title: Lower serum calcium levels are associated with greater calcium hydroxyapatite deposition in native aortic valves of male patients with severe calcific aortic stenosis.
abstract: OBJECTIVE
  The study aim was to evaluate the relationship between serum calcium levels and the degree of calcification found in stenotic aortic valves.
  
  
  METHODS
  Using atomic absorption spectroscopy, the hydroxyapatite content of 228 excised human stenotic aortic valves was determined and expressed as a percentage of valve mass. Left heart catheterization preceded valve replacement. In addition, serum levels of calcium and creatinine were determined before native calcific aortic valve excision.
  
  
  RESULTS
  Valves from male patients contained more hydroxyapatite than those of female patients (26 +/- 9 versus 22 +/- 9 mass%; p < 0.001). Patients presenting with lower serum calcium levels showed a slight trend towards higher levels of valve calcification (r = -0.15, p = 0.026), but this association appeared only within the subgroup of male patients. Male patients with lowest serum calcium levels displayed greatest valvular hydroxyapatite deposition (1st calcium tertiary: 29.5 +/- 8.9 mass% versus 2nd calcium tertiary 26.4 +/- 7.8 mass% versus 3rd calcium tertiary 21.4 +/- 8.9 mass%; n = 122; p = 0.001; r = -0.25; p = 0.006). This association was even more distinct in male patients with normal serum creatinine levels. Furthermore, serum calcium was inversely and significantly associated with serum C-reactive protein in male patients (r = - 0.34; p < 0.001).
  
  
  CONCLUSIONS
  Serum calcium levels appear to be inversely related to valve calcification in patients with severe calcific aortic stenosis (AS). This finding indicates the importance of systemic calcium metabolism in calcific AS, independent of manifest disorders of calcium metabolism or renal function. Interestingly, this association was evident only in male patients, suggesting a gender-dependent pathogenesis.
authors.affiliation: Clinic for Interdisciplinary Intermediate Care and Medical Clinic I, University Hospital of Aachen, Germany. jrortlepp@ukaachen.de
authors.forename: Jan R
authors.initials: JR
authors.lastname: Ortlepp
authors.forename: Manuela
authors.initials: M
authors.lastname: Pillich
authors.forename: Fabian
authors.initials: F
authors.lastname: Schmitz
authors.forename: Vera
authors.initials: V
authors.lastname: Mevissen
authors.forename: Ralf
authors.initials: R
authors.lastname: Koos
authors.forename: Stefan
authors.initials: S
authors.lastname: Weiss
authors.forename: Ludwig
authors.initials: L
authors.lastname: Stork
authors.forename: Richard
authors.initials: R
authors.lastname: Dronskowski
authors.forename: Georg
authors.initials: G
authors.lastname: Langebartels
authors.forename: Rüdiger
authors.initials: R
authors.lastname: Autschbach
authors.forename: Vincent
authors.initials: V
authors.lastname: Brandenburg
authors.forename: Seth
authors.initials: S
authors.lastname: Woodruff
authors.forename: Jens J
authors.initials: JJ
authors.lastname: Kaden
authors.forename: Rainer
authors.initials: R
authors.lastname: Hoffmann
mesh_terms: D000368:Aged; D001021:Aortic Valve / Q000737:chemistry / Q000378:metabolism*; D001024:Aortic Valve Stenosis / Q000378:metabolism*; D002097:C-Reactive Protein / Q000032:analysis; D002114:Calcinosis / Q000378:metabolism*; D002118:Calcium / Q000097:blood*; D017886:Durapatite / Q000032:analysis*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012720:Severity of Illness Index; D012737:Sex Factors
chemical_list: D002097:C-Reactive Protein; D017886:Durapatite; D002118:Calcium