Independent Association of Sleep Apnea-Specific Hypoxic Burden and Sleep Breathing Impairment Index with Thyroid Function in Obstructive Sleep Apnea: A Retrospective Study

Yanuo Zhou; Yewen Shi; Simin Zhu; Zine Cao; Yushan Xie; Chendi Lu; Xiaoxin Niu; Lina Ma; Zitong Wang; Yonglong Su; Zihan Xia; Yuqi Yuan; Jiayi Yang; Rui Lu; Yani Feng; Xiaoyong Ren; Wei Hou

doi:10.2147/NSS.S525750

Independent Association of Sleep Apnea-Specific Hypoxic Burden and Sleep Breathing Impairment Index with Thyroid Function in Obstructive Sleep Apnea: A Retrospective Study

Nat Sci Sleep. 2025 Jul 5:17:1543-1556. doi: 10.2147/NSS.S525750. eCollection 2025.

Authors

Yanuo Zhou^#^{1

2}, Yewen Shi^#^{1

2}, Simin Zhu^#^{1

2}, Zine Cao³, Yushan Xie^{1

2}, Chendi Lu^{1

2}, Xiaoxin Niu^{1

2}, Lina Ma^{1

2}, Zitong Wang^{1

2}, Yonglong Su^{1

2}, Zihan Xia^{1

2}, Yuqi Yuan^{1

2}, Jiayi Yang^{1

2}, Rui Lu^{1

2}, Yani Feng^{1

2}, Xiaoyong Ren^{1

2}, Wei Hou^{1

2}

Affiliations

¹ Department of Otorhinolaryngology-Head and Neck Surgery, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, People's Republic of China.
² Shaanxi Provincial Key Laboratory for Precision Diagnosis and Treatment of Otorhinolaryngology, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, People's Republic of China.
³ Department of Otorhinolaryngology Head and Neck Surgery, The Affiliated Children Hospital of Xi'an Jiaotong University, Xi'an, People's Republic of China.

^# Contributed equally.

Abstract

Purpose: This study aimed to explore thyroid function changes in patients with obstructive sleep apnea (OSA) and analyze the relationships among the sleep apnea-specific hypoxic burden (SASHB), the sleep breathing impairment index (SBII), and the function during different sleep stages.

Methods: This retrospective study included 452 patients with OSA who visited the Second Affiliated Hospital of Xi'an Jiaotong University between August 2017 and March 2024. The severity of OSA was evaluated, grouping patients by their apnea-hypopnea index (AHI), SASHB, SBII, and both SASHB and SBII during non-rapid eye movement (NREM) and rapid eye movement (REM) sleep. Multiple linear regression analyzed the independent relationships between the AHI, SASHB, SBII, and thyroid function indicators while adjusting for potential confounders.

Results: Significant intergroup differences were observed in thyroid function indicators under various grouping methods, with different trends. After adjusting for confounding factors, SASHB, SASHB during NREM sleep (NREM-SASHB), SASHB during REM sleep (REM-SASHB), SBII, SBII during NREM sleep (NREM-SBII), and SBII during REM sleep (REM-SBII) were independently associated with elevated serum free triiodothyronine (FT3) levels (p < 0.05). Similar results were noted in the male patients, whereas no significant associations were observed in the female patients.

Conclusion: There is an association between OSA and thyroid function, with SASHB and SBII independently linked to elevated FT3 levels across different sleep stages and sex subgroups. Future research should further explore these mechanisms to optimize clinical management and treatment strategies for patients with OSA.

Keywords: obstructive sleep apnea; sleep apnea-specific hypoxic burden; sleep breathing impairment index; thyroid function.