To more precisely and comprehensively estimate the genetic and environmental correlations between various indices of obesity and BP.
We estimated heritability and genetic correlations of obesity indices with BP in the Oman family study (n = 1231). Ambulatory and office beat-to-beat BP was measured and mean values for SBP and DBP during daytime, sleep, 24-h and 10 min at rest were calculated. Different indices were used to quantify obesity and fat distribution: BMI, percentage of body fat (%BF), waist circumference and waist-to-height ratio (WHtR). SOLAR software was used to perform univariate and bivariate quantitative genetic analyses adjusting for age, age2, sex, age-sex and age2-sex interactions.
Heritabilities of BP ranged from 30.2 to 38.2% for ambulatory daytime, 16.8–21.4% for sleeping time, 32.1–40.4% for 24-h and 22–24.4% for office beat-to-beat measurements. Heritabilities for obesity indices were 67.8% for BMI, 52.2% for %BF, 37.3% for waist circumference and 37.9% for WHtR. All obesity measures had consistently positive phenotypic correlations with ambulatory and office beat-to-beat SBP and DBP (r-range: 0.14–0.32). Genetic correlations of obesity indices with SBP and DBP were higher than environmental correlations (rG: 0.16–0.50; rE: 0.01–0.31).
The considerable genetic overlap between a variety of obesity indices and both ambulatory and office beat-to-beat BP highlights the relevance of pleiotropic genes. Future GWAS analyses should discover the specific genes both influencing obesity indices and BP to help unravel their shared genetic background.||en_US