title: Different regional dynamics of end-stage renal disease in Japan by different causes.
abstract: BACKGROUND
  We recently showed that there were clear regional differences in the dynamics of end-stage renal disease (ESRD) within Japan, which has an ethnically homogenous population. We speculate on the reason for these regional differences by correlating the regional distributions in the incidence of ESRD due to each of the following individual causes of ESRD: chronic glomerulonephritis (CGN), diabetic nephropathy (DMN) and polycystic kidney disease (PKD).
  
  
  METHODS
  The number of ESRD patients entering maintenance dialysis therapy due to individual causes of renal disease in each prefecture was reported annually for a 6-year period by the Japanese Society for Dialysis Therapy. After combining data from several prefectures into 11 geopolitical regions in Japan, the mean annual incidence of ESRD across the 11 regions was correlated among the three causes of ESRD.
  
  
  RESULTS
  There were significant regional differences in the incidence of ESRD due to CGN (P<0.0001) and DMN (P=0.0015), the distributions of which were similar to each other across the 11 regions. In contrast, no regional differences were found in the incidence of ESRD due to PKD (P=0.6) as the major genetic disorder of the kidneys, suggesting that genetic backgrounds are relatively uniform throughout Japan. The regional distributions due to PKD were not correlated with those due to other causes: CGN and DMN.
  
  
  CONCLUSIONS
  Risk factors common to nephropathy progression, rather than an underlying disease incidence and genetic predisposition, might contribute to regional differences in the overall ESRD incidence in Japan. Other possibilities such as the prevalence of underlying diseases, and acceptance or rejection rates into treatment programmes must be considered further for better explanations.
authors.affiliation: Department of Internal Medicine and Pathophysiology, Nagoya City University Graduate School of Medical Sciences, Mizuho-ku, Nagoya, Japan.
authors.forename: Nobuo
authors.initials: N
authors.lastname: Kato
authors.forename: Takeshi
authors.initials: T
authors.lastname: Usami
authors.forename: Michio
authors.initials: M
authors.lastname: Fukuda
authors.forename: Masahiro
authors.initials: M
authors.lastname: Motokawa
authors.forename: Yoshinobu
authors.initials: Y
authors.lastname: Kamiya
authors.forename: Atsuhiro
authors.initials: A
authors.lastname: Yoshida
authors.forename: Genjiro
authors.initials: G
authors.lastname: Kimura
mesh_terms: D002908:Chronic Disease; D003928:Diabetic Nephropathies / Q000150:complications; D005921:Glomerulonephritis / Q000150:complications; D006801:Humans; D015994:Incidence; D007564:Japan / Q000453:epidemiology; D007676:Kidney Failure, Chronic / Q000453:epidemiology* / Q000209:etiology; D007690:Polycystic Kidney Diseases / Q000150:complications; D012307:Risk Factors