Insulin pumps can treat poorly controlled type 2 diabetes, trial finds

Insulin pumps may be a useful treatment in patients who have poorly controlled type 2 diabetes despite multiple daily insulin injections, a new trial indicates.

Researchers performed a randomized, open-label controlled trial at 36 sites in Canada, Europe, Israel, South Africa, and the United States to examine whether insulin pump treatment was effective for treating poorly controlled type 2 diabetes. Patients whose type 2 diabetes was poorly controlled with multiple daily insulin analogue injections were enrolled in a dose-optimization run-in period for 2 months, after which those whose HbA1c ranged from 8.0% to 12.0% were randomly assigned in a nonblinded manner to continue receiving multiple daily injections or to receive treatment via an insulin pump. The study's primary endpoint was change from baseline in mean HbA1c. The study results were published online July 3 by The Lancet.

Four hundred ninety-five patients 30 to 75 years of age participated in the run-in phase of the trial, and 311 were randomly assigned to a treatment group (168 to insulin pumps and 163 to multiple injections). Mean age was 55.5 years in the pump group and 56.4 years in the multiple injection group; 56% and 53% of patients in each group, respectively, were men. The patients assigned to the pump group received training on the use of the pump up to 3 weeks after the end of the run-in phase, and both groups continued to receive support at regularly scheduled health care visits.

At baseline, both groups had a mean HbA1c of 9.0%; at 6 months, this had decreased by 1.1% in the insulin pump group and 0.4% in the injection group (between-group difference, −0.7%; P<0.0001). The mean total daily insulin dose at the end of the study was 97 units in the insulin pump group and 122 units in the injection group (P<0.0001). The 2 groups did not differ in change in body weight during the study (1.5 kg vs. 1.1 kg; P=0.322). Three serious adverse events related to diabetes (hyperglycemia or ketosis without acidosis) resulted in hospital admission during the study, 2 in the insulin pump group and 1 in the injection group. No patient in either group developed ketoacidosis, but 1 patient in the injection group developed severe hypoglycemia.

The authors noted that neither patients nor investigators were blinded to study group assignment and that patients who required more than 220 units of insulin per day were excluded. They also noted that they did not include comparison groups involving other treatments for type 2 diabetes, such as new oral drugs, among other limitations. However, they concluded that based on their results, insulin pumps may reduce HbA1c levels better than multiple daily injections in some patients with type 2 diabetes. Their results, they wrote, “suggest that selection of patients who could most benefit from pump treatment is of paramount importance.” They called for further research into the reasons why insulin pumps might provide better control and use less insulin than multiple daily injections.

The author of an accompanying editorial noted that achieving adequate glucose control can be a struggle for many diabetic patients. The current study “provides a compelling case for the clinical effectiveness of insulin pump treatment in type 2 diabetes, suggesting that it can help improve glycaemic control in this difficult to treat group of patients who are unable to achieve glucose control despite increasing doses of insulin,” he wrote. “However, cost effectiveness of pumps in different health-care systems will need to be evaluated.”