BMI during childhood and puberty - associations with blood pressure and hypertension.

Aim: The present study aimed to evaluate the association between BMI during childhood and puberty and blood pressure and hypertension in midlife, and to explore midlife BMI as a potential mediator of these associations.

Method: We linked the BMI Epidemiology Study Gothenburg (BEST) with developmental BMI, with the Swedish CArdioPulmonary bioImage Study (SCAPIS) with blood pressure and hypertension in midlife (n= 2394). The associations between childhood BMI (7-8 years) and pubertal BMI change (young adult BMI minus childhood BMI), and blood pressure and hypertension in midlife, were evaluated using linear or logistic regression models. Mediation analysis was conducted to evaluate the indirect effect, via midlife BMI, and the direct effect on blood pressure and hypertension. The analyses were adjusted for birth year and smoking.

Results: The pubertal BMI change was positively associated with systolic and diastolic blood pressure and hypertension in midlife, independent of childhood BMI, in both men and women (p<0.01). For men but not for women, childhood BMI was positively associated with systolic and diastolic blood pressure in midlife, independent of the pubertal BMI change (p<0.01). No significant independent association was observed for childhood BMI with hypertension. Mediation analyses for the association between the pubertal BMI change and blood pressure and hypertension in midlife indicate that these associations were largely mediated by BMI in midlife.

Conclusion: These findings indicate that high blood pressure may originate in early life. A life-course approach for targeted prevention, starting already during the developmental years, could reduce the risk of high blood pressure.