title: Relationships between serum and urine phosphorus with all-cause and cardiovascular mortality: the Osteoporotic Fractures in Men (MrOS) Study.
abstract: BACKGROUND
  Serum phosphorus is associated with cardiovascular disease (CVD) in the general population, but may not comprehensively reflect phosphorus homeostasis. Whether urine phosphorus-creatinine ratio (a marker of intestinal absorption) or urine fractional excretion of phosphorus (FEPi; a marker of urinary phosphorus handling) is associated with risk of mortality or CVD is uncertain.
  
  
  METHODS
  Prospective observational study.
  
  
  METHODS
  1,325 community-dwelling men 65 years or older participating in the MrOS Study.
  
  
  METHODS
  Serum phosphorus, urine phosphorus-creatinine ratio, and FEPi.
  
  
  RESULTS
  All-cause and CVD death.
  
  
  RESULTS
  Mean age was 74 ± 6 (SD) years, estimated glomerular filtration rate was 75 ± 16 mL/min/1.73 m(2), and serum phosphorus level was 3.2 ± 0.4 mg/dL. During a median follow-up of 9.3 years, there were 364 (120 CVD) deaths. After adjustment for demographics, CVD risk factors, and kidney function, the risks of all-cause death in the highest quartiles of serum phosphorus (≥3.6 mg/dL), urine phosphorus-creatinine ratio (≥0.55), and FEPi (≥18%) were 1.63 (95% CI, 1.23-2.17), 1.22 (95% CI, 0.90-1.65), and 0.88 (95% CI, 0.64-1.23), respectively, compared to the lowest quartiles of each. Results were similar for CVD death. Results also were similar in those with estimated glomerular filtration rate ≥60 and <60 mL/min/1.73 m(2).
  
  
  CONCLUSIONS
  Older all-male cohort. Few had advanced chronic kidney disease. Spot urine specimens were used.
  
  
  CONCLUSIONS
  In community-living older men, higher serum phosphorus concentrations are associated with all-cause and CVD death. In contrast, urine phosphorus-creatinine ratio and FEPi are not. These findings do not support using urine phosphorus-creatinine ratio or FEPi as adjuvant measures to predict risk of mortality or CVD in the general population.
authors.affiliation: Division of Nephrology and Hypertension, Department of Medicine, University of California San Diego, San Diego, CA 92161, USA.
authors.forename: Julie R
authors.initials: JR
authors.lastname: Dominguez
authors.forename: Bryan
authors.initials: B
authors.lastname: Kestenbaum
authors.forename: Michel
authors.initials: M
authors.lastname: Chonchol
authors.forename: Geoffrey
authors.initials: G
authors.lastname: Block
authors.forename: Gail A
authors.initials: GA
authors.lastname: Laughlin
authors.forename: Cora E
authors.initials: CE
authors.lastname: Lewis
authors.forename: Ronit
authors.initials: R
authors.lastname: Katz
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Barrett-Connor
authors.forename: Steve
authors.initials: S
authors.lastname: Cummings
authors.forename: Eric S
authors.initials: ES
authors.lastname: Orwoll
authors.forename: Joachim H
authors.initials: JH
authors.lastname: Ix
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002318:Cardiovascular Diseases / Q000401:mortality*; D005919:Glomerular Filtration Rate; D006801:Humans; D008297:Male; D058866:Osteoporotic Fractures / Q000378:metabolism*; D010758:Phosphorus / Q000097:blood* / Q000652:urine*; D011446:Prospective Studies; D018570:Risk Assessment
chemical_list: D010758:Phosphorus