Evaluation of Creatine Kinase as a Diagnostic Tool for Thyroid Function.

ABSTRACT

Thyroid disorders are very commonly affecting the general population, even the persons residing in non goitrous areas are no exception. Currently used tests for the assessment of thyroid functions (throid-stimulating hormone [TSH], tri-iodothyronine [T3] and throxine [T4]) are not sometimes sufficient to clearly make out the diagnosis as T3 and T4 levels are affected by so many other nonspecific conditions. The present study was done to evaluate the role of alternative biochemical parameter creatine kinase (CK) in diagnosing thyroid disorders. Sixty hypothyroid and 40 hyperthyroid patients were compared with 50 age, sex and sociocoeconomic status matched healthy controls. FT3, FT4 and TSH levels were measured by ELISA method and CK levels were measured by modified IFCC method. In hypothyroid patients, significant increase in CK levels was found as compared to control group (190 ± 40 IU/l in hypothyroid patients and 100 ± 70 IU/l in control group). A negative correlation was also found between FT3 and CK (r = –0.51; p < 0.005). In patients of hyperthyroidism, the levels of CK were found to be on the lower side. It was concluded that CK measurements may be useful as alternative diagnostic tool for the diagnosis of thyroid function disorders, which may be not only because of prevalence of muscular dystrophies in thyroid disorders but also due to role of FT3 in gene expression.