Interplay between vitamin D, Thyroid function tests and Thyroid Peroxidase antibodies in female patients with sub-clinical hypothyroidism reporting to a Tertiary Care Hospital in Rawalpindi, Pakistan.

Abstract

Objective: To assess the correlation between Serum Vitamin D levels, thyroid function tests and Thyroxine Peroxidase Antibosies (TPOAb) levels in the female patients of sub-clinical hypothyroidism. Study Design: Case Control study. Setting: HBS General Hospital and Department of Chemical Pathology, HBS Medical and Dental College, Islamabad. Period: Jun 2023 to Dec 2023. Methods: Total of 790 female subjects aged 18 to 45 years reporting to the female Endocrine Clinic were consecutively recruited, out of which 450 participated in the study. Those with serum TSH >4.3 to 10 mU/l and normal levels of fT4 and fT3 and TPOAb positive were recruited as cases (n=200). Those who had normal TSH between 0.4 to 4.0 mIU/L and TPOAb negative were recruited as controls (n=250). Results: BMI and smoking was higher amongst controls. In biochemical parameters, there was a highly significant negative correlation between the serum TSH levels and TPO antibodies with the serum 25 (OH) Vit-D level (p<0.0001).fT4 showed a moderately significant positive correlation with serum 25 (OH) Vit-D level (p<0.001) while fT3 did not show any significant correlation with the serum 25 (OH) Vit-D levels. Conclusion: The identified correlations emphasize the importance of comprehensive thyroid assessments, including vitamin D levels, in the clinical management of sub-clinical hypothyroidism.