Bone Metabolism According to Chronic Kidney Disease Stages in
Patients Undergoing Kidney Transplantation: a 5-Year
Database Analysis
G. Fernández-Fresnedo, E. Rodrigo, J.C. Ruiz, A.L. Martín de Francisco, and M. Arias
ABSTRACT
Introduction. While kidney transplantation successfully reverses many complications of
uremia that are not corrected with dialysis therapy, elevated parathyroid hormone (PTH)
levels and other alterations of mineral metabolism persist in transplant recipients.
Patients and Methods. A single-center cohort retrospective database analysis was
performed of 497 consecutive adult patients who underwent first kidney transplanta-
tion between 1994 and 2004. At 1- and 5-year follow-up, a descriptive analysis was
performed of mineral metabolism parameters of chronic kidney disease stage accord-
ing to NKF KDOQI (National Kidney Foundation Kidney Disease Outcomes Quality
Initiative) in patients with a functional graft at 1 year. Glomerular filtration rate was
estimated using the abbreviated MDRD (Modification of Diet in Renal Disease)
equation.
Results. Most of the transplants (99.2%) were from cadaveric donors. Mean (SD)
patient age was 47.7 (13.3) years, and 69% of patients were men. The causes of chronic
kidney disease were glomerular (35.4%), congenital (15.4%), systemic (14.1%), vascular
(11.3%), interstitial (10.1%), and other (1%). The percentage of patients in each stage
of chronic kidney disease with calcium levels less than 8.5 mg/dL, phosphorus greater than
4.5 mg/dL, and PTHi greater than 150 pg/mL increased as graft function declined. Six
posttransplantation parathyroidectomies were performed. Only 130 patients received
secondary hyperparathyroidism treatment within 5 years after transplantation: calcium
carbonate, 36.9%; calcium acetate, 1.5%; calcium carbonate plus cholecalciferol, 21%;
calcitriol, 71%; and calcifediol, 0.8%.
Conclusions. The prevalence of hypocalcemia, hyperphosphatemia, and elevated PTH
level increased with chronic kidney disease stage. Classification of renal transplant
recipients by KDOQI stage may enable clinicians to identify patients at increased risk and
to target appropriate therapy to improve outcome. There is an opportunity for enhanced
management of secondary hyperparathyroidism in these patients.
S
ECONDARY HYPERPARATHYROIDISM (SHPT),
which develops in chronic kidney disease (CKD),
progresses after initiation of dialysis therapy. While kidney
transplantation reverses many complications of uremia that
are not corrected by dialysis therapy, elevated intact parathy-
roid hormone (iPTH) and other alterations of mineral metab-
olism persist in many transplant recipients.
1,2
In 2003, the
National Kidney Foundation published guidelines, the Kidney
Disease Outcomes Quality Initiative (KDOQI) that recom-
mend tight control of serum calcium, phosphorus, calcium-
phosphorus product, and iPTH levels in patients with CKD.
3
Disturbances in mineral and PTH metabolism result not only
in bone disease but also in increased morbidity and mortality.
Thus, the implementation of the KDOQI guidelines is becom-
From the Nephrology Service, University Hospital Marqués de
Valdecilla. Santander, Cantabria, Spain.
Address reprint requests to Dr Gema Fernández-Fresnedo,
Nephrology Service, Hospital Marqués de Valdecilla, Avda de
Valdecilla, 39008 Santander, Spain. E-mail: nefffg@humv.es
© 2009 by Elsevier Inc. All rights reserved. 0041-1345/09/$–see front matter
360 Park Avenue South, New York, NY 10010-1710 doi:10.1016/j.transproceed.2009.06.071
Transplantation Proceedings, 41, 2403–2405 (2009) 2403