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

Background. Metabolic 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. Methods. Physical fitness, ox-LDL, tumor necrosis factor alpha (TNF alpha), 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 (VO(2)max) 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). Results. The MetS group had lower results in VO(2)max 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, TNF alpha 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 VO(2)max (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). Conclusions. Young men with MetS possess significantly poorer cardiorespiratory and muscle fitness, together with elevated systemic levels of ox-LDL, TNF alpha and IL-6 compared to non-MetS young men. Of these variables, ox-LDL, VO(2)max 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. (C) 2013 Elsevier Inc. All rights reserved.