Aims: To evaluate the effectiveness of rosiglitazone in reducing hyperglycaemia in patients with Type 2 diabetes mellitus (DM) of Indo-Asian origin taking concurrent sulphonylurea therapy.
Methods: A randomized, double-blind, placebo-controlled study of 26 weeks' duration at 31 primary and secondary care centres in areas of the UK with a high Indo-Asian population, including 177 patients aged 28-78 years. Rosiglitazone 8 mg/day or matching placebo was added to existing sulphonylurea therapy. The primary endpoint was change from baseline in glycosylated haemoglobin A1c (HbA1c) at week 26.
Results: The mean changes in HbA1c were -1.16% with rosiglitazone (baseline 9.21%) and +0.26% with placebo (baseline 9.06%) (treatment difference P < 0.001; 95% confidence interval (CI) -1.81, -1.08). HbA1c fell below 8% in 55% and 19% of patients, respectively (treatment difference P < 0.001; 95% CI 0.22, 0.51). The greatest improvements occurred in patients whose glycaemic control was initially poor. Improvements in homeostasis model assessment of insulin sensitivity and pancreatic beta-cell function with rosiglitazone were not accompanied by a change in plasma insulin or C-peptide after 26 weeks. Free fatty acids fell by 0.09 mmol/l with rosiglitazone and increased by 0.03 mmol/l with placebo (treatment difference P < 0.001; 95% CI -0.19, -0.07).
Conclusion: Rosiglitazone improved insulin sensitivity, pancreatic beta-cell function, and glycaemic control in Indo-Asian patients with Type 2 DM who are at greater risk of the complications of Type 2 DM than other ethnic groups.