title: Japan Diabetic Nephropathy Cohort Study: study design, methods, and implementation.
abstract: BACKGROUND
  Diabetic nephropathy, leading to end-stage renal disease, has a considerable impact on public health and the social economy. However, there are few national registries of diabetic nephropathy in Japan. The aims of this prospective cohort study are to obtain clinical data and urine samples for revising the clinical staging of diabetic nephropathy, and developing new diagnostic markers for early diabetic nephropathy.
  
  
  METHODS
  The Japanese Society of Nephrology established a nationwide, web-based, and prospective registry system. On the system, there are two basic registries; the Japan Renal Biopsy Registry (JRBR), and the Japan Kidney Disease Registry (JKDR). In addition to the two basic registries, we established a new prospective registry to the system; the Japan Diabetic Nephropathy Cohort Study (JDNCS), which collected physical and laboratory data.
  
  
  RESULTS
  We analyzed the data of 321 participants (106 female, 215 male; average age 65 years) in the JDNCS. Systolic and diastolic blood pressure was 130.1 and 72.3 mmHg, respectively. Median estimated glomerular filtration rate (eGFR) was 33.3 ml/min/1.73 m(2). Proteinuria was 1.8 g/gCr, and serum levels of albumin were 3.6 g/dl. The majority of the JDNCS patients presented with preserved eGFR and low albuminuria or low eGFR and advanced proteinuria. In the JRBR and JKDR registries, 484 and 125 participants, respectively, were enrolled as having diabetes mellitus. In comparison with the JRBR and JKDR registries, the JDNCS was characterized by diabetic patients presenting with low proteinuria with moderately preserved eGFR.
  
  
  CONCLUSIONS
  There are few national registries of diabetic nephropathy to evaluate prognosis in Japan. Future analysis of the JDNCS will provide clinical insights into the epidemiology and renal and cardiovascular outcomes of type 2 diabetic patients in Japan.
authors: Division of Blood Purification, Kanazawa University Hospital, Kanazawa, Japan.
authors: Kengo
authors: K
authors: Furuichi
authors: Miho
authors: M
authors: Shimizu
authors: Tadashi
authors: T
authors: Toyama
authors: Daisuke
authors: D
authors: Koya
authors: Yoshitaka
authors: Y
authors: Koshino
authors: Hideharu
authors: H
authors: Abe
authors: Kiyoshi
authors: K
authors: Mori
authors: Hiroaki
authors: H
authors: Satoh
authors: Masahito
authors: M
authors: Imanishi
authors: Masayuki
authors: M
authors: Iwano
authors: Hiroyuki
authors: H
authors: Yamauchi
authors: Eiji
authors: E
authors: Kusano
authors: Shouichi
authors: S
authors: Fujimoto
authors: Yoshiki
authors: Y
authors: Suzuki
authors: Seiya
authors: S
authors: Okuda
authors: Kiyoki
authors: K
authors: Kitagawa
authors: Yasunori
authors: Y
authors: Iwata
authors: Shuichi
authors: S
authors: Kaneko
authors: Shinichi
authors: S
authors: Nishi
authors: Hitoshi
authors: H
authors: Yokoyama
authors: Yoshihiko
authors: Y
authors: Ueda
authors: Masakazu
authors: M
authors: Haneda
authors: Hirofumi
authors: H
authors: Makino
authors: Takashi
authors: T
authors: Wada
mesh_terms: D000368:Aged; D000419:Albuminuria / Q000453:epidemiology; D001706:Biopsy; D015331:Cohort Studies; D003924:Diabetes Mellitus, Type 2 / Q000175:diagnosis; D003928:Diabetic Nephropathies / Q000175:diagnosis* / Q000453:epidemiology / Q000503:physiopathology; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D007564:Japan / Q000453:epidemiology; D007668:Kidney / Q000473:pathology; D007674:Kidney Diseases / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011507:Proteinuria / Q000453:epidemiology; D012042:Registries