Glargine is associated with slightly but significantly lower A1c and with fewer hypoglycemic events than ultralente insulin used as a basal insulin for treatment of type 1 diabetes.
"Multiple daily insulin injection programs are commonly accompanied by considerable glycemic variation and hypoglycemia," write Yogish C. Kudva, MD, MBBS, from the Mayo Clinic in Rochester, Minnesota, and colleagues. "Several studies have shown that when compared with NPH [neutral protamine Hagedorn or isophane] insulin, use of glargine as a basal insulin preparation results in comparable or lower HbA1c concentrations and lower frequency of nocturnal hypoglycemia."
In this crossover design clinical trial, 22 individuals with type 1 diabetes who were experienced with taking multiple daily insulin injections and who had an HbA1c of less than 7.8% were randomized to receive either glargine or ultralente as the basal insulin for four months, with aspart insulin used as the prandial insulin. Physicians who supervised adjustment of insulin dose were masked to the type of basal insulin used. Mean patient age was 44 ± 14 years, and 55% were men.
Compared with ultralente treatment, glargine treatment was associated with lower mean HbA1c (6.82 ± 0.13 vs 7.02 ± 0.13; difference, 0.2 ± 0.08; P = .03), less nocturnal variability (plasma glucose, 49.06 ± 4.74 vs 62.36 ± 5.21 mg/dL; P = .04), and less hypoglycemia (24.5 ± 2.99 vs 31.3 ± 4.04 events; P = .05), primarily because of less daytime hypoglycemia (P = .002). However, serious hypoglycemia and average glucose concentration measured with continuous subcutaneous glucose monitoring was the same with both treatments.
"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," the authors write. "Taken together, these data indicate that glargine is a safer and more effective basal insulin than ultralente."
Study conclusions: NPH and human ultralente insulin have a peak effect in vivo that can promote hypoglycemia. Glargine insulin lacks this peak effect. In this small trial, glargine insulin produced superior HbA1C values and less hypoglycemic episodes compared with ultralente in patients with type 1 diabetes.
Diabetes Care. 2005;28:10-14