Effect of Exercise Training on Inflammatory Markers in Overweight and Obese Boys and Girls

Abstract

PURPOSE: The aim of the present study was to examine the effect of exercise training on inflammatory markers in overweight and obese pre-pubertal boys and girls. METHODS: Forty-six overweight and obese children (age range 9-11 yr old, mean Tanner stage 1.2) volunteered for the study and were randomized to no-exercise control (CON, 6 boys and 7 girls) and exercise training (EX, 14 boys and 19 girls) groups for 16 weeks. Serum monocyte chemoattractant protein-1 (MCP-1), interleukin 6 (IL-6) and tumor necrosis factor (TNF-alpha) were measured as markers of inflammation before and after the intervention. RESULTS: There was no difference between boys and girls in age (9.1±0.6 and 9.3±0.5 yr) or BMI percentile (94±1 and 97±1%) before the intervention. After the intervention, a significant increase in fitness (time to exhaustion for incremental treadmill test, p < 0.05) was observed in the EX (81±13 sec) but not in CON (12±22 sec). There was no effect of exercise training on MCP-1, IL-6 or TNF-alpha; however, percent changes in these pro-inflammatory markers were significantly decreased in girls, while the percent change values were significantly increased in boys, regardless of intervention group (significant main effect of sex, p < 0.05, table 1). There was no correlation between changes in body weight and inflammatory markers. RESULTS: There was no difference between boys and girls in age (9.1±0.6 and 9.3±0.5 yr) or BMI percentile (94±1 and 97 ± 1%) before the intervention. After the intervention, a significant increase in fitness (time to exhaustion for incremental treadmill test, p < 0.05) was observed in the EX (81 ± 13 sec) but not in CON (12 ± 22 sec). There was no effect of exercise training on MCP-1, IL-6 or TNF-alpha; however, percent changes in these pro-inflammatory markers were significantly decreased in girls, while the percent change values were significantly increased in boys, regardless of intervention group (significant main effect of sex, p < 0.05, table 1). There was no correlation between changes in body weight and inflammatory markers. CONCLUSION: There was a decrease in inflammatory markers over 16 weeks in girls, but not in boys, that is not due to exercise training. These data indicate previous findings that exercise training, in the absence of weight loss, do not affect inflammatory markers may be sex (and perhaps age) specific.Table 1: Inflammatory markers and changes in body weight in boys and girls before and after the intervention.Supported by NIH RO1DK071081