Improved Glycemic Control Without an Increase in Severe Hypoglycemic Episodes in Intensively Treated Patients With Type 1 Diabetes Receiving Morning, Evening, or Split-Dose Insulin Glargine

Garg SK, Gottlieb PA, Hisatomi ME, D’Souza A, Walker AJ, Izuora KE, Chase HP. Diabetes Res Clin Pract. 2004;66:49-56.

Insulin glargine is a basal insulin approved for once-daily administration at bedtime in type 1 and type 2 diabetes. In May 2003, the US Food and Drug Administration also approved flexible daily dosing of insulin glargine, and this is the first published study to compare morning, evening, and a split-dose (morning and evening) regimen of insulin glargine in adults with type 1 diabetes.

Data from an electronic record system of an outpatient diabetes clinic were used in this retrospective analysis. All patients evaluated in the study (N=292) had been receiving intensive insulin therapy (≥4 injections per day) with a premeal short-acting insulin (insulin lispro or aspart) and had also been treated with insulin glargine as a morning (n=63; 13 months), evening (n=125; 12 months), or split-dose regimen (n=104; 14 months). All patients completed a health status and lifestyle survey (unvalidated).

At the end of the study period, the evening and split-dose groups and all treatment groups combined showed significant improvements in A1C. Compared with baseline, the mean dose of insulin glargine was significantly lower in all treatment groups with no change in dose of the short-acting insulin at the end of the study. The occurrence of severe hypoglycemia decreased by 54% (all groups combined), and a greater decrease in hypoglycemic events occurred in the morning (69%) and evening dose (64%) groups compared with those receiving the split-dose regimen (no change). Compared with the other treatment groups, weight gain was found to be significantly higher in the split-dose group (P<.01).
 
Patients reported an improved quality of life with the insulin glargine regimen, compared with their perceived quality of life prior to taking it. Further, patients taking the morning or evening single-dose regimen reported greater flexibility in lifestyle and demonstrated improved glycemic control, compared with patients taking the split-dose regimen.

When administered as a single dose (in the morning or evening) or as a split-dose regimen (in the morning and evening), patients receiving insulin glargine showed improved glycemic control without an increase in severe hypoglycemia. The investigators concluded that a split-dose regimen of insulin glargine does not offer an advantage of improved glycemic control compared with single-dose morning or evening administration.