British South Asians aged 13-16 years have higher fasting glucose and insulin levels than Europeans

Aim To examine whether plasma glucose, insulin resistance and markers of adiposity differed between British adolescents of South Asian and European origin. Methods School-based cross-sectional study (1998-2000), in which detailed measurements of adiposity, fasting plasma glucose and serum insulin were made in 90 South Asian and 1248 European pupils (overall 69% response rate). Results Compared with Europeans, South Asian subjects had higher mean fasting insulin levels (percentage mean difference 17.2%, 95% confidence interval 7.2-26.1%, P = 0.001), a higher mean fasting glucose (mean difference 0.19 mmol/l, 95% confidence interval 0.08-0.29 mmol/l, P = 0.0005) and a higher prevalence of impaired fasting glucose (>= 6.1 mmol/l) (5.6% vs. 1.5%, odds ratio 3.9, 95% confidence interval 1.4-10.9, P = 0.004). Although South Asian children tended to have slightly higher indices of adiposity than Europeans (other than body mass index), the differences in glucose and insulin levels persisted after adjustment for adiposity and for pubertal status. Conclusions The predisposition to Type 2 diabetes observed in South Asian adults is apparent before adult life. Establishing the contributions of the childhood and fetal environments and of genetic factors to the development of these ethnic differences is an important priority. Prevention of Type 2 diabetes in British South Asians needs to begin before adult life.