title: Associations of urinary, glomerular, and tubular markers with the development of diabetic kidney disease in type 2 diabetes patients.
abstract: OBJECTIVE
  To evaluate the associations of urinary markers (eg albumin), glomerular (eg transferrin [TRF], immunoglobulin G [IgG]), and tubular (eg α1-microglobulin [α1-MG], β2-microglobulin [β2-MG]) markers with the development of diabetic kidney disease (DKD) in type 2 diabetes patients, as assessed by estimated glomerular filtration rate (eGFR) and albuminuria.
  
  
  METHODS
  A total of 252 type 2 diabetes patients and 50 nondiabetic controls from Tianjin, China, were selected. Diabetic patients were divided into three groups according to eGFR levels, including groups A, B, and C with eGFR ≥90 (n=94), 60-89 (n=94), and 30-59 (n=64) mL/min/1.73 m2. Urine levels of glomerular and tubular markers were detected in first morning urine samples, and their associations with eGFR and albuminuria analyzed.
  
  
  RESULTS
  Urinary levels of IgG, TRF, and β2-MG were significantly elevated in diabetic patients with normal eGFR compared with nondiabetic control subjects. Urinary levels of all markers increased per eGFR stratum. All kidney damage markers were significantly associated with eGFR in univariate analysis (standard β between -0.35 and -0.28; all P<.001). After adjusting for known confounders, only the tubular markers α1-MG (standard β=-0.25; P=.013) and β2-MG (standard β=-0.18; P=.039) retained significant associations with eGFR. All kidney damage markers were significantly associated with albuminuria, independent of age, duration of diabetes, and eGFR (standard β between 0.45 and 0.86; all P<.001).
  
  
  CONCLUSIONS
  Only the tubular markers α1-MG and β2-MG were associated with eGFR independent of albuminuria, suggesting that they may play an important role in the development of DKD.
authors.affiliation: Graduate School of Tianjin Medical University, Tianjin, China.|Department of Clinical Laboratory, Tianjin Union Medical Center, Tianjin, China.
authors.forename: Xu
authors.initials: X
authors.lastname: Jiang
authors.affiliation: Graduate School of Tianjin Medical University, Tianjin, China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: Jinhua Municipal Central Hospital, Jinhua, China.
authors.forename: Hua-Bin
authors.initials: HB
authors.lastname: Wang
authors.affiliation: Department of Clinical Laboratory, Tianjin Union Medical Center, Tianjin, China.
authors.forename: Xiao-Fan
authors.initials: XF
authors.lastname: Cui
authors.affiliation: Department of Clinical Laboratory, Tianjin Union Medical Center, Tianjin, China.
authors.forename: Rui
authors.identifier: http://orcid.org/0000-0001-6068-0827
authors.initials: R
authors.lastname: Liu
mesh_terms: D000368:Aged; D000419:Albuminuria; D000510:Alpha-Globulins / Q000652:urine; D000704:Analysis of Variance; D015415:Biomarkers / Q000652:urine*; D016022:Case-Control Studies; D003924:Diabetes Mellitus, Type 2 / Q000453:epidemiology / Q000652:urine; D003928:Diabetic Nephropathies / Q000453:epidemiology / Q000652:urine; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D012044:Regression Analysis; D001613:beta 2-Microglobulin / Q000652:urine
chemical_list: D000510:Alpha-Globulins; D015415:Biomarkers; C016001:alpha-1-microglobulin; D001613:beta 2-Microglobulin
keywords: albuminuria; diabetic kidney disease; glomerular filtration rate; α1-microglobulin; β2-microglobulin