Elevated concentration of oxidized LDL together with poor cardiorespiratory and abdominal muscle fitness predicts metabolic syndrome in young men

BackgroundMetabolic syndrome (MetS) is associated with increased oxidized LDL (ox-LDL), systemic inflammation, and poor cardiorespiratory fitness. We examined affiliations of these factors and the effect of muscular fitness on MetS in young healthy men.MethodsPhysical fitness, ox-LDL, tumor necrosis factor α (TNFα), interleukin-6 (IL-6) and serum lipids were measured in a nationally representative sample of Finnish young men with and without MetS. Participants (mean age 25.1 years) performed tests of maximal oxygen uptake (VO2max) and muscle fitness, and were divided into MetS (n = 54, IDF 2007 criteria) and non-MetS (n = 790). Age, smoking and leisure-time physical activity were used as covariates (ANCOVA).ResultsThe MetS group had lower results in VO2max and all of the muscular fitness tests (excluding grip strength) (P < 0.0001, in all). Ox-LDL, ox-LDL/HDL-cholesterol, ox-LDL/LDL-cholesterol, TNFα and IL-6 were all higher in the MetS group than in the non-MetS group (P < 0.01, in all). In stepwise multivariate logistic regression analysis (adjusted to MetS criteria), higher ox-LDL (OR 1.118, 95% CI 1.078-1.160), lower VO2max (OR 0.938, 95% CI 0.901-0.977) and lower sit-ups (OR 0.898, 95% CI 0.844-0.956) predicted MetS (p < 0.05, in all).ConclusionsYoung men with MetS possess significantly poorer cardiorespiratory and muscle fitness, together with elevated systemic levels of ox-LDL, TNFα and IL-6 compared to non-MetS young men. Of these variables, ox-LDL, VO2max and sit-ups predicted MetS. Based on these findings, poor physical fitness and elevated concentration of ox-LDL are significant predisposing factors in the development of MetS.