The incidence of painless ischemic heart disease is increased in diabetic patients, and it has been suggested that this may be partly due to diabetic neuropathy involving cardiac afferent nerves. We have performed exercise electrocardiography in middle-aged diabetic men without cardiac symptoms to see if silent myocardial ischemia is more common in patients with neuropathy. Thirty patients had diabetic neuropathy (group 1), and 30 did not (group 2). The groups were matched for age and duration of diabetes. The exercise test was abnormal in 14 patients. A positive test was no more common in patients with diabetic neuropathy.
During a mean follow-up period of 50 mo, five patients developed clinical heart disease, four of whom had a positive exercise test. An abnormal exercise ECG is common in diabetic men without cardiac symptoms, but our study does not suggest that the high incidence of silent myocardial ischemia in diabetic patients is related to the presence of diabetic neuropathy. In patients with diabetes a positive exercise test is associated with a high risk of developing clinical heart disease in subsequent years.