The 12-Month Efficacy and Safety of Insulin Detemir and NPH Insulin in Basal-Bolus Therapy for the Treatment of Type 1 Diabetes

Background: This trial compared the long-term safety and efficacy of the basal insulin preparations, insulin detemir and NPH insulin, in basal-bolus therapy for patients with type 1 diabetes.

Methods: This multinational open, parallel-group trial randomized patients to receive insulin detemir or NPH insulin twice daily in addition to mealtime human soluble insulin. Doses were titrated towards predefined glycemic targets. After an initial 6-month treatment period, patients were invited to participate in a 6-month extension period. A total of 289 from 421 elected to continue in the trial, of which 252 completed.

Results: Glycemic control as assessed by hemoglobin A_1c (insulin detemir, 7.88%; NPH insulin, 7.78%; difference not significant) and fasting plasma glucose (insulin detemir, 10.1 mmol/L; NPH insulin, 9.84 mmol/L; difference not significant) was similar in both treatment groups at end point, with hemoglobin A_1c little changed from baseline and fasting plasma glucose slightly decreased. There was some evidence for a risk reduction for hypoglycemia in association with insulin detemir, although this was not statistically significant (relative risk overall hypoglycemia, 0.71, P = 0.139; relative risk nocturnal hypoglycemia, 0.71, P = 0.067), and hypoglycemic events were fewer in each of the 12 months. There was a significant treatment difference with regard to weight outcome; NPH insulin was associated with weight gain (1.4 kg), but there was no mean weight gain (-0.3 kg) in the insulin detemir cohort (baseline-adjusted between-group difference at 12 months, 1.66 kg, P = 0.002). There were no obvious between-group differences in other safety parameters.

Conclusions: Glycemic control is maintained with insulin detemir during long-term treatment. At equivalent glycemic control to NPH insulin, insulin detemir is associated with a lack of weight gain and a trend towards a reduced risk of nocturnal hypoglycemia when used in basal-bolus therapy with mealtime soluble human insulin.