title: Calcium nephrolithiasis and bone demineralization: pathophysiology, diagnosis, and medical management.
abstract: OBJECTIVE
  To establish the relationship between calcium nephrolithiasis, bone densitometry scoring, and bone mineral density (BMD) loss according to bone turnover markers (BTMs) and urinary metabolites.
  
  
  RESULTS
  Patients with recurrent calcium nephrolithiasis and idiopathic fasting hypercalciuria (urinary calcium/creatinine ratio >0.11) are more likely to have BMD loss that may lead to osteopenia or osteoporosis. In these patients, BTMs may be used as a surrogate for both bone health and stone recurrence. Suspect higher lithogenic states when calcium stone formers have serum beta-crosslaps (resorptive marker) greater than 0.311 ng/ml, serum osteocalcin (formative marker) greater than 13.2 ng/ml, and beta-crosslaps/osteocalcin ratio greater than 0.024.
  
  
  CONCLUSIONS
  Patients with recurrent calcium nephrolithiasis and fasting hypercalciuria have a higher incidence of osteopenia and osteoporosis, measured by the dual-energy X-ray absorptiometry. These patients present not only with hypercalciuria and increased BTMs (mainly resorptive), but also up to 30% have hypocitraturia and increased urinary calcium/citrate ratio (>0.25). On the basis of these results, a diagnostic algorithm was created, classifying hypercalciurics according to their fasting calcium/creatinine and calcium/citrate ratio. Medical therapy for these patients is aimed at improving the dietary habits (normocalcemic, low salt, low animal protein diet), prescribing combinations of potassium citrate, thiazides, and bisphosphonates, and correcting bone and urinary abnormalities that may lower future skeletal and kidney stone risk.
authors.affiliation: aUrology Department, Hospital La Inmaculada, Huercal-Overa, Almeria, Spain bDepartment of Urology, University of Florida, Gainesville, Florida, USA cUrology Department, San Cecilio University Hospital, Granada, Spain.
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Arrabal-Polo
authors.forename: María del Carmen
authors.initials: Mdel C
authors.lastname: Cano-García
authors.forename: Benjamin K
authors.initials: BK
authors.lastname: Canales
authors.forename: Miguel
authors.initials: M
authors.lastname: Arrabal-Martín
mesh_terms: D018488:Bone Demineralization, Pathologic / Q000175:diagnosis / Q000188:drug therapy / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism*; D006801:Humans; D053565:Hypercalciuria / Q000175:diagnosis / Q000188:drug therapy / Q000378:metabolism*; D053040:Nephrolithiasis / Q000175:diagnosis / Q000188:drug therapy / Q000378:metabolism*; D010024:Osteoporosis / Q000175:diagnosis / Q000188:drug therapy / Q000378:metabolism*
chemical_list: D002118:Calcium