ATLANTA — Insulin use appears to protect against atrial fibrillation in diabetic patients with heart failure, Dr. Somjot S. Brar said at the annual meeting of the American College of Cardiology.
If this initial observation in a large community-based population of patients with heart failure is subsequently confirmed, it could lead to a lower threshold for switching diabetic patients from oral agents to insulin therapy. They might benefit in two ways: improved glycemic control and protection against the most common sustained arrhythmia, added Dr. Brar of Kaiser Permanente and the University of California, Los Angeles.
He identified 28,009 patients with heart failure in a managed care data base, 45% of whom were diabetic; 38% of the diabetic patients with heart failure were on insulin therapy. “These heart failure patients are similar to what most internists, family physicians, and cardiologists would see,” he said.
Insulin users had an adjusted prevalence of atrial fibrillation (AF) that was 20% less than diabetic non-insulin users or nondiabetic heart failure patients in a multivariate logistic regression analysis. The model controlled for numerous potential confounders including age; gender; socioeconomic status; cardiovascular risk factors; and the use of statins, ACE inhibitors, and other drugs that may potentially prevent AF. Insulin's apparent protective effect was equally robust and consistent in men and women of all ages, according to Dr. Brar.
He hypothesized that insulin use protects against AF on the basis of reports in the literature suggesting that patients on insulin have a lower incidence of postoperative AF.