title: Relationship between magnesium and clinical biomarkers on inhibition of vascular calcification.
abstract: BACKGROUND
  Arteriosclerosis and cardiovascular disease are strongly associated with vascular calcification. Hyperphosphatemia is an essential risk factor for increased vascular calcification. End-stage renal disease (ESRD) patients could serve as an in vivo model for accelerated calcification. This study focuses on the most likely protective effects of magnesium ion (Mg(2+)) on phosphate-induced vascular calcification ex vivo/in vitro. Furthermore, plasma Mg(2+) concentrations of ESRD and healthy controls were investigated for association with surrogate parameters of vascular calcification in vivo.
  
  
  METHODS
  Aortic segments of male Wistar-Kyoto rats were incubated and the phosphate concentration of the medium was elevated. The aortic segments were incubated in the absence and presence of MgCl(2); tissue calcification was quantified by different methods. Serum Mg(2+) concentrations of patients with chronic kidney disease (CKD stage 5; ESRD) and patients without CKD (controls) were associated with carotid intima media thickness (IMT) and aortic pulse wave velocity (PWV) as surrogate parameter for arteriosclerosis and arterial stiffening.
  
  
  RESULTS
  Incubation of aortic segments in the presence of β-glycerophosphate and NaH(2)PO(4) caused an increased tissue Ca(2+) deposition compared to control conditions. This increased amount of Ca(2+) in the aortic rings was significantly decreased in the presence of Mg(2+). In CKD patients, but not in controls, magnesium serum concentration was associated with the IMT of the carotid arteries. In addition, CKD patients with higher magnesium serum concentration had a significantly lower PWV.
  
  
  CONCLUSIONS
  Elevated phosphate concentrations in the culture media induce ex vivo/in vitro medial calcification in intact rat aortic rings in the presence of alkaline phosphatase. Mg(2+) ions reduced ex vivo/in vitro vascular calcification despite increased phosphate concentration. This hypothesis is additionally based on the fact that CKD patients with high Mg(2) serum levels had significantly lower IMT and PWV values, which may result in a lower risk for cardiovascular events and mortality in these patients. Therefore, Mg(2+) supplementation may be an option for treatment and prevention of vascular calcification resulting in a reduction of cardiovascular events in CKD patients.
authors.affiliation: Charité, Medical Clinic IV, University of Berlin, Germany.
authors.forename: Silvia
authors.initials: S
authors.lastname: Salem
authors.forename: Heike
authors.initials: H
authors.lastname: Bruck
authors.forename: Ferdinand H
authors.initials: FH
authors.lastname: Bahlmann
authors.forename: Mirjam
authors.initials: M
authors.lastname: Peter
authors.forename: Jutta
authors.initials: J
authors.lastname: Passlick-Deetjen
authors.forename: Axel
authors.initials: A
authors.lastname: Kretschmer
authors.forename: Sonja
authors.initials: S
authors.lastname: Steppan
authors.forename: Michaela
authors.initials: M
authors.lastname: Volsek
authors.forename: Andreas
authors.initials: A
authors.lastname: Kribben
authors.forename: Marc
authors.initials: M
authors.lastname: Nierhaus
authors.forename: Vera
authors.initials: V
authors.lastname: Jankowski
authors.forename: Walter
authors.initials: W
authors.lastname: Zidek
authors.forename: Joachim
authors.initials: J
authors.lastname: Jankowski
mesh_terms: D000818:Animals; D001011:Aorta; D001161:Arteriosclerosis / Q000097:blood; D015415:Biomarkers / Q000097:blood*; D001794:Blood Pressure; D002118:Calcium / Q000378:metabolism; D004195:Disease Models, Animal; D005260:Female; D006801:Humans; D008274:Magnesium / Q000097:blood* / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D051381:Rats; D011921:Rats, Inbred WKY; D012307:Risk Factors; D061205:Vascular Calcification / Q000097:blood* / Q000503:physiopathology
chemical_list: D015415:Biomarkers; D008274:Magnesium; D002118:Calcium