Introduction
Cognitive impairment (CI) is a significant decline in cognitive functions such as memory, attention, and language. It can range from mild cognitive impairment (MCI) to severe dementia, impacting daily life and imposing economic burdens on society. Identifying modifiable risk factors is crucial for delaying disease progression. Thyroid dysfunction, particularly overt hypothyroidism (oHT), is considered a potentially reversible cause of CI. This study aims to evaluate the association between oHT and the risk of CI through a systematic review and meta-analysis.
Methods
A comprehensive search was conducted across databases including PubMed, Web of Science, Scopus, Cochrane Library, and EMBASE for studies published up to March 2025. Two independent investigators extracted data, and discrepancies were resolved through discussion. The Newcastle-Ottawa Scale (NOS) and the Agency for Healthcare Research and Quality (AHRQ) scale were used to assess study quality. The meta-analysis followed PRISMA guidelines and was registered with PROSPERO.
Results
The review included 11 studies with 1,190,059 participants. The meta-analysis revealed that oHT is associated with an increased risk of CI (OR = 1.18, 95%CI=1.04–1.34). Specifically, oHT was linked to an increased risk of MCI (OR = 1.24, 95%CI=1.13–1.36) but not with Alzheimer’s disease (AD) or all-cause dementia. Subgroup analysis indicated that oHT diagnosed solely by TSH levels was associated with a reduced risk of CI (OR = 0.87, 95%CI=0.79–0.95).
Discussion
The findings suggest a significant association between oHT and CI, particularly MCI. However, the observational nature and heterogeneity of the studies necessitate further high-quality prospective research for confirmation. Thyroid hormones play a critical role in brain function, and their deficiency in oHT may impair cognitive functions. Despite the potential link, the study’s limitations, such as high heterogeneity and lack of detailed clinical data, highlight the need for more rigorous research.
Conclusion
This meta-analysis provides preliminary evidence of the association between oHT and increased CI risk. While the results suggest oHT as an independent risk factor for CI, particularly MCI, further research is needed to confirm these findings and explore the underlying mechanisms. Future studies should focus on standardized diagnostic criteria and consider the impact of treatment on cognitive outcomes.
References
The original contributions presented in the study are included in the article/Supplementary Material. Further inquiries can be directed to the corresponding author.
JZ: Software, Investigation, Writing – original draft, Writing – review & editing, Methodology, Data curation. JX: Data curation, Writing – review & editing, Methodology. ZL: Writing – review & editing, Methodology, Software. JL: Resources, Writing – review & editing, Project administration.
The author(s) declare that no financial support was received for the research and/or publication of this article.
The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
The author(s) declare that no Generative AI was used in the creation of this manuscript.
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The Supplementary Material for this article can be found online at: https://www.frontiersin.org/articles/10.3389/fendo.2025.1643589/full#supplementary-material
🔗 **Fuente:** https://www.frontiersin.org/journals/endocrinology/articles/10.3389/fendo.2025.1643589/full