title: Bone mineral density loss in patients with urolithiasis: a follow-up study.
abstract: BACKGROUND
  Recurrent calcium urolithiasis is often associated with disorders of calcium metabolism. The purpose of this investigation was to assess bone mineral content (BMC) and bone mineral density (BMD) over a period of 1 year in patients with urolithiasis and to determine the factors that could have influenced the changes in bone density during that period.
  
  
  METHODS
  The patient group comprised 34 men aged 41.2 plus minus 7.9 years with recurrent urolithiasis. A wide spectrum of biochemical measurements was performed. Bone mineral density (g/cm(2)), bone mineral content (BMC), and bone area (BA) were measured twice during a period of 1 year at the lumbar spine (L2-L4), femoral neck, Ward triangle, and trochanter, using dual energy absorptiometry. Patient results were compared to those obtained from 30 healthy male controls of a comparable age group.
  
  
  RESULTS
  Nine patients were hypercalciuric, while the majority of the remaining metabolic parameters were within the reference values. Bone mineral content and bone areas at all regions were lower in patients comparing to controls, but not significantly. The greatest annual reduction of BMD was noticed at Ward triangle (-5.70% in patients and -2.36% in controls), followed by femoral neck (-4.06% patients, -2.03% controls) and trochanter (-3.06% patients, -1.39% controls). There was no significant decrease of the BMD of the spine. Analyzing the influence of age, body mass index (BMI), metabolic parameters, and dietary calcium intake on the annual reduction of bone density, we found that age, hyperuricosuria, and calcium intake were significantly associated with bone loss in that time period.
  
  
  CONCLUSIONS
  Bone mass reduction in patients with urolithiasis over a 1-year period did not differ significantly from that in controls and was principally related to age, hyperuricosuria, and calcium dietary restriction but not to increased calcium excretion.
authors.affiliation: Center for Osteoporosis, Institute for Medical Research and Occupational Health, Ksaverska cesta 2, P.O. Box 291, Zagreb, 10001 Croatia. cvijetic@imi.br
authors.forename: Selma
authors.initials: S
authors.lastname: Cvijetic
authors.forename: Helga
authors.initials: H
authors.lastname: Füredi-Milhofer
authors.forename: Vesna
authors.initials: V
authors.lastname: Babic-Ivancic
authors.forename: Antun
authors.initials: A
authors.lastname: Tucak
authors.forename: Josip
authors.initials: J
authors.lastname: Galic
authors.forename: Darinka
authors.initials: D
authors.lastname: Dekanic-Ozegovic
mesh_terms: D015502:Absorptiometry, Photon; D000328:Adult; D015519:Bone Density; D002118:Calcium / Q000378:metabolism; D005269:Femur / Q000000981:diagnostic imaging; D005500:Follow-Up Studies; D006801:Humans; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D014545:Urinary Calculi / Q000503:physiopathology*
chemical_list: D002118:Calcium