Effectiveness of Chinese herbal medicine for primary Raynaud's phenomenon: a systematic review and Meta-analysis of randomized controlled trials

OBJECTIVE: To evaluate the effectiveness of Chinese herbal medicine for primary Raynaud’s phenomenon(PRP).METHODS: The Cochrane Central Register of Controlled Trials, Pub Med, Chinese Biomedical Literature Database, China National Knowledge Infrastructure, China Science and Technology Journal Database, and Wanfang Database were searched up to February 13, 2018. Randomized controlled trials(RCTs) on treatment of PRP with Chinese herbal medicine compared with placebo, blank control,lifestyle changes, or calcium antagonists were identified and reviewed. The quality of included trials was assessed using a risk of bias tool.RESULTS: Eight RCTs involving 674 participants were included. The methodological quality of the included trials was generally poor. Meta-analysis of two trials showed that Buyang Huanwu Tang plus Danggui Sini Tang produced greater improvement in global symptoms than nifedipine. One trial showed that Danggui Sini Tang and a self-composed Chinese herbal medicine decoction, respectively, produced greater improvement in global symptoms than nifedipine alone. In one trial, modified Danggui Sini Tang showed greater improvement in global symptoms and arterial peak systolic velocity compared with nifedipine. One trial showed that Jiejing Tongmi Tang produced greater improvement in global symptoms, plasma endothelin, and plasma nitric oxide than cinepazide maleate injection. However, Jiejing Tongmi Tang did not produce a significant difference in skin temperature and peripheral artery blood stream drawing after cold pressor testing compared with cinepazide maleate injection. None of the trials reported frequency of attacks, duration of attacks, participant preference scores, or adverse events.CONCLUSION: Chinese herbal medicine may have a positive effective on PRP. However, owing to weak methodology, the benefits of Chinese herbal medicine for PRP are inconclusive. More rigorously designed studies are needed to confirm these findings.