Article
The Effects of Resistance Training on Visceral Adipose Tissue and Inflammatory Response: A Meta-Analysis
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Published: | October 24, 2011 |
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Outline
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Objective: Whether resistance training (RT) alters visceral fat and several proinflammatory cytokines produced in adipose tissue has not been convinced established. The objective of this review was (1) to perform a meta-analysis of randomized controlled trials (RCT) regarding the effect of RT on a) visceral adipose tissue (VAT) and b) on specific biomarkers of inflammation, i.e. adiponectin, leptin, C-reactive protein (CRP), interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α). One additional aim was (2) to investigate the potential of a dose-response relationship between RT variables (duration, intensity, volume) and assessed outcomes.
Material/Methods: Studies were retrieved by searching MEDLINE and Cochrane Library (1990–December 2010). Studies were included if they were RCTs comparing RT with an exercise or non-exercise control group among sedentary healthy or overweight/obese adults. 21 RCTs met our inclusion criteria. We performed random effects meta-analysis to determine weighted mean differences (WMD) with 95% confidence intervals using the software package Review Manager 5.0 of the Cochrane Collaboration. A random-effects meta-regression model was performed to examine dose-response relationships between RT variables and assessed outcomes.
Results: RT reduced VAT by 10.77 cm² (95%CI: -20.94 to -0.59, p=0.04) or 0.19 liter (95%CI: -0.37 to -0.01, p=0.04). The pooled reduction in CRP was 0.23mg/liter (95%CI: -0.41 to -0.04, p=0.02) (Table 1 [Tab. 1]). There was no statistically significant effect of RT on serum concentration of adiponectin, leptin, IL-6 and TNF-α. Further, it appears that there is a dose-response relationship between RT intensity and adiponectin – i.e., that higher intensity RT leads to additional benefits – and RT duration and leptin. However, additional research will be necessary to confirm these findings.
Conclusion: In summary, this meta-analysis found that RT significantly decreases visceral fat and seems to be effective in reducing resting levels of serum CRP, and therefore should be recommended in the management of obesity.
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