Higher insulin dose in type 2 diabetes is not a risk factor for cardiovascular death, according to new research. The research comes from analyzing a National Institutes of Health (NIH) sponsored double-blind, randomized clinical trial, which revealed that diabetics who underwent intensive therapy had higher mortality rates. The reason for the results was unclear, but some previous research suggested higher dosages of insulin may be to blame.
Researchers from the Temple University Health System further explored the older research to try and uncover the reason for high mortality rates in intensive diabetic care.
Lead investigator, Dr. Elias S. Siraj, said, “Insulin is a very important medication for patients with diabetes and everyone really wanted to know if insulin could be harmful at higher doses. Our initial unadjusted analysis showed that an increase in insulin dose by one unit/kg of body weight increased the risk of cardiovascular death by 83 to 236 percent (Hazards ratio of 1.83 to 3.36). But, we had to adjust the data for various medical conditions and other factors potentially associated with insulin use.”
After statistical adjustment, insulin dosages were not associated with an increased risk of mortality due to cardiovascular events. Dr. Siraj added, “This is reassuring for many physicians and their patients. But, our findings won’t lay to rest the on-going discussion about insulin use and the potential for increased risk, especially at higher doses. There are still unanswered questions and more studies are needed to answer them definitively.”
Diabetes contributes to blindness, kidney failure and cardiovascular disease. An estimated 29 million Americans have diabetes – and many require insulin therapy.
Assistant professor Dr. Daniel J. Rubin said, “Whether or not insulin has harmful cardiovascular effects is an important question. We were pleased with the opportunity to be the first group to test our hypothesis in a relatively large and well-characterized population. While this does not end the debate, our results are reassuring.”