Status of Serum Calcium, Phosphorus, Magnesium and Copper in Hypothyroid Patients- A Case Control Study

Abstract

Introduction: Thyroid disorders are the most common endocrine abnormality in the world secondary to diabetes mellitus. Thyroid hormones are essential for growth, neuronal development, reproduction and regulation of energy metabolism. It influences the metabolism of all substrates including minerals. Many studies have shown that mineral metabolism is frequently disturbed in thyroid disorders. Aim: To estimate the levels of serum calcium, phosphorus, magnesium and copper in hypothyroid cases and to correlate each of the parameter with serum Triiodothyronine (T3), Thyroxine (T4), Free T3 (FT3), Free T4 (FT4) and Thyroid-Stimulating Hormone (TSH), respectively. Materials and Methods: The study was conducted on sixty newly confirmed hypothyroid cases based on the thyroid profile and sixty euthyroid cases were recruited as controls. Blood samples were collected from all the patients for the estimation of serum T3, T4, FT3, FT4, TSH, calcium, phosphorus and magnesium by autoanalyser method. Modified spectrophotometric micro-method was used to measure Serum copper using Bathocuprine Disulphonate Disodium Salt (BCDS) and Guanidine hydrochloride salt. The Statistical software namely SPSS 18.0, and R environment ver.3.2.2 were used for the analysis of the data. Results: Study results shows that mean serum calcium, magnesium and copper levels were significantly (p<0.001) decreased while serum phosphorus levels were increased significantly (p<0.001) in hypothyroid cases as compared to euthyroid cases. A significant positive correlation was found between serum Ca vs T3, serum Ca vs T4, negative correlation with serum Ca vs TSH, serum Ca has no significant correlation with serum FT3 and FT4. Significant positive correlation was found between serum phosphorus and TSH while significant negative correlation of phosphorus in comparison with T3 and T4. No significant correlation was found between serum phosphorus with FT3 and FT4. Suggestive significant positive correlation was found between serum Mg with T3, T4 and significant negative correlation with serum TSH, Mg has no significant correlation with FT3 and FT4, there was no significant correlation of serum copper with serum T3, T4, TSH and FT4 but significant positive correlation with serum Cu with FT3 were observed. Conclusion: The present study has shown that metabolism of minerals are altered in thyroid dysfunction cases. This study concluded that impaired metabolism of minerals like calcium, phosphorus, magnesium and copper can lead to various metabolic disorders. Preventive measures like supplementation of minerals or hormone replacement therapy can be initiated early to control these secondary disorders.