Objective: Available basal insulin formulations do not provide a constant and reliable 24-h insulin supply. We compared the efficacy and safety of glargine (a long-acting insulin analog) and NPH insulins in insulin-naive type 2 diabetic patients treated with oral antidiabetic agents.
Research design and methods: There were 426 type 2 diabetic patients (age 59 +/- 9 years, BMI 28.9 +/- 4.3 kg/m2, mean +/- SD) with poor glycemic control on oral antidiabetic agents randomized to treatment for 1 year with bedtime insulin glargine or bedtime NPH insulin. Oral agents were continued unchanged. The fasting blood glucose (FBG) target was 6.7 mmol/l (120 mg/dl).
Results: Average glycemic control improved similarly with both insulins (HbA(1c), [reference range <6.5%] 8.3 +/- 0.1 vs. 8.2 +/- 0.1% at 1 year, glargine vs. NPH, mean +/- SEM, P < 0.001 vs. baseline for both). However, there was less nocturnal hypoglycemia (9.9 vs. 24.0% of all patients, glargine vs. NPH, P < 0.001) and lower post-dinner glucose concentrations (9.9 +/- 0.2 vs. 10.7 +/- 0.3 mmol/l, P < 0.02) with insulin glargine than with NPH. Insulin doses and weight gain were comparable. In patients reaching target FBG, HbA(1c) averaged 7.7 and 7.6% in the glargine and NPH groups at 1 year.
Conclusions: Use of insulin glargine compared with NPH is associated with less nocturnal hypoglycemia and lower post-dinner glucose levels. These data are consistent with peakless and longer duration of action of insulin glargine compared with NPH. Achievement of acceptable average glucose control requires titration of the insulin dose to an FBG target < or =6.7 mmol/l. These data support use of insulin glargine instead of NPH in insulin combination regimens in type 2 diabetes.