title: Serum beta2-microglobulin level is a significant predictor of mortality in maintenance haemodialysis patients.
abstract: BACKGROUND
  Beta(2)-microglobulin (beta(2)-M) is recognized as a surrogate marker of middle-molecule uraemic toxins and is a key component in the genesis of dialysis-associated amyloidosis. Few studies have evaluated the association of beta(2)-M levels with clinical outcome in dialyzed patients.
  
  
  METHODS
  The prognostic implication of serum beta(2)-M levels for the survival of haemodialysis patients was examined in 490 prevalent haemodialysis patients (60.1 +/- 11.8 years, haemodialysis duration of 87.4 +/- 75.7 months, 288 males and 202 females; 24% diabetics). The patients were divided into two groups according to their serum beta(2)-M levels: lower beta(2)-M group (n = 245) with serum beta(2)-M <32.2 mg/L (the median serum beta(2)-M) and higher beta(2)-M group (n = 245) with that >or=32.2 mg/L.
  
  
  RESULTS
  During the follow-up period of 40 +/- 15 months, there were 91 all-cause deaths, and out of them, 36 were from cardiovascular diseases. Kaplan-Meier analysis revealed that all-cause mortality in the higher beta(2)-M group was significantly higher compared to that in the lower beta(2)-M group (P < 0.001). Multivariate Cox proportional hazards analyses showed that serum beta(2)-M level was a significant predictor for all-cause mortality (hazard ratio, 1.05; 95% CI, 1.01-1.08; P = 0.005), and for non-cardiovascular mortality (hazard ratio, 1.06; 95% CI, 1.02-1.10; P = 0.006), after adjustment for age, gender, haemodialysis duration, the presence of diabetes, serum albumin and serum C-reactive protein.
  
  
  CONCLUSIONS
  These results demonstrate that the serum beta(2)-M level is a significant predictor of mortality in haemodialysis patients, independent of haemodialysis duration, diabetes, malnutrition and chronic inflammation, suggesting the clinical importance of lowering serum beta(2)-M in these patients.
authors.affiliation: Kidney Center, Shirasagi Hospital, Japan.
authors.forename: Senji
authors.initials: S
authors.lastname: Okuno
authors.forename: Eiji
authors.initials: E
authors.lastname: Ishimura
authors.forename: Kaori
authors.initials: K
authors.lastname: Kohno
authors.forename: Yoko
authors.initials: Y
authors.lastname: Fujino-Katoh
authors.forename: Yoshifumi
authors.initials: Y
authors.lastname: Maeno
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Yamakawa
authors.forename: Masaaki
authors.initials: M
authors.lastname: Inaba
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Nishizawa
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000097:blood; D002318:Cardiovascular Diseases / Q000209:etiology / Q000401:mortality; D005260:Female; D006801:Humans; D007564:Japan / Q000453:epidemiology; D053208:Kaplan-Meier Estimate; D007676:Kidney Failure, Chronic / Q000097:blood / Q000150:complications / Q000401:mortality / Q000628:therapy; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011379:Prognosis; D016016:Proportional Hazards Models; D006435:Renal Dialysis / Q000009:adverse effects / Q000401:mortality*; D014118:Toxins, Biological / Q000097:blood; D001613:beta 2-Microglobulin / Q000097:blood*
chemical_list: D015415:Biomarkers; D014118:Toxins, Biological; D001613:beta 2-Microglobulin; C026865:uremia middle molecule toxins