Insulin Sensitivity in Heart Surgery

During heart surgery, some patients experience weakened insulin sensitivity. That is, their bodies do not respond as well to insulin - a hormone that regulates blood sugar. This could increase diabetes risk. Cholesterol-lowering drugs called statins are often recommended to patients with heart disease.

However, statins may further weaken insulin sensitivity in patients undergoing heart surgery.

Ask your doctor about the risks of heart surgery.

Insulin is a natural hormone that lowers levels of sugar in the blood. When the body responds poorly to insulin, a patient's blood sugar can rise to dangerous levels, increasing the risk of diabetes and other complications.

Past studies have shown that statin drugs may increase insulin resistance and the risk of diabetes.

Knowing that heart surgery also may affect insulin sensitivity, Hiroaki Sato, MD, PhD, of McGill University Health Center in Montreal, and colleagues set out to study the links between statin treatment before surgery and insulin sensitivity during surgery.

The researchers compared insulin sensitivity during heart surgery between patients taking statins and those not taking statins.

They found that insulin sensitivity gradually dropped in both groups during surgery. However, insulin sensitivity was, on average, about 20 percent lower in patients taking statins than in patients not taking statins.

While in the intensive care unit, blood sugar levels were higher among patients in the statin group, compared to those in the control group. More specifically, statin patients had a blood sugar level of about 153 mg/dL, while non-statin patients had a blood sugar level of about 140 mg/dL.

In addition, statin patients had larger swings in blood sugar levels during surgery than their non-statin counterparts.

For their research, Dr. Sato and colleagues studied 120 non-diabetic patients with abnormal lipid (blood fat) levels.

The study was published July 24 in Diabetes Care, a journal of the American Diabetes Association.