Abstract P230: Left Ventricular Structure and Function Over 25 Years of Occupational Physical Activity Exposure in Cardia

Abstract

Introduction: Leisure-time physical activity (LTPA) is known to promote cardiovascular health, while occupational physical activity (OPA) may have paradoxically negative impacts. One proposed, though untested, explanation for the paradoxical associations may be unfavorable vascular remodeling from OPA-induced chronic cardiovascular strain. Hypothesis: High amounts of OPA over 25 years from young adulthood to midlife is associated with adverse left ventricular (LV) structure and function. Methods: Data are from 1,893 participants (48.9% female, 57.3% White, aged 30.4±3.4 years at baseline [the Year 5 exam]) from the Coronary Artery Risk Development in Young Adults (CARDIA) Study who reported working full time at baseline and two years later. LV structure and function was measured as LV mass, end-diastolic volume (EDV), end-systolic volume (ESV), ejection fraction (EF), stroke volume (SV), and e/a-wave ratio (EA) via M-mode and 2-dimensional echocardiograms at baseline and 25-years later. OPA was reported at seven exams during the study period as months/year where the participant performed “vigorous job activities such as lifting, carrying, or digging” for ≥5 hours/week. The 25-year OPA patterns were categorized into three trajectories: zero OPA (0 months/year; n=995), medium OPA (~2-3 months/year; n=526), and high OPA (~6-8 months/year; n=372). Linear regression estimated longitudinal associations between the OPA trajectories and the echocardiogram variables at final follow-up after adjusting for baseline values. Case-wise deletion was used for each model where only those with valid outcome data were included (n=623-1,475). Results: EF and EA were significantly lower in high versus zero OPA. No other statistically significant associations were observed. (Figure 1) Conclusions: In this sample, OPA’s paradoxical impact on cardiovascular health was partially supported by null or adverse associations between high OPA and LV structure and function. Confirmation is needed using more precise OPA measures.