Long-acting, once-a-day insulin dose may be best for type 2 diabetics

Adding insulin to standard diabetes drugs results in better blood sugar control for many with type-2 diabetes, and the dose and timing of insulin received can make a big difference, British researchers reported. A once-a-day, long-acting dose of insulin may be the best approach for patients making the move to insulin therapy, the study found.

The report was published in the Oct. 22 online edition of the New England Journal of Medicine, to coincide with its presentation at the 20th World Diabetes Congress in Montreal. The study received funding from drug maker Novo Nordisk and the nonprofit group Diabetes UK.

Researchers, lead by Rury Holman, FRCP, a professor of diabetic medicine at the University of Oxford, compared different forms of insulin therapy for patients with type-2 diabetes. Insulin treatment can start with a “basal” dose that is long acting, a “prandial” or mealtime dose of insulin that is short acting or a so-called biphasic dose, a mixture of both short- and long-acting insulin.

However, which of these regimens works best, was not clear, Dr. Holman said. To find out, researchers randomly assigned 708 patients to biphasic insulin injections twice a day (NovoMix30), mealtime insulin injections three times a day (NovoRapid) or basal insulin injected once a day (Levemir).

These patients had poor blood sugar control even though they were taking two common oral diabetes medications, metformin and sulfonylurea, the researchers noted.

Three years into the trial, researchers found that slightly more than 43% of the patients taking basal insulin and about 45% of the patients taking insulin at mealtime achieved good blood sugar control, compared with about 32% of those taking biphasic insulin.

In addition, those on basal insulin had a lower incidence of low blood sugar, a serious side effect of insulin therapy, compared to those on biphasic or mealtime insulin, Dr. Holman and his team found. Patients on basal insulin gained less weight than people on the other two regimens.

Michael Roden, MD, from the Institute for Clinical Diabetology, German Diabetes Center, Heinrich Heine University Clinics, Dusseldorf, and author of an accompanying journal editorial, said that, “You need to do a lot to control blood glucose in type 2 diabetic patients when they need insulin.”

Dr. Roden noted that while basal insulin is the place to start insulin therapy in type-2 diabetes, over time, mealtime insulin would need to be added to maintain blood sugar control.

Whether lowering blood sugar with insulin and other medications will prevent complications from diabetes, this study was too short to tell, Dr. Roden said. “The study was not powered to analyze the so-called hard endpoints, such as eye complications or, most importantly, cardiovascular problems,” he said.

However, there were fewer deaths among those in the study started on basal insulin, he added. “Which is only a hint, but is not a firm conclusion [of the benefit of basal insulin therapy].”