National Journal of Laboratory Medicine (Apr 2018)

Study of Correlation of Serum Thyroid Hormones with Plasma Insulin and Insulin Resistance Index in Patients of Hypothyroidism

  • Vanita Sharma,
  • Ushyender Sharma,
  • Kiranjeet Kaur

DOI
https://doi.org/10.7860/NJLM/2018/35382:2280
Journal volume & issue
Vol. 7, no. 2
pp. BO01 – BO05

Abstract

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Introduction: Hypothyroidism, a condition of hyposecretion of T3 and T4 with high TSH is associated with hyperinsulinaemia and increased insulin resistance index due to disturbances in insulin secretion with deranged lipid profile. Aim: The present study was designed to find out the correlation of total Triiodothyronine (T3), total Thyroxine (T4) and Thyroid Stimulating Hormone (TSH) with plasma insulin and insulin resistance index in patients suffering from clinical hypothyroidism. Materials and Methods: In the present study, 40 diagnosed hypothyroid patients were considered as cases and 30 age and sex matched individuals were taken as controls. ELISA techniques were used for estimation of serum TSH, total T3, total T4 and fasting plasma insulin. Homeostasis Model Assessment (HOMA) was used for calculation of insulin resistance index. Results: There was highly significant negative correlation between plasma insulin and T3 in hypothyroid patients (r=- 0.421, p=0.007). The coefficient of correlation was significantly negative between plasma insulin and T4 (r= -0.354, p=0.025). In these patients, a highly significant positive correlation was found between plasma insulin and TSH (r=0.898, p0.001). In present patients, there was significant negative correlation between insulin resistance index and T3 (r= -0.385, p=0.014). There was significant negative correlation between insulin resistance index and T4 in hypothyroid patients (r= -0.355, p=0.025). Correlation was highly significant positive between insulin resistance index and TSH in these patients (r=0.894, p=0.001). Conclusion: Plasma insulin is increased in hypothyroidism because thyroid hormones have metabolic effects on insulin sensitive organs (skeletal muscle and adipose tissue). In hypothyroidism, there is increased insulin resistance through its insulin receptor and post receptor defects. So in patients of hypothyroidism, regular screening of diabetes mellitus should be required. Screening should be done for hypothyroidism in all diabetic patients.

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