Diurnal heart rate variability in healthy subjects: effects of aging and sex difference

The effects of aging and gender on diurnal heart rate variability was investigated as measurements of R-R intervals during a 24-hr. period using a Holter electrocardiogram. Male subjects showed higher values for the low-frequency (LF) component of cardiac beta-adrenergic function than female subjects. There were no differences in the peak of parasympathetic function between the two sexes. There was a significant relationship between LF and age, suggesting that heart beat is affected by aging and gender.