Abstract 19900: Impact of Baseline Fitness in Young Adulthood and Age Related Fitness Changes on Cardiac Structure and Function in Middle Age: The CARDIA Study

Abstract

Introduction: Low cardiorespiratory fitness (CRF) in mid-life is a significant risk factor for heart failure (HF) at a later age. However, the contribution of CRF in early adulthood to HF risk is not well understood. Because of the established association of subclinical abnormalities in left ventricular (LV) structure and function with HF risk, we studied the association between early life CRF levels and measures of LV structure and function in middle-age. Methods: We included the Coronary Artery Risk Development in Young Adults (CARDIA) study participants who had a maximal exercise treadmill test (modified Balke protocol) at year 0 and an echocardiogram at year 25. Percent change in CRF [ΔCRF (%)] was calculated in the subgroup of participants who had a repeat CRF test at year 20. Associations of baseline CRF and ΔCRF (%) with measures of LV structure [end-diastolic volume (LVEDV), relative wall thickness (RWT)] and function [global longitudinal strain (GLS), Septal & Lateral E/e`] were assessed using multivariable linear regression. Results: We included 3,433 participants (baseline age: 25 years, 55% women) in the study. After adjustment for baseline characterstics, cumulative cardiovascular risk factor burden, and baseline and follow up body mass index (BMI), lower baseline CRF was associated with higher septal E/e`(β = -0.05, p = 0.01), higher lateral E/e` (β = -0.06, p = 0.008), and lower LVEDV (β = 0.07, p = 0.004). In contrast, CRF was not associated with GLS (p = 0.22) and RWT (p=0.27). Among participants with repeat CRF test (n =2,544), ΔCRF (%) was associated with LVEDV but not with measures of LV function. The association of baseline CRF with E/e` did not attenuate after additional adjustment for ΔCRF (%) (Table). Conclusions: Lower CRF in young adulthood is associated with subclinical abnormalities in diastolic function in middle age. These findings suggest that low CRF may identify young adults at increased risk of HF with preserved ejection fraction in later life.