Age-specific prevalence and risk associations for impaired glucose tolerance in urban southern Indian population

Abstract

Objectives: A national survey of diabetes and impaired glucose tolerance (IGT) conducted in 2000 AD in six major cities of India showed a high prevalence of diabetes (12.1%) and IGT (14%). Prevalence of IGT was higher than that of diabetes in subjects with less than 40 years when compared with older subjects. This analysis was done to look for differences in the risk factors associated with IGT in the younger and older subjects.

Methods: Associations of body mass index (BMI), waist : hip ratio, physical activity, family history of diabetes and monthly income with IGT and with diabetes were tested in the age groups of < 40 and > or = 40 years separately. Multiple logistic regression analyses were done to test the associations.

Results: Prevalence of IGT was higher than diabetes in the younger group (13.1% Vs 5%, P < 0.001). Prevalence of obesity was higher in the older IGT subjects (38% Vs 30.5%, p < 0.003). Presence of positive family history of diabetes was similar in both the groups. In the > or = 40 year group age, BMI and family history of diabetes were common risk factors for diabetes and IGT. In the younger group, only BMI showed an association with IGT. The association of family history of diabetes with IGT was weaker than for diabetes even in the older subjects (Odds Ratio (OR) = 3.5 for diabetes, 1.33 for IGT).

Conclusions: Prevalence of IGT was higher than diabetes in the age group < 40 years. Only BMI showed an association with IGT in them while the risk associations were similar to diabetes in the older group. Prospective studies will throw more light on the implications of these findings.