Lack of associations between thyroid dysfunction and obstructive sleep apnea-hypopnea syndrome: A meta-analysis

Abstract

Background: Obstructive sleep apnea-hypopnea syndrome (OSAHS) is a comprehensive syndrome with endocrine and metabolic complications. This review aims to explore the correlation between thyroid hormone levels and the severity of OSAHS in patients. Methods: The protocol for this meta-analysis has been registered on PROSPERO. Searches were carried out from the inception of the databases to July 18, 2023, utilizing 6 databases (PubMed, CNKI, EMBASE, Web of Science, Cochrane Library, China Biology Medicine, and Wanfang). Standardized mean difference (SMD) and correlation coefficients were used as the effect size measures. Additionally, random effects or fixed effects models were used for pooled analysis. Moreover, data were statistically evaluated with the help of STATA 11.0 and R 4.1.3. Results: This study included 23 articles that satisfied the pre-defined criteria. The prevalence of hypothyroidism and subclinical hypothyroidism in OSAHS patients was 6% and 8%, whereas hyperthyroidism had a prevalence of 2%. Moreover, thyroid hormone levels in OSAHS individuals exhibited no significant difference relative to healthy subjects. Subgroup analysis based on disease severity also established no significant changes in thyroid hormone levels between OSAHS individuals and controls. There was no significant correlation between the Apnea-Hypopnea Index (AHI) and free triiodothyronine (FT3), serum thyroid stimulating hormone (TSH), and free thyroxine (FT4) levels. Conclusion: The prevalence of thyroid dysfunction is relatively low in OSAHS individuals. Thyroid hormone levels show no significant difference between OSAHS patients and healthy subjects. Furthermore, there is no significant correlation between AHI and serum TSH, FT3, and FT4 levels. Based on existing data, the relationship between OSAHS and thyroid function remains controversial, and further in-depth research is warranted to validate the connection and elucidate the underlying mechanisms.