Assessment of fluoride status in patients with hypothyroidism

Introduction: Fluorosis an endemic problem affects many tissues including endocrine glands such as thyroid. Iodine deficiency remains the most common cause of primary hypothyroidism worldwide. Fluoride and iodine are both halogens. Fluoride, the negative ion of the element fluorine, easily displaces iodine in the body because it is much lighter and therefore more reactive. Few studies have reported no relationship between serum fluoride levels and thyroid disorders, while others have reported decreased serum thyroid hormone levels are associated with increased fluoride levels in hypothyroidism. Goiter and hypothyroidism are known to be caused by iodine deficiency. However, it has also been found to occur in areas where there are adequate supplies of iodine, but where there is an excess fluoride in the water. The present study was conducted to assess the fluoride status in newly diagnosed cases of hypothyroidism. Aims & objectives 1) To assess the fluoride status in the patients of hypothyroidism and healthy controls. 2) To correlate the fluoride status with the severity of hypothyroidism. Material & Methods: The present study was conducted in the Department of Biochemistry in collaboration with Department of Medicine (Endocrinology), Pt. B.D. Sharma PGIMS, Rohtak. Fifty newly diagnosed patients with hypothyroidism in the age group 20-55 years and fifty age and sex matched healthy controls were taken in the study. Fasting venous blood samples were collected from cases and controls for routine biochemical, hormone analysis and fluoride estimation after obtaining informed written consent and complete history. Results: Mean water fluoride level of cases was 2.308 ± 0.282 ppm (Mean ± SE) and of controls was 1.659 ± 0.183 ppm and found to be statistically significant. Mean value of serum fluoride levels in study group was 0.234 ± 0.023ppm and of controls was 0.058 ± 0.007ppm and found to be statistically significant. Mean urine fluoride level of cases was 2.359 ± 0.146 ppm and of controls was 1.577 ± 0.166 ppm and found to be statistically significant. TSH in the study group (20.924 ± 2.398) and control group (2.817 ± 0.186) were compared and found to be statistically significant. Discussion & Conclusion- In the present study the serum & urinary fluoride levels in the study & control groups indicate the likelihood of fluoride ingestion from food & other sources is apparently, like dental products, cosmetics etc. It is evident in consistent with the findings of reported studies that analysis of fluoride in body fluids besides drinking water is highly relevant & necessary for understanding & prevention of potential health implications like hypothyroidism seen in endemic areas.