A randomized clinical trial comparing breakfast, dinner, or bedtime administration of insulin glargine in patients with type 1 diabetes

Abstract

Objective: Insulin glargine (Lantus), a long-acting human insulin analog, provides effective glycemic control when administered at bedtime. This open-label, randomized, parallel group, multicenter study investigated whether insulin glargine is equally effective if administered before breakfast, before dinner, or at bedtime.

Research design and methods: Patients with type 1 diabetes on basal-bolus therapy (n = 378, 18-68 years, HbA(1c) 5.5-9.8%) were treated with once-daily individually titrated insulin glargine in combination with prandial insulin lispro for 24 weeks.

Results: Baseline characteristics were similar in the three groups (overall age 40.9 +/- 11.9 years, diabetes duration 17.3 +/- 11.5 years). Median total daily insulin dose was similar at baseline (0.65, 0.65, and 0.66 IU/kg for breakfast, dinner, and bedtime, respectively) and remained relatively constant over the study period; however, the insulin glargine-to-total insulin dose ratio increased more in the breakfast group than in the dinner and bedtime groups. A similar reduction of adjusted mean HbA(1c) from baseline to end point occurred in all patients (7.6-7.4, 7.6-7.5, and 7.6-7.5% for breakfast, dinner, and bedtime, respectively), and a similar percentage achieved HbA(1c) <7.0% at end point in all groups (29.5, 29.8, and 25.8%, respectively). The 24-h blood glucose profiles in relation to injection time were similar in all groups. The incidences of total symptomatic and severe hypoglycemia did not differ between the three treatment groups; however, nocturnal hypoglycemia occurred in significantly fewer patients in the breakfast group (59.5%) compared with the dinner (71.9%) and bedtime (77.5%) groups (P = 0.005).

Conclusions: These data suggest that insulin glargine, in combination with insulin lispro, is safe and effective when administered before breakfast, before dinner, or at bedtime.