronic stress and depression,  which can lead to increased caloric intake, elevated BMI, and  associated metabolic and coronary risks (Dallman et al., 2003).  Chronic stress can trigger a complex cascade of behavioral  and physiological changes that contribute to the development of  the metabolic syndrome (MetS). MetS is characterized by a  constellation of risk factors including abdominal obesity, insu-  lin resistance, and elevated blood pressure and plasma lipid  levels that ultimately can lead to type 2 diabetes (Sattar et al.,  2008) and cardiovascular disease (Byrne & Wild, 2005). Though  there is a burgeoning literature on Latino adult and child obe-  sity, type 2 diabetes, hypertension, and their contributors, few  studies have focused on psychosocial stress and Latino meta-  bolic function (McClure et al., 2010b; Weigensberg et al.,  2008). In the SAP study, 33% of mothers had values indicating  MetS, comparable to high (and rising) national prevalence  rates.  Measurement. In both studies, stature, body mass, and WC  were recorded using established procedures (Lohman et al.,  1988). Body mass index (BMI) was calculated as mass divided  by height in meters squared (kg/m2). In the first study, glucose  and total cholesterol concentrations (mg/dL) were obtained  from fasted participants using 30 µL samples of capillary blood  collected from finger prick and using a CardioChek PA ana-  lyzer and PTS Panels (Polymer Technology Systems, Indian-  apolis, IN). This professional testing system meets standard  clinical guidelines for accuracy and precision. In the second  study, Cholestech LDX monitors (Hayward, CA) were used for  the measurement of fasting glucose and lipid levels from 35 µL  samples of capillary blood collected from finger prick. Presence  of the metabolic syndrome was assessed using the updated ATP  III criteria (Grundy et al., 2005).  Hemoglobin  Chronic childhood anemia can contribute to delays in mental  and physical development, and evidence is increasing that La-  tino toddlers have a high rate of anemia related in part to pov-  erty and acculturation factors (Brotanek et al., 2007). As parents  in our first project considered this health information highly  valuable, we included it in the SAP study to encourage recruit-  ment and retention.  Measurement. Hemoglobin is considered a standard measure  for assessing anemia, and values are interpreted based on age-  and sex-specific cutoffs. Children’s blood hemoglobin in SAP  was measured from a drop of blood obtained from finger stick,  and assessed using the HemoCue Hb201+ (Lake Forest, CA) to  determine if levels were within normal range (typically over 11  g/dL). This system has been extensively validated and its accu-  racy is within ±1.5% of the reference method.  Lessons Learned  Despite the development of new techniques for the meas-  urement of stress outside of clinical settings, there can be barri-  ers to their incorporation in studies with Latino populations in  general and with Latino immigrant groups in particular (Na-  tional Institutes of Health, 2002). We were interested to learn  whether the integration of health measures and biomarkers into  our studies reduced historic barriers or instead served as an  additional challenge to participation in research. Lessons learn-  ed (Table 1) include ways to best support participants’ com-  pliance with complex and time-sensitive protocols, especially  given long days spent in agricultural work and unpredictable  daily routines. Ultimately, our goal is to contribute to knowl-  edge about successful practices for engaging ethnic minorities,  including immigrant populations, in research in order to con-  tribute to effective interventions with these populations (Na-  tional Institutes of Health, 2001).  Copyright © 2013 SciRes. 115  
 H. H. MCCLURE   ET    AL.  Copyright © 2013 SciRes.  116    Table 1.  Summary of lessons learned: challenges, solutions, and future strategies for biomarker research with Latino immigrants.    Challenge Solution/Future Strategy  Training staff with no prior experience collecting health and biological  data Ample training time + “hands-on” supervised training  Barriers to care (BtC) Provision of health information & follow-up  referrals as indicated  BtC: Limited knowledge about pre-existing conditions that could  render ineligible for study Testing (e.g., of glucose) as pre-condition of study enrollment  BtC: Potential over-enrollment of sick/health-focused participants Eligibility criteria and encouragement of healthy enrollees  Distrust among prospective participants Recruiter characteristics + recruitment methods that rely on trusted social networks Lack of familiarity with biological data collection  Creation of strong rapport to ensure open  communication; assessors offer clear explanations; on-line videos of data   collection techniques to increase participant exposure  Measurement of very obese participants’ blood pressure with Omron  422-CRLC  Manual blood pressure readings by trained staff person or use of Omron  HEM-907XL for automatic measure  Saliva sample return rate  One-on-one training of participants; reminders; support for participants with low  literacy;  involvement of children  Busy morning schedules Collection of one morning sample; participants advised to collect on days with less  busy morning schedules  Filling out saliva diaries Reminders; fewer questions; support for  participants with low literacy; participants call automated system  Conducting finger sticks with farmworker participants with calloused  hands  Use of BD Microtainer Contact-Activated lancets (blue) with a high flow blade  (2.0 × 1.5 mm)  Effective follow-up with participants  Partner with community organization with trained staff and resources for   follow-up; hire or have volunteer trained health professional as part of research  team to conduct follow-up    Assessor Training  As previously mentioned, staff members in TFS received  four hours of intensive training followed by 4 to 8 hours of on-  site supervision to hone their newly acquired skills. Following  training, staff from our partner organization that had no prior  experience with biological measures was able to consistently  and accurately collect health data and biomarker samples. The  same training model was implemented with the SAP study with  staff measurement techniques remaining consistent across both  studies. Though assessors had ample time to gain the necessary  skills, assessor confidence was the largest issue in training staff  new to biological data collection. Assessors often reported  feeling comfortable applying their newly acquired skills only  after having completed two or three actual visits with families,  which included an experienced staff person to provide guidance  if necessary.  Recruitment and Health Information  The incorporation of biomarkers into our studies did not  serve as a disincentive or barrier to participation. On the con-  trary, participants were eager for information about their health,  and for referrals and information about bilingual/bicultural, sli-  ding scale, and immigrant-friendly health services. In exit in-  terviews, participants frequently cited our provision of their  health values as a major reason for their study participation.  Although financial compensation was appreciated, many fami-  lies regarded it as an added benefit and some stated it was un-  necessary. The value of health information was further reflected  in some families’ offers to pay to obtain measures for non-  participating family members, and in requests that we include  additional family members in future studies. In addition to pro-  viding participants with immediate information about their  levels of fasting glucose, total cholesterol and other lipids, sev-  eral participants requested their individual cortisol, EBV and  CRP measures after laboratory analyses were completed.  The provision of health information to participants raised two  critical issues: 1) the need for adequately trained health per-  sonnel and a referral system (discussed below), and 2) the po-  tential overrepresentation of sick or health-focused participants  in the study, particularly as we did not utilize a random sam-  pling approach. The second concern was addressed to some  extent by eligibility criteria stating that prospective participants  be healthy, and excluding individuals with colds, the flu, or  chronic conditions such as diabetes or autoimmune disorders  (e.g., Crohn’s disease). Given barriers to access to care that are  particularly acute for recent immigrants, a number of prospec-  tive participants had no knowledge of whether they had chronic  and potentially disqualifying conditions. For instance, some  women had been diagnosed with gestational diabetes but had  never received follow-up testing and were unaware if they cur-  rently had diabetes. In cases involving possible diabetes, asses-  sors conducted a preliminary fasting glucose test as a pre-con-  dition of study enrollment, and individuals with a glucose value  indicating diabetes were excluded from participation (and pro-  vided with referrals for follow-up). As this circumstance affect-  ed approximately 15% of all potential participants, our studies  required additional supplies and assessor time than previously  anticipated. Given pervasive barriers to care in the US among  Latinos in general and immigrant populations in particular, we   
 H. H. MCCLURE    ET    AL.  anticipate researchers nationwide will encounter this challenge.  Finally, to date, we have conducted cross-sectional studies  and have yet to confront the prospect that could arise in a lon-  gitudinal study of influencing participant behavior and subse-  quent waves of data through the provision of health information  in the first wave of assessment. Because of the risk of influenc-  ing participant behavior, some OSLC longitudinal studies that  incorporate health data and stress biomarkers have opted not to  provide participants with information about their health.  Rapport and Effe cti ve Com m unication  As in most prevention research, strong rapport between par-  ticipants and assessors in our studies was key to participants’  full engagement. This rapport was especially important for re-  cruittment of some Latino immigrants who wished to remain  part of a “hidden” population in response to a hostile social and  political climate (Martinez et al., 2012). In addition, rapport led  to open communication that facilitated participants’ learning  about potentially complex procedures (e.g., saliva collection),  their timely communication with us when there were problems,  and our ability to effectively support participants’ involvement.  Familiarity with Methods  Nearly all participants were familiar with measures of height,  weight, and blood pressure, though most were unfamiliar with  finger sticks and saliva collection. In addition to providing an  overview of methods as part of our informed consent process,  assessors took special care while performing all health assess-  ment procedures, including finger sticks, to explain each step  and invite questions. During one-on-one saliva collection train-  ing, assessors also discussed insights we hoped to gain into  stress among Latino immigrants through analysis of salivary  cortisol, and the importance of participants’ adherence to in-  structions for the accuracy of results. Finally, in the SAP study,  assessors pricked mothers’ fingers first, which often helped to  reduce any anxiety the child felt. Together, these steps may  have contributed to only one SAP mother and three children re-  porting that finger sticks were challenging, and to high return  rates of saliva samples (details below). In the future, our team  has considered creating short Spanish language demonstrations  that could be accessed via DVD or the Internet to provide fami-  lies with even more information about and exposure to biologi-  cal data collection methods.  Blood Pressure:  Me asurement  Ch al le ng es  In TFS, when using Omron manual blood pressure machines  (HEM-422CRLC), we had trouble getting blood pressure read-  ings for several morbidly obese participants. Though blood pres-  sure cuffs were appropriately sized for each participant, error  messages persisted. This challenge of reading blood pressure  among some obese individuals, which has been noted in clinical  settings, was worrisome given high rates of obesity within the  study population at 30% for men and 33% for women, which  included approximately 7% with morbid obesity.  In the second phase of TFS, our staff included a registered  nurse who took manual blood pressure readings using a sphyg-  momanometer. In order to avoid stigmatizing visibly obese par-  ticipants whose blood pressure we anticipated might be difficult  to measure, the nurse worked at station one (where the first of  two blood pressure measures was taken) and volunteered to take  the participant’s blood pressure. As it was common at station  one for multiple assessors to measure participants’ blood pres-  sure at the same time, this strategy worked well to normalize  the nurse’s intervention. The nurse then tracked participants  throughout the health exam and stepped in to take the second  blood pressure reading at the final station to ensure consistency  of measurement. In the SAP study, we used Omron HEM-  907XL professional oscillometric instruments (Bannockburn,  IL) for the automatic measure of mothers’ and children’s blood  pressure. Though these devices were significantly more expen-  sive than the Omron 422-CRLC, they proved more reliable and  we encountered no measurement difficulties.  Finger Sticks: Lancets  The choice of lancets was important for ensuring that a single  finger prick was sufficient to produce an adequate number of  blood drops for the measurement of glucose and lipids (adults),  hemoglobin (children), and for blood spot cards. In TFS, we  initially used Stat-Let Auto lancets (Stat Medical Devices, Inc.)  with a depth of 2.2 mm. These lancets, however, were too shal-  low to draw sufficient blood as most male and some female  participants had thick calluses from agricultural work. The most  effective lancets we identified for use with this population are  BD Microtainer Contact-Activated lancets (blue) with a high  flow blade (2.0 × 1.5 mm). We also used BD lancets with  mothers and children in the SAP study. However, for very  young children, researchers may wish to consider using smaller  lancets (e.g., Stat-Let Auto lancets of 2.0 mm).  Saliva Collection: Supporting Participant   Engagement  In TFS, 70% of participants returned all six saliva samples.  In the SAP study, 98% of participants returned all nine saliva  samples, considered an excellent return rate (Adam & Kumari,  2009). We attribute these high return rates to training (dis-  cussed above), collection reminders, support for participants  with limited literacy and the involvement of children (in SAP).  Reminders. Participants reported that the following methods  helped them to remember to collect their saliva according to  instructions: 1) toothbrush cover labels and removable stickers  for bathroom mirrors reading “Pare! Colecte su muestra” (Stop!  Collect your sample); 2) colorful wrist “gel” bands that partici-  pants donned the evening before as a reminder to collect their  saliva when they woke in the morning; and 3) assessors’ re-  minder calls made the evening before. Additional calls the day  of collection served as a further reminder, and provided par-  ticipants with a chance to ask questions, voice concerns, or re-  quest additional supplies.  Literacy. In the first study, we learned that our saliva collec-  tion directions were difficult for participants with limited liter-  acy to understand. Though we considered designing an alterna-  tive set of instructions composed of diagrams and two or three  words in lieu of each step, staff from our partner organization  advised that a customized approach would be more useful to  participants. Ultimately, when working with participants with  low literacy, assessors handwrote instructions on the saliva col-  lection guide tailored for each participant’s comprehension level.  Involvement of children. During the SAP study, we learned  that children as young as six years of age were often eager and  quick to learn saliva collection procedures. As a result, we   Copyright © 2013 SciRes. 117  
 H. H. MCCLURE   ET    AL.  actively involved both mother and child in the training, with  children often reinforcing their mother’s learning. Though we  did not formally ask about children’s involvement in saliva  collection (e.g., whether they initiated collection, or reminded  mothers of the need to collect), participant comments indicated  that children were an important factor in the family’s full par-  ticipation in the saliva collection portion of the study.  Saliva Collection: Morning Schedules   In the SAP study, early morning visits for the collection of  fasting measures, which could involve arriving at the family’s  home as early as 5 am so that the mother could leave for work  on time, were disruptive for families. In order to collect two  morning samples 30 minutes apart, busy morning schedules led  some mothers to alter their own and their youngster’s wake up  times, potentially influencing morning cortisol levels. For stud-  ies incorporating two or more morning measures, assessors may  wish to relay to participants the possible need to alter their  schedules to allow for extra time (not including an earlier  wake-up time or collection on a day that is not a typical week-  day) or discuss reducing the number of samples on a given  morning.  Saliva Collection: Saliva Diaries   In TFS, of participants who returned saliva samples, 86%  also filled out and returned a half-page form where they re-  corded the days and times they collected their saliva. In the  SAP study, 95% of participants recorded the time of day and  date they collected each sample. These data are critical because  they allow staff to track irregularities in collection schedules,  and make possible the calculation of time lapses between sam-  ples for the study of cortisol level changes throughout the day.  Again, reminder calls by staff seemed to facilitate these high  response rates.  Mothers in SAP also were asked to respond to questions in a  saliva diary for both themselves (6 - 16 Questions) and their  participating child (2 - 8 Questions) every time they collected a  saliva sample. Questions ranged from the time and day of saliva  collection to inquiries about sleep patterns and emotional state  during each 24-hour period, factors known to covary with Sali-  vary cortisol levels. Though most participants responded to items  whose range of responses were on a five-point Likert scale,  open-ended questions asking for more detail were rarely filled  out. Participant feedback to assessors indicated that some par-  ticipants lacked time to respond to all questions. In addition,  some participants reported that the saliva diaries were over-  whelming in length. In the future, assessors advised asking  fewer questions and having a binder for the saliva diaries where  all questions would be color coded to the sample collection  tubes for that day and clearly separated by collection time.  Literacy. Saliva diaries in the SAP study presented signifi-  cant challenges to the participation of a few mothers with low  literacy. In these cases, the assessor called the family at each  collection time and administered the saliva diary as a telephone  interview. Though saliva diary data collected by telephone pro-  ved to be more complete than data in saliva diaries that partici-  pants filled out themselves, telephone interviews were burden-  some schedule-wise for mothers and assessors and less cost-  effective. In the future, we will investigate new strategies that  support the inclusion of participants with low literacy, such as  requesting that participants call in and respond to pre-recorded  questions through an automated system.  Referral System and Follow-Up  As mentioned, the receipt of health information was one of  the greatest incentives for participants’ involvement in the  studies. Despite widespread enthusiasm regarding this facet of  our studies, however, several issues were raised. Approximately  one-third of all TFS and SAP participants had high levels of  glucose, total cholesterol or other lipids, and blood pressure  indicating the need for follow-up testing. Additional partici-  pants were referred for follow-up relating to chronic pain, low  blood pressure, impaired vision (needing glasses), smoking, nu-  triation, the self-administration of medication, and desire to lose  weight.  Effective follow-up in TFS was facilitated by a number of  factors. All participants were easy to re-contact as they were re-  sidents of housing complexes owned and run by the organiza-  tion, and the organization’s staff (many of whom were study  assessors) already referred residents to a range of services. Also,  a key member of the organization’s staff and of our research  team was an experienced health promoter who had strong rela-  tionships with local public health agencies and community  clinics.  The SAP study was distinct in that it was not a community-  partnered project and all follow-up was conducted by LRT asse-  ssors. In this study, some participants’ busy schedules contrib-  uted to assessors feeling rushed to explain the results, which  was worrisome to staff when trying to explain values that indi-  cated need for follow-up testing. Further, although assessors  clearly explained that they were not medical personnel and  could not offer advice, participants frequently asked health  related follow-up questions. Finally, a few families requested  assessor support in making appointments with clinics. Though  staff provided support to every participant who requested it,  future studies involving larger sample sizes and more com-  pressed assessment timelines would do well to include funding  for a health professional (or have a committed volunteer) to re-  spond to families’ questions and concerns, and to serve as a  health care navigator by assisting participants to access fol-  low-up care.  Conclusion  Though recent developments in minimally-invasive biologi-  cal measurement allow for more refined understandings of the  effects of psychosocial stress, these methods have been under-  utilized in studies with Latino populations. This is unfortunate  given existing Latino health disparities and the need to better  understand contributors to these disparities. Studies involving  recent immigrants, however, can confront unique challenges.  There is a clear need to fully support Latino immigrants’ invol-  vement in research involving biomarkers—and to identify the  strategies that make this possible—in order to better inform  public health policy and clinical practice. Further, carefully  designed studies can provide potential positive benefits to indi-  viduals who take part and to the larger communities in which  they are members. Finally, though the studies described here  focus on the Latino immigrant community, better models of  stress processes that rely on multiple measures may have im-  plications for a range of preventive interventions that target the  Copyright © 2013 SciRes.  118   
 H. H. MCCLURE    ET    AL.  effects of stress on family health within diverse communities.  Acknowledgements  The authors thank the Oregon Latino families who partici-  pated in the studies and study assessors. We also thank Felicia  Madimenos for biomarker training assistance, Julia Ridgeway-  Díaz and Sasha Johnson-Freyd for cortisol analyses, and Lynn  Stephen and Frances White for discussions of the project. We  appreciate the support of the National Institutes on Drug Abuse,  National Institutes of Health (R01 DA017937 and R01 DA-  01965), as well as the Oregon Social Learning Center Scien-  tists’ Council, Northwestern University, the University of Ore-  gon (UO), and the UO Center for Latino/a and Latin American  Studies (CLLAS).  REFERENCES  Adam, E. K., & Kumari, M. (2009). Assessing salivary cortisol in lar-  ge-scale, epidemiological research. Psychoneuroendocrinology, 34,  1423-1436. doi:10.1016/j.psyneuen.2009.06.011  Brotanek, J. M., Gosz, J., Weitzman, M., & Flores, G. (2007). Iron  deficiency in early childhood in the United States: Risk factors and  ethnic/racial disparities. Pediatrics, 120, 568-575.    doi:10.1542/peds.2007-0572    Byrne, C. D., & Wild, S. H. (2005). Review of the metabolic syndrome.  Chichester, West Sussex: John Wiley & Sons, Ltd.    doi:10.1002/0470025131  Capps, R., Fix, M. E., & Passel, J. S. (2002). The dispersal of immi-  grants in the 1990s: Policybrief #2.    http://www.urban.org/publications/410589.html  Chobanian, A. V., Bakris, G. L., Black, H. R., Cushman, W. C., Green,  L. A., Izzo Jr., J. L. et al. (2003). Seventh report of the Joint National  Committee on prevention, detection, evaluation, and treatment of  high blood pressure. Hypertension, 42, 1206-1252.    doi:10.1161/01.HYP.0000107251.49515.c2  Dallman, M. F., Pecoraro, N., Akana, S. F., la Fleur, S. E., Gomez, F.,  Houshyar, H. et al. (2003). Chronic stress and obesity: A new view  of “comfort food”. Proceedings of the National Academy of Scienes,  20, 11696-11701. doi:10.1073/pnas.1934666100   DeSantis, A., Adam, E., Doane, L., Mineka, S., Zinbarg, R., & Craske,  M. (2007). Racial/ethnic differences in cortisol diurnal rhythms in a  community sample of adolescents. Journal of Adolescent Health, 41,  3-13. doi:10.1016/j.jadohealth.2007.03.006   DeVogli, R., Brunner, E., & Marmot, M. G. (2007). Unfairness and the  social gradient of metabolic syndrome in the Whitehall II Study.  Journal of Psychosomat i c   Research, 63, 413-419.    doi:10.1016/j.jpsychores.2007.04.006   Dressler, W. W., Oths, K. S., & Gravlee, C. G. (2005). Race and eth-  nicity in public health research: Models to explain health disparities.  Annual Review of Anthropology, 34, 231-252.    doi:10.1146/annurev.anthro.34.081804.120505   Ford, E. S., Loucks, E. B., & Berkman, L. F. (2006). Social integration  and concentrations of C-reactive protein among US adults. Annals of  Epidemiology, 16, 78-84. doi:10.1016/j.annepidem.2005.08.005   Glaser, R., Pearson, G. R., Jones, J. F., Hillhouse, J., Kennedy, S., Mao,  H. et al. (1991). Stress-induced activation of Epstein-Barr virus.  Brain, Behavior,  a nd  Immunity, 5, 219-232.    doi:10.1016/0889-1591(91)90018-6   Grundy, S. M., Cleeman, J. I., Daniels, S. R., Donato, K. A., Eckel, R.  H., Franklin, B. A. et al. (2005). Diagnosis and management of the  metabolic syndrome: An American Heart Association/National Heart,  Lung, and Blood Institute Scientific Statement. Circulation, 112,  2735-2752. doi:10.1161/CIRCULATIONAHA.105.169404   Henle, W., & Henle, G. (1982). Epstein-Barr virus and infectious mo-  nonucleosis. In R. Glaser, & T. Gottleib-Stematsky (Eds.), Human  herpesvirus infections: Clinical aspects (pp. 151-162). New York:  Marcel Dekker.   Jones, J. F., & Straus, S. E. (1987). Chronic Epstein-Barr virus infec-  tion. Annual Rev i e w  o f   M e d i c in e , 38, 195-209.    hdoi:10.1146/annurev.me.38.020187.001211   Kiecolt-Glaser, J. K., Malarkey, W., Cacioppo, J. T., & Glaser, R.  (1994). Stressful personal relationships: Endocrine and immune func-  tion. In R. Glaser & J. K. Kiecolt-Glaser (Eds.), Handbook of human  stress and immunity (pp. 321-339). San Diego, CA: Academic Press.   Kirschbaum, C., & Hellhammer, D. H. (2000). Salivary cortisol. In G.  Fink (Ed.), Encyclopedia of stress (Vol. 3, pp. 379-384). San Diego:  CA: Academic Press.  Lohman, T. G., Roche, A. F., & Martorell, R. (Eds.) (1988). Anthro-  pometric standardization reference manual. Champaign, IL: Human  Kinetics Books.  Lopez, M. H., & Taylor, P. (2010). Latinos and the 2010 census: The  foreign born are more positive.    http://pewhispanic.org/files/reports/121.pdf  Martinez Jr., C. R. (2006). Effects of differential family acculturation  on Latino adolescent substance use. Family Relations, 5 5 , 306-317.  doi:10.1111/j.1741-3729.2006.00404.x  Martinez Jr., C. R., & Eddy, J. M. (2005). Effects of culturally adapted  parent management training on Latino youth behavioral health out-  comes. Journal of Consulting and Clinical Psychology, 73, 841-851.    doi:10.1037/0022-006X.73.5.841  Martinez Jr., C. R., McClure, H. H., & Eddy, J. M. (2009). Language  brokering contexts and behavioral and emotional adjustment among  Latino parents and adolescents. The Journal of Early Adolescence,  29, 71-98. doi:10.1177/0272431608324477   Martinez Jr., C. R., McClure, H. H., Eddy, J. M., Ruth, B., & Hyers, M.  J. (2012). Recruitment and retention among Latino immigrant fami-  lies in Oregon in prevention research. Prevention  S ci ence, 13, 15-26.    doi:10.1007/s11121-011-0239-0  McClure, H. H., Martinez Jr., C. R., Snodgrass, J. J., Eddy, J. M.,  Jiménez, R., Isiordia, L. E. et al. (2010a). Discrimination-related  stress, blood pressure, and Epstein Barr Virus antibodies among  Latin American immigrants in Oregon. Journal of Biosocial Science,  42, 433-461. doi:10.1017/S0021932010000039  McClure, H. H., Snodgrass, J. J., Martinez Jr., C. R., Eddy, J. M.,  Jiménez, R. A., & Isiordia, L. E. (2010b). Discrimination, psychoso-  cial stress, and health among Latin American immigrants in Oregon.  American Journal of Human Biology, 22, 421-423.    doi:10.1002/ajhb.21002  McClure, H. H., Snodgrass, J. J., Martinez Jr., C. R., Eddy, J. M.,  Midttveit, E. C., & Jiménez, R. A. (2010c). Psychosocial stress ex-  posure and salivary cortisol among Latino immigrants in Oregon.  Denver, CO: Society for Prevention Research Annual Conference.    McClure, H. H., Snodgrass, J. J., Martinez Jr., C. R., Squires, E. C.,  Jiménez, R. A., Isiordia, L. E. et al. (2012). Stress, place, and al-  lostatic load among Mexican immigrant farmworkers in Oregon.  Journal of Immigrant and Minority Health, Submitted.    McDade, T. W. (2007). Measuring immune function: Markers of cell-  mediated immunity and inflammation in dried blood spots. In G. H.  Ice, & G. D. James (Eds.), Measuring stress in humans: A practical  guide for the field. Cambridge: University Press.  McDade, T. W., Burhop, J., & Dohnal, J. (2004). High sensitivity en-  zyme immunoassay for C-reactive protein in dried blood spots.  Clinical Chemistry, 50, 652-654. doi:10.1373/clinchem.2003.029488   McDade, T. W., Stallings, J. F., Angold, A., Costello, E. J., Burleson,  M., Cacioppo, J. T., et al. (2000). Epstein-Barr Virus antibodies in  whole blood spots: A minimally invasive method for assessing an  aspect of cell-mediated immunity. Psychosomatic Medicine, 62, 560-  567.  McDade, T. W., Williams, S., & Snodgrass, J. J. (2007). What a drop  can do: Dried blood spots as a minimally invasive method for inte-  grating biomarkers into population-based research. Demography, 44,  899-925. doi:10.1353/dem.2007.0038   McEwen, B. S. (2000). Allostasis and allostatic load: Implications for  neuropsychopharmacology. Neuropsychopharmacology, 22, 108-124.  doi:10.1016/S0893-133X(99)00129-3   McEwen, B. S., & Wingfield, J. (2003). The concept of allostatis in  biology and biomedicine. Hormones and Behavi or , 43, 2-15.    doi:10.1016/S0018-506X(02)00024-7   Copyright © 2013 SciRes. 119  
 H. H. MCCLURE   ET    AL.  Copyright © 2013 SciRes.  120  Midttveit, E. C., McClure, H. H., Snodgrass, J. J., McDade, T. W.,  Martinez Jr., C. R., Eddy, J. M. et al. (2010). Body composition and  lifestyle correlates of high sensitivity C-reactive protein among La-  tino immigrants in Oregon. American Journal of Human Biology, 22,  263.   National Institutes of Health (NIH) (2001). NIH policy and guidelines  on the inclusion of women and minorities as subjects in clinical re-  search.  http://grants.nih.gov/grants/funding/women_min/guidelines_amende d_10_2001.htm  National Institutes of Health (NIH) (2002). Outreach notebook for the  inclusion, recruitment and retention of women and minority subjects  in clinical research. URL (last checked 12 May 2009).  http://orwh.od.nih.gov/pubs/outreach.pdf   Nazmi, A., & Victora, C. G. (2007). Socioeconomic and racial/ethnic  differentials of C-reactive protein levels: A systematic review of  population-based studies. BMC Public Health, 7, 212.    doi:10.1186/1471-2458-7-212  Pepys, M. B., & Hirschfeld, M. (2003). C-reactive protein: A critical  update. Journal of Clin i c al Investigation, 111, 1805-1812.    doi:10.1172/JCI18921  Pollard, T. M., & Ice, G. H. (2007). Measuring hormonal variation in  the hypothalamic pituitary adrenal axis: Cortisol. In G. H. Ice, & G.  D. James (Eds.), Measuring stress in humans: A practical guide for  the field. Cambridge: University Press.    Rexrode, K. M., Pradhan, A., Manson, J. E., Buring, J. E., & Ridker, P.  M. (2003). Relationship of total and abdominal adiposity with CRP  and IL-6 in women. Anna l s   o f   Epidemiology, 13, 674-682.    doi:10.1016/S1047-2797(03)00053-X   Ridker, P. M., Buring, J. E., Shih, J., Matias, M., & Hennekens, C. H.  (1998). Prospective study of C-reactive protein and the risk of future  cardiovascular events among apparently healthy women. Circulation,  98, 731-733. doi:10.1161/01.CIR.98.8.731  Rumbaut, R. G., & Portes, A. (2001). Ethnicities: Children of immi-  grants in America. New York: Sage.    Ryan, A. M., Gee, G. C., & Laflamme, D. F. (2006). The association  between self-reported discrimination, physical health and blood pres-  sure: Findings from African Americans, Black immigrants, and La-  tino immigrants in New Hampshire. Journal of Health Care for the  Poor and Underserved, 17, 116-132. doi:10.1353/hpu.2006.0092  Sapolsky, R. M., Romero, L. M., & Munck, A. U. (2000). How do  glucocorticoids influence stress responses? Integrating permissive,  suppressive, stimulatory, and preparative actions. Endocrine Revi ews,   21, 55-89. doi:10.1210/er.21.1.55    Sattar, N., McConnachie, A., Shaper, A. G., Blauw, G. J., Buckley, B.  M., de Craen, A. J. et al. (2008). Can metabolic syndrome usefully  predict cardiovascular disease and diabetes? Outcome data from two  prospective studies. Lancet, 371, 1927-1935.    doi:10.1016/S0140-6736(08)60602-9    Selye, H. (1956). The stress of life. New York: McGraw-Hill.  Smokowski, P. R., & Bacallao, M. L. (2007). Acculturation, internaliz-  ing mental health symptoms, and self-esteem: Cultural experiences  of Latino adolescents in North Carolina. Child Psychiatry and Hu-  man Development, 37, 273-292. doi:10.1007/s10578-006-0035-4  Squires, E. C., McClure, H. H., Martinez Jr., C. R., Eddy, J. M., Jim-  enez, R. A., Isiordia, L. E. et al. (2012). Diurnal cortisol rhythms  among Latino immigrants in Oregon. Journal of Physiological An-  thropology, 31, 19. doi:10.1186/1880-6805-31-19  Steffen, P. R., Smith, T. B., Larson, M., & Butler, L. (2006). Accul-  turation to Western Society as a risk factor for high blood pressure:  A meta-analytic review. Psychosomatic Medicine, 68, 386-397.    doi:10.1097/01.psy.0000221255.48190.32  The Urban Institute (2010). Children of immigrants data tool. Minne-  sota Population Center Integrated Public Use Microdata Series.   http://datatool.urban.org/charts/datatool/pages.cfm   US Census Bureau (2011). 2011 Population estimates.    http://www.census.gov/popest/data/national/asrh/2011/index.html   Vega, W. A., & Kolody, B. (1985). The meaning of social support and  the mediation of stress across cultures. In W. A. Vega, & M. R. Mi-  randa (Eds.), Stress and Hispanic mental health: Relating research to  science delivery (pp. 48-75). Rockville, MD: National Institute of  Mental Health.  Vega, W. A., Sribney, W., Aguilar-Gaxiola, S., & Kolody, B. (2004).  12-month prevalence of DSM-II-R psychiatric disorders among Me-  xican Americans: Nativity, social assimilation, and age determinants.  The Journal of Nervous a n d  M e n t a l   Disease, 192,  532-541.    doi:10.1097/01.nmd.0000135477.57357.b2  Villarruel, A. M., Jemmott, L. S., Jemmott, J. B., & Eakin, B. L. (2006).  Recruitment and retention of Latino adolescents to a research study:  Lessons learned from a randomized clinical trial. Journal for Spe-  cialists in Pediatric Nursing, 11, 244-250.    doi:10.1111/j.1744-6155.2006.00076.x  Vitaliano, P. P., Scanlan, J. M., Zhang, J., Savage, M. V., Hirsch, I. B.,  & Siegler, I. C. (2002). A path model of chronic stress, the Metabolic  Syndrome, and coronary heart disease. Psychosomatic Medicine, 64,  418-435.  Weigensberg, M. J., Toledo-Corral, C. M., & Goran, M. I. (2008).  Association between the Metabolic Syndrome and serum cortisol in  overweight Latino youth. Journal of Clinical Endocrinology & Me-  tabolism, 93, 1372-1378. doi:10.1210/jc.2007-2309   Williams, D. R., Neighbors, H. W., & Jackson, J. S. (2003). Racial/  ethnic discrimination and health: Findings from community studies.  American Journal of Public Health, 93, 200-208.    doi:10.2105/AJPH.93.2.200     
			 
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