A comparison of glycaemic and metabolic control over time among South Asian and European patients with Type 2 diabetes: results from follow-up in a routine diabetes clinic

Aims Although South Asians have a higher prevalence of diabetes which develops at a younger age, data on change in metabolic parameters post-diagnosis are relatively sparse. We therefore wished to determine whether South Asians with diabetes had similar or greater year-on-year deterioration in metabolic parameters compared with Europeans. Methods We analysed longitudinal change in metabolic parameters [glycated haemoglobin (HbA(1c)), blood pressure, body mass index (BMI), lipids] among South Asian (n = 210) and European (n = 1557) patients consecutively attending the same diabetes clinic over a mean period of 5.3 years. Resulst South Asians were younger than Europeans at first recorded diagnosis of diabetes (mean age 45.9 vs. 57.3 years, P < 0.001) and had significantly lower (similar to 1.2 units) BMI and blood pressure. Mean HbA(1c) was not different across ethnic groups at first visit, but with time glycaemic control was worse in South Asians than Europeans, with average deterioration 1.31% (= 0.23%/year) in Asians vs. 0.82% (0.16%/year) in Europeans, P = 0.003. This ethnic difference in mean change in HbA(1c) persisted after adjustment for age, sex, baseline HbA(1c), and weight change in linear regression analysis (beta = 0.46, 95% CI 0.24-0.69, P < 0.001), and with additional adjustment for time to referral and duration of diabetes (P = 0.01). Moreover, South Asians had significantly smaller improvements in blood pressure (P < 0.001) and cholesterol (P = 0.044) over the follow-up period in keeping with fewer prescriptions of anti-hypertensive agents and lipid-lowering agents. Conclusions These data suggest the need to be more aggressive in the management of diabetes and related risk factors in South Asians.