Bone Mineral Status in Sub-clinical Hypothyroidism: A Case-control Study

Introduction: Hypothyroidism is the most common thyroid disorder which results in various metabolic disturbances. The disturbance in the bone minerals, calcium and phosphorus contribute to the most common imbalance. This is commonly overlooked in sub-clinical hypothyroidism, based on the absence of symptoms in patients related to thyroid hormone imbalance. The diagnosis of sub-clinical hypothyroidism is generally incidental and is based on the Thyroid Stimulating Hormone (TSH) level. The concentration of the circulating thyroid hormones, T3 (Triiodothyronine) and T4 (Thyroxine) are not altered in this condition. Aim: To study the Ca/P ratio, an early indicator of osteoporotic marker among the patients with hypothyroidism. Materials and Methods: The present study was designed as a case-control study and involved 35 controls with normal thyroid function and 35 subjects with sub-clinical hypothyroidism, of age group 20-45 years. The serum samples were analysed for calcium and phosphorus by their respective methods. The samples were analysed on the same day to maintain the stability of the parameters. Calcium/Phosphorus ratio (Ca/P) was calculated. Results: Serum Calcium was found to be less (8.33±0.30) and serum phosphorus was more (6.61±0.88) in sub-clinical hypothyroidism when compared to control group. Therefore, a reversal of Ca/P ratio was (1.26±0.34) was noted. Conclusion: This study underlines the necessity for patients with sub-clinical hypothyroidism to be monitored for bone mineral status to avoid complications in bone health.