Thyroid hormone signaling regulates various biological functions like maintenance of homeostasis, thermogenesis, cell proliferation and differentiation as well as metabolism. Hypothyroidism patients commonly presents with generalized symptoms such as weakness, fatigue, tiredness and myalgia which indicates the involvement of the skeletal muscle system. More over in Hypothyroidism, there is myxoedematous infiltration, specially accumulation of mucopolysaccarides in the tissue of different organs including skeletal muscles. A cross sectional study was conducted among 50 patients of Hypothyroidism,attending tertiary care hospital of central India.Serum CK and LDH activity were measured by modified IFCC method using fully automatic biochemistry analyzer (BA400). Data was analyzed by using chi-square test and correlation analysis was done by using Pearson correlation coefficient as per statistical calculations. Elevation of CK activity was found in 15 patients (65%, 15/23) with overt hypothyroidism and in 13 patients (48%, 13/27) with subclinical hypothyroidism. The mean CK activity in overt hypothyroid patients is significantly increased (225.22 ± 83.93 U/L) compared to subclinical hypothyroid patients (157.59 ± 53.37 U/L). Also, elevation of LDH activity was found in 13 patients (56%, 13/23) with overt hypothyroidism and in 10 patients (37%, 10/27) with subclinical hypothyroidism. In the hypothyroid patients, a positive correlation was found between CK activity and TSH (r = 0.497, P = 0.0002 ), but a negative correlation between LDH activity and TSH (r = - 0.01697, P = 0.91). Serum enzymes levels of CK, LDH can be used for screening of myopathy in hypothyroid patients. The estimation of these enzymes can also help to predict and monitor the outcome of hormone replacement therapy.
Keywords: Hypothyroidism, CK (Creatine Kinase), LDH (Lactate Dehydrogenase), TSH (Thyroid Stimulating Hormone), FT4(Free T4)
