title: Bone involvement in idiopathic hypercalciuria.
abstract: BACKGROUND
  To evaluate bone involvement in idiopathic hypercalciuria, 40 lithiasic patients and 10 controls were studied.
  
  
  METHODS
  According to urinary calcium excretion, patients were first classified as hypercalciuric (Hca, n = 22) and normocalciuric (Nca, n = 18). The Hca patients were then subclassified according to bone densitometry (BMD) as osteopenic (HcaO, n = 10) and non-osteopenic (HCaNO, n = 12). Routine biochemistry, dietary records, bone histomorphometry. and cytokines (IL-1beta, IL-6, and TNF) production by peripheral blood mononuclear cell cultures were studied.
  
  
  RESULTS
  There were no differences in routine biochemistry between Hca and Nca groups, except for urinary calcium. Inadequate nutrition was observed in Hca group, showing high protein (80.9% of the patients), carbohydrate (76.2%) and sodium (90%) intake. Calcium intake was low in Hca (57%) and Nca (83%) groups. IL-6 and TNF were not different between the Hca and Nca groups. IL-1beta levels were significantly high in both groups when compared to controls. IL-6 and TNF were higher in HcaO than Nca. BMD in femoral neck in HcaO was lower than in HcaNO and Nca groups. Eroded surface (ES/BS) increased in 91% of the Hca group and 36% had a mineralization defect. In the HcaO group serum PTH correlated negatively with trabecular bone volume (BV/TV) and positively with ES/BS. 1,25(OH),D3 levels correlated positively with osteoblastic surface. Calcium intake correlated positively with BV/TV and inversely with ES/BS. A negative correlation was observed between IL-6 levels and Z score of the femoral neck.
  
  
  CONCLUSIONS
  Bone involvement was detected in a young population with nephrolithiasis demonstrating that a strict follow-up is necessary in order to control hypercalciuria.
authors.affiliation: Nephrology Division, University of São Paulo Medical School, São Paulo, Brazil. vandajor@usp.br
authors.forename: A M
authors.initials: AM
authors.lastname: Misael da Silva
authors.forename: L M
authors.initials: LM
authors.lastname: dos Reis
authors.forename: R C
authors.initials: RC
authors.lastname: Pereira
authors.forename: E
authors.initials: E
authors.lastname: Futata
authors.forename: C T
authors.initials: CT
authors.lastname: Branco-Martins
authors.forename: I L
authors.initials: IL
authors.lastname: Noronha
authors.forename: B L
authors.initials: BL
authors.lastname: Wajchemberg
authors.forename: V
authors.initials: V
authors.lastname: Jorgetti
mesh_terms: D015502:Absorptiometry, Photon; D000293:Adolescent; D000328:Adult; D015519:Bone Density / Q000502:physiology*; D002118:Calcium / Q000652:urine*; D002478:Cells, Cultured; D002648:Child; D016207:Cytokines / Q000096:biosynthesis*; D004032:Diet; D005260:Female; D006801:Humans; D007669:Kidney Calculi / Q000276:immunology / Q000503:physiopathology* / Q000652:urine; D007963:Leukocytes, Mononuclear / Q000378:metabolism; D008297:Male; D008875:Middle Aged
chemical_list: D016207:Cytokines; D002118:Calcium