Ethnic diversity in type 2 diabetes

Background and Methods  The present review assesses published data relating to the main ethnic groups in the UK Prospective Diabetes Study (UKPDS), namely White Caucasians (WC; 82% of the cohort), Indian-Asians (IA; 10%) and Afro-Caribbeans (AC; 8%).

Results  At entry, the IA patients were younger than WC and AC patients, had a greater waist–hip ratio and more sedentary lifestyle, but had the lowest prevalence of hypertension and current smoking. The AC patients had the poorest glycaemic control but the most favourable lipid profile. The differences in modifiable vascular risk factors did not change over 9 years of follow-up. Consistent with UKPDS exclusion criteria, few patients had complications at baseline and there were no between-group differences. An interim analysis of incident fatal/non-fatal myocardial infarction (median follow-up 8.7 years) showed that the AC patients had a 70% lower risk than WC after adjustment for explanatory variables and that IA patients had a similar risk to WC. An analysis of complete albuminuria and renal failure data (median follow-up 15 years) showed that IA ethnicity was independently associated with an increased risk.

Conclusions  There are sustained ethnic differences in the nature of diabetes, including vascular risk factors. AC patients had a substantially reduced risk of myocardial infarction that was not explained by their more favourable lipid profile, while IA patients were more likely to develop nephropathy than WC and IA patients. Longer follow-up is needed to determine whether the increased macrovascular risk observed in IA patients in other studies is replicated in the UKPDS cohort.