Comparison of Total and Ionic Calcium in Hypothyroidism

• Main Authors: Vasanthan Mani, Meenakshi Sundari Subramaniyan Natarajan, Vinodhini Vellore Mohanakrishnan
• Format: Article
• Language: English
• Published: JCDR Research and Publications Private Limited 2019-05-01
• Series: Journal of Clinical and Diagnostic Research
• Subjects: free thyroxine; thyroid stimulating hormone; total and ionic calcium
• Online Access: https://jcdr.net/articles/PDF/12842/39521_F(KM)_PF1(AJ_KM)_PFA(AJ_SHU)_PF2(TR_SHU)_PN(SL).pdf

Introduction: Thyroid hormones are involved in various functions of human body such as metabolic activities, homeostasis of electrolytes and minerals like calcium and potassium. The blood calcium level is believed to increase glucose uptake of cells by acting as a messenger under the influence of thyroid hormone. Some studies report alteration in calcium levels with respect to the thyroid status, while other studies report alteration in ionic calcium and normal levels of total calcium levels in hypothyroidism. Aim: To estimate and find the correlation between total and ionic calcium levels in hypothyroidism. Materials and Methods: The study was conducted on 35 healthy controls (Groups A) and 35 hypothyroid subjects (Groups B) of age group 20-45 years. Blood samples were analysed for Thyroid Stimulating Hormone (TSH) and Free Thyroxine (FT4) by Chemiluminescence Immunoassay (CLIA), serum albumin by Bromocresol Green (BCG) method and calcium levels by the Arsenazo method. Independent student’s t-test and Pearson’s correlation were used to analyse the results. A p-value <0.05 was considered as statistically significant. Results: The study confirmed the direct correlation between blood total (r-value 0.32, p-value <0.001) and an ionic (r-value 0.03, p-value <0.001) calcium levels in hypothyroid patients. Significant differences (p value <0.001) were observed in FT4 and TSH levels between hypothyroid and control group. However, no significant (p-value=0.498) difference was found between the albumin levels between the groups, which indirectly reflects the values of total and ionic calcium. Conclusion: This study concluded that both total calcium and ionised calcium were decreased in patients with hypothyroidism when compared to those with euthyroid status. Thus the study highlights the need for hypothyroid patients to be screened for serum calcium levels to prevent hypocalcemia and its related complications.