Issue 137 Item 12 Low Heart Rate Variability Tied to Heart Disease in Diabetics

Impaired heart rate variability is associated with an increased risk of coronary heart disease (CHD) In type 2 diabetics. The data suggest that poor cardiac autonomic balance–which can be assessed before clinical symptoms of neurological damage due to elevated glucose levels–is related to higher risks of developing coronary heart disease, especially among persons with type 2 diabetes". stated investigator Dr. Duanping Liao.

Dr. Liao of Pennsylvania State University College of Medicine, Hershey, and colleagues came to these conclusions following a prospective cohort study of 11,654 people (aged 45 to 64 years at outset).

The researchers used a variety of baseline cardiac parameters to determine heart rate variability and thus cardiac autonomic control.

After an average of 8 years of follow-up, 635 cases of CHD were identified. In diabetics–comparing the lowest quartile of high frequency spectral power with the remaining quartiles-the adjusted proportional hazard ratio was 2.03 for myocardial infarction, 1.60 for incident CHD, 1.50 for fatal CHD and 1.27 for non-CHD death.

Analysis using other cardiac parameters led to similar outcome patterns. In non-diabetics, however, no consistent associations were identified.

They concluded that at a population level, a lower heart rate variability, which reflects impaired cardiac autonomic control, is statistically significantly related to the development of CHD among individuals with diabetes. Diabetes 2002;52:3524-3531.