Higher doses of insulin not linked to risk of cardiovascular death, study finds

Taking higher doses of insulin is not linked to a higher risk of cardiovascular (heart-related) death, according to new research.
The study, conducted by researchers at the Lewis Katz School of Medicine at Temple University, Philadelphia, contradicts previous research.
In 2008, the large-scale study Action to Control Cardiovascular Risk in Diabetes (ACCORD) found that more intensive diabetes therapies were linked to a higher cardiovascular mortality rate. The results were puzzling; no subsequent research was able to identify why this might be the case.
In this study, the researchers explored whether insulin dosage might be responsible. After analysing the data from the ACCORD study – which involved more than 10,000 participants -the researchers initially believed that it was. “Insulin is a very important medication for patients with diabetes and everyone really wanted to know if insulin could be harmful at higher doses,” said Dr. Elias S. Siraj, lead investigator.
“Our initial unadjusted analysis showed that an increase in insulin dose by 1 unit/kg of body weight increased the risk of cardiovascular death by 83 to 236 per cent. But, we had to adjust the data for various medical conditions and other factors potentially associated with insulin use.”
Once the results were adjusted for other potential factors and various medical conditions, there was no observable link between insulin dosage and cardiovascular death. Dr Siraj explained: “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.”
The findings were published in Diabetes Care.