Randomized Controlled Clinical Trial of Glargine Versus Ultralente Insulin in the Treatment of Type 1 Diabetes

OBJECTIVE—Multiple daily insulin injection programs are commonly accompanied by considerable glycemic variation and hypoglycemia. We conducted a randomized crossover design clinical trial to compare glargine with ultralente insulin as a basal insulin in type 1 diabetes. RESEARCH DESIGN AND METHODS—To determine whether the use of glargine insulin as a basal insulin would result in a comparable HbA1c and less glycemic variation and hypoglycemia than ultralente insulin, 22 individuals (aged 44 ± 14 years [±SD], 55% men) with type 1 diabetes who were experienced with multiple daily insulin injections and had an HbA1c of RESULTS—Treatment with glargine resulted in lower mean HbA1c (6.82 ± 0.13 vs. 7.02 ± 0.13, difference: 0.2 ± 0.08, P = 0.026), less nocturnal variability (plasma glucose 49.06 ± 4.74 vs. 62.36 ± 5.21 mg/dl, P = 0.04), and less hypoglycemia (24.5 ± 2.99 vs. 31.3 ± 4.04 events, P = 0.05), primarily due to less daytime hypoglycemia (P = 0.002). On the other hand, serious hypoglycemia and average glucose concentration measured with continuous subcutaneous glucose monitoring did not differ. CONCLUSIONS—We conclude that while use of either ultralente or glargine as a basal insulin can result in excellent glycemic control, treatment with glargine is associated with slightly but significantly lower HbA1c and less nocturnal glycemic variability and hypoglycemia.