Abstract des Autors

The influences of age and VO2max on serum lipoproteins with special regard to the concentration, composition and distribution of HDL subfractions were investigated in 51 healthy males of different characteristics: younger than 35 years, untrained (n = 14, mean age 28.2 years; VO2max, 47.9 ml/kg/min) and trained (n = 11, mean age 27.9 years; VO2max, 61.1 ml/kg/min), older than 50 years untrained (n = 14, mean age 58.9 years; VO2max, 29.3 ml/kg/min) and trained (n = 12, mean age 59.3 years; VO2max, 45.7 ml/kg/min). The fasting-state serum concentrations of total CHOL, tri-acylglycerol and lipoprotein-CHOL were measured. The HDL-subfractions were separated by density (p) gradient ultracentrifugation. Concentrations of CHOL, cholesterylester, tri-acylglycerol, phospholipids, apolipoprotein (apo) A-I and A-II were measured in the subfractions HDL2b: p = 1.063-1.100 g/ml; HDL2a2: p = 1.00-1.110 g/ml; HDL2a2: p = 1.110-1.150 g/ml; HDL3: p = 1.150-1.210 g/ml. Elderly untrained subjects showed increased serum concentrations of total-, VLDL- and LDL-CHOL and elevated tri-acylglycerol levels. The HDL-CHOL concentration was decreased, due to reduced concentrations of HDL2-subfractions. Significant changes in the composition of HDL2-subfractions were found in elderly untrained subjects. The HDL2-subfractions had more protein, a decreased apoA-I:A-II ratio and less phospholipids than those of the younger and the elderly trained subjects. Thus, physical activity may be an important factor in influencing HDL-metabolism in the elderly.