A problem with the nerves that control internal body functions, known as diabetic autonomic neuropathy, was always considered the main risk factor for sudden cardiac death in diabetics, but new research suggests that heart and kidney disease play bigger roles.

Dr. Guillermo A. Suarez, at the Mayo Clinic College of Medicine in Rochester, Minnesota, and colleagues identified 21 cases of sudden cardiac death among 462 diabetic patients who were followed for 15 years.

Heart disease, including plaques in the blood vessels feeding the heart and heart attacks, was the greatest risk factor for sudden cardiac death, the team reports in the Journal of Neurology, Neurosurgery, and Psychiatry. All of the patients who died had some degree of plaque build-up.

Kidney disease was also an important risk factor for sudden cardiac death. In fact, after accounting for this risk factor, diabetic autonomic neuropathy was no longer a significant predictor of sudden cardiac death.

“In the light of our results,” the investigators conclude, “the role of autonomic neuropathy as the pivotal event in sudden cardiac death in diabetic patients probably needs revision.”

It’s possible that “diabetic autonomic neuropathy may act as the transient factor conducive to the final event,” they add, “but further studies are necessary to determine this.”

SOURCE: Journal of Neurology, Neurosurgery, and Psychiatry, February 2005.