Endocrine disorders following SARS-CoV-2 vaccination: a comprehensive systematic review.

Purpose: To synthesize and analyze the current available evidence on the development of new-onset endocrine disorders associated with coronavirus disease 2019 (COVID-19) vaccination. Materials and Methods: We performed a systematic review of literature by searching PubMed, Scopus, Embase and Web of Science. Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were applied, the Joanna Briggs Institute tool and New Castle-Ottawa score were used to assess the risk of bias and quality. SPSS 25.0 software was used for statistical analysis. Results: A total of 245 patients were reported from the selected studies. The most frequently reported endocrine disorders associated with COVID-19 vaccination were thyroid conditions (70.6%), primarily subacute thyroiditis (69.9%) and Graves' disease (28.9%). Cases of type 1 diabetes mellitus (10.2%), adrenal disorders (9.8%), and pituitary disorders (9.4%) were also identified. Most cases occurred in women (64%) and following the first vaccine dose (50.6%). Messenger ribonucleic acid-based vaccines primarily Pfizer-BioNTech and Moderna were the most reported (56.7%). Additionally, studies on fertility found no significant adverse effects on ovarian reserve or semen quality. Clinical outcomes were favorable in most cases (82%), with no significant mortality reported. Conclusion: Overall, although cases of endocrine disorders following COVID-19 vaccination have been reported, a causal relationship has not been definitively established. The benefits of vaccination significantly outweigh the potential risks of endocrinological complications at both the individual and population levels. Nevertheless, clinicians should remain alert to the possibility of endocrine manifestations following vaccination. Trial Registration: PROSPERO identifier: CRD42024512710.