Assessment of mineral status in subclinical hypothyroidism patients – A case control study

Abstract

One of the important functions of thyroid hormones is homeostasis of mineral metabolism. So thyroid disorders usually lead to disturbances in mineral metabolism. Objective: To analyze serum levels of minerals like calcium, phosphorus and magnesium in patients of subclinical hypothyroidism and to correlate these parameters with TSH levels in cases. Materials and Methods: The study group included 70 patients who are diagnosed with subclinical hypothyroidism and 70 healthy controls who are age and sex matched with cases. Thyroid profile which includes estimation of serum T3, T4, TSH was done. Serum calcium, phosphorus and magnesium were also estimated in both cases and controls. Results: The study showed that in subclinical hypothyroidism patients serum calcium levels were significantly low with mean values of 8.9±0.62 and p<0.05, whereas serum phosphorus and magnesium levels were significantly higher with mean values of 4.6±0.65 and 3.03±0.58 respectively and p<0.05 compared to controls. Conclusion: The serum levels of minerals like calcium, phosphorus and magnesium levels are significantly altered in subclinical hypothyroidism. Frequent follow up and checking the levels of these minerals in SCH patients should be done. Along with the treatment of the disease, it is necessary to give mineral supplements to prevent bone complications. Introduction Deficiency of thyroid hormones cause Hypothyroidism, which is one of the most common endocrine disorder nowadays. The disease causes generalized slowing of metabolic processes. 1,2 2-15% of population worldwide suffer from the disease. Incidence is higher in women compared to men. 2 Subclinical hypothyroidism refers (SCH) to thyroid hormone deficiency in patients who have very less or no standard clinical features of hypothyroidism. 3 In SCH there is increased serum thyroid stimulating hormone (TSH) levels with almost normal thyroxine (T 4) and tri iodothyronine (T 3) concentrations. 4 It is the mildest form of hypothyroidism and the patients usually lack classical signs and symptoms of overt hypothyroidism. The prevalence of SCH is between 3% and 18% in the general population and higher in women than in men. 5 SCH patients are at risk for progression to overt hypothyroidism with an average yearly progression rate of 2% to 6% with an increased risk in females. 5 TSH elevation in SCH is typically between 4-15 mIU/L. SCH is much more common than overt hypothyroidism, therefore it should be diagnosed early to prevent occurrence of clinical hypothyroidism. 3 Thyroid hormones are vital for skeletal system growth and maturation. Recent studies have shown that TSH acts as a direct regulator of bone remodelling, highlighting the importance of integrity of the hypothalamo-pituitary-thyroid axis. 6 Thyroid diseases have adverse effects on bone and mineral homeostasis. 7 Calcium, Phosphorus, and Magnesium are divalent metal ions, which are necessary for