Effect of Exercise Training on Metabolic Syndrome z-score : the Association of C- reactive protein

Abstract

PURPOSE: Previous studies have shown that metabolic syndrome z-score (MetSynZ) is improved with exercise training. Metabolic syndrome is based upon insulin resistance, such that it would be expected for insulin resistance to improve with exercise training. Currently, it is unknown if improvements in MetSynZ from exercise training are associated with improvements in systemic inflammation. The purpose of the present study is to evaluate the effect of exercise training on MetSynZ in participants with elevated C- reactive protein (CRP), and determine if changes in MetSynZ with exercise training were associated with changes in CRP and HOMA-IR (Homeostatic Model Assessment- Insulin Resistance). METHODS: The study sample included 123 participants with elevated CRP levels from the Inflammation and Exercise (INFLAME) study. The participants were randomized into a control group and an exercise group. MetSynZ was defined as the sum of the z-scores from the NCEP-ATP III criteria. MetSynZ, CRP, and HOMA-IR were evaluated at baseline and follow up. The intervention consisted of aerobic exercise training for 4 months where total energy expenditure was approximately 16 kilocalories/week per kilogram of body weight. RESULTS: Baseline CRP showed small associations with MetSynZ (r=0.193, p=0.034). Analysis of covariance showed no significant change in MetSynZ between the exercise (-0.3, CI: -0.7 to 0.2) and control groups (0.2, CI: -0.2 to 0.6). Change in MetSynZ was not associated with change in CRP (r=-0.15, p=0.914), but was associated with change in the homeostatic model assessment of insulin resistance (HOMA-IR) (r=0.286, p=0.036). DISCUSSION: Results from the present study suggest that 4 months of aerobic exercise training may not be a sufficient time to favorably change MetSynZ. Reductions in MetSynZ with exercise training were not associated with improvements in systemic inflammation, but were associated with significant improvement in insulin resistance.