Sitting time enhances the effect of genetic liability to obesity on hypertension

Background and purpose: Excessive sitting and genetic liability to obesity are associated with risk of obesity and hypertension, two significant risk factors for cardiovascular disease. This study aimed to investigate the interactive effects of genetic liability to obesity and excessive sitting on prevalence of hypertension. Methods: Obesity genetic liability was estimated in unrelated individuals of European ancestry (n=208,594) using previously identified genetic variants and their effect sizes for adiposity related traits. Hypertension was defined as systolic blood pressure ? 140 mmHg, diastolic blood pressure ? 90 mmHg, or the use of anti-hypertensive medications. Logistic regression was used to examine the association between obesity genetic liability and across different levels of self-reported sitting time. Results: excessive sitting and increased genetic liability were independently associated with higher odds of hypertension. The greatest odds of hypertension was observed in participants with high sitting time combined with increased genetic liability to obesity (OR=1.29; 95% CI = 1.25, 1.33, P <2 x10-16) compared to individuals with low genetic liability and low sitting time. Interaction analysis identified that in individuals with excessive sitting, the effect of genetic liability of waist circumference on hypertension was greater compared to individuals with low sitting time (P interaction=0.03). Conclusion: Combined excessive sitting and high genetic susceptibility to obesity is associated with greatest odds of hypertension. These findings highlight the importance of lifestyle in offsetting risk imposed by genetic factors.