[Efficacy of black cohosh extracts for improving low estrogen status induced by postoperative GnRHa treatment in patients with endometriosis: a systematic review]

OBJECTIVE: To evaluate the efficacy of black cohosh extracts (BCE) in improving the low estrogen status induced by postoperative gonadotropin-releasing hormone agonist (GnRHa) in patients with endometriosis. METHODS: Randomized clinical controlled trial about the improvement of low estrogen status caused by GnRHa with the treatment of BCE in patients with endometriosis after laparoscopic surgery were retrieved from Medline (Ovid), PubMed, Cochrane Library, CNKI, CBMdisc, Wanfang and VIP databases before January 2020, and meta-analysis of included studies was performed by Revman 5.3 software. RESULTS: Seven randomized controlled trials involving 745 patients were included in this study. Meta-analysis results showed that the addition of BCE did not alter hormone levels of patients, including serum estradiol levels [ MD=1.24, 95% CI(-4.58, 7.08), P>0.05] and luteinizing hormone levels [ MD=-0.02, 95% CI(-0.15, 0.11), P>0.05]. BCE effectively improved the perimenopausal symptoms induced by low estrogen status:improving hectic fever and sweating [ OR=0.1, 95% CI(0.02, 0.47), P < 0.01], reducing the occurrence of insomnia symptoms [ OR=0.23, 95% CI(0.13, 0.39), P < 0.01], improving fatigue [ OR=0.09, 95% CI(0.04, 0.20), P < 0.01], reducing the occurrence of vaginal dryness [ OR=0.04, 95% CI(0.01, 0.30), P < 0.01]. BCE affected Kupperman's menopausal index (KMI) score 12 weeks after the surgery [ MD=-11.50, 95% CI(-20.09, -2.90), P < 0.01] and KMI score 24 weeks after the surgery [ MD=-23.68, 95% CI(-39.66, -7.69), P < 0.01]. CONCLUSIONS: The limited evidence so far indicates that BCE could efficiently improve perimenopausal symptoms cause by low estrogen status of the patients recieved GnRHa treatment after surgery for endometriosis, but does not alter hormone levels of patients.