title: Urinary calcium is a determinant of bone mineral density in elderly men participating in the InCHIANTI study.
abstract: BACKGROUND
  It is generally acknowledged that calcium excretion is a determinant of bone mineral density. Since data confirming this hypothesis are not conclusive, the present study evaluates the relationship between calcium excretion and volumetric bone mineral density (vBMD) in a sample of general population mostly composed of elderly subjects.
  
  
  METHODS
  This relationship was studied in 595 subjects in good health (M/F 302/293), selected from the InCHIANTI population, an epidemiologic survey on aging in Tuscany (Italy). Of these subjects, 432 (72.6%) were 65 years old or older. Trabecular and cortical apparent vBMDs were measured by peripheral quantitative computed tomography at right tibia and standardized to age and body mass index (BMI) in each gender (z-score).
  
  
  RESULTS
  Men in the highest tertile of calcium excretion had significantly lower trabecular vBMD, and were more likely to have a trabecular z-score of -1 or less. These results were confirmed in men older than 64 years, but not in women and younger men. Sodium excretion and 25-hydroxycolecalciferol (25(OH)D) were greater in men and women in the highest tertile. No differences among tertiles were observed for cortical vBMD, circulating levels of interleukin-1beta and interleukin-6, and intake of principal nutrients and calcium. The lower levels of vBMD z-score were confirmed in men in the highest tertile of calcium excretion, standardized to creatinine clearance, sodium excretion, plasma calcium, and logarithm of circulating 25(OH)D, and resulted to be associated with calcium excretion at multiple regression analysis in men.
  
  
  CONCLUSIONS
  High calcium excretion is associated with a decreased trabecular BMD in elderly men and may predispose men to trabecular bone loss.
authors.affiliation: Division of Nephrology Dialysis and Hypertension, IRCCS San Raffaele Hospital, Postgraduate School of Nephrology, Vita Salute University, Milan, Italy. vezzoli.giuseppe@hsr.it
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Vezzoli
authors.forename: Laura
authors.initials: L
authors.lastname: Soldati
authors.forename: Teresa
authors.initials: T
authors.lastname: Arcidiacono
authors.forename: Annalisa
authors.initials: A
authors.lastname: Terranegra
authors.forename: Rita
authors.initials: R
authors.lastname: Biasion
authors.forename: Cosimo Roberto
authors.initials: CR
authors.lastname: Russo
authors.forename: Fulvio
authors.initials: F
authors.lastname: Lauretani
authors.forename: Stefania
authors.initials: S
authors.lastname: Bandinelli
authors.forename: Benedetta
authors.initials: B
authors.lastname: Bartali
authors.forename: Antonio
authors.initials: A
authors.lastname: Cherubini
authors.forename: Daniele
authors.initials: D
authors.lastname: Cusi
authors.forename: Luigi
authors.initials: L
authors.lastname: Ferrucci
mesh_terms: D000328:Adult; D000368:Aged; D015519:Bone Density; D002118:Calcium / Q000652:urine*; D003404:Creatinine / Q000378:metabolism; D016021:Epidemiologic Studies; D005260:Female; D006801:Humans; D007558:Italy; D008297:Male; D008875:Middle Aged; D012964:Sodium / Q000652:urine; D013977:Tibia / Q000000981:diagnostic imaging / Q000378:metabolism; D014057:Tomography, X-Ray Computed
chemical_list: D012964:Sodium; D003404:Creatinine; D002118:Calcium