Association between serum bilirubin levels and decline in estimated glomerular filtration rate among patients with type 2 diabetes.
Studies indicate that elevated serum total bilirubin (TBil) levels are associated with lower risk of diabetic kidney disease (DKD). Few studies examined the associations of direct bilirubin (DBil) and indirect bilirubin (IBil) with the development of DKD.



Type 2 diabetes patients (n=2,958) with estimated glomerular filtration (eGFR)≥60mlmin(-1) 1.73m(-2) from the Dongfeng-Tongji cohort were selected and followed up for 5years. Development of DKD was defined as decline in eGFR≥30% during follow-up. Generalize linear model was used to assess the associations of bilirubin levels with DKD development.



Compared with those in the first tertile of serum TBil, the relative risks (RRs) and 95% confidence intervals (CIs) of incident eGFR decline for tertile 2 to 3 were 0.83 (0.64-1.09) and 0.74 (0.56-0.98), Ptrend=0.04. The counterpart RRs (95% CIs) in IBil were 0.74 (0.57-0.97) and 0.75 (0.57-0.98), Ptrend=0.04. No significant associations were observed in DBil. Moreover, TBil and IBil interacted with smoking, the bilirubin-DKD associations were evident in ever smokers.



Our findings suggest that elevation of serum TBil or IBil levels are independent protective factors for development of DKD, particularly in smokers.
Department of Occupational and Environmental Health and State Key Laboratory of Environmental Health for Incubating, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China.
Jing
J
Wang
Department of Occupational and Environmental Health and State Key Laboratory of Environmental Health for Incubating, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China.
Yaru
Y
Li
Department of Occupational and Environmental Health and State Key Laboratory of Environmental Health for Incubating, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China.
Xu
X
Han
Department of Occupational and Environmental Health and State Key Laboratory of Environmental Health for Incubating, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China.
Hua
H
Hu
Department of Occupational and Environmental Health and State Key Laboratory of Environmental Health for Incubating, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China.
Fei
F
Wang
Department of Occupational and Environmental Health and State Key Laboratory of Environmental Health for Incubating, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China.
Caizheng
C
Yu
Dongfeng Central Hospital, Dongfeng Motor Corporation and Hubei University of Medicine, Shiyan, Hubei, China.
Xiulou
X
Li
Dongfeng Central Hospital, Dongfeng Motor Corporation and Hubei University of Medicine, Shiyan, Hubei, China.
Kun
K
Yang
Department of Occupational and Environmental Health and State Key Laboratory of Environmental Health for Incubating, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China.
Jing
J
Yuan
Department of Occupational and Environmental Health and State Key Laboratory of Environmental Health for Incubating, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China.
Ping
P
Yao
Department of Epidemiology and Biostatistics, School of Public Health, Tongji Medical College Huazhong University of Science and Technology, Wuhan, Hubei, China.
Xiaoping
X
Miao
Department of Epidemiology and Biostatistics, School of Public Health, Tongji Medical College Huazhong University of Science and Technology, Wuhan, Hubei, China.
Sheng
S
Wei
Department of Occupational and Environmental Health and State Key Laboratory of Environmental Health for Incubating, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China.
Youjie
Y
Wang
Department of Occupational and Environmental Health and State Key Laboratory of Environmental Health for Incubating, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China.
Weihong
W
Chen
Department of Occupational and Environmental Health and State Key Laboratory of Environmental Health for Incubating, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China.
Yuan
Y
Liang
Department of Occupational and Environmental Health and State Key Laboratory of Environmental Health for Incubating, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China.
Xiaomin
X
Zhang
Department of Occupational and Environmental Health and State Key Laboratory of Environmental Health for Incubating, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China.
Huan
H
Guo
Department of Epidemiology and Biostatistics, School of Public Health, Tongji Medical College Huazhong University of Science and Technology, Wuhan, Hubei, China.
An
A
Pan
Dongfeng Central Hospital, Dongfeng Motor Corporation and Hubei University of Medicine, Shiyan, Hubei, China.
Handong
H
Yang
Department of Occupational and Environmental Health and State Key Laboratory of Environmental Health for Incubating, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China.
Tangchun
T
Wu
Department of Occupational and Environmental Health and State Key Laboratory of Environmental Health for Incubating, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China. Electronic address: hemeian@hotmail.com.
Meian
M
He
D001663:Bilirubin / Q000097:blood*; D015331:Cohort Studies; D003924:Diabetes Mellitus, Type 2 / Q000097:blood* / Q000503:physiopathology; D003928:Diabetic Nephropathies / Q000097:blood / Q000175:diagnosis*; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D012907:Smoking
D001663:Bilirubin
Bilirubin; Chinese; Cohort study; Kidney disease; Type 2 diabetes