Related Experiment Videos
Summer-winter differences in 24 h variability of heart rate
E Kristal-Boneh1, P Froom, G Harari
1Occupational Health and Rehabilitation Institute, Raanana, Israel.
Journal of Cardiovascular Risk
|July 6, 2000
Summary
Heart rate variability (HRV) in healthy men is lower in summer than in winter. These seasonal changes in HRV may contribute to increased cardiovascular disease mortality during winter months.
Area of Science:
- Cardiology and Environmental Health
- Physiology and Public Health
Background:
- Winter mortality from cardiovascular disease (CVD) is higher in many countries.
- Reduced heart rate variability (HRV) predicts cardiac death and may be influenced by seasons.
- HRV is an important indicator of cardiovascular health.
Purpose of the Study:
- To investigate seasonal variations in heart rate variability (HRV).
- To determine if HRV differs between summer and winter in healthy individuals.
Main Methods:
- Compared 24-hour HRV data from 120 healthy men in summer and winter.
- Utilized multivariate analyses with HRV indexes as dependent variables.
- Controlled for factors including age, cholesterol, smoking, BMI, and blood pressure.
Main Results:
- All HRV indexes were lower in summer compared to winter.
- No seasonal difference was observed in mean R-R interval.
- Multivariate analyses confirmed lower HRV in winter, even after adjustments.
Conclusions:
- HRV physiologically varies by season, with the lowest values in winter.
- Seasonal HRV changes are significant for individuals with CVD.
- The findings suggest a potential link between seasonal HRV and winter CVD mortality.