Glucose intolerance (diabetes and IGT) in a selected South Indian population with special reference to family history, obesity and lifestyle factors--the Chennai Urban Population Study (CUPS 14).

AIM OF THE STUDY The aim of the study was to assess the impact of family history of diabetes, obesity and lifestyle factors particularly physical activity on glucose intolerance in a selected south Indian population. MATERIALS AND METHODS The Chennai Urban Population Study (CUPS) is an epidemiological study involving two residential areas in Chennai in South India representing the middle and lower socio-economic group. Of the total of 1399 eligible subjects (age > or = 20 years), 1262 (90.2%) participated in the study. A detailed questionnaire was used to collect details on medical history, family history of diabetes, family income and physical activity. All the study subjects underwent a glucose tolerance test (GTT) and were categorized as having normal glucose tolerance (NGT), impaired glucose tolerance (IGT) or diabetes using WHO consulting group criteria. Obesity and abdominal obesity were defined using the new Asia Pacific guidelines. RESULTS The overall prevalence of diabetes in the study population was 12.0%, (age-standardized -9.3%), which included 7.2% of known diabetic subjects and 4.8% undiagnosed diabetic subjects, while the prevalence of impaired glucose tolerance was 5.9% (age-standardized prevalence 5.0%). The prevalence of glucose intolerance (Diabetes + IGT) was significantly higher among subjects with both parents diabetic (55%) compared to those with one parent diabetic (22.1%, p = 0.005) and those with no family history (15.6%, p < 0.0001). Prevalence of glucose intolerance was significantly higher among subjects who had light grade physical activity (23.2%) compared to moderate (17.5%, p = 0.04) and heavy grade activity (8.1 % p < 0.00001). Subjects belonging to higher socio-economic status (SES) and who also had a positive family history of diabetes had five times greater prevalence of glucose intolerance compared to subjects from lower socioeconomic status and no family history (p < 0.0001). Regression analysis revealed age (p < 0.0001), waist circumference (p < 0.0001), body mass index (p < 0.0001), waist-hip ratio (p < 0.0001), systolic blood pressure (p < 0.0001), diastolic blood pressure (p < 0.0001), family history of diabetes (p < 0.0001), higher SES (p < 0.0001), moderate (p = 0.001) and light (p < 0.001) grade physical activity to be associated with glucose intolerance. Multiple logistic regression analysis showed that even after adjusting for variables like age and family history of diabetes, physical activity showed a significant association with glucose intolerance CONCLUSION The prevalence of glucose intolerance is high in this selected urban south Indian population. Lifestyle factors and family history have a synergistic effect on increasing the risk for diabetes in this population.