Reduction in metabolic syndrome among obese young men is associated with exercise-induced body composition changes during military service

Aims: A population-based study of 1046 young Finnish men was performed to evaluate whether body composition changes observed during military service are associated with a reduction in prevalence of metabolic syndrome (MetS), and whether the effect is body mass index (BMI)-dependent. Methods: A prospective study of 1046 men (mean age 19.2 years, SD 1.0), with follow-up during 6-12 months of military service in northern Finland. Anthropometry, body composition, biochemical measurements and physical fitness were assessed at baseline and follow-up. MetS was defined using the International Diabetes Federations (IDF) criterion, continuous MetS Z-score calculated, and changes evaluated in BMI categories. Results: Prevalence of MetS at baseline and follow-up was 6.1% and 3.6%, respectively (p < 0.001). Prevalence of MetS decreased by 40% (p < 0.001) among the obese young men (BMI >= 30 kg/m(2)). Reduction in the MetS Z-score was mainly attributable to weight loss and reduced fat mass (p < 0.001) and improvement in physical fitness (muscle fitness index, p = 0.016). Conclusions: Beneficial exercise-induced changes in body composition significantly reduced the prevalence of MetS among young, obese men. Our findings support the efficacy of increased physical activity for prevention of early-onset cardiovascular disease, particularly among overweight and obese young men. (C) 2012 Elsevier Ireland Ltd. All rights reserved.