ObjectiveTo systematically review the association between the level of plasma YKL-40 and obstructive sleep apnea hypopnea syndrome (OSAHS).MethodsWe searched PubMed, EMbase, MEDLINE, CNKI, WanFang Data, VIP database and supplemented by Google academic retrieval to collect case-control studies about the association between the level of plasma YKL-40 and OSAHS from inception to April 2017. Two reviewers independently screened literature, extracted data and evaluated the risk of bias of included studies. And then, meta-analysis was performed by RevMan 5.3 software.ResultsA total of 5 case-control studies were included, involving 755 OSAHS patients and control population. The results of meta-analysis showed that the level of plasma YKL-40 in OSAHS patients was higher than that in control group (SMD=1.20, 95%CI 0.33 to 2.06, P=0.007). The subgroup analysis showed that the level of plasma YKL-40 in OSAHS patients from Asia was significantly higher than that in control group (SMD=1.79, 95%CI 0.83 to 2.75, P=0.000 2). The comparison between different severity of OSAHS showed that the wild-medium group had lower plasma level of YKL-40 than the severe group (SMD=–0.83, 95%CI –1.46 to –0.19, P=0.01).ConclusionYKL-40 may play an important role in the pathogenesis of OSAHS. Due to limited quantity and quality of the included studies, more high quality studies are needed to verify above conclusions.
