Low serum bilirubin concentration is a predictor of chronic kidney disease.
OBJECTIVE
Chronic kidney disease (CKD) is a worldwide public health problem. It is very important to identify the factors that affect CKD. Previous studies have reported that serum bilirubin concentration was positively correlated with renal function in a cross-sectional study. The aim of this study was to investigate the relationship between serum bilirubin concentration and the progression of CKD.


METHODS
A cohort study was performed on a consecutive series of 2784 subjects without CKD, defined as estimated glomerular filtration rate (eGFR) < 60 ml/min/1.73 m(2), at baseline. We analyzed the relationship between serum total bilirubin concentration at baseline and new-onset CKD in the general population.


RESULTS
We followed the subjects for a median period of 7.7 years. There were 1157 females and 1627 males, and 231 females and 370 males developed CKD during this period. Multiple Cox regression analyses revealed that serum total bilirubin concentration (hazard ratio (HR) per 1.0 μmol/L increase 0.97 (95% CI 0.95-0.99), P = 0.0084) in addition to age, gamma-glutamyl transpeptidase (GGT), uric acid (UA), creatinine and medication for hypertension in men and serum total bilirubin concentration (HR per 1.0 μmol/L increase 0.96 (95% CI 0.93-1.00), P = 0.0309) in addition to age, GGT, alanine aminotransferase, UA, creatinine and medication for dyslipidemia in women were independent predictors of new-onset CKD, after adjusting for confounders.


CONCLUSIONS
Our study demonstrated that serum total bilirubin concentration could be a novel risk factor for the progression of CKD, defined as eGFR <60 ml/min/1.73 m(2), in the general population.
Department of Endocrinology and Metabolism, Kyoto Prefectural University of Medicine, Graduate School of Medical Science, Japan.
Muhei
M
Tanaka
Department of Endocrinology and Metabolism, Kyoto Prefectural University of Medicine, Graduate School of Medical Science, Japan. Electronic address: sayarinapm@hotmail.com.
Michiaki
M
Fukui
Department of Endocrinology and Metabolism, Kyoto Prefectural University of Medicine, Graduate School of Medical Science, Japan.
Hiroshi
H
Okada
Department of Endocrinology and Metabolism, Kyoto Prefectural University of Medicine, Graduate School of Medical Science, Japan.
Takafumi
T
Senmaru
Department of Endocrinology and Metabolism, Kyoto Prefectural University of Medicine, Graduate School of Medical Science, Japan.
Mai
M
Asano
Department of Cardiology, Yamashiro Public Hospital, Japan.
Satoshi
S
Akabame
Department of Endocrinology and Metabolism, Kyoto Prefectural University of Medicine, Graduate School of Medical Science, Japan.
Masahiro
M
Yamazaki
Department of Cardiology, Yamashiro Public Hospital, Japan.
Ki-Ichiro
K
Tomiyasu
Department of Endocrinology and Metabolism, Kyoto Prefectural University of Medicine, Graduate School of Medical Science, Japan.
Yohei
Y
Oda
Department of Endocrinology and Metabolism, Kyoto Prefectural University of Medicine, Graduate School of Medical Science, Japan.
Goji
G
Hasegawa
Department of Internal Medicine, Oike Clinic, Kyoto, Japan.
Hitoshi
H
Toda
Department of Endocrinology and Metabolism, Kyoto Prefectural University of Medicine, Graduate School of Medical Science, Japan.
Naoto
N
Nakamura
D000328:Adult; D001663:Bilirubin / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D018450:Disease Progression; D015536:Down-Regulation; D005260:Female; D005919:Glomerular Filtration Rate; D006306:Health Surveys; D006801:Humans; D007564:Japan / Q000453:epidemiology; D007668:Kidney / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D051436:Renal Insufficiency, Chronic / Q000097:blood* / Q000175:diagnosis / Q000453:epidemiology / Q000503:physiopathology; D012307:Risk Factors
D015415:Biomarkers; D001663:Bilirubin
Antioxidant; Bilirubin; Chronic kidney disease