Sari, Isilay KalanArikan, SenayYavuz, SeymaCarlioglu, Ayse2025-01-212025-01-2120222147-2092https://doi.org/10.12996/gmj.2022.76https://hdl.handle.net/20.500.12587/25792Objective: Mean platelet volume (MPV) has been associated with autoimmune diseases and is considered a potentially useful parameter to assess platelet activity and subclinical inflammation. In the present study, we aimed to investigate the effects of thyroid autoimmunity on MPV. Methods: 84 patients with newly diagnosed Hashimoto's thyroiditis (HT), including 44 euthyroid (EHT, mean age 41.4 +/- 10.8 years) and 40 hypothyroid (HHT, mean age 44.6 +/- 13.2 years) patients, 61 patients with newly diagnosed Graves' disease (GD, mean age 42.8 +/- 12.4 years) and 57 euthyroid control subjects (age-matched 46.4 +/- 11.6 years) were included in the study. Patients were not taking antithyroid medication or levothyroxine. Thyroid hormones and platelet parameters were determined in all study participants. Results: The MPV of the patients was significantly higher than that of the control group (p:0.008). There was no association between MPV and age, sex, or TSH (p:0.06, p:0.4, and p:0.9, respectively). MPV increased in chronic autoimmune thyroid disease regardless of age, sex, and TSH. Conclusion: Our results suggest that autoimmunity, rather than thyroid hormone levels, affects MPV in GD and HT.eninfo:eu-repo/semantics/openAccessGraves' disease; hashimoto's thyroiditis; mean platelet volume; platelets; thyroid; thyroid-stimulating hormoneArticle33433734010.12996/gmj.2022.762-s2.0-85140309469Q4WOS:000863207700004N/A