Heart rate variability in obesity.

Analyses of beat-to-beat interval variations on a continuous electrocardiogram and cardiovascular reaction during deep breathing and handgrip exercise were used as a test for autonomic nervous function in 35 obese and 18 control women. Reduced heart rate variability (HRV) in obesity indicates depression in parasympathetic activity. Indices of HRV were smaller at 17:00 h than at 08:00 h. The more significant increase of blood pressure during handgrip in obese women might suggest over-reactivity of the sympathetic nervous system. Circulatory responses to parasympathetic activation during deep breathing and sympathetic activation during handgrip were less marked after slimming treatment than before.