Chinese herbal medicine for obstructive sleep apnoea: a systematic review with meta-analysis

Purpose: Chinese Herbal Medicine (CHM) may have a place in the treatment of obstructive sleep apnoea (OSA), but the evidence has not been systematically assessed. The objective of this study is to evaluate the evidence for the effectiveness of CHM for OSA. Methods: CENTRAL, EMBase, PubMed, CINAHL, CNKI, Wanfang and Chongqing VIP were searched from database inception to the 13th of August 2023. Randomised-controlled trials in which the effect of CHM on sleep variables was tested in the treatment of OSA were selected. The primary outcomes of this review and meta-analysis were the apnoea hypopnoea index (AHI) measured with polysomnography. Results: A total of 58 studies, involving 4,590 participants, were included. The meta-analysis showed that CHM reduced AHI more significantly than placebo (mean difference = -7.10 events/hour, 95% CI = -11.95, -2.25, P < 0.01, 7 studies, 583 participants) and the combination of CHM and Continuous Positive Airway Pressure (CPAP) more effective than CPAP alone (mean difference = -4.71 events/hour, 95% CI = -5.62, -3.80, P < 0.001, 28 studies, 2,267 participants). CHM improved sleepiness, quality of life, body weight, oxidative biomarkers, inflammatory biomarkers, cognitive function, blood pressure and respiratory function. Conclusion: Our results suggest that CHM, alone and as an adjunct treatment, can improve various aspects of OSA and its comorbidities and is therefore a viable therapeutic option for OSA.