Effects Of Yoga Exercise Programs On TNF-? Levels: A Systemic Review And Meta-Analysis

Background: Previous studies have shown that yoga involves in the biological functions of inflammatory mediator tumor necrosis factor alpha(TNF-?)by regulating its expression level.Yoga has been widely used as a complementary and alternative medicine.However,the exact mechanism of how yoga benefits on the patient's body and the best way to perform yoga to achieve its maximum effect remain unclear so far.Methods: Studies related to yoga and TNF-? were retrieved from PubMed,Embase,Cochrane,and Web of Knowledge up to Nov 8,2017.Risk of bias was assessed by using the Cochrane risk of bias tool and the modified Newcastle-Ottawa scale.We assessed pooled data by using a random-effects model.Results: Among the 53 identified studies,6 studies were eligible and were included in our analysis(n=240 participants).Compared with the non-exercise group,yoga had improved effects on reducing TNF-? expression(5 trials,194 participants,SMD: 0.67,95% CI :0.34 to0.99;I2= 32.7%).Based on fluctuations of the expression level of TNF-?,subgroup analysis indicated that the yoga are benefit to those people suffering from chronic disease(1 trial,43 participants;SMD: 1.17,95% CI: 0.52 to 1.82),cancer(3 trials,130 participants;SMD:0.68,95% CI: 0.33 to 1.04;I2= 0.0%)or occupational exposure(1 trial,37 participants;SMD:0.82,95% CI: 0.15 to 1.49).Additionally,the effect of yoga on down-regulation of TNF-? in cancer patients with corresponding treatment has been proved statistically.(2 trials,84 participants;SMD: 0.78,95% CI:0.33 to 1.22;I2= 0.0%).Furthermore,a better exercise plan of yoga is recommended as following:the duration should at least exceed 8 weeks(3trials,126 participants;SMD: 0.82,95% CI: 0.43 to 1.20;I2= 7.3%)and the total time per week should be no less than 180 minutes(3 trials,152 participants;SMD: 0.73,95% CI:0.40 to 1.06;I2= 0.0%).Conclusion: This study has provided a systemic review of existing studies on the relationship between yoga and TNF-? and further confirmed that fluctuating expression level of TNF-? could serve as an effective biological marker to evaluate the effect of yoga.Our findings indicate that the most suitable beneficiaries of the yoga exercise program.