(890) Body mass index and persistent hypertension in patients with hypertension disorders of pregnancy one-year postpartum

To determine the association between body mass index (BMI) and persistent hypertension one-year postpartum following pregnancies complicated by hypertensive disorders of pregnancy (HDP).

Study Design:

This was a retrospective cohort study of patients with HDP (defined as gestational hypertension or preeclampsia) in a single US Midwestern academic institution from 2014 to 2018. The primary outcome was persistent hypertension at one-year postpartum, defined as systolic blood pressure (BP) ≥130 mm Hg or diastolic BP ≥80 mm Hg. Both categorical BMI (model 1) (normal, overweight, and obese) and continuous BMI (model 2) were examined as predictor variables. Descriptive statistics and logistic and linear regression analyses were run for categorical and continuous BMI respectively. Odds ratios (OR) and 95% confidence intervals (CI) were reported.

Results:

Out of 564 patients with HDP included in this analysis, 271 (48.1%) had persistent hypertension at one-year postpartum. Median [interquartile range (IQR)] one-year postpartum BMI was 28.3 [17.2-43.9] kg/m². Prevalence of persistent hypertension at one-year postpartum following HDP was higher in overweight and obese groups compared to normal weight group (Table). In multivariable logistic regression (model 1), presence of obesity (BMI≥30 kg/m²) at one-year postpartum, compared to normal BMI category, was associated with 85% higher likelihood of persistent hypertension following HDP (OR 1.85, 95%CI 1.10-3.11). In model 2, looking at BMI as a continuous predictor variable for persistent hypertension postpartum, each unit increase in postpartum BMI was associated with 6% higher likelihood of hypertension at one-year postpartum (OR 1.06, 95%CI 1.03-1.11).

 

Conclusion:

We found that BMI≥ 30 kg/m² at one-year postpartum following HDP was associated with 85% higher risk of persistent hypertension compared to a normal BMI. We identified a modifiable risk factor that can be targeted in future interventions designed to reduce cardiovascular disease risk following hypertensive pregnancies.