Background: Despite the rising prevalence of diabetes in Nigeria and sub-Saharan Africa , few studies have assessed the prevalence of prediabetes and diabetes in people with low socioeconomic status or urban slums. Methods: Using the WHO STEP-wise approach to surveillance of noncommunicable diseases, we estimated the prevalence of diabetes and prediabetes among adults 20 years and older living in two urban slums in Enugu south east Nigeria. Diabetes was defined as previous history of diabetes, use of hypoglycemic agents and fasting blood glucose within the diabetes range on two occasions during the survey period. Study duration was 5 months. Results: Out o f the 811 individuals invited to the clinic, 605 (74.6%) participants had their fasting blood glucose measured based on the study protocol. The prevalence of diabetes and prediabetes in the population was 11.7% (95% CI; 9.2 - 14.3) and 7.6% (95% CI; 5.0 - 9.7) respectively. About 54.9% were newly detected and 28.1% of them had normal control. The prevalence of diabetes peaked at 55 - 64 years. The odds ratio for diabetes was significantly higher in participants ≥ 45 years (1.033, 95% CI; 1.208 - 3.420), participants with hypertension (0.442, 95% CI; 0.257 - 0.762) and stroke (1.638, 95% CI; 0.459 - 5.848). Conclusion: There is a relatively high prevalence of diabetes among adults in two urban slums in Enugu. Public health educational measures promoting prevention and early detection of diabetes should be encouraged. Efforts should be made to educate the populace on the need for early detection and treatment.
Diabetes is rising in sub-Saharan Africa (SSA) [
Most type 2 diabetes patients go through a “pre-diabetes” phase for several years [
Low socioeconomic status has been associated with both incidence and mortality in diabetes [
Using a purposive sampling method, we selected 2 isolated urban settlements (Agu-Abor and Ugbodogwu) in Enugu, the capital of Enugu State, south east Nigeria. The two settlements have an estimated adult population of 7000 - 9000 individuals (based on church and local records). The total area occupied by both settlements is approximately 2.5 - 5 km2 and are located about 1 - 2.5 km from the nearest state-owned teaching hospital. The two settlements were selected purposively because of their relatively isolated location. The inhabitants of Agu-Abor were surveyed over a 4-week period (August 12-September 9, 2013), while Ugbodogwu inhabitants were surveyed between November 25 and December 21, 2013. This study was approved by the ethics committee of the University of Nigeria Teaching Hospital Ituku/Ozalla, P M B 01129 Enugu. No NHREC/05/01/2008B-FWA00002458-1RB00002323. Date of approval 28th July 2013.
A cross-sectional descriptive study was done to survey the adult population living in both localities. In order to facilitate the participation of the populace, sensitization meetings in the community which included both religious and elected leaders. Community-wide awareness announcements were carried out in churches and by town criers followed by sensitization meeting(s) on selected days. Following community entry, all participants who came out for the survey were interviewed by teams of research assistants. Using the WHO STEPS instrument [
Fasting blood glucose (FBG) was measured using a glucometer (Fine test premium, Infobia co Ltd., Dongan-gu. South Korea) after an overnight fast. Fine test coding strips contains glucose oxidase and potassium ferricyanide and displays results between 0.6 - 33.3 mmol/L with a coefficient of variation of <10%. Accuracy of the results obtained from the Fine test meter compared with Hitachi glucose auto analyzer 747 and showed a system accuracy within ±0.8 mmol/L of 100%. Fine test control solution was used to check and test strips to make sure they are properly working. Participants with fasting blood glucose within normal range on two consecutive measurements (measured 2 - 5 days apart) were considered as having normal blood glucose [
Blood pressure was measured after 5 - 10 minutes rest in a sitting position and was measured thrice by means of mercury sphygmomanometer according to the guidelines of the European Society of Hypertension [
Classification of diabetes and prediabetes was based on the WHO criteria [
FBG < 6.1, mmol/L, n(%)-normal range
FBG 6.1 - <7, mmol/L, n(%)-Prediabetes range
FBG ≥ 7, mmol/L, n(%)-Diabetes range
Definition of diabetes included two categories:
1) Previous diabetes and/or use of hypoglycemic agents;
2) FBG within the diabetic range on two occasions during the survey period.
Awareness was assessed based on past medical history of diabetes diagnosed by a health professional. Normal blood glucose control was defined as normal FBG measurements in individuals taking hypoglycemic agents at the time of survey. Individuals with systolic blood pressure (SBP) of ≥140 mmHg and/or diastolic blood pressure (DBP) of ≥90 mmHg, past medical history of hypertension and/or use of anti-hypertensive drugs were considered as having hypertension. Stroke was defined as a clinical syndrome of rapidly progressive symptoms and signs of focal or global neurological deficit lasting more than one hour of which there is no apparent cause other than vascular origin, and/or past medical history stroke diagnosed by a qualified personnel (doctors). Current tobacco use was defined as the use of any form of tobacco in the past 4 weeks. Alcohol use and quantity was defined as (mean quantity) the consumption of any alcoholic beverage in a week. The safe limit of alcohol was defined based on WHO guidelines of 21 units for men and 14 units for women per week [
Artisans were defined as skilled manual laborers. Level of education was the individual’s highest educational (formal) attainment based on the Nigerian school system.
Sample size was calculated using the Taro Yamane formula [
N = estimated population of the community (9000), e = 0.05.
N = 9000/9000 × 0.0025 = 9000/22.5 = 400. With an expected 10% attrition rate, a minimum of 440 individuals will be screened.
For database management and statistical analyses, we used the SPSS version 20 (IBM Corporation, New York, USA). Data were presented in tables. Age standardization was done using the WHO standard population distribution and Enugu East (EE) 2006 population data [
Out of the 811 individuals invited to the clinic, 605 (74.6%) participants (414 women (68.4%) and 191 (31.6%) men p < 0.01) had their fasting blood glucose measured based on the study protocol. The male to female ratio of those screened was 0.5:1. The distribution of the participants showed that 444 (54.7%) came from Ugbodogwu while 367 (45.3%) were from Aguabor. The participants’ age ranged from 20 to 90 years, averaging 44.5 (43.3 - 45.8) years. Males were older than females by about a decade (mean age: 51.1 vs 41.5 years, p < 0.01). The age distribution and other characteristics of the participants are shown in
Fasting blood glucose (p < 0.01; skewness, 3.5; kurtosis, 21.6) and body mass index (P < 0.01; skewness, 0.9; kurtosis, 0.9) were skewed to the right. Twenty-four (4%) subjects were underweight, 285 (47.1%) had normal BMI while 296 (48.9%) were either overweight or obese. The mean body mass index (BMI) was 25 kg/m2 higher in females (26.7 kg/m2) than males (24 kg/m2) P < 0.01. The mean fasting glucose level was similar in males and females. P = 0.98 (
The mean blood pressure of the participants was 133.7 mmHg (95% CI, 131.7 - 135.9) systolic and 83.4 mmHg (95% CI, 82.4 - 84.7) diastolic. Systolic blood pressure was significantly higher in males than in females. P = 0.01. Past medical history of hypertension, previous diabetes and stroke was documented in 23%, 5.3% and 2.8% of the population sample respectively. The overall prevalence of hypertension (newly diagnosed and previous cases) was (52.2%) 316/605 (
The overall prevalence of diabetes and prediabetes in the population was 71 (11.7%), (95% CI; 9.2 - 14.3) and 7.6% (95% CI; 5.5 - 9.7); similar in males and females P = 0.21 and 0.25 respectively. More than half of all the cases of diabetes (39/71 (54.9%) were newly detected (65.9% in females and 37% in males, p = 0.02). Out of the remaining 32 (45.1%) who were aware of having diabetes 28.1% had normal fasting serum glucose at the time of the study. Control was almost similar in males and females P = 0.06. The highest prevalence of diabetes was in females 60 years and above (17.2%, 95% CI, 7.5 - 26.7) (
The highest prevalence of prediabetes was in males 40 - 49 years (95% CI, 16.7%, 3.4 - 30). The prevalence of prediabetes was similar in all sub-groups compared. It however increased with increasing BMI reaching 10.2% in those with a BMI of 30 kg/m2 and above (
Characteristic | Female | Male | Total | P-value |
---|---|---|---|---|
Anthropometrics | ||||
n (%) | 414 (68.4) | 191 (31.6) | 605 (100) | <0.01 |
Age, years, (mean 95% CI) | 41.5 (40.2 - 42.9) | 51.1 (48.7 - 53.5) | 44.5 (43.3 - 45.8) | <0.01 |
Height, cm (mean 95% CI) | 158.2 (157.5 - 159) | 165.3 (164.2 - 166.5) | 160.5 (159.8 - 161.1) | <0.01 |
Weight, kg (mean 95% CI) | 66.9 (65.2 - 68.6) | 65.6 (63.8 - 67.4) | 66.5 (65.2 - 67.8) | 0.38 |
Body mass index, kg/m2 (mean 95% CI) | 26.7 (26.1 - 27.3) | 24.0 (23.4 - 24.6) | 25.8 (25 - 4 - 26.3) | 0.01 |
Age group 20 - 29 n (%) 30 - 39 n (%) 40 - 49 n (%) 50 - 59n (%) ≥60 n (%) | 104 (25.1) 88 (21.3) 92 (22.2) 72 (17.4) 58 (14) | 35 (18.3) 13 (6.8) 30 (15.7) 41 (21.5) 72 (37.7) | 139 (23) 101 (16.7)) 122 (20.2) 113 (18.7) 130 (21.5) | <0.01 |
Level of Education | ||||
None/Primary, n (%) | 196 (47.3) | 97 (50.8) | 293 (48.4) | |
Secondary and above, n (%) | 218 (52.7) | 94 (49.2) | 312 (51.6) | 0.43 |
Blood pressure | ||||
Systolic pressure, mm Hg (mean 95% CI) | 132 (129.3 - 134.6) | 137.8 (134.3 - 141.3) | 133.7 (131.7 - 135.9) | 0.01 |
Diastolic pressure, mm Hg (mean 95% CI) | 83.1 (81.5 - 84.7) | 84.0 ( 81.7 - 86.2) | 83.4 (82.4 - 84.7) | 0.51 |
BMI group <18.5, n (%) 18.5 - 24.9, n (%) 25 - 29.9, n (%) ≥30, n (%) blood | 15 (3.6) 172 (41.5) 124 (30) 103 (24.9) | 9 (4.7) 113 (59.2) 54 (28.3) 15 (7.9) | 24 (4) 285 (47.1) 178 (29.4) 118 (19.5) | 0.52 <0.01 0.67 <0.01 |
---|---|---|---|---|
Glucose, mmol/L (mean 95% CI) <6.1, mmol/L, n (%) 6.1 - <7, mmol/L, n (%) ≥7, mmol/L, n (%) | 5.4 (93.7 - 99.3) 346 (83.6) 30 (7.2) 38 (9.2) | 5.4 (92.2 - 101) 151 (79.1) 23 (12) 17 (8.9) | 5.4 (94.2 - 98.9) 497 (82.1) 53 (8.8) 55 (9.1) | 0.98 |
Lifestyle | ||||
Current tobacco use, n (%) | 61 (14.7) | 73 (38.2) | 134 (22.1) | <0.01 |
Current alcohol use, n (%) | 306 (73.9) | 160 (83.8) | 466 (77) | <0.01 |
Quantity of alcohol (mean units/week) | 0.04 (0.03 - 0.04) | 0.06 (0.05 - 0.07) | 0.73 (0.66 - 0.81) | <0.01 |
Medical History of | ||||
Hypertension n (%) | 93 (22.5) | 46 (24.1) | 139 (23) | 0.66 |
Diabetes n (%) | 15 (3.6) | 17 (8.9) | 32 (5.3) | <0.01 |
Stroke n (%) | 10 (2.4) | 7 (3.7) | 17 (2.8) | 0.39 |
P-values are for the sex differences. Peripheral systolic and diastolic blood pressure were the average of 3 consecutive measurements.
Characteristic | Total N (%, 95 CI) | Males N (%, 95%, CI) | Females N (%, 95%, CI) | P-value |
---|---|---|---|---|
- Diabetes | - | - | - | - |
Overall prevalence | 71 (11.7, 9.1 - 14.3) | 27 (14.1, 9.2 - 19.1) | 44 (10.6, 7.6 - 13.6) | 0.22 |
*Detected | 39 (54.9) | 10 (37) | 29 (65.9) | 0.02 |
Not Aware †Controlled Prevalence of diabetes in different groups Age group | 32 (45.1) 9 (28.1) | 17 (63) 5 (29.4) | 15 (34.1) 4 (26.7) | 0.02 0.06 |
20 - 29 30 - 39 40 - 49 50 - 59 ≥60 | 8 (5.8, 1.9 - 9.7) 11 (10.9, 4.8 - 17) 16 (13.1, 7.1 - 19.1) 15 (13.3, 7 - 19.6) 21 (16.2, 9.9 - 14.3) | 5 (14.3, 2.7 - 25.9) 1 (7.7, −6.8 - 22.2) 4 (13.3, 1.1 - 25.4) 6 (14.6, 3.8 - 25.4) 11 (15.3, 7 - 23.6) | 3 (2.9, −0.3 - 6.1) 10 (11.4, 4.8 - 18) 12 (13, 6.1 - 19.9) 9 (12.5, 4.9 - 20.1) 10 (17.2,7.5 - 26.9) | 0.02** 0.69 0.97 0.75 0.76 |
BMI category <18.5 18.5 - 24.9 25 - 29.9 ≥30 | - 24 (8.4, 5.2 - 11.6) 34 (19.1, 13.3 - 24.9) 13 (11, 5.4 - 16.7) | - 12 (10.6, 4.9 - 16.3) 10 (18.5, 8.2 - 28.9) 5 (33.3, 9.4 - 57.2) | - 12 (7, 3.2 - 10.9) 24 (19.4, 12.4 - 26.3) 8 (7.8, 2.6 - 12.9) | - 0.28 0.9 <0.01 |
Medical History Stroke Hypertension | - 3 (17.6, −0.5 - 35.8) 27 (8.5, 5.5 - 11.6) | - 1 (14.3, −11.6 - 40.2) 9 (9.9, 3.8 - 16) | - 2 (20, −4 - 44.8) 18 (8, 4.5 - 11.5) | - 0.1** 0.34 |
*percentage of overall prevalence of hypertension, β previous history of diabetes. **Fisher’s exact test, †Controlled percentage of Aware with fasting blood glucose within normal range during the survey, P-values for sex differences.
Characteristic | Total N (%, 95% CI) | Males N (%, 95%, CI) | Females N (%, 95%, CI) | P-value |
---|---|---|---|---|
Prediabetes | 46 (7.6, 5.5 - 9.7) | 18 (9.4, 5.2 - 13.6) | 28 (6.8, 4.3 - 9.2) | 0.25 |
Prevalence of Prediabetes Age group | ||||
20 - 29 30 - 39 40 - 49 50 - 59 ≥60 | 9 (6.5, 2.4 - 10.5) 3 (3,6, −0.3 - 6.3) 13 (10.7, 5.2 - 16.2) 11 (9.7, 4.2 - 15.2) 10 (7.7, 3.1 - 12.3) | 2 (5.7, −2 - 13.8) −5 (16.7, 3.4 - 30) 3 (7.3, −0.7 - 15.3) 8 (11.1, 3.8 - 13.5) | 7 (6.7, 1.8 - 11.5) 3 (3.4, −0.4 - 7.2) 8 (8.7, 2.9 - 14.4) 8 (11.1, 3.8 - 18.3) 2 (3.4, −1.3 - 8.1) | 0.83 1* 0.22 0.51 0.25 |
BMI category <18.5 18.5 - 24.9 25 - 29.9 ≥30 | - 20 (7, 4.1 - 10) 14 (7.9, 3.9 - 11.8) 12 (10.2, 4.7 - 15.6) | - 12 (10.6, 4.9 - 16.3) 5 (9.3, 1.5 - 17) 1 (6.7, −6 - 19.3) | - 8 (4.7, 1.5 - 7.8) 9 (7.3, 2.7 - 11.8) 11 (10.7, 4.7 - 16.6) | - 0.05 0.65 1 |
Medical History Stroke Hypertension | - 5 (29.4, 7.6 - 51.1) 18 (5.7, 3.1 - 8.3) | - 2 (28.6, −4.9 - 62) 7 (7.7, 2.2 - 13.2) | - 3 (30, 1.6 - 58.4) 11 (4.9, 2.1 - 7.7) | - 0.95 0.33 |
*Fisher’s exact test.
Enugu East weighted population | Enugu East adjusted population | Expected number of cases | Adjusted Prevalence (%) | WHO weighted population | WHO adjusted population | WHO expected cases | Adjusted prevalence (%) | |
---|---|---|---|---|---|---|---|---|
<20 | 0.48 | - | - | - | 0.35 | - | - | - |
20 - 44 | 0.37 | 224 | 17 | 7.5 | 0.38 | 230 | 19 | 8.3 |
45 - 54 | 0.08 | 48 | 7 | 14.5 | 0.11 | 67 | 10 | 14.9 |
55 - 64 | 0.04 | 24 | 4 | 16.7 | 0.08 | 48 | 8 | 16.7 |
≥65 | 0.03 | 18 | 3 | 16.7 | 0.08 | 48 | 7 | 14.6 |
Total | 1.0 | 315 | 31 | 9.8 | 1.0 | 392 | 43 | 11.0 |
Disease | Odds ratio | 95% CI | P = value |
---|---|---|---|
Males | 0.384 | 0.829 - 2.313 | |
Females | 0.722 | 0.432 - 1.207 | 0.21 |
≥45 years | 2.033 | 1.208 - 3.420 | 0.01* |
Obesity | 0.916 | 0.484 - 1.1734 | 0.79 |
Hypertension | 0.442 | 0.257 - 0.762 | <0.01* |
History of stroke | 1.639 | 0.459 - 5.848 | <0.01* |
*significant P-values.
Diabetes in SSA presents a critical public health challenge. Current estimates on the prevalence of diabetes in the continent included a wide age-range of participants and therefore do not provide information on people living in urban slums who may have higher risk of the disorder [
The prevalence of diabetes in our report is almost 1.3 times higher than the WHO regional estimate for Africa (8.7%) and 1.2 times higher than IDF regional estimate for Africa (9.7%) [
The present study revealed that the prevalence of diabetes was similar in men and women, which is consistent with findings of previous studies [
Similar to the present study, in developing countries the majority of people with diabetes are in the 45 - 64-year age range [
Newly diagnosed diabetes defined as the percentage of people with diabetes who were detected for the first time during the survey was (54.9%) more in females than males. Data from international diabetes federation in 2013 suggests that currently Nigeria has the greatest number of people living with diabetes (1.997.8 million) with only about 225,000 (21.4%) being aware of their condition [
Prediabetes identifies patients at risk of diabetes. The conversion rate from prediabetes to diabetes changes with population characteristics and the criteria used to define prediabetes [
Mean SBP was significantly higher in males than females similar to a previous report [
Strengths of the study. This is the first study in south east Nigeria to study the prevalence of diabetes in a slum. In addition, we estimated of disorders linked to diabetes such as hypertension obesity and stroke in the population.
This study has some limitations. The glucometer is not the most appropriate instrument for the diagnosis of diabetes mellitus. A laboratory method would have been most appropriate. We collected data on past medical history directly from the participants without any supporting medical records hence cases like gestational diabetes may be omitted. The low response rate to the invitation for screening (5% - 10%) may also affect the overall result. The present study did not discriminate between types 1 and 2 diabetes. Notwithstanding these shortcomings, our results suggest that diabetes and pre-diabetes are common among poor urban slums in Enugu and can be useful in formulating local health policies, at least for the age groups studied.
There is a relatively high prevalence of diabetes among adults in an Enugu slum. Public health educational measures promoting prevention and early detection of diabetes should be encouraged. Efforts should be made to educate the populace on the need for early detection and treatment.
The authors declare no conflicts of interest regarding the publication of this paper.
Ezeala-Adikaibe, B.A., Mbadiwe, N., Okwara, C., Onodugo, O., Onyekonwu, C., Ijoma, U., Ekenze, O.S., Orjioke, C., Chime, P., Aneke, E., Nwatu, C.B., Young, E. and Anyim, O. (2018) Diabetes and Pre-Diabetes among Adults in an Urban Slum in South East Nigeria. Journal of Diabetes Mellitus, 8, 131-144. https://doi.org/10.4236/jdm.2018.84013