Association of aerobic fitness and body composition with protein and major lipid class composition of high-density lipoprotein.

Although high-density lipoprotein (HDL) has cardiometabolic protecting properties, interventions to raise HDL cholesterol concentration have failed to improve cardiometabolic health. Hence, HDL composition and functionality might be key factors in its anti-atherogenic capacity. Alterations in HDL composition have been linked to pathophysiological states, whereas endurance training is known to increase HDL concentration with a shift toward bigger particle sizes, but its effect on the HDL composition is not well understood. Therefore, we selected subjects with the highest and the lowest aerobic fitness from a study group resembling population and compared HDL protein and lipid composition and serum metabolic profiles using mass spectrometry, thin-layer chromatography, and nuclear magnetic resonance spectroscopy methodologies. High aerobic fitness and normal body composition were associated with elevated proportion of cholesteryl esters suggesting improved cholesterol metabolism. Low aerobic fitness and elevated amount of adipose tissue increased the proportion of phospholipids in HDL, whereas elevated proportion of triacylglycerols was associated only with higher adiposity level, suggesting modulations in particle surface fluidity and tendency for particle catabolism. Serum metabolic profiles supported the observations highlighting differences in the concentration of large HDL₂ particles, very-low-density lipoprotein, and serum triacylglycerols between the groups. Higher adipose tissue level increased proteins related to inflammation and hemostasis in HDL, whereas normal body composition was linked to increased amounts of apolipoprotein A-II and C-II suggesting improved HDL composition. Results suggest that high aerobic fitness and normal body composition have positive effects on HDL composition through reduced inflammation and better serum lipid homeostasis.NEW & NOTEWORTHY High aerobic fitness is linked to elevated HDL concentration and a shift toward bigger particle sizes, but its effect on the HDL composition is not well understood. For the first time, this study compared HDL lipid and proteomic compositions between two groups with differences in aerobic fitness level and body composition. The findings suggest positive modulations in HDL composition due to regular physical activity associated with better body composition, inflammation status, and serum lipid homeostasis.