title: Associations of serum skeletal alkaline phosphatase with elevated C-reactive protein and mortality.
abstract: OBJECTIVE
  Higher serum total alkaline phosphatase (AP) levels are associated with increased serum C-reactive protein (CRP) levels and mortality in the general and CKD populations. It is unclear to what extent these associations are related to bone disease.
  
  
  METHODS
  In a nationally representative sample of 10,707 adult participants from the 1999-2004 National Health and Nutrition Examination Survey, serum nonskeletal AP levels were estimated from the measured serum skeletal and total AP levels. The associations of serum skeletal AP and nonskeletal AP levels with elevated serum CRP concentrations (>3 mg/L) and mortality were examined in multivariable models.
  
  
  RESULTS
  Skeletal AP was not associated with elevated CRP (for each doubling in non-CKD: odds ratio [OR], 1.00; 95% confidence interval [95% CI], 0.90-1.11; in CKD: OR, 1.19; 95% CI, 0.83-1.70) or mortality (for each doubling in non-CKD: hazard ratio [HR], 1.10; 95% CI, 0.94-1.29; in CKD: HR, 0.98; 95% CI, 0.75-1.28). In contrast, nonskeletal AP was associated with elevated CRP (for each doubling in non-CKD: OR, 4.51; 95% CI, 3.80-5.35; in CKD: OR, 5.98; 95% CI, 3.40-10.51). Nonskeletal AP was associated with mortality in non-CKD (for each doubling: HR, 1.96; 95% CI, 1.37-2.80) but not in CKD (for each doubling: HR, 0.92; 95% CI, 0.51-1.67) (interaction P=0.03).
  
  
  CONCLUSIONS
  Bone disease is unlikely to account for the known associations of serum total AP with increased inflammation and mortality.
authors.affiliation: Department of Medicine, University of Utah School of Medicine, 85 North Medical Drive East, Salt Lake City, UT 84112, USA.
authors.forename: Rebecca
authors.initials: R
authors.lastname: Filipowicz
authors.forename: Tom
authors.initials: T
authors.lastname: Greene
authors.forename: Guo
authors.initials: G
authors.lastname: Wei
authors.forename: Alfred K
authors.initials: AK
authors.lastname: Cheung
authors.forename: Kalani L
authors.initials: KL
authors.lastname: Raphael
authors.forename: Bradley C
authors.initials: BC
authors.lastname: Baird
authors.forename: Srinivasan
authors.initials: S
authors.lastname: Beddhu
mesh_terms: D000328:Adult; D000469:Alkaline Phosphatase / Q000097:blood*; D001847:Bone Diseases / Q000097:blood* / Q000401:mortality*; D001842:Bone and Bones / Q000201:enzymology; D002097:C-Reactive Protein / Q000378:metabolism*; D005260:Female; D006801:Humans; D016014:Linear Models; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009749:Nutrition Surveys; D051436:Renal Insufficiency, Chronic / Q000097:blood* / Q000401:mortality*; D012307:Risk Factors; D055815:Young Adult
chemical_list: D002097:C-Reactive Protein; D000469:Alkaline Phosphatase