Heritability of ambulatory and office blood pressure in the Swiss population

Background: Blood pressure (BP) is known to aggregate in families. Yet, heritability estimates are population-specific and no Swiss data have been published so far. We estimated the heritability of ambulatory and office BP in a Swiss population-based sample. Methods: The Swiss Kidney Project on Genes in Hypertension is a population-based family study focusing on BP genetics. Office and ambulatory BP were measured in 1009 individuals from 271 nuclear families. Heritability was estimated for SBP, DBP, and pulse pressure using a maximum likelihood method implanted in the Statistical Analysis in Genetic Epidemiology software. Results: The 518 women and 491 men included in this analysis had a mean (±SD) age of 48.3 (±17.4) and 47.3 (±17.7) years, and a mean BMI of 23.8 (±4.2) and 25.9 (±4.1) kg/m 2, respectively. Narrow-sense heritability estimates (±standard error) for ambulatory SBP, DBP, and pulse pressure were 0.37±0.07, 0.26±0.07, and 0.29±0.07 for 24-h BP; 0.39±0.07, 0.28±0.07, and 0.27±0.07 for day BP; and 0.25±0.07, 0.20±0.07, and 0.30±0.07 for night BP, respectively (all P<0.001). Heritability estimates for office SBP, DBP, and pulse pressure were 0.21±0.08, 0.25±0.08, and 0.18±0.07 (all P<0.01). Conclusions: We found significant heritability estimates for both ambulatory and office BP in this Swiss population-based study. Our findings justify the ongoing search for the genetic determinants of BP.