Abstract Body: Background. Adverse pregnancy outcomes are sex-specific risk factors for maternal cardiovascular disease (CVD). Elevated blood pressure (BP) response to exercise (i.e. when BP rises more steeply than expected given the workload) can reveal underlying abnormalities that are not evident at rest. BP response to submaximal exercise may represent the hemodynamic burden of daily activity and is associated with CVD independent of resting BP but has not been examined in women following pregnancy. Our objective was to examine the association between an adverse pregnancy outcome in a first birth and exercise response in the years after delivery in women in the CARDIA study. Methods. Included participants were nulliparous at baseline and reported a first birth prior to either the year 7 or year 20 symptom-limited graded exercise test (GXT). Adverse pregnancy outcomes were combined into a composite outcome including preterm birth, gestational diabetes, and preeclampsia. If more than one birth occurred prior to the GXT, only the first birth was defined as the exposure. Linear regression estimated the association between an adverse pregnancy outcome in a first birth and 1) systolic and diastolic BP at stage 2 of a modified Balke protocol (3.4 miles/hour at a 6% incline; workload=6.4 METs) and 2) total duration of exercise. BP models were adjusted for baseline BP; all models were adjusted for age and time between delivery and GXT. Results. Parous women completing a GXT at the year 7 (n=311) or 20 (n=220) CARDIA exam with stage 2 data were included. After adjustment, women with an adverse pregnancy outcome had higher stage 2 systolic and diastolic BP while total GXT duration was shorter than women with uncomplicated pregnancy (Table). Conclusions. Women who experienced an adverse pregnancy outcome in a first birth had a less favorable exercise response: higher stage 2 BP and shorter exercise duration in a GXT. These results suggest that women exposed to an adverse pregnancy outcome may have a greater cumulative BP load even if they have normal resting BP. Exercise response may be a useful tool to stratify risk in women following pregnancy.
Acknowledgements. The Coronary Artery Risk Development in Young Adults Study (CARDIA) is supported by contracts 75N92023D00002, 75N92023D00003, 75N92023D00004, 75N92023D00005, and 75N92023D00006 from the National Heart, Lung, and Blood Institute. Additional support was provided by the CARDIA Fitness Study (R01 HL078972 to BS).