title: Association between circulating osteoblast progenitor cells and aortic calcifications in women with postmenopausal osteoporosis.
abstract: OBJECTIVE
  Ectopic artery calcification has been documented in women with postmenopausal osteoporosis, in whom an imbalance in the number of circulating osteoprogenitor cells (OPCs) has been identified. Circulating OPCs form calcified nodules in vitro; however, it remains unknown whether an association exists between the number of circulating OPCs and aortic calcifications. We investigated the relationship between OPCs and aortic calcifications in women with postmenopausal osteoporosis.
  
  
  RESULTS
  The number of circulating OPCs was quantified by FACS analysis in 50 osteoporotic postmenopausal women. OPCs were defined as CD15-/alkaline-phosphatase(AP)+ cells coexpressing or not CD34. Participants underwent measurement of markers of bone metabolism, bone mineral density and abdominal aortic calcium (AAC) by 64-slice computed tomography. Patients with AAC were older, had lower 25(OH)vitamin D levels and higher circulating CD15-/AP+/CD34- cells than those without AAC. Significant correlates of AAC included age (rho = 0.38 p = 0.006), calcium (rho = 0.35 p = 0.01), 25(OH)vitamin D (rho = -0.31, p = 0.03) and the number of CD15-/AP+/CD34- cells (rho = 0.55 p < 0.001). In regression analyses, the log-transformed number of CD15-/AP+/CD34- cells was associated with the presence (OR = 6.45, 95% CI 1.03-40.1, p = 0.04) and severity (β = 0.43, p < 0.001) of AAC, independent of age, 25(OH)vitamin D, calcium and other potential confounders. Patients with low 25(OH)vitamin D and high CD15-/AP+/CD34- cells had higher median AAC than other patients (1927/μL, 862-2714/μL vs 147/μL, 0-1665/μL, p = 0.003).
  
  
  CONCLUSIONS
  In women with postmenopausal osteoporosis, the number of circulating CD15-/AP+/CD34- cells is significantly associated with increased aortic calcifications, that appear to be correlated also with reduced 25(OH)vitamin D levels.
authors.affiliation: Unit of Internal Medicine, Angiology and Arteriosclerosis Diseases, Department of Clinical and Experimental Medicine, University of Perugia, Hospital Santa Maria della Misericordia, Piazzale Menghini, 1, 06129 Perugia, Italy. mpirro@unipg.it
authors.forename: M
authors.initials: M
authors.lastname: Pirro
authors.forename: M R
authors.initials: MR
authors.lastname: Manfredelli
authors.forename: G
authors.initials: G
authors.lastname: Schillaci
authors.forename: R S
authors.initials: RS
authors.lastname: Helou
authors.forename: F
authors.initials: F
authors.lastname: Bagaglia
authors.forename: F
authors.initials: F
authors.lastname: Melis
authors.forename: G B
authors.initials: GB
authors.lastname: Scalera
authors.forename: A M
authors.initials: AM
authors.lastname: Scarponi
authors.forename: E
authors.initials: E
authors.lastname: Gentile
authors.forename: E
authors.initials: E
authors.lastname: Mannarino
mesh_terms: D000368:Aged; D000469:Alkaline Phosphatase / Q000097:blood; D018952:Antigens, CD34 / Q000097:blood; D001012:Aorta, Abdominal / Q000378:metabolism / Q000503:physiopathology; D001021:Aortic Valve / Q000473:pathology* / Q000503:physiopathology; D001024:Aortic Valve Stenosis / Q000150:complications / Q000503:physiopathology*; D015415:Biomarkers / Q000097:blood; D015519:Bone Density / Q000187:drug effects; D001842:Bone and Bones / Q000166:cytology / Q000378:metabolism; D002114:Calcinosis / Q000150:complications / Q000503:physiopathology*; D002118:Calcium / Q000097:blood; D003430:Cross-Sectional Studies; D005260:Female; D005647:Fucosyltransferases / Q000097:blood; D006801:Humans; D016256:Lewis X Antigen / Q000097:blood; D008875:Middle Aged; D010006:Osteoblasts / Q000378:metabolism*; D015663:Osteoporosis, Postmenopausal / Q000150:complications / Q000503:physiopathology*; D017698:Postmenopause; D012044:Regression Analysis; D013234:Stem Cells / Q000166:cytology / Q000378:metabolism*; D014807:Vitamin D / Q000097:blood; D014808:Vitamin D Deficiency / Q000150:complications / Q000503:physiopathology
chemical_list: D018952:Antigens, CD34; D015415:Biomarkers; D016256:Lewis X Antigen; D014807:Vitamin D; C066693:FUT4 protein, human; D005647:Fucosyltransferases; D000469:Alkaline Phosphatase; D002118:Calcium