title: Are peritoneal calcifications in long-term peritoneal dialysis related to aortic calcifications and disturbances in mineral metabolism?
abstract: BACKGROUND
  Peritoneal calcifications are associated with long-term peritoneal dialysis (PD). Case reports have suggested a relation with disturbances in mineral metabolism such as the presence of severe hyperparathyroidism. Our aim was to investigate whether relationships are present between peritoneal calcifications and aortic calcifications or disturbances in mineral metabolism in long-term PD patients.
  
  
  METHODS
  We included all long-term PD patients (PD ≥ 4 years) in our centre from 1996 to 2008 who had undergone an abdominal computed tomographic (CT) scan. The scans were reviewed by two experienced radiologists in consensus. The presence or absence of peritoneal calcifications was scored, and a severity scoring system for abdominal aortic calcifications was used: 1 = none, 2 = mild, 3 = moderate, 4 = severe and 5 = very severe. For each patient, laboratory data on plasma calcium corrected for albumin, phosphorus and parathyroid hormone (PTH) levels were retrieved every 6 months up to 5 years prior to the CT scan. Individual mean values over 5 years were calculated.
  
  
  RESULTS
  We included 31 patients: 12 patients with peritoneal calcifications and 19 patients without. No difference was found in aortic calcification scores (median scores: 3 versus 3). Also, median (range) calcium, 10.7 (9.6-11.5) versus 10.3 (9.4-11.3) mg/dL; phosphorus, 5.2 (3.4-7.0) versus 4.9 (2.9-6.5) mg/dL; and PTH levels, 271 (101-910) versus 263 (40-1197) pg/mL were not different between patients with and without peritoneal calcifications.
  
  
  CONCLUSIONS
  The presence of peritoneal calcifications in long-term PD patients could not be related to the presence of aortic calcifications or disturbances in mineral metabolism. Perhaps, local peritoneal factors play a role in the formation of peritoneal calcifications.
authors.affiliation: Division of Nephrology, Department of Medicine, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands. a.vlijm@amc.uva.nl
authors.forename: Anniek
authors.initials: A
authors.lastname: Vlijm
authors.forename: Saffire S K S
authors.initials: SS
authors.lastname: Phoa
authors.forename: Marlies
authors.initials: M
authors.lastname: Noordzij
authors.forename: Anje M
authors.initials: AM
authors.lastname: Spijkerboer
authors.forename: Joost
authors.initials: J
authors.lastname: van Schuppen
authors.forename: Jaap
authors.initials: J
authors.lastname: Stoker
authors.forename: Dirk G
authors.initials: DG
authors.lastname: Struijk
authors.forename: Raymond T
authors.initials: RT
authors.lastname: Krediet
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001011:Aorta / Q000503:physiopathology*; D002114:Calcinosis / Q000209:etiology*; D005500:Follow-Up Studies; D006801:Humans; D008875:Middle Aged; D008903:Minerals / Q000378:metabolism*; D010530:Peritoneal Dialysis; D010532:Peritoneal Diseases / Q000209:etiology*; D011379:Prognosis; D011446:Prospective Studies; D013997:Time Factors; D055815:Young Adult
chemical_list: D008903:Minerals