title: [Urinary calcium and bone turnover markers].
abstract: OBJECTIVE
  To know the relationship between bone turnover markers and urinary calcium excretion with and without oral calcium load in postmenopausal and young women.
  
  
  METHODS
  A cross-sectional study in 100 women (50 with normal menstrual cycle and 50 postmenopausal). After 5 days with a specific diet, urine of 24 hours, 2 hours in fasting, and 4 hours after oral calcium load was collected (the last urine collection was only done in 20 patients in each group. In these patients, an x-ray absorptiometry of distal forearm and vitamin D levels were evaluated too). Calcium, alkaline phosphatase, calcitonin, parathormone, N-telopeptides of type I collagen, and osteocalcin serum levels were measured in fasting. Creatinine and calcium were measured in urine to obtain the Ca/cr index.
  
  
  RESULTS
  Postmenopausal women had lower calcitonin levels while the Ca/cr index of 2 hours in fasting was higher than the eumenoreic women. We found significant correlation between Ca/cr index of 2 hours with age (R = .21; p = .04), parathormone (R = .21; p = .04), and calcitonin levels (R = -.29; p = .005). There was not correlation with the urinary calcium excretion including the 4 hour postload collection with the biochemical markers of bone turnover or mineral bone density of distal forearm.
  
  
  CONCLUSIONS
  The urinary Ca/Cr index of 2 hours in fasting is related to parathormone levels and has a negative relationship with calcitonin levels in postmenopausal women. However, the urinary calcium excretion after oral calcium load was not related with the bone turnover grade.
authors.affiliation: Unidad metabólica del Hospital de Especialidades, IMSS, Delegación Guanajuato.
authors.forename: José Pío X
authors.initials: JP
authors.lastname: de la Torre Vega
authors.forename: Norma
authors.initials: N
authors.lastname: Amador Licona
authors.forename: Lilia
authors.initials: L
authors.lastname: Zamora Mata
authors.forename: Alan El Jach
authors.initials: Ael J
authors.lastname: Morales Ramos
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000032:analysis*; D015519:Bone Density; D016723:Bone Remodeling / Q000187:drug effects / Q000502:physiology*; D002118:Calcium / Q000378:metabolism / Q000652:urine*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008875:Middle Aged; D017698:Postmenopause / Q000097:blood / Q000187:drug effects / Q000502:physiology*; D014807:Vitamin D / Q000032:analysis
chemical_list: D015415:Biomarkers; D014807:Vitamin D; D002118:Calcium