***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Objective YKL-40 , a chitinase-like glycoprotein associated with inflammation and tissue remodeling , is produced by joint tissues and recognized as a c and i date auto-antigen in rheumatoid arthritis ( RA ) . In the present study , we investigated YKL-40 as a potential biomarker of disease activity in patients with early RA at baseline and during intensive treatment aim ing for early remission . Methods Ninety-nine patients with early DMARD-naïve RA participated in the NEO-RACo study . For the first four weeks , the patients were treated with the combination of sulphasalazine , methotrexate , hydroxychloroquine and low dose prednisolone ( FIN-RACo DMARD combination ) , and subsequently r and omized to receive placebo or infliximab added on the treatment for further 22 weeks . Disease activity was evaluated using the 28-joint disease activity score and plasma YKL-40 concentrations were measured by immunoassay . Results At the baseline , plasma YKL-40 concentration was 57 ± 37 ( mean ± SD ) ng/ml . YKL-40 was significantly associated with the disease activity score , interleukin-6 and erythrocyte sedimentation rate both at the baseline and during the 26 weeks ’ treatment . The csDMARD combination decreased YKL-40 levels already during the first four weeks of treatment , and there was no further reduction when the tumour necrosis factor-α antagonist infliximab was added on the combination treatment . Conclusions High YKL-40 levels were found to be associated with disease activity in early DMARD-naïve RA and during intensive treat-to-target therapy . The present results suggest YKL-40 as a useful biomarker of disease activity in RA to be used to steer treatment towards remission 
    Output:
    
This study indicates that OSAHS patients  have higher serum YKL-40 level  , which may serve as a potential biomarker for OSAHS diagnosis and monitoring