Insulin glargine in combination with nateglinide in people with Type 2 diabetes: a randomized placebo-controlled trial.

OBJECTIVE: To determine the effect of adding nateglinide to therapy with insulin glargine in adults with Type 2 diabetes previously treated with insulin and with poor blood glucose control. RESEARCH DESIGN AND METHODS: In this 16-week, double-blind, placebo-controlled study, people with Type 2 diabetes [n = 55, HbA(1c) 8.2 +/- 1.0 (+/- sd)%, duration of diabetes 12.8 +/- 6.0 years, duration of insulin treatment 6.0 +/- 4.0 years] were transferred to single bedtime injection of insulin glargine for a titration period of 4 weeks, and then randomized to nateglinide or matching placebo before meals in addition to insulin glargine. Metformin was continued if taken. Doses of insulin and oral medication were titrated to protocol for the treatment period of 12 weeks. RESULTS: Baseline-adjusted self-monitored capillary blood glucose concentration at 12 weeks was significantly lower with nateglinide + insulin glargine compared with placebo + insulin glargine after breakfast [difference -2.3 (95% confidence interval -4.4, -0.2) mmol/l, P = 0.030], before lunch [-2.5 (-4.6, -0.3) mmol/l, P = 0.029], and after lunch [-2.3 (-4.3, -0.4) mmol/l, P = 0.021], but not at other times. Baseline-adjusted HbA(1c) was not lower with nateglinide + insulin glargine as compared with placebo + insulin glargine [7.8 +/- 1.4 vs. 8.3 +/- 1.0%, difference -0.43 (-0.98, 0.12)%]. CONCLUSIONS: Addition of nateglinide before meals to once-daily insulin glargine in people with long-standing diabetes already requiring insulin therapy improves blood glucose control in the early part of the day after breakfast and lunch, but does not provide good control of blood glucose levels overall.