Aim:  The aim of this study was to compare the efficacy and safety of a basal‐bolus insulin regimen comprising either insulin detemir or neural protamine hagedorn (NPH) insulin in combination with mealtime insulin aspart in patients with type 2 diabetes.

Methods:  This was a 26‐week, multinational, open‐label, parallel group trial with 505 patients with type 2 diabetes (mean age, 60.4 ± 8.6 years; mean BMI, 30.4 ± 5.3 kg/m²; mean HbA_1c, 7.9 ± 1.3%). Patients, randomized 2 : 1 to insulin detemir or NPH insulin, received basal insulin either once or twice daily according to their pretrial insulin treatment and insulin aspart at mealtimes.

Results:  After 26 weeks of treatment, significant reductions in HbA_1c were observed for insulin detemir (0.2%‐points, p = 0.004) and NPH insulin (0.4%‐points; p = 0.0001); HbA_1c levels were comparable at study end (insulin detemir, 7.6%; NPH insulin, 7.5%). The number of basal insulin injections administered per day had no effect on HbA_1c levels (p = 0.50). Nine‐point self‐measured blood glucose (SMBG) profiles were similar for the two treatment groups (p = 0.58), as were reductions in fasting plasma glucose (FPG) (insulin detemir, 0.5 mmol/l; NPH insulin, 0.6 mmol/l). At study end, FPG concentrations were similar for the two treatment groups (p = 0.66). By contrast, within‐subject day‐to‐day variation in fasting SMBG was significantly lower with insulin detemir (p = 0.021). Moreover, patients receiving insulin detemir gained significantly less body weight than those who were administered NPH insulin (1.0 and 1.8 kg, respectively, p = 0.017). The frequency of adverse events and the risk of hypoglycaemia were comparable for the two treatment groups.

Conclusions:  Patients with type 2 diabetes, treated for 26 weeks with insulin detemir plus insulin aspart at mealtimes, experienced comparable glycaemic control but significantly lower within‐subject variability and less weight gain compared to patients treated with NPH insulin and insulin aspart. Insulin detemir was well tolerated and had a similar safety profile to NPH insulin.