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

A dyslipoproteinemia of increased concentrations of small, dense LDL partic les and reduced HDL2 cholesterol has shown to be associated with coronary h eart disease (CHD). In contrast, an increase in physical fitness and a redu ction of body mass index (BMI) improve the lipoprotein profile and reduce t he incidence of cardiovascular events. The association of physical exercise , physical fitness, and body weight: with an atherogenic lipoprotein subfra ction profile has been investigated before in obese subjects, but the relat ionship is unknown in a healthy non-obese population without insulin resist ance 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, (V)over dotO(2)max) was asse ssed by ergometry and physical activity by questionnaire. Those men with th e lowest physical fitness ((V)over dotO(2)max <40 ml/kg/min) and the lowest physical activity score had a significantly less favourable lipoprotein su bfraction profile of increased concentration of small, dense LDL particles (d: > 1.044 g/ml) and reduced HDL2a cholesterol than those with a (V)over d otO(2)max >50 ml/kg/min. Multivariate regression analysis revealed that con centrations of small, dense LDL particles were primarily determined by BMI whereas HDL2a cholesterol and apolipoprotein A-I were primarily determined by physical fitness. These findings underline the relationship between a go od physical fitness, a low body weight, and a favourable lipoprotein subfra ction profile even in a healthy young male population.