ABSTRACT
A randomize prospective study include thirty-two patients [age:30-77 years] of clinical hypo- and hyperthyroidism was planned to evaluate the changes which produced in serum cystatin C compared to creatinine as a sensitive test for early detection of renal failure in patients with thyroid disorders and to determine if significant thyroid hormones disturbance affect cystatin C concentrations. The assays were proposed again when the patients become euthyroid state after treatment. Patients with hyperthyroidism showed significant decrease of cystatin C from 1.0 +/- 0.31 mg/L at time of diagnosis to 0.71 +/- 0.32 mg/L after treatment and significant increase of creatinine from 79.5+26.51 micromol/L to 97.2+26.7 micromol/L in euthyroid state [p<0.001]. In hypothyroid group, it was showed a significant increase in serum cystatin from 0.76 +/- 0.27mg/L to 1.0 +/- 0.21 mg/L in euthyroid state while serum creatinine exhibited significant decrease from 88.4 +/- 26.5micromol/L at time of diagnosis to 70.7 +/- 26.0 micromol/L in euthyroid state [p<0.001]. Our results showed that significant changes in thyroid hormones alternate serum cystatin C concentration so cystatin C should be considered as a sensitive marker for the early prediction of glomerular filtration rate disturbance after thyroid hormones investigations