The influence of hypothyroidism, hyperthyroidism, autoimmune thyroiditis and thyroid cancer on the risk of polycystic ovary syndrome: a Mendelian Randomization study

Abstract

Abstract Background Observational studies have found a correlation between thyroid diseases and polycystic ovary syndrome (PCOS). However, their causal relationship remains uncertain. Our purpose was to investigate the causal relationship between four common thyroid diseases (hypothyroidism, hyperthyroidism, autoimmune thyroiditis, thyroid cancer) and PCOS risk. Methods In this study, using the Mendelian randomization (MR) approach, we obtained single nucleotide polymorphisms (SNPs) from the genome-wide association study (GWAS) database as instrumental variables (IVs) and used inverse variance weighting (IVW) to explore the causal relationship between four common thyroid diseases and PCOS. Results We found a significant causal association between hypothyroidism and increased risk of PCOS [OR = 34.90, 95% CI: (1.68, 724.53), P = 0.02]. However, hyperthyroidism, autoimmune thyroiditis, thyroid cancer has no significant causal association with PCOS. Conclusion Hypothyroidism may increase the risk of PCOS. Hyperthyroidism, autoimmune thyroiditis, thyroid cancer has no significant causal association with PCOS.