Additional Insulin Dose May Protect Diabetes Patients Against Heart Disease

A dose of insulin 3 hours after eating may prevent blood vessel damage among patients with type 1 diabetes.

Maintaining proper blood glucose levels is necessary for patients with type 1 diabetes. Along with diet and exercise, many patients self-inject insulin throughout the day to prevent complications associated with uncontrolled blood sugar, such as cardiovascular disease.

Findings from a preliminary clinical trial have found that patients with type 1 diabetes can take a simple step to improve control of their blood glucose levels. The authors found that 1 additional dose of insulin taken 3 hours after eating can prevent fat and inflammatory markers in the blood.

Notably, these factors can damage the blood vessels and cause heart disease. Patients with type 1 diabetes are up to 10 times more likely to develop heart disease compared with the general population and accounts for a substantial number of deaths. Preventing heart disease is key in these patients, the authors noted.

A majority of patients with type 1 diabetes inject insulin after meals; however, the dose is typically calculated by how much carbohydrates are consumed rather than how much fat content the meal has, according to the study.

“Many people with type 1 diabetes struggle to regulate their blood sugar levels around mealtimes, because the fat content in their food is metabolized [sic] after their standard insulin injection has lost its potency or has left their blood,” said Matthew Campbell, PhD, study co-author. “Most meals in a typical UK diet have a high fat content, and slower metabolism of this fat can lead to raised blood sugar levels — with risk of hyperglycaemia [sic]– and also higher levels of fat and inflammatory markers in the blood, which increase the risk of cardiovascular disease.”

The clinical trial included 10 men with type 1 diabetes who were given 3 meals that contained the same amount of carbohydrates and proteins. One of the meals was low in fat content, while the other 2 were high in fat content.

With the low-fat meal, patients administered their normal insulin dose, but with the high-fat meal, they also administered another insulin injection 3 hours after eating. The second dose was one-third of the original dose. Blood samples were taken every 30 minutes for 6 hours.

The authors discovered that sugar, fat, and inflammatory markers in the blood increased 6 hours after eating the high fat meal and 1 injection of insulin, according to the study. When the extra dose of insulin was given, the levels of the markers were normalized.

“Improving the sugar and fat levels in the blood after eating is important for the long-term health of the heart and blood vessels,” said study co-author Dr Daniel West, PhD. “But calculating insulin injection dose based on carbohydrates alone is clearly too simplistic, as most people eat meals that include fat and protein too.”

The authors are now looking to study the approach in a larger trial over a longer period of time to determine how the blood vessels and disease control is affected.

While these findings were positive, the authors caution that patients should consult their physicians prior to changing their insulin regimen, according to the study.

“Our findings show that, after a high fat meal, an extra dose of insulin provides a very simple way of both regulating blood sugar levels for short term health and protecting against the long-term risks of cardiovascular disease,” Dr Campbell said. “We feel strongly that the advice given to people with type 1 diabetes needs to be updated to take this new information into account.”