Heart rate recovery after exercise is related to the insulin resistance syndrome and heart rate variability in elderly men.

OBJECTIVE: We investigated the associations between heart rate recovery after exercise (as a suggested measure of vagal activity), heart rate variability, and measurements of the insulin resistance syndrome.
MATERIAL AND METHODS: Seventy men aged 70 years were examined with a symptom-limited bicycle exercise test, a 24-hour heart rate variability test, and different measurements of different components of the insulin resistance syndrome.
RESULTS: Heart rate recovery after exercise (mean +/- SD 20 +/- 9 beats during the first minute) was related to both the SD of the R-R interval and the low frequency power at the heart rate variability analyses (r = 0.39, P <.002 for both). Furthermore, heart rate recovery after exercise was related to insulin sensitivity at the hyperinsulinemic eugleucemic clamp (r = 0.28, P <.03), and to high-density lipoprotein cholesterol and exercise capacity, and inversely to obesity and insulin and glucose levels 2 hours after an oral glucose load (P <.05 for all). Heart rate recovery after exercise was not related to left ventricular mass measured by means of echocardiography or to the number of ventricular premature complexes at a 24-hour Holter recording.
CONCLUSION: Heart rate recovery 1 minute after exercise was related to measurements of 24-hour heart rate variability. Furthermore, heart rate recovery after exercise was related to several of the major components of the insulin resistance syndrome, thereby establishing a link between this syndrome and cardiac autonomic nervous activity.