The Effects of Fat Mass and Lean Mass on Blood Pressure Determinants in Healthy Young Men and Women

Abstract

BackgroundObesity is commonly associated with high blood pressure (BP) and cardiovascular risk, but it is not clear whether BP elevation is primarily associated with increased fat mass or lean mass, which is also increased in obesity. Moreover, few studies have focused on the relationship between haemodynamic determinants of BP, such as stroke volume (SV), cardiac output (CO), and peripheral vascular resistance (PVR), and fat mass or lean mass in healthy men and women.ObjectiveThis study was undertaken to determine whether BP and its haemodynamic determinants were more strongly associated with fat mass or lean mass, and whether the associations differed between males and females.Methods203 healthy human volunteers (103 males, 100 females) aged <50 years were recruited. Body composition was analysed using a Tanita bio‐impedance scale. Clinic (seated) systolic blood pressure (SBP) and diastolic blood pressure (DBP) were measured after 5 minutes of rest. Stroke volume and CO were measured using an inert gas re‐breathing method. Peripheral vascular resistance (PVR) was calculated from mean arterial pressure and CO. Data were analysed using Spearman correlation.ResultsIn men, fat mass was positively correlated with DBP (r = 0.51, p < 0.001) only, while lean mass was positively correlated with SBP, CO, and SV (rSBP = 0.33, pSBP < 0.01; rCO = 0.37, pCO < 0.001; rSV = 0.45, pSV < 0.001); lean mass was inversely correlated with PVR (r = −0.31, p < 0.01). In women, fat mass and lean mass were both positively correlated with SBP, DBP, CO and SV (fat mass: rSBP = 0.48, pSBP < 0.001; rDBP = 0.51, pDBP < 0.001; rCO = 0.40, pCO < 0.001; rSV = 0.29, pSV < 0.01) (lean mass: rSBP = 0.41, pSBP < 0.001; rDBP = 0.40, pDBP < 0.001; rCO = 0.52, pCO < 0.001; rSV = 0.47, pSV < 0.01), while lean mass was also inversely correlated with PVR (r = −0.34, p < 0.01).ConclusionsThe relationship between body composition and blood pressure determinants differs between young men and women. These differences should be kept in mind when investigating the physiological mechanisms underlying obesity‐associated hypertension in humans. The impact of lean mass on blood pressure elevation should not be overlooked, particularly in younger males.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.