Long-acting insulin works best for many diabetics

Adding insulin to standard diabetes drugs results in better blood sugar control for many with type 2 diabetes, British researchers report, and the dose and timing of insulin received can make a big difference.

Specifically, 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.

Keeping blood sugar under control reduces the risk of complications in type 2 diabetes. But diabetes is also a progressive disease, which disrupts insulin production. Consequently, for many diabetes patients, the drugs used to control blood sugar need to be increased repeatedly and most patients will eventually need to take insulin, the researchers said.

“Any treatment which keeps blood sugar under control will minimize risk of complications, but in the end insulin may be the only effective way of doing this,” explained lead researcher Dr. Rury Holman, a professor of diabetic medicine at the University of Oxford. “The vast majority will need insulin in the longer term.”

The report is 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.

For the study, Holman’s team 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, Holman said. To find out, the 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). All of the formulations are made by Novo Nordisk.

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, the researchers found that slightly more than 43 percent of the patients taking basal insulin and about 45 percent of the patients taking insulin at mealtime achieved good blood sugar control, compared with about 32 percent 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, Holman’s team found. Moreover, patients on basal insulin gained less weight than people on the other two regimens.

“These findings provide clear evidence for people with type 2 that supports starting insulin therapy with a once-a-day basal insulin and subsequently adding a mealtime insulin if glycemic targets are not met,” Holman said.

Dr. Michael Roden, from the Institute for Clinical Diabetology at the German Diabetes Center at Heinrich Heine University Clinics in 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.”

Roden noted that while basal insulin is the place to start insulin therapy in type 2 diabetes, over time, mealtime insulin will 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, 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, Roden said. “Which is only a hint, but is not a firm conclusion [of the benefit of basal insulin therapy].”

For more information on diabetes, visit the U.S. National Library of Medicine.

 

SOURCES: Rury Holman, M.B., professor, diabetic medicine, University of Oxford, UK; Michael Roden, M.D., Institute for Clinical Diabetology, German Diabetes Center, Department of Metabolic Diseases, Heinrich Heine University Clinics, Dusseldorf, Germany; Oct. 22, 2009, New England Journal of Medicine, online

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