Paradoxical effects of thyroid function on glomerular filtration rate estimated from serum creatinine or standardized cystatin C in patients with Japanese Graves' disease.
BACKGROUND
Estimated glomerular filtration rate (eGFR) is clinically valuable for evaluating renal function. Recently, serum cystatin C (sCysC) measurement has been standardized and has demonstrated utility as a novel indicator of renal function. Thyroid hormone is known to affect serum creatinine (sCr) and sCysC, however, the clinical significance of post-treatment renal function evaluation is yet to be completely elucidated. This study examined the effects of thyroid hormones on eGFR by sCr (eGFRCr), and standardized sCysC (eGFRCysC) in patients with Japanese Graves' disease (GD).


METHODS
Serum samples were obtained from 113 outpatients with GD. Following pharmacotherapy, 41 of the 113 outpatients with GD achieved remission. Renal function was evaluated by eGFRCr and eGFRCysC. Reference method used Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations.


RESULTS
eGFRCr levels significantly increased whereas eGFRCysC levels significantly decreased with elevated FT3 and FT4 levels in patients with GD. In the remission group, eGFRCr levels significantly decreased and eGFRCysC levels significantly increased. No significant differences between eGFRCr and eGFRCysC levels were observed. Furthermore, CKD-EPI equations show a similar trend and eGFRCr-CysC levels were no significant differences regardless of before and after treatment.


CONCLUSIONS
Renal function evaluation by eGFRCr and eGFRCysC had clinical utility in post-treatment euthyroidism.
Department of Laboratory Medicine, Chiba University Hospital, 1-8-1 Inohana, Chuo-ku, Chiba 260-8677, Japan. Electronic address: yoshi2006.s@ho.chiba-u.ac.jp.
Yoshitake
Y
Suzuki
Department of Laboratory Medicine, Chiba University Hospital, 1-8-1 Inohana, Chuo-ku, Chiba 260-8677, Japan; Department of Molecular Diagnosis, Chiba University Graduate School of Medicine, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670, Japan. Electronic address: kmatsu@faculty.chiba-u.jp.
Kazuyuki
K
Matsushita
Department of Laboratory Medicine, Chiba University Hospital, 1-8-1 Inohana, Chuo-ku, Chiba 260-8677, Japan; Department of Molecular Diagnosis, Chiba University Graduate School of Medicine, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670, Japan.
Masanori
M
Seimiya
Department of Laboratory Medicine, Chiba University Hospital, 1-8-1 Inohana, Chuo-ku, Chiba 260-8677, Japan.
Toshihiko
T
Yoshida
Department of Laboratory Medicine, Chiba University Hospital, 1-8-1 Inohana, Chuo-ku, Chiba 260-8677, Japan.
Yuji
Y
Sawabe
Department of Gastroenterology and Nephrology, Chiba University Graduate School of Medicine, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670, Japan.
Makoto
M
Ogawa
Department of Laboratory Medicine, Chiba University Hospital, 1-8-1 Inohana, Chuo-ku, Chiba 260-8677, Japan; Department of Molecular Diagnosis, Chiba University Graduate School of Medicine, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670, Japan.
Fumio
F
Nomura
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003404:Creatinine / Q000097:blood*; D055316:Cystatin C / Q000097:blood* / Q000592:standards; D005260:Female; D005919:Glomerular Filtration Rate; D006111:Graves Disease / Q000097:blood* / Q000188:drug therapy; D006801:Humans; D007564:Japan; D008297:Male; D008875:Middle Aged; D012015:Reference Standards; D013961:Thyroid Gland / Q000503:physiopathology*; D055815:Young Adult
D055316:Cystatin C; D003404:Creatinine
Creatinine; Estimated glomerular filtration rate; Standardized cystatin C; Thyroid hormone