Effect of Exercise and Pharmacological Interventions on Visceral Adiposity: A Systematic Review and Meta-analysis of Long-term Randomized Controlled Trials

Objective: To assess the effectiveness of exercise and pharmacotherapy interventions in reducing visceral adipose tissue (VAT). Patients and Methods: A systematic search of Ovid MEDLINE, Scopus, Web of Science, Cochrane Library, ClinicalTrials.gov, New York Academy of Science Grey Literature Report, and OpenGrey was combined with hand searches of existing literature. A total of 2515 titles and abstracts were reviewed. Only randomized controlled trials evaluating the effectiveness of monitored exercise or pharmacological interventions in reducing VAT by using computed tomography or magnetic resonance imaging during a sustained intervention period (≥6 months) were included. Data were independently extracted by reviewers according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and assessed for quality and risk of bias. Separate analyses for each intervention were performed using random effect models, with pooled estimates of the change in VAT area (in centimeters squared) from baseline to follow-up reported as standardized mean difference (SMD; with 95% CI). Results: A total of 3602 participants from 17 randomized controlled trials were included in the final analysis. Both exercise and pharmacological interventions were associated with significant reductions in VAT: small reduction with pharmacological interventions (SMD, −0.27; 95% CI, −0.47 to −0.07; P=.02) and more substantial reductions with exercise interventions (SMD, −0.54; 95% CI, −0.63 to −0.46; P<.001). The mean absolute VAT reduction was greater in pharmacological trials than in exercise trials. Meta-regression exhibited a linear correlation between VAT and weight loss (R²=0.52 for exercise and R²=0.88 for pharmacological interventions), but VAT reduction relative to weight loss differed by intervention type. Conclusion: Exercise interventions resulted in greater reduction in VAT relative to weight loss than did pharmacological interventions. A preferential reduction in VAT may be clinically meaningful when monitoring success of interventions because weight loss alone may underestimate benefits.