Biphasic insulin aspart 30 plus metformin: an effective combination in type 2 diabetes.

AIM: This study compared glycaemic control achieved with biphasic insulin aspart 30 (BIAsp 30) monotherapy, BIAsp 30 plus metformin and glibenclamide plus metformin in patients with type 2 diabetes not adequately controlled with metformin.

METHODS: In this multinational, open-labelled, parallel group, 16-week trial, 341 patients (patients not adequately controlled with metformin for at least 1 month) with type 2 diabetes were studied. Patients were randomized to receive BIAsp 30, twice daily (n = 107 exposed to treatment), or BIAsp 30, twice daily, plus metformin (n = 108) or glibenclamide plus metformin (n = 114). The primary endpoint was HbA(1c) at end of trial; adverse events, hypoglycaemia episodes, blood lipids and weight were also monitored.

RESULTS: In the total population (HbA(1c) 7.5-13.0% at screening), end-of-trial HbA(1c) levels were lower in patients receiving BIAsp 30 plus metformin compared with those receiving BIAsp 30 only [mean treatment difference (+/-s.e.m), 0.39 +/- 0.15%, p = 0.007]. In a subpopulation (HbA(1c) > or = 9.0% at baseline, n = 193), patients receiving BIAsp 30 plus metformin had significantly lower HbA(1c) levels at the end of the trial compared with those receiving glibenclamide plus metformin (treatment difference, 0.46 +/- 0.21%, p = 0.027). Mean body weight (+/-s.d) at the end of the trial was significantly lower in patients receiving glibenclamide plus metformin compared with those receiving BIAsp 30 only (84.3 +/- 13.3 kg vs. 88.9 +/- 16.9 kg, p < 0.001). No major hypoglycaemic episodes were recorded during the trial, and incidence rates for minor and symptoms-only hypoglycaemia were low and similar between treatment groups (0.03-0.04 events/patient/week).

CONCLUSION: BIAsp 30 added to metformin could be an appropriate therapeutic option for achieving good glycaemic control, compared with the addition of a second oral agent, particularly where HbA(1c) > or = 9%.