Association of vitamin D with triglyceride-glucose index and cardiometabolic risk factors in subclinical hypothyroidism

Background

The present study aimed to explore the association of vitamin D with triglyceride-glucose (TyG) index and cardiometabolic risk factors in subclinical hypothyroidism (SCH).

Methods

We recruited 75 individuals diagnosed with SCH and 75 healthy controls of both genders aged 20 to 65 years. Triiodothyronine (T₃), thyroxine (T₄), thyroid stimulating hormone (TSH) and 25-hydroxyvitamin D [25(OH)D] were measured using chemiluminescent immunoassay. Fasting plasma glucose and lipid profile were analyzed by standard methods. The TyG index was calculated as Ln [fasting triglycerides (mg/dL) × fasting glucose (mg/dL)]/2.

Results

There were significant decreases in 25(OH)D levels and changes in cardiometabolic risk factors among individuals with SCH compared to healthy controls. Additionally, there was a significant increase in the TyG index among the SCH group. Correlation and regression analysis revealed that 25(OH)D was significantly and negatively associated with TyG index, diastolic blood pressure (DBP), total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C) and very low-density lipoprotein cholesterol (VLDL-C). However, it was positively associated with high-density lipoprotein cholesterol (HDL-C).

Conclusion

Present study shows that SCH patients have lower vitamin D levels and higher TyG index, increasing cardiovascular disease risk. Screening and managing vitamin D deficiency is crucial in these subjects. In addition, TyG index could be used as an indicator for identifying vitamin D deficiency.