Early bone loss in patients with obstructive sleep apnea: a cross-sectional study.

"Declarations Ethics approval and consent to participateEthical clearance and approval were obtained from Ethics Committee of the Peking Union Medical College Hospital, Beijing, China (review number: ZA-1502). All study participants were informed about the purpose of the study and additional information was given as they need. Written informed consent was obtained from all participants. We had complied with the Declaration of Helsinki Ethical Principles for medical research involving human subjects. Consent for publicationNot applicable. Competing interestsThe authors declare no competing interests. Competing interests The authors declare no competing interests."

"Funding This study was supported by the National Key Research and Development Projects of China [No. 2013BAI09B10]."