Leukocyte activation, erythrocyte damage, lipid profile and oxidative stress imposed by high competition physical exercise in adolescents

Background: The aim of this study was to evaluate and to compare the lipid profile and the levels of leukocyte activation, red blood cell (RBC) damage and of oxidative stress in two groups of adolescents, with similar body ma ss index: high competition swimmers and adolescents practising moderate reg ular physical exercise. Methods: As markers of leukocyte activation, we mea sured plasma lactoferrin, elastase and granulocyte-monocyte colony stimulat ing factor. We studied RBC membrane band 3 profile and membrane-bound hemog lobin, as markers of RBC damage and aging; total and differential leukocyte count and RBC count, hematocrit, hemoglobin concentration and hematimetric indexes were also measured. Lipid profile included the evaluation of trigl ycerides (TG), total cholesterol (Chol), high-density lipoprotein cholester ol (HDLc), low-density lipoprotein cholesterol (LDLc), apolipoproteins AI a nd B (Apo Al and B), and lipoprotein (a) (Lp(a)). To evaluate oxidative str ess, lipoperoxidation products and total antioxidant capacity were measured . Results: We found that high competition adolescents presented increased p lasma levels of leukocyte activation products, increased RBC damage suggest ing aging and premature removal, and higher oxidative stress. Lipid profile showed some risk and some protective changes. Conclusions: Our data sugges t that high competition exercise, by imposing a higher and sustained oxidat ive and proteolytic stress, may contribute in the future to a higher risk o f cardiovascular disease. We believe these findings warrant a reevaluation of current views in the intensity, duration and regularity of physical exer cise, and that the evaluation of leukocyte activation products, RBC damage, oxidative stress and lipid profile may represent good markers to establish putative protective thresholds. (C) 2001 Elsevier Science B.V. All rights reserved.