Reproducibility and Gender-Related Differences of Heart Rate Variability during All-Day Activity in Young Men and Women

• Published in: Annals of noninvasive electrocardiology Vol. 13; no. 3; pp. 270 - 277
• Main Authors: Sztajzel, Juan, Jung, Michel, Bayes de Luna, Antonio
• Format: Journal Article
• Language: English
• Published: Malden, USA Blackwell Publishing Inc 01.07.2008
• Subjects: Activities of Daily Living; Adult; Age Distribution; Analysis of Variance; Cohort Studies; Electrocardiography, Ambulatory - methods; Female; gender-related changes; Heart Rate - physiology; Humans; Male; Motor Activity; Original; Probability; Reference Values; reproducibility; Reproducibility of Results; Sex Distribution; standard heart rate variability parameters; young men and women
• ISSN: 1082-720X; 1542-474X
• DOI: 10.1111/j.1542-474X.2008.00231.x

Background: Only few data are available on reproducibility over time in healthy young men and women and the corresponding gender‐related changes of heart rate variability (HRV) measurements. Methods: We studied temporal and spectral HRV indices obtained from 24‐hour Holter recordings in 32 healthy volunteers (14 men and 18 women, mean age 29 ± 3 years) during 2 days of their usual all‐day activity. Results: Time‐domain measures and the spectral low‐frequency (LF) and high‐frequency (HF) components as well as the LF/HF ratio were comparable on both test days. Significantly higher values on test day 2 were observed only for the spectral very‐low‐frequency (VLF) component and for the resulting total power. Compared to men, women had higher day‐ and nighttime vagus‐associated HRV indices, including root mean square of successive differences (RMSSD), pNN50 (NN50 count divided by the total number of all NN intervals), and HF power, and lower day‐ and nighttime VLF and LF power with lower LF/HF ratio and total power. Conclusions: Temporal indices and the LF and HF spectral HRV measures are reproducible over usual all‐day activity in young healthy subjects. Young women have higher day‐and nighttime vagal tone than men with similar age range.