Abstract P372: Association of Pre-pregnancy Body Mass Index with Stroke and Coronary Heart Disease Mortality

Abstract

Background: Few studies have investigated the relationship between body mass index (BMI) measured before middle age and cardiovascular disease mortality in women. We hypothesized that higher pre-pregnancy BMI would be associated with increased stroke and coronary heart disease (CHD) mortality. Methods: We conducted a retrospective cohort study using the Child Health and Development Studies cohort of 10,889 women enrolled between 1959 and 1967 at the time of pregnancy diagnosis. Stroke and CHD death were assessed annually by matching study participants to the California Department of Motor Vehicles and the California Vital Status Records. We calculated pre-pregnancy BMI using self-reported pre-pregnancy weight and height measured at enrollment. Self-reported weights were similar to weights measured at the first visit. Covariates included age, race/ethnicity, education, total family income, smoking status, parity, and co-morbid conditions such as chronic hypertension, pre-pregnancy diabetes, and kidney disease. We used parametric survival analysis to calculate hazard ratios for stroke and CHD death for each BMI category. Results: At enrollment, mean age was 26.9 years, 66% (7190 of 10,889) were Caucasian, and 24% (2632 of 10,889) were African American. During a mean follow-up of 28.5 years, 1518 participants died. Among these, 79 participants died from stroke and 205 from CHD. Classified by pre-pregnancy BMI, 1008 women had a BMI <18.5, 8406 had a BMI 18.5-24.9, 1143 had a BMI 25-29.9, and 332 had a BMI ≥ 30. With increasing BMI, participants had higher prevalence of pre-pregnancy co-morbid conditions, higher age and parity, and lower family income. In adjusted models, higher pre-pregnancy BMI was associated with increased stroke and CHD risk compared to normal BMI ( Table 1 ). Conclusion: We identified an association between pre-pregnancy BMI and cardiovascular mortality. Pregnancy may offer an opportunity to promote behavior change in women with elevated BMI to reduce later life risk for cardiovascular disease. Table 1. Adjusted hazard ratios for stroke and CHD mortality by pre-pregnancy BMI BMI Category Stroke Coronary Heart Disease <18.5 1.33 (0.57, 3.13) 0.91 (0.48, 1.75) 18.5 - 24.9 1.0 (REF) 1.0 (REF) 25.0 - 29.9 1.75 (0.97, 3.14) 2.20 (1.53, 3.16) ≥ 30.0 3.61 (1.69, 7.69) 4.35 (2.70, 7.01)