Body composition and blood pressure: Haemodynamic links in young men and women

Abstract The aim of this study was to explore the sex‐specific haemodynamic links between body composition parameters and systolic and diastolic blood pressure (SBP and DBP, respectively) in adults free of cardiovascular disease and not receiving cardiovascular medications. Body mass index (BMI), fat mass (FM), fat‐free mass (FFM), SBP and DBP, cardiac output (CO), peripheral vascular resistance (PVR) and aortic pulse wave velocity (PWV) were determined in 235 men and 192 women aged 18–40 years. Multivariable linear regression and single‐ as well as multiple‐mediator models were used to assess haemodynamic mechanisms underlying the associations between body composition and blood pressure. BMI showed positive associations with SBP and DBP in both sexes ( P < 0.001 for all). In men, FFM was the main body composition correlate of SBP ( P < 0.001), with the positive association driven in part by CO and partially offset by opposing effects through PVR. FM was the dominant body composition correlate of DBP in men and both SBP and DBP in women ( P < 0.001 for all), with the positive associations mediated by PVR and PWV in both sexes, and additionally by heart rate in the FM–DBP association in men. Changes in FFM may affect SBP predominantly through CO in young men. Changes in FM may affect DBP in young men and both SBP and DBP in young women, predominantly through vascular mechanisms. These findings provide important insights into sex differences in the physiology of adiposity‐related BP changes in young adults and may help inform sex‐specific strategies for the management of adiposity‐related hypertension.