BACKGROUND: Low baroreflex sensitivity (BRS) is an established risk factor for cardiovascular disorders. We investigated determinants of BRS in a large sample from general population.
METHODS: In a population-based study (n=901) data were collected on BRS, arm cuff blood pressure (BP) and obesity indices including body mass index (BMI), waist-to-hip ratio (WHR), waist circumference and percentage body fat (%BF). BRS was calculated by spectral analysis software based on continuously recorded spontaneous fluctuations in beat-to-beat finger BP for 10 to 15 minutes. Correlations and multivariable regression analyses were used to test associations of age, sex, obesity indices and hypertension with BRS while considering effects of lifestyle factors (smoking, alcohol consumption and physical activity).
RESULTS: In multivariable analysis, age, sex, %BF, and hypertension were independently associated with BRS. BRS decreased with -0.10 (95% confidence interval [CI]: -0.15 to -0.06) ms/mmHg with each year of increase in age. Women had -1.55 (95% CI: -2.28 to -0.73) ms/mmHg lower mean BRS than men. The effects of %BF (per 10% increase) and hypertension on BRS were -0.55 (95% CI: -0.97 to -0.13) ms/mmHg and -1.23 (95% CI: -1.92 to -0.46) ms/mmHg, respectively. There was no evidence of associations between BRS and lifestyle factors. Age, age 2, sex, and their interactions plus %BF and hypertension contributed 16.9% of total variance of BRS.
CONCLUSIONS: In this large general population study, we confirm prior findings that age and sex are important factors associated with BRS and find %BF is more strongly related to less favorable BRS levels than BMI.