This family study from Oman (n=1231) explored the heritability and genetic and environmental correlations of heart rate variability (HRV) and baroreceptor refex sensitivity (BRS) with ambulatory and beat-to-beat blood pressure (BP). Ambulatory BP was measured for 24hours to calculate mean values for daytime and sleep separately. Time and frequency domain HRV indices, BRS, ofce beatto-beat BP, and heart rate (HR) were measured for 10minutes at rest. SOLAR software was used to perform univariate and bivariate quantitative genetic analyses adjusting for age, age2, sex, their interactions and BMI. Heritability of SBP and DBP ranged from 16.8% to 40.4% for daytime, sleeping, 24-hour and ofce beat-to-beat measurements. HR and BRS showed a heritability of 31.9% and 20.6%, respectively, and for HRV indices heritability ranged from 11.1% to 20.5%. All HRV measurements and BRS were found to be negatively correlated with BP, but phenotypic correlation coefcients were relatively weak; HR was positively correlated with BP. None of the genetic correlations were statistically signifcant while environmental factors explained most of the correlations for all HRV indices with BP. Our study found consistent but weak correlations among HRV, HR, BRS and ambulatory/ofce beat-tobeat BP. However, environmental rather than genetic factors contributed most to those correlations.

This family study from Oman (n=1231) explored the heritability and genetic and environmental correlations of heart rate variability (HRV) and baroreceptor refex sensitivity (BRS) with ambulatory and beat-to-beat blood pressure (BP). Ambulatory BP was measured for 24hours to calculate mean values for...