The significance of body impedance and blood viscosity measurements in thyroid diseases

In this work, we examined the significance of various hemorheological, body composition, body impedance, cardiac output and blood flow parameters in thyroid disorders on a data set from 48 subjects that consisted of 18 euthyroidics, 15 hypothyroidics and 15 hyperthyroidics. Impedance variations that reflect cardiac parameters for the hyperthyroid patient group, stroke volume, cardiac output, cardiac index, percentage change in blood flow and average respiratory rate (p<0.01; p<0.001; p<0.001; p<0.01; and p<0.01) were found to be higher than those for the hypothyroidics. Body fat mass, percentage of body fat mass and percentage of body fat- free mass have been found to be significant parameters (p<0.05) in differentiating the hypothyroidics from the hyperthyroid group. They have also been found to be significant when the hypothyroidics and the euthyroidics were compared to each other (p<0.01). The percentage of total body water has also been found to be significant (p<0.01). RBC, TG, TC, LDL, albumin and fibrinogen were found to be significant when hypothyroidics and hyperthyroidics were compared to each other (p<0.05; p<0.01; p<0.001; p<0.01; p<0.01; and p<0.01, respectively). When the hypothyroidics and the euthyroidics were compared to each other, TG, VLDL, −1 total protein, fibrinogen, WBV at shear rates of 22.5 s and −1 112.5s were found to be significant (p<0.01; p<0.05; p<0.05; p<0.01; p<0.05 and p<0.01). When the hyperthyroidics and the controls were compared to each other, RBC, TC, LDL, albumin and −1 WBV at the shear rate of 22.5s were found to be statistically significant (p<0.05; p<0.01; p<0.01; p<0.01 and <0.05). Our results show that, body resistance, body impedance changes and blood viscosity reflect even subtle metabolic manifestations of thyroid disease. These measurements are safe and inexpensive and can be used to complement conventional clinical and biochemical assessments.