Association of physical fitness with LDL and HDL subfractions in young healthy men

A dyslipoproteinemia of increased concentrations of small, dense LDL particles and reduced HDL₂ cholesterol has shown to be associated with coronary heart disease (CHD). In contrast, an increase in physical fitness and a reduction of body mass index (BMI) improve the lipoprotein profile and reduce the incidence of cardiovascular events. The association of physical exercise, physical fitness, and body weight with an atherogenic lipoprotein subfraction profile has been investigated before in obese subjects, but the relationship is unknown in a healthy non-obese population without insulin resistance or CHD. Therefore, a detailed lipoprotein subfraction profile of 3 HDL and 6 LDL subfractions was determined in 125 healthy men (26 ± 5 years). Physical fitness (maximal oxygen consumption, V̇O₂max) was assessed by ergometry and physical activity by questionnaire. Those men with the lowest physical fitness (V̇O₂max < 40 ml/kg/min) and the lowest physical activity score had a significantly less favourable lipoprotein subfraction profile of increased concentration of small, dense LDL particles (d: > 1.044 g/ml) and reduced HDL(2a) cholesterol than those with a V̇O₂max > 50 ml/kg/min. Multivariate regression analysis revealed that concentrations of small, dense LDL particles were primarily determined by BMI whereas HDL(2a) cholesterol and apolipoprotein A-I were primarily determined by physical fitness. These findings underline the relationship between a good physical fitness, a low body weight, and a favourable lipoprotein subfraction profile even in a healthy young male population.