Exploring the direct and indirect effects of cardiovascular disease risk factors on exercise blood pressure

Abstract

Objective: Exaggerated exercise blood pressure (BP) is independently associated with cardiovascular disease (CVD) outcomes. However, it is unknown how individual CVD risk factors may interact with one another to influence exercise BP. The aim of this study was to quantify direct and indirect associations between CVD risk factors and exercise BP, to determine what CVD risk factor/s most-strongly relate to exercise BP. Methods: In a cross-sectional design, 660 participants (44 ± 2.6 years, 54% male) from the population-based Childhood Determinants of Adult Health Study had BP measured during low-intensity fixed-workload cycling. CVD risk factors were measured, including body composition, clinic (rest) BP, blood biomarkers, and cardiorespiratory fitness. Associations between CVD risk factors and exercise BP were assessed using linear regression, with direct and indirect pathways of association assessed via structural equation model. Results: Sex, waist-to-hip ratio, fitness, and clinic BP were independently associated with exercise systolic BP (SBP), and along with age, had direct associations with exercise SBP (p < 0.05 all). Most CVD risk factors were indirectly associated with exercise SBP via a relation with clinic BP (p < 0.05 all). Clinic BP, waist-to-hip ratio, and fitness were most-strongly associated (direct and indirect association) with exercise SBP (β[95% CI]: 9.35 [8.04, 10.67], 4.91 [2.56, 7.26], and −2.88 [−4.25, −1.51] mm Hg/SD, respectively). Conclusion: Many CVD risk factors are associated with exercise BP, mostly with indirect effects via clinic BP. Clinic BP, body composition, and fitness were most-strongly associated with exercise BP. These results may elucidate how lifestyle modification could be a primary strategy to decrease exaggerated exercise BP-related CVD risk.