Spontaneous baroreflex sensitivity and its association with age, sex, obesity indices and hypertension: a population study.

BACKGROUND: Low baroreflex sensitivity (BRS) was 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, waist-to-hip ratio, 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 10-15 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: -0.15 to -0.06) ms/mm Hg with each year of increase in age. Women had -1.55 (95% confidence interval: -2.28 to -0.73) ms/mm Hg lower mean BRS than men. The effects of %BF (per 10% increase) and hypertension on BRS were -0.55 (95% confidence interval: -0.97 to -0.13) ms/mm Hg and -1.23 (95% confidence interval: -1.92 to -0.46) ms/mm Hg, respectively. There was no evidence of associations between BRS and lifestyle factors. Age, age2, sex, and their interactions plus %BF and hypertension contributed 16.9% of total variance of BRS. CONCLUSIONS: In this large general population study, we confirmed prior findings that age and sex were important factors associated with BRS and found %BF was more strongly related to less favorable BRS levels than body mass index.