[Urinary calcium and bone turnover markers].
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.
de la Torre Vega
José Pío X
JP
Unidad metabólica del Hospital de Especialidades, IMSS, Delegación Guanajuato.
Amador Licona
Norma
N
Zamora Mata
Lilia
L
Morales Ramos
Alan El Jach
Ael J
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
D015415:Biomarkers; D014807:Vitamin D; D002118:Calcium