Hypertensive disorders of pregnancy, obesity, and hypertension in later life by age group: a cross-sectional analysis.

We investigated whether the association between a history of hypertensive disorders of pregnancy (HDP) and hypertension in later life varies by age group and the effect of obesity on the association between a history of HDP and hypertension in later life. This cross-sectional population-based study was conducted at the Tohoku Medical Megabank Project in Miyagi and Iwate, Japan. The study subjects were 33,412 parous women of 20 years of age and older. We used multivariate logistic regression analysis to assess the association between a history of HDP and hypertension. We constructed a composite variable that combined a history of HDP (±) and overweight/obesity (BMI ≥ 25 kg/m) (±), resulting in four categories, and analyzed the risks of each category by multivariate logistic regression analysis. In total, 1585 (4.7%) women had a history of HDP. The prevalence of hypertension was higher in women with HDP (51.4%) than in those without HDP (36.8%; p < 0.01). The adjusted odds ratios (ORs) for hypertension in women with HDP in their 30s, 40s, 50s, 60s, and 70s or older were 3.63, 1.84, 2.15, 1.48, and 1.86, respectively. In the interaction analysis, the association between a history of HDP and hypertension was stronger in women in their 30s-50s than in women who were 60 or older (p = 0.057). The adjusted ORs for hypertension were higher in overweight/obese women with HDP than in their nonoverweight/obese counterparts in all age groups (30s: 27.17 vs. 2.22; 70s: 4.75 vs. 1.90). In conclusion, the association between HDP and later hypertension was stronger in younger women and in obese women in the 30-70 age group.