title: Prevalence of chronic kidney disease (CKD) in the Japanese general population predicted by the MDRD equation modified by a Japanese coefficient.
abstract: BACKGROUND
  The number of patients with end-stage renal disease (ESRD) in Japan has continuously increased in the past three decades. In 2005, 36,063 patients whose average age was 66 years entered a new dialysis program. This large number of ESRD patients could be just the tip of the iceberg of an increasing number of patients with chronic kidney disease (CKD). However, to date, a nationwide epidemiological study has not been conducted yet to survey the CKD population.
  
  
  METHODS
  Data for 527,594 (male, 211,034; female, 316,560) participants were obtained from the general adult population aged over 20 years who received annual health check programs in 2000-2004, from seven different prefectures in Japan: Hokkaido, Fukushima, Ibaraki, Tokyo, Osaka, Fukuoka, and Okinawa prefectures. The glomerular filtration rate (GFR) for each participant was estimated from the serum creatinine values, using the abbreviated Modification of Diet in Renal Disease (MDRD) study equation modified by the Japanese coefficient.
  
  
  RESULTS
  The prevalences of CKD stage 3 in the study population, stratified by age groups of 20-29, 30-39, 40-49, 50-59, 60-69, 70-79, and 80-89 years, were 1.4%, 3.6%, 10.8%, 15.9%, 31.8%, 44.0%, and 59.1%, respectively, predicting 19.1 million patients with stage 3 CKD in the Japanese general adult population of 103.2 million in 2004. CKD stage 4 + 5 was predicted in 200,000 patients in the Japanese general adult population. Comorbidity of hypertension, diabetes, and proteinuria increased as the estimated GFR (eGFR) decreased. The prevalence of concurrent CKD was significantly higher in hypertensive and diabetic populations than in the study population overall when CKD was defined as being present with an eGFR of less than 40 ml/min per 1.73 m(2) instead of less than 60 ml/min per 1.73 m(2).
  
  
  CONCLUSIONS
  About 20% of the Japanese adult population (i.e., approximately 19 million people) are predicted to have stage 3 to 5 CKD, as defined by a GFR of less than 60 ml/min per 1.73 m(2).
authors.affiliation: Department of Nephrology, Osaka University Graduate School of Medicine, Suita, Osaka, 565-0871, Japan. imai@medone.med.osaka-u.ac.jp.
authors.forename: Enyu
authors.initials: E
authors.lastname: Imai
authors.affiliation: Department of Functional Diagnostic Science, Osaka University Graduate School of Medicine, Osaka, Japan.
authors.forename: Masaru
authors.initials: M
authors.lastname: Horio
authors.affiliation: Dialysis Unit, University Hospital of The Ryukyus, Okinawa, Japan.
authors.forename: Kunitoshi
authors.initials: K
authors.lastname: Iseki
authors.affiliation: Department of Nephrology, Institute of Clinical Medicine, Graduate School of Comprehensive Human Sciences, University of Tsukuba, Ibaraki, Japan.
authors.forename: Kunihiro
authors.initials: K
authors.lastname: Yamagata
authors.affiliation: Third Department of Medicine, Fukushima Medical University, Fukushima, Japan.
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Watanabe
authors.affiliation: Health Medical Center, Toranomon Hospital, Tokyo, Japan.
authors.forename: Shigeko
authors.initials: S
authors.lastname: Hara
authors.affiliation: Second Department of Internal Medicine, Sapporo Medical University School of Medicine, Sapporo, Hokkaido, Japan.
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Ura
authors.affiliation: Department of Environmental Medicine, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Kiyohara
authors.affiliation: Nephrology and Dialysis Center, Fukuoka Red Cross Hospital, Fukuoka, Japan.
authors.forename: Hideki
authors.initials: H
authors.lastname: Hirakata
authors.affiliation: Healthcare Center, Osaka University, Osaka, Japan.
authors.forename: Toshiki
authors.initials: T
authors.lastname: Moriyama
authors.affiliation: Department of Nephrology, Jichi Medical School, Tochigi, Japan.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Ando
authors.affiliation: Department of Medicine, Kidney Center, Tokyo Women's Medical University, Tokyo, Japan.
authors.forename: Kosaku
authors.initials: K
authors.lastname: Nitta
authors.affiliation: Tosei General Hospital, Aichi, Japan.
authors.forename: Daijo
authors.initials: D
authors.lastname: Inaguma
authors.affiliation: Division of Nephrology and Rheumatology, Niigata University, Niigata, Japan.
authors.forename: Ichiei
authors.initials: I
authors.lastname: Narita
authors.affiliation: Department of Public Health, Osaka University Graduate School of Medicine, Osaka, Japan.
authors.forename: Hiroyasu
authors.initials: H
authors.lastname: Iso
authors.affiliation: Aichi Cancer Institute, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Wakai
authors.affiliation: Department of Nephrology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Yoshinari
authors.initials: Y
authors.lastname: Yasuda
authors.affiliation: Syuwa General Hospital, Japan.
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Tsukamoto
authors.affiliation: Division of Nephrology, Endocrinology and Vascular Medicine, Tohoku University Graduate School of Medicine, Miyagi, Japan.
authors.forename: Sadayoshi
authors.initials: S
authors.lastname: Ito
authors.affiliation: Department of Medicine and Clinical Science, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan.
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Makino
authors.affiliation: First Department of Medicine, Hamamatsu University School of Medicine, Shizuoka, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Hishida
authors.affiliation: Department of Nephrology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Seiichi
authors.initials: S
authors.lastname: Matsuo
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D002908:Chronic Disease; D003404:Creatinine / Q000097:blood; D004032:Diet; D005260:Female; D005919:Glomerular Filtration Rate / Q000502:physiology; D006306:Health Surveys; D006801:Humans; D007564:Japan / Q000453:epidemiology; D007674:Kidney Diseases / Q000453:epidemiology* / Q000208:ethnology / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D008962:Models, Theoretical; D015995:Prevalence
chemical_list: D003404:Creatinine