Increased erythrocyte osmotic fragility in hypothyroidism

Abstract

Hypothyroidism a quite common thyroid disorder is often associated with anemia. Osmotic fragility is altered with an alteration of the thyroid profile. Hypothyroidism induced reduction of membrane cholesterol and compromised the activity of Na+K+ATPase and increased peroxidation of membrane lipids appear to be responsible for damaging the red blood corpuscle (RBC) membranes which alter the permeability of themembrane and thus ionic environment within the cell. The objective of this study was to evaluate the relation between the association of hypothyroidism and RBC membrane lipid peroxidation in the development of increased RBC osmotic fragility. A complete clinical history and biochemical investigations, including thyroid function tests namely, thyroid -stimulating hormone (TSH) and free T4 (fT4), RBC membrane osmotic fragility test by gradient concentration of NaCl, and RBC membrane peroxidation using thiobarbituric acid reactive substances (TBARS) tests were performed among thirty two hypothyroidism patients and healthy controls. Serum TSH & TBARS in the RBC membrane were significantly higher (P <0.001) than healthy controls which also showed a significant positive correlation (r =0.8, P =0.01) when compared without grouping. Osmotic fragility of RBC was found significantly increased among hypothyroid patients (P <0.001) at NaCl conc. of 0.3%, 0.4%, 0.5% & (P <0.05) at NaCl conc. of 0.6%. In conclusion, the results indicated that RBC osmotic fragility increases significantly in hypothyroidism possibility due to increased membrane lipid peroxidation as observed in the study.