Objective: This study aimed to assess the relationship of cognition, depression and anxiety to glycemic control in elders with diabetes. DM is a chronic medical condition. Its control depends on adherence to medical therapy and making decisions related to lifestyle changes. This decision making capacity is affected by many factors including cognition and psychological status. Design: It was a case control study. Setting: It was done in Ain Shams University Hospital inpatients and DM outpatient clinic, Cairo, Egypt. Participants: Of the one hundred diabetic patients aged ≥ 60 years, 50 had Hemoglobin A1c (HbA1c) ≥ 7.5 (cases) and 50 had Hb A1c < 7.5 (controls). Measurements: Cognition was assessed using minimental status examination (MMSE) test, Mattis Organic Mental Syndrome Screening Examination (MOMSSE) and Cambridge Cognitive Examination (CAMCOG) test. Geriatric depression scale-15 (GDS-15) was performed for depression assessment, while anxiety was assessed by DSM IV criteria. Laboratory investigations included: fasting blood sugar (FBS), post-prandial blood sugar (PPBS), glycated haemoglobin (Hb A1c), low density lipoprotein (LDL), high-density lipoprotein (HDL), total cholesterol, and triglycerides (TG). Results: Significant difference was found between the two groups regarding scores of cognitive tests: MMSE score (p = 0.004); below average (p = 0.02) and average scores (p = 0.05) of MOMSSE; CAMCOG score (p = 0.015); and CAMCOG divided items score including orientation (p = 0.003), comprehension (p = 0.005), expression (p = 0.020), attention (p = 0.002), and abstraction (p = 0.008) as well as depression screening scores (P = 0.002). Using Receiver Operating Characteristic, CAMCOG had better sensitivity and MOMSSE had better specificity. Conclusion: Cognitive impairment was associated with poor glycemic control, and impairment in attention and abstraction, related to executive function, functions were found to be associated with poor glycemic control. These functions may be more needed in self management of DM and hence affected glycemic control. Depression was associated with poor glycemic control but anxiety was not.
Diabetes mellitus (DM) is a group of metabolic diseases characterized by hyperglycemia. The chronic hypergly- cemia of diabetes is associated with long-term damage, dysfunction, and failure of various organs, especially the eyes, kidneys, nerves, heart, and blood vessels. Several pathogenic processes are involved in the development of diabetes. These range from autoimmune destruction of the cells of the pancreas with consequent insulin deficiency to abnormalities that result in resistance to insulin action. Impairment of insulin secretion and defects in insulin action frequently coexist in the same patient, and it is often unclear which abnormality, if either alone, is the primary cause of the hyperglycemia. Symptoms of marked hyperglycemia include polyuria, polydipsia, weight loss, sometimes with polyphagia, and blurredvision. Susceptibility to certain infections may also accompany chronic hyperglycemia. Acute, life-threatening consequences of uncontrolled diabetes are hyperglycemia with ketoacidosis or the nonketotic hyperosmolar syndrome [
DM in older adults has become a major public health problem affecting an increasing number of individuals worldwide. Glycemic control is an essential element of DM management. It is failed to be achieved or maintain- ed by many older adults [
Previous studies have confirmed that both old age & DM are independently associated with an increased risk of cognitive dysfunction; the risk is even greater for older adults with DM [
Not only cognitive dysfunction, but also previous studies reported significant association between psychiatric illnesses and poor glycemic control. Data on the relation between depression and anxiety and glycemic control in diabetic elderly patients are scarce. Depression comorbidity with DM has many hazards as it is a risk factor for poor metabolic control, decreased physical activity, and potentially more complications and functional impairment [
In addition, some authors suggest that anxiety comorbidity with DM has been associated with poor glycemic control, regimen adherence, and with accelerated rates of coronary heart disease [
Therefore, the aim of the current study was to assess the relationship of cognition, depression and anxiety to glycemic control in elders with diabetes.
The study was a case control study. The study was carried out on diabetic elderly patients, aged 60 years or more, visiting the geriatric hospital inpatient and DM outpatient clinic of Ain Shams University Hospital, Cairo, Egypt. However, patients with impaired Minimental Status Examination (MMSE) screening test, with a score less than 24 [
All participants were subjected to complete medical history taking (including age, DM history, and history of
other co-morbidities). Each patient then underwent cognitive assessment by MMSE [
Each patient was instructed to fast 12 hours, venous blood sample was drawn from each participant into potassium EDTA tube; 5 ml was collected of venous blood by venipuncture. Serum was separated by centrifugation and was divided into 2 samples:
The first sample was used for measurement of fasting blood sugar.
The second sample was frozen at −20˚C until assayed in the laboratory of clinical pathology department; Ain Shams University, Faculty of medicine. Serum level of low density lipoprotein (LDL), high-density lipoprotein (HDL), total cholesterol (TC), and triglycerides (TG) were measured by enzymatic hydrolysis and oxidation.
A third sample of 2 ml was withdrawn by venipuncture 2 hours after eating. Centrifugation was done and serum was used for measurement of 2 hour postprandial blood sugar. Hb A1c was measured spectrophotometrically at the central laboratories of Ain Shams university hospital using (Biosystem, BTS-330, S.A. Costa Brava, Barcelona, Spain) spectrophotometer. Lipid profile was done in the central laboratory in Ain Shams University teaching hospital.
Data were collected and analytical statistics were done using the 16th version of statistical package for social sciences (SPSS, Chicago, IL, USA). Qualitative data were presented in the form of frequency tables (number and percent). Quantitative data were presented in the form of means and SD.
Normality distribution of the variables was tested using one sample Kolmogorov Smirnov test. Regarding Quantitative data, differences between two groups were assessed using the Student’s t test for parametric data or Mann Whitney U test for non-parametric data. Regarding qualitative data, the chi-square test or Fisher’s Exact test was used to compare between the two groups.
Receiver operator curve (ROC) analysis was used to test the discriminatory power of anxiety, depression and cognitive tests in prediction of uncontrolled DM, with calculation for sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). MedCalc 9.6.2.0 package (MedCalc Software, Mariakerke, East-Flanders, Belgium) was used to compare between area under the curves (AUCs) of cognitive tests for the prediction of uncontrolled DM.
The level of significance was taken at P value < 0.05.
The mean age of all participants was 67.12 ± 6.36 years, the mean duration of DM was 9.96 ± 6.9 years, and the mean HbA1c was 8.2 ± 1.7. Forty four percent of participants were males. A significant difference was found between ADL score, application of treatment, follow up status and glycemic control (p < 0.001 for all) (
. Comparing studied groups as regard the age, gender, education, functional status and treatment status
Variables | Controlled | Uncontrolled | P | |
---|---|---|---|---|
Age | 66.5 ± 5.6 | 67.7 ± 7 | 0.332 | |
Male gender | 25 (50%) | 19 (38%) | 0.227 | |
Education | Illiterate | 19 (38%) | 24 (48%) | 0.31 |
Below high school | 11 (22%) | 13 (26%) | 0.63 | |
High school | 4 (8%) | 1 (2%) | 0.15 | |
Above high school | 16 (32%) | 12 (24%) | 0.33 | |
Functional status | ||||
ADL | 5.6 ± 1.4 | 4.1 ± 2.4 | <0.001 | |
IADL | 7 ± 2.1 | 5.2 ± 3.2 | 0.001 | |
Treatment | ||||
Duration of diagnosis of diabetes* | 9.8 ± 5.7 | 10.1 ± 7.9 | 0.818 | |
Type of treatment | Oral tab N(%) | 28 (56%) | 28 (56%) | 0.548 |
Insulin | 22 (44%) | 25 (50%) | ||
Application of treatment | Self | 47 (94%) | 32 (64%) | <0.001 |
Other person | 3 (6%) | 18 (36%) | ||
Follow up status | YES | 40 (80%) | 22 (44%) | <0.001 |
No | 10 (20%) | 28 (56%) |
Values were expressed in form of mean +/− SD for quantitative data and number (%) for qualitative data. ADL = activities of daily living, IADL = instrumental activities of daily living.
. Comparing the studied groups as regard cognitive and psychological status
Variables | Controlled | Uncontrolled | P | |||
---|---|---|---|---|---|---|
Cognitive assessment | ||||||
Adjusted MMSE score | Not impaired | 37 (74%) | 29 (58%) | 0.091 | ||
Impaired | 13 (26%) | 21 (42%) | ||||
CAMCOG | 76.3 ± 18.1 | 66.7 ± 20.1 | 0.015 | |||
MOMSSE | Below average | 10 (20%) | 25 (50%) | 0.02 | ||
Average | 22 (44%) | 13 (26%) | 0.05 | |||
Above average | 18 (36%) | 12 (24%) | 0.19 | |||
Psychological assessment | ||||||
GDS15 (depressed) | 7 (14) | 21 (42) | 0.002 | |||
Anxiety (anxious) | 6 (10) | 12 (24) | 0.096 | |||
Laboratory results | ||||||
HbA1c | 6.9 ± 0.5 | 9.5 ± 1.5 | <0.001 | |||
FBS | 116.7 ± 32.9 | 167.4 ± 49 | <0.001 | |||
PPBS | 161.1 ± 46.9 | 230 ± 45.8 | <0.001 | |||
TC | 145 ± 44.3 | 182.4 ± 56.1 | <0.001 | |||
TG | 122.3 ± 47.8 | 150.4 ± 66.4 | 0.017 | |||
LDL | 88.2 ± 34.6 | 125.9 ± 47.9 | <0.001 | |||
HDL | 34.1 ± 11.3 | 31.2 ± 14.0 | 0.264 | |||
Values were expressed in form of mean +/− SD for quantitative data and number (%) for qualitative data. CAMCOG = Cambridge Cognitive Examination; FBS = Fasting Blood Sugar; GDS 15 = Geriatric depression scale-15; HbA1c = Glycated Hemoglobin; HDL = High density lipoprotein; LDL = Low density lipoprotein; MMSE = Minimental Status examination test; MOMSSE = Mattis Organic Mental Syndrome Screening Examination; PPBS = Post Prandial Blood Sugar; TC = Total Cholesterol; TG = Triglycerides.
There was no significant association between education and follow up status (P = 0.052) (data were not presented).
. Comparing studied groups as regard the CAMCOG divided items score
CAMCOG | Groups | P-value | |||||
---|---|---|---|---|---|---|---|
Controlled | Uncontrolled | ||||||
Mean | ± | SD | Mean | ± | SD | ||
Orientation | 9.5 | ± | 1.2 | 8.4 | ± | 2.0 | 0.003 |
Comprehension | 7.8 | ± | 1.5 | 6.9 | ± | 1.6 | 0.005 |
Expression | 14.1 | ± | 2.9 | 12.5 | ± | 3.7 | 0.020 |
Recall | 8.6 | ± | 2.0 | 8.0 | ± | 2.2 | 0.177 |
Recent memory | 2.8 | ± | 1.1 | 2.6 | ± | 1.4 | 0.604 |
Remote memory | 3.7 | ± | 2.1 | 3.3 | ± | 2.0 | 0.303 |
Attention | 5.8 | ± | 1.7 | 4.4 | ± | 2.6 | 0.002 |
Praxis | 9.1 | ± | 2.8 | 8.0 | ± | 3.0 | 0.065 |
Calculation | 1.9 | ± | 0.2 | 2.0 | ± | 0.0 | 0.320 |
Perception | 8.4 | ± | 2.1 | 7.8 | ± | 2.3 | 0.184 |
Abstraction | 4.2 | ± | 3.1 | 2.5 | ± | 3.3 | 0.008 |
Values were expressed in form of mean +/− SD; CAMCOG = Cambridge Cognitive Examination.
. Sensitivity, specificity, positive predictive value (PPV), negative predicative vale (NPV) and accuracy of depression, anxiety and cognitive tests (adjusted MMSE, MOMSSE, CAMCOG)
Sensitivity | Specificity | PPV | NPV | Accuracy (%) | |
---|---|---|---|---|---|
Depression | 42 | 86 | 75 | 59.72 | 64 |
Anxiety | --- | ---- | ---- | ---- | 57 |
MOMSSE | 50 | 80 | 71.43 | 61.54 | 65 |
Adjusted MMSE | --- | --- | --- | --- | 58 |
CAMCOG score | 66 | 56 | 60 | 62.22 | 61 |
CAMCOG = Cambridge Cognitive Examination, MMSE = Minimental Status examination test; MOMSSE = Mattis Organic Mental Syndrome Screening Examination.
Current results showed that there was no significant differences between the two groups as regard the age, gender or education. This was consistent with the findings of another study [
On the other hand, this was not consistent with the findings of another study [
The absence of significant difference between both groups in education could be attributed to the insignificant association between education and follow up status.
In the current work, comparison of the duration of DM diagnosis between the two groups was not significant. This might be due to the difficulty of estimating DM duration, especially in older adults as patients usually have longer duration of DM. DM is frequently diagnosed after a long period of its occurrence. The international DM foundation overall estimates that, across all the surveys, approximately 50% of all people with DM were undiagnosed [
Regarding cognition, our study showed that there was no significant difference between the two groups as regard the age and education adjusted MMSE total score. On the other hand, other batteries, CAMCOG and MOMSSE which assess a wide range of mental abilities, for cognitive assessment showed significant difference between the 2 groups.
There was a significant difference between the two groups as regard the MOMSSE below average and average scores, as the below average score was more common in uncontrolled group, while the average score was more common in the controlled group.
These findings are supported by the findings of van Harten, et al. [
Furthermore, our study showed that there was a highly significant difference between the two groups as regard CAMCOG score which was significantly higher in the controlled group. This could be attributed to the fact that CAMCOG contains more items on memory, language, and construction and allows a more differentiated judgment about these functions than the MMSE.
Our study revealed that CAMCOG had better sensitivity and MOMSSE had better specificity for the prediction of uncontrolled DM.
The better specificity of MOMSSE could be linked to its testing of certain cognitive functions that could be affected by DM, as most of its items namely memory, executive functions (digit span backward in the attention item using working memory, verbal abstraction item), language, visuospatial (construction skills), insight into illness, which is affected by memory, as verbal memory had an effect on total insight and all dimensions of insight, [
On the other hand, CAMCOG was more sensitive to assess cognitive functions as it includes more items that assess wider variety of cognitive functions not included in MOMSSE as praxis involved in parietal region of the brain [
As regards Depression, our study found a significant difference between the two groups as regard the presence of depression. This was not consistent with the finding of Munshi, et al. [
On the other hand, our study was consistent with finding of Lustman & Clouse [
In the current study, there was no significant difference between the two groups as regard the anxiety diagnostic criteria. This was not consistent with the findings of Masmoudi, et al. [
On the other hand, our findings were supported by the findings of Gois et al. [
As regards functional status, in the current study ADL showed a highly significant difference between the two groups where the controlled group was more independent than the uncontrolled group. Similarly, the IADL showed significant difference between the two groups as the controlled group was more independent than the uncontrolled group.
This can be supported by Kalyani et al. [
Regarding ability of self application of treatment; our study showed a significant difference between the two groups as the majority of the uncontrolled were those who received treatment by caregiver rather than by self. This was convenient with our findings that the uncontrolled group was more dependent in ADL & IADL. This is consistent indirectly with the ideas discussing the association between dependency and poor glycemic control [
Also, there was a significant difference between the two groups as regard the follow up status, where those who used to follow up their blood glucose were found to be more in the controlled group.
Our findings was not consistent with the findings of Harris [
Meanwhile, our findings were supported by a study of Deiss et al. [
In the current study, there was no significant difference between the two groups as regard the type of treatment used. This was supported by the findings of the United Kingdom prospective DM study, in which subjects were randomized to four groups: insulin, sulfonylurea, metformin, or continued diet therapy. Only 50 percent of the patients in any group had HbA1C levels of less than 7% after three years [
In addition, the current study showed that there was a highly significant difference between the two groups as regard the levels of the TC, LDL and TG. However, there was no significant difference between the two groups as regard the HDL. This was supported by Petitti et al. [
Cognitive impairment was associated with poor glycemic control. Impairment in attention and abstraction, relat- ed to executive function, functions were found to be associated with poor glycemic control. These functions may be more needed in self management of DM and hence affected glycemic control. Also, depression was associ- ated with poor glycemic control but anxiety was not. Poor functional state, application of treatment by other person and poor follow up of glucose were all associated with poor glycemic control.
Causal relation between poor glycemic control and both cognition and depression is suggested to be studied in a follow up study.
This paper was partially funded by Ain Shams University, there were no sponsors.
The authors would like to thank Ain Shams University, faculty of medicine for the partial funding of this paper.