Nateglinide or gliclazide in combination with metformin for treatment of patients with type 2 diabetes mellitus inadequately controlled on maximum doses of metformin alone: 1-year trial results

Aim:  To compare long-term efficacy and safety of nateglinide plus metformin with those of gliclazide plus metformin in patients with type 2 diabetes not adequately controlled with metformin monotherapy. Methods:  Double-blind, double-dummy, multicentre study extended to a total of 52 weeks. Patients with inadequate glucose control on maximal doses of metformin were randomized to nateglinide (N = 133) or gliclazide (N = 129) add-on treatment. After the initial 6-month study, the majority of patients in the nateglinide group [n = 112 (93.3%)] and in the gliclazide group [n = 101 (92.7%)] entered a 6-month, double-blind, extension study. Results:  There was no significant difference between treatment regimens in haemoglobin Alc (HbA1c) change from baseline to 52 weeks (−0.14% for nateglinide vs. −0.27% for gliclazide; p = 0.396). Proportions of patients achieving an endpoint HbA1c of <7% were similar (40 vs. 47.4%) for nateglinide and gliclazide groups. There was no significant between-treatment difference in fasting plasma glucose change from baseline to 52 weeks (nateglinide: −0.2 mmol/l and gliclazide: −0.7 mmol/l; p = 0.096). The decreases in prandial plasma glucose area under the curve0–4 h from baseline were −3.26 and −1.86 h × mmol/l in the nateglinide and the gliclazide groups respectively, and the change was statistically significant in the nateglinide group only (p = 0.006). Initial insulin response to a meal was augmented with nateglinide treatment only, without between-treatment difference in 2-h insulin response. The overall rate of hypoglycaemic events was similar with nateglinide and gliclazide combinations with metformin. Nateglinide plus metformin treatment was not associated with weight gain. Conclusions:  No significant difference was seen between nateglinide plus metformin and gliclazide plus metformin in terms of HbA1c. Treatment with nateglinide plus metformin for up to 12 months was not associated with weight gain.