title: In a non-diabetic Japanese population, the combination of macroalbuminuria and increased urine beta 2-microglobulin predicts a decline of renal function: the Takahata study.
abstract: BACKGROUND
  Glomerular and tubular damage are important factors in the development of renal insufficiency. However, the interaction of these factors is largely unknown in the non-diabetic Japanese population. To clarify the relationship between renal insufficiency and both glomerular and tubular damage, we conducted a community-based study using albuminuria and urine beta 2-microglobulin as markers of glomerular and tubular damages, respectively.
  
  
  METHODS
  Subjects of this study were 2816 non-diabetic individuals >40 years old in Takahata, Japan. The urine albumin-creatinine ratio (UACR) and urine beta 2-microglobulin-creatinine ratio (UBCR) were assessed from single spot urine. The glomerular filtration rate (eGFR) was estimated using the abbreviated MDRD equation with a Japanese coefficient.
  
  
  RESULTS
  The prevalence of albuminuria (UACR >20 mg/ g in men and >30 mg/g in women), increased UBCR (>300 microg/g) and renal insufficiency (eGFR <60 mL/ min/1.73 m(2)) were 21.0%, 12.5% and 21.7%, respectively, and there was only a small overlap between the three. The mean eGFR was significantly lower in subjects with macroalbuminuria (UACR >200 mg/g in men and >300 mg/g in women) and increased UBCR. No urinary abnormalities were observed in 71.7% of the 611 subjects with renal insufficiency, and were more common in young, women and the non-hypertensive population. The 1-year decline of eGFR was greatest in subjects with an overlap of macroalbuminuria and increased UBCR.
  
  
  CONCLUSIONS
  This study indicated that only a small part of renal insufficiency accompanied increased urine albumin or beta 2-microglobulin in the non-diabetic Japanese population. The combination of macroalbuminuria and increased urine beta 2-microglobulin might predict faster renal deterioration.
authors.affiliation: Department of Cardiology, Yamagata University School of Medicine, Yamagata, Japan.
authors.forename: Ami
authors.initials: A
authors.lastname: Ikeda
authors.forename: Tsuneo
authors.initials: T
authors.lastname: Konta
authors.forename: Satoshi
authors.initials: S
authors.lastname: Takasaki
authors.forename: Zhimei
authors.initials: Z
authors.lastname: Hao
authors.forename: Kazuko
authors.initials: K
authors.lastname: Suzuki
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Sato
authors.forename: Yoko
authors.initials: Y
authors.lastname: Shibata
authors.forename: Yasuchika
authors.initials: Y
authors.lastname: Takeishi
authors.forename: Takeo
authors.initials: T
authors.lastname: Kato
authors.forename: Sumio
authors.initials: S
authors.lastname: Kawata
authors.forename: Isao
authors.initials: I
authors.lastname: Kubota
mesh_terms: D000328:Adult; D000368:Aged; D000419:Albuminuria / Q000150:complications* / Q000503:physiopathology / Q000652:urine*; D044466:Asian People; D015331:Cohort Studies; D003404:Creatinine / Q000652:urine; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D007564:Japan; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D051437:Renal Insufficiency / Q000453:epidemiology* / Q000473:pathology / Q000652:urine*; D012307:Risk Factors; D001613:beta 2-Microglobulin / Q000652:urine*
chemical_list: D001613:beta 2-Microglobulin; D003404:Creatinine