C4B and obstructive sleep apnea syndrome: Consistently, our study found similar results that triglyceride and fasting blood glucose were positively associated with the risk of both OSA and pre-OSA, whereas HDL-CH was negatively associated with the risk of both OSA and pre-OSA, further suggesting that regardless of the number of OSA-related symptoms or severity of OSA, glycolipid biomarkers may help determine risk and should be controlled during daily life.