Serum concentration of cystatin C is more reliable, specific and sensitive indicator for GFR,
in comparison with serum creatinine concentration. This study is planned for the purpose of pointing
out the utility of creatinine and cystatin C in evaluating the kidney functions during thyroid diseases,
which are important community health problems.
Materials and Methods: In this study, variations on levels of cystatin C and creatinine are compared,
which were measured with hypothyroid and hyperthyroid patients before the treatment and euthyroid
status after the treatment. In this study 31 hyperthyroid patients and 29 hypothyroid patients selected,
who were already diagnosed but not treated yet, and 29 healthy people as control group.
Results: Cystatin C and creatinine levels were compared between at first diagnosed status and after
treatment levels. In hyperthyroid patients, the serum cystatin C levels at first diagnosed were sinificantly
higher than the after treatment levels (p<0,0001). In the same group serum creatinine levels were
clearly lower than the after treatment levels (p<0,0001). In hypothyroid patients the serum cystatin C
levels at first diagnosed were significantly lower than the after treatment levels (p<0,0001). In the same
group, even the serum creatinine levels were higher than the after treatment levels, statistically
significant difference can not be determined (p>0,05).
Conclusion: Thyroid dysfunction affects the serum creatinin and cystatin C levels significantly.
According to these results; when cystatin C or creatinine is used as kidney function identifier, disruptive
effects of thyroid dysfunction need to be taken into consideration.