Background and objective: Acupuncture is widely used in complementary and alternative medicine to reduce body weight. However, a systematic review and meta-analysis to assess an effect of acupuncture has not yet been performed. Aim of this study is to critically assess evidence for reduction of body weight and to evaluate adverse events of acupuncture therapy based on the results of randomized controlled trials (RCTs) that evaluate the effect of various types of acupuncture therapies.
Data sources: A total of 19 electronic databases, including English, Korean, Japanese and Chinese databases, were systematically searched for RCTs of acupuncture for reduction of body weight or improvement in obesity up to March 2008 with no language restrictions.
Methods: RCTs for acupuncture compared either with placebo controlled or with comparator intervention were considered. Studies' methodological qualities were assessed using the Jadad scale. If no evidence of heterogeneity existed across study results, statistical pooling of data was performed using a fixed effects model; otherwise, a random effects model was used. Publication bias was assessed using funnel plots. Subgroup analyses were performed according to types of acupuncture.
Results: A total of 31 studies, which comprised a total of 3013 individual cases, were systematically reviewed. Owing to insufficient data in 2 RCTs, 29 RCTs were used for meta-analysis. About two-thirds of the trials (20 out of 31) showed the lowest score of the Jadad. Compared to control of lifestyle, acupuncture was associated with a significant reduction of average body weight (95% confidence interval, CI) of 1.72 kg (0.50-2.93 kg) and associated with an improvement in obesity (relative risk=2.57; 95% CI, 1.98-3.34). Acupuncture significantly reduced a body weight of 1.56 kg (0.74-2.38 kg), on average, compared to placebo or sham treatments. Acupuncture also showed more improved outcomes for body weight (mean difference=1.90 kg; 1.66-2.13 kg), as well as for obesity (relative risk=1.13; 1.04-1.22), than conventional medication. Only four RCTs reported acupuncture-related adverse events, which were mostly minimal.
Conclusions: Our review suggests that acupuncture is an effective treatment for obesity. However, the amount of evidence is not fully convincing because of the poor methodological quality of trials reviewed. In conclusion, there is an urgent need for well-planned, long-term studies to address the effectiveness of acupuncture for treating obesity.