Potential anti-inflammatory effects of exercise training with and without energy restriction-induced fat loss
Abstract
The purpose of this project was to examine differences in anti-inflammatory adaptations to exercise training with or without energy restriction-induced fat loss. Monocyte subtype, TLR4 cell surface expression, C-reactive protein (CRP), and lipopolysaccaride (LPS) stimulated tumor necrosis factor alpha (TNFα) and interleukin (IL) 6 production were measured to determine inflammatory differences between activity levels and interventions. Forty (28 female, 12 male) physically inactive (PI) subjects with a BMI between 25-39.9 kg/m2 (mean 30.1±4.3) completed all baseline testing and 26 (17 females, 9 males) completed the intervention. An additional 10 (3 females, 7 males) physically active (PA) subjects with a BMI between 22.4-29.9 kg/m2 (mean 25.8±3.1) served as control subjects and completed two bouts of testing. After collection of baseline measures, PI subjects were randomly assigned to exercise training with (EX-ER) or without (EX) and energy-restriction diet designed to elicit ~5 kg of weight loss during the study period. All PI subjects participated in 12 wk of 3 d/wk upper and lower body resistance exercise training. The PA subjects continued their habitual activity. At baseline, PI subjects had a significantly lower estimated VO 2max (25.4±4.9 mL˙kg-1˙min -1) than PA subjects (50.1±11.0 mL˙kg-1˙min -1), as well as higher CRP (4.02±4.15 mg/L vs. 1.28±0.93 mg/L) and circulating CD14+CD16+ monocyte percentage (13.3±7.9 % vs. 7.1±5.2 %). Overweight PI subjects had significantly lower circulating CD14+CD16+ monocyte percentage than obese PI subjects (10.9±7.1 % vs. 16.3±8.1). The PA group had a significantly higher unstimulated IL-6 production than the PI group (0.38±0.26 ng/CD14+ monocyte vs. 0.14±0.40 ng/CD14+ monocyte). There were no group differences in Toll-like receptor (TLR) 4 cell-surface expression, but CD14+CD16+ monocytes had a significantly higher percentage of cells stain positive for TLR4 (83.9±19.1 % vs. 54.7±10.6 %) and had a greater mean fluorescence intensity (MFI; 2.79±0.64 vs. 1.81±0.16) than CD14+CD16- monocytes. After the intervention the EX group had a significant decrease in circulating CD14+CD16+ monocyte percentage (11.5±6.5 % pre vs. 7.7±3.4 post %) and 25μg/mL LPS-stimulated TNFα (1648.3±739.5 pg/mL pre vs. 1331.2±521.6 pg/mL post) and IL-6 (12525.8±4552.8 pg/mL pre vs. 9409.2±4633.9 pg/mL post) production. There were no changes in CRP or TLR4. PA subjects have significantly lower biomarkers of inflammation, specifically CRP and circulating CD14+CD16+ monocytes. Exercise training without fat loss significantly decreased circulating CD14+CD16+ monocyte percentage. Physically active adults have a lower risk of diseases with an inflammatory etiology, and a reduction in markers of inflammation indicate an anti-inflammatory effect of exercise.
Degree
Ph.D.
Advisors
Sedlock, Purdue University.
Subject Area
Nutrition|Physiology|Immunology
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