Exploring the Association Between Hypothyroidism, Mean Platelet Volume, and Red Cell Distribution Width: A Case-Control Study.

Background: Thyroid hormones are important in regulating hematopoiesis. Recent research has suggested that red cell distribution width (RDW) and mean platelet volume (MPV) may be useful inflammatory markers in various disorders, including thyroid disorders. Hence, the study aimed to evaluate the association between hypothyroidism, RDW, and MPV.

Methods: We used data from King Abdulaziz Medical City, Jeddah (KAMC-J) from May 2016 to June 2022. One hundred ninety-eight adults, 99 patients with hypothyroidism and 99 healthy controls, were assessed for thyroid function tests and a complete blood count (CBC). The association between hypothyroidism, RDW, and MPV was assessed using the Wilcoxon rank sum test. The sensitivity and specificity of RDW and MPV were plotted using the ROC curve.

Results: The median RDW levels of the hypothyroid and control groups were 14 (13-14.8)% and 13 (12.6-14)%, respectively (p<0.001). The median MPV levels of the hypothyroid and control groups were 10.43 (9.46-11.1) fL and 8.9 (8.47-10.1) fL, respectively (p<0.001). MPV levels greater than 9.40 have 77% sensitivity and 70% specificity in predicting hypothyroidism (AUC: 0.796 [95% CI: 0.735-0.858]; p<0.001). RDW levels greater than 13 have a sensitivity value of 75% and a specificity value of 51.5% in predicting hypothyroidism (AUC: 0.683 [95% CI: 0.608-0.758]; p<0.001).

Conclusion: Elevated mean platelet volume (MPV) and RDW levels were observed in individuals with hypothyroidism, suggesting that these parameters may serve as potential indicators of the condition. While this study identifies a significant association between MPV, RDW, and hypothyroidism, it does not conclude causality. Further investigation is warranted to determine the clinical utility of MPV and RDW as screening tools for hypothyroidism. These findings have potential implications for future research on the early detection and management of hypothyroidism.