About half of patients with type 2 diabetes eventually require insulin. Recent guidelines suggest starting insulin therapy with once-daily basal insulin, titrated to control fasting blood glucose. However, some studies suggest that postprandial glucose correlates more closely with glycosylated hemoglobin (HbA1c) and that better control might be achieved with preprandial short-acting insulin.
Researchers, funded by the manufacturer of insulin glargine (Lantus), randomized 415 patients with type 2 diabetes and HbA1c levels between 7.5% and 10.5% to take either once-daily insulin glargine or thrice-daily preprandial insulin lispro (Humalog). Insulin doses were titrated weekly by algorithm to achieve fasting blood glucose levels <99 mg/dL for insulin glargine, or preprandial and postprandial blood glucose levels <99 mg/dL and <135 mg/dL, respectively, for insulin lispro. All patients continued prerandomization oral hypoglycemic regimens.
After 44 weeks, mean HbA1c levels had declined similarly in the glargine and lispro groups (by 1.71% and 1.87%, respectively). More patients achieved HbA1c levels
7.0% in the lispro group (69% vs. 57% for the glargine group), but more patients achieved HbA1c levels 
5.5% in the glargine group (38% vs. 6% in the lispro group). Mean fasting blood glucose was significantly lower with glargine than with lispro, and mean postprandial glucose was significantly lower with lispro than with glargine. Patients in the glargine group reported significantly fewer hypoglycemic events and a greater mean increase in treatment satisfaction than did those taking lispro. Mean weight gain in both groups was about 3 kg.Comment: Basal and prandial insulin regimens have different effects on diurnal glucose curves but seem to have the same bottom-line effect on HbA1c levels. Because it involves fewer injections and finger-sticks and less frequent hypoglycemia, basal insulin appears to be more acceptable to patients.
— Bruce Soloway, MD
Published in Journal Watch General Medicine April 22, 2008