Addition of nateglinide to rosiglitazone monotherapy suppresses mealtime hyperglycemia and improves overall glycemic control

OBJECTIVE - To determine the effects of nateglinide added to rosiglitazone monotherapy on glycemic control and on postprandial glucose and insulin levels in patients with type 2 diabetes. RESEARCH DESIGN AND METHODS - This 24-week, multicenter, double-blind, randomized study compared the efficacy of nateglinide (120 mg a.c.) and placebo added to rosiglitazone monotherapy (8 mg q.d.) in 402 patients with type 2 diabetes with HbA(1c) between 7 and 11% (inclusive). Efficacy parameters tested included HbA(1c) and plasma glucose and insulin levels in the fasting state and after a standardized meal challenge. Safety data were also collected. RESULTS - in placebo-treated patients, HbA(1c) did not change (Delta = 0.0 +/- 0.1%). In patients randomized to nateglinide, HbA(1c) decreased from 8.3 to 7.5% (Delta = -0.8 +/- 0.1%, P < 0.0001 vs. placebo). Target HbA(1c) (<7.0%) was achieved by 38% of patients treated with combination therapy and by 9% of patients remaining on rosiglitazone monotherapy. In nateglinide-treated patients, fasting plasma glucose levels decreased by 0.7 mmol/l, 2-h postprandial glucose levels decreased by 2 7 mmol/l, and 30-min insulin levels increased by 165 pmol/l compared with no changes from baseline of these parameters with placebo added to rosiglitazone (P < 0.001). CONCLUSIONS - By selectively augmenting early insulin release and decreasing prandial glucose excursions, nateglinide produced a clinically meaningful improvement in overall glycemic exposure in patients with type 2 diabetes inadequately controlled with rosiglitazone. Therefore, nateglinide substantially improves the likelihood of achieving a therapeutic target of HbA(1c) <7.0%.