Effects of Lifestyle Intervention on Inflammatory Markers and Waist Circumference in Overweight/Obese Adults With Metabolic Syndrome: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

Background: Physical inactivity and an imbalanced diet could lead to some cardio metabolic risk factors.

Objective: The objective of this meta-analysis was to investigate the effects of lifestyle modification on inflammatory indicators and waist circumference (WC) in overweight/obese subjects with metabolic syndrome (MS).

Data sources: A systematic search was conducted in PubMed, CINAHL, MEDLINE, Cochrane, Google Scholar, and Web of Science.

Study selection: The selection criteria were randomized controlled trials (RCTs) investigating the effects of lifestyle interventions on inflammation and WC from inception to 20 December 2020. The weighted mean difference (WMD) and 95% confidence interval (CI) between interventions were computed using a random or fixed-effects model.

Results: Six RCTs (including 1246 MS patients who had, on average, overweight/obesity) met all inclusion criteria. Interventions lasted 6 to 12 months (2-5 sessions per week). Lifestyle intervention significantly reduced C-reactive protein (WMD: -0.52 mg/ml, 95% CI: -0.72, -0.33), IL-6 (WMD: -0.50 pg/ml, 95% CI: -0.56, -0.45), and increased adiponectin (WMD: 0.81 µg/ml, 95% CI, 0.64, 0.98). Moreover, lifestyle modification significantly decreased WC (WMD: -3.12 cm, 95% CI, -4.61, -1.62).

Conclusion: Our findings provide evidence that lifestyle alterations, including physical activity and diet, can lead to significant improvement in abdominal obesity, measured by WC and some inflammation markers among overweight/obese individuals with MS. Further high-quality research is needed to clarify the mechanisms underlying the effect of such interventions on this population's inflammatory markers.