Association between monocyte to high-density lipoprotein cholesterol ratio and thyroid function: a cross-sectional study

This study aimed to explore the association between the Monocyte to high-density lipoprotein cholesterol (HDL-C) ratio (MHR) and thyroid function in adults. From the 2007 to 2012 National Health and Nutrition Examination Survey (NHANES), 6,963 adults aged 18 years and above were included in this cross-sectional study. Serum MHR levels and thyroid function indicators were extracted from laboratory data. Weighted multivariate linear regression models, subgroup analyses, interaction tests, smoothed curve fitting, and threshold effects were used to investigate the associations of the MHR with thyroid function. In the complete adjusted model, lnMHR was positively correlated with FT3 (beta = 0.10, 95% CI 0.07, 0.12), TT3 (beta = 3.33, 95% CI 2.01, 4.65), and TT4(beta = 0.20, 95% CI 0.11, 0.29) and negatively correlated with TPOAb (p = 0.019 for trend) after categorizing lnMHR into quartiles. We observed a J-shaped curve between lnMHR and FT3 and TT4 using a smoothed curve fitting. The subgroup analysis suggested the relationship between lnMHR and various thyroid function indicators was influenced by age, body mass index (BMI), urinary iodine concentration (UIC), hypertension. The findings of this study suggest that MHR is closely related to thyroid functions. Further research is required to confirm this association.