Bone mineral content and mineral metabolism during cyclosporine treatment of nephrotic Syndrome.
OBJECTIVE
Although cyclosporine (Cy) has been associated with bone loss following transplantation, its effects on bone in growing children are largely unknown.


METHODS
Thirty-seven patients (2-16 years of age) with remitting nephrotic syndrome (NS), n = 16 receiving Cy for 39 +/- 27 months and n = 21 without Cy, underwent mineral metabolism and bone turnover assessment. In 28 of 37 patients, bone mineral density (BMD) was obtained while off corticosteroid therapy (Rx).


RESULTS
Urinary calcium (Ca), phosphate (PO(4)), and magnesium (Mg) excretion was normal, but serum Mg was lower in patients receiving Cy (1.8 +/- 0.1 v 1.95 +/- 0.2 mg/dL, P < .05). BMD Z scores were similar at the spine (-0.45 +/- 0.74 v 0.04 +/- 0.9) and femur (-0.17 +/- 0.52 v 0.38 +/- 1.28) with no Z score <-2. Serum bone-specific alkaline phosphatase was normal, and N-telopeptide of type I collagen also normal, was higher on Cy (P < .05). Cumulative prednisone exposure was similar and had no significant effect on height and BMD Z scores. Length of Cy-Rx and time elapsed from onset of NS did not correlate with BMD, height Z score, or markers of bone turnover.


CONCLUSIONS
In growing children with NS, during long-term Cy-Rx urinary wasting of Ca and Mg was absent and bone density was preserved.
Freundlich
Michael
M
Department of Pediatrics, University of Miami, Miami, Florida, USA. mfmefex@pol.net
D000293:Adolescent; D015519:Bone Density / Q000187:drug effects*; D016723:Bone Remodeling / Q000187:drug effects*; D002648:Child; D002675:Child, Preschool; D016572:Cyclosporine / Q000008:administration & dosage*; D004334:Drug Administration Schedule; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D007166:Immunosuppressive Agents / Q000008:administration & dosage*; D008297:Male; D008903:Minerals / Q000378:metabolism*; D009404:Nephrotic Syndrome / Q000188:drug therapy / Q000378:metabolism*; D012189:Retrospective Studies
D007166:Immunosuppressive Agents; D008903:Minerals; D016572:Cyclosporine