Upper airway lengthening caused by weight increase in obstructive sleep apnea patients

  • PDF / 2,576,605 Bytes
  • 10 Pages / 595.276 x 790.866 pts Page_size
  • 33 Downloads / 190 Views

DOWNLOAD

REPORT


RESEARCH

Open Access

Upper airway lengthening caused by weight increase in obstructive sleep apnea patients Hongyi Lin1,2, Huahui Xiong1,2, Changjin Ji1,2, Cunting Wang1,2, Yong Li1,2, Yunqiang An1,2, Geng Li1,2, Jianggui Guo1,2, Xiaoqing Huang1,2, Han Zhang1,2, Hong Liu1,2, Ting Li3, Zheng Li3, Junfang Xian3* and Yaqi Huang1,2*

Abstract Background: The longer upper airway is more collapsible during sleep. This study aims to reveal relationships among upper airway length, weight, and obstructive sleep apnea (OSA), particularly to answer why the upper airway of OSA patients is longer than that of healthy people and why some obese people suffer from OSA while others do not. Methods: We perform head and neck MRI on male patients and controls, and measure > 20 morphological parameters, including several never before investigated, to quantify the effect of weight change on upper airway length. Results: The upper airway length is longer in patients and correlates strongly to body weight. Weight increase leads to significant fat infiltration in the tongue, causing the hyoid to move downward and lengthen the airway in patients. The apnea-hypopnea index (AHI) strongly correlates to airway length and tongue size. Surprisingly, a distance parameter h and angle β near the occipital bone both show significant differences between healthy males and patients due to their different head backward tilt angle, and strongly correlates with AHI. The contributions of downward hyoid movement and head tilt on airway lengthening are 67.4–80.5% and19.5–32.6%, respectively, in patients. The parapharyngeal fat pad also correlates strongly with AHI. Conclusions: The findings in this study reveal that the amount of body weight and distribution of deposited fat both affect airway length, and therefore OSA. Fat distribution plays a larger impact than the amount of weight, and is a better predictor of who among obese people are more prone to OSA. Keywords: Obstructive sleep apnea, Upper airway length, Body weight effect

* Correspondence: [email protected]; [email protected] 1 School of Biomedical Engineering, Capital Medical University, 10 Xitoutiao, Youanmenwai, Beijing 100069, China 3 Department of Radiology, Beijing Tongren Hospital, Capital Medical University, No 1 Dongjiaominxiang Street, Beijing 100730, China Full list of author information is available at the end of the article © The Author(s). 2020 Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permi