Background: The purpose of this analysis was to investigate the relationship between body composition, metabolic parameters and endothelial function among physically active healthy middle-aged and older men.
Methods: Out of 101 asymptomatic men prospectively tracked for traditional cardiovascular risk factors (mean observation period 25.1 years), 55 metabolically healthy individuals who maintained stable leisure time physical activity (LTPA) level throughout the observation and agreed to participate in the body composition assessment were recruited (mean age 60.3 ± 9.9 years). Body composition and raw bioelectrical parameters were measured with bioelectrical impedance analysis (BIA). Microvascular endothelial function was evaluated by means of the reactive hyperemia index (RHI) using Endo-PAT2000 system.
Results: Strong correlations were observed between lifetime physical activity (PA), aerobic fitness and most of analyzed body composition parameters. The strongest inverse correlation was found for fat mass (p < 0.01) while positive relationship for fat-free mass (p < 0.01), total body water (p < 0.05 for current aerobic capacity and p < 0.01 for historical PA), body cell mass (p < 0.001), muscle mass (p < 0.001), calcium and potassium (p < 0.01 and p < 0.001 for current aerobic capacity and p < 0.001 and p < 0.01 for historical PA, respectively) and glycogen mass (p < 0.001). Among metabolic parameters, HDL cholesterol (HDL-C) and uric acid were significantly associated with most body composition indicators. Regarding endothelial function, a negative correlation was found for RHI and body mass (p < 0.05) while positive relationship for RHI and body cell mass (p < 0.05), calcium (p < 0.05) and potassium mass (p < 0.05). Impaired endothelial function was observed among 8 subjects. Among bioelectrical parameters, impedance (Z) and resistance (R) normalized for subjects' height were negatively related with body mass, body mass index (BMI) and waist circumference (p < 0.001); while reactance (Xc) normalized for patients' height was negatively related with body mass (p < 0.05). The mean phase angle value was relatively high (8.83 ± 1.22) what reflects a good level of cellularity and cell function. Phase angle was positively related with body mass and BMI (p < 0.05).
Conclusions: Both fat mass and muscle mass components are important predictors of metabolic profile. Maintaining regular high PA level and metabolically healthy status through young and middle adulthood may have beneficial influence on body composition parameters and may prevent age-related decrease of fat-free mass and endothelial dysfunction.
Keywords: Atherosclerosis; Body composition; Endothelial; Metabolic syndrome; Physical activity.