Reduced bone mineral density in male renal transplant recipients: evidence for persisting hyperparathyroidism.
BACKGROUND
Osteoporosis is increasingly recognized as a major source of morbidity following renal transplantation. The aim of this cross-sectional study was to determine the prevalence of osteoporosis in a cohort of male transplant recipients and examine factors that may influence their bone loss.


METHODS
Bone mineral density (BMD) and biochemical markers of bone metabolism were measured in 134 out of 154 male renal allograft recipients in our center.


RESULTS
The mean age of the patients was 49.7 years (range 26-76) with a median of 6 years post-transplant. Only 17% had normal BMD, 30% were osteoporotic at either hip or spine, and this proportion rose to 41% if the ultradistal radius was included. Parathyroid hormone (PTH) was negatively correlated with BMD at all skeletal sites. In a multiple regression model, independent predictors of femoral neck BMD included body mass index (p=0.004), diabetes (p=0.025), and PTH (p=0.049). The only independent predictor of BMD at the ultradistal radius was PTH (p<0.001). Nineteen men sustained a total of 25 appendicular fractures after transplantation (median time to fracture was 3 years). Prevalent vertebral fractures were only identified in five men. PTH was elevated in 72.4% of patients (mean PTH 142 +/- 118 pg/ml). Bone resorption markers were increased in 48% of patients. PTH was positively correlated with serum carboxyterminal telopeptide of type 1 collagen (r=0.473, p<0.001) and procollagen type 1 amino terminal propeptide (r=0.419, p<0.001).


CONCLUSIONS
Osteopenia and osteoporosis are common in male transplant recipients, and the hip and radius are the most severely affected sites. Elevated rates of bone resorption driven by hyperparathyroidism appear to be the most important contributing factor.
Roe
Simon D
SD
Nottingham Renal and Transplant Unit, Nottingham City Hospital, Hucknall Road, Nottingham, NG5 1PB, UK. sroe2@ncht.trent.nhs.uk
Porter
Christine J
CJ
Godber
Ian M
IM
Hosking
David J
DJ
Cassidy
Michael J
MJ
D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000032:analysis; D015519:Bone Density / Q000502:physiology*; D001862:Bone Resorption / Q000503:physiopathology; D002118:Calcium / Q000378:metabolism; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D050723:Fractures, Bone / Q000209:etiology / Q000503:physiopathology; D006706:Homeostasis / Q000502:physiology; D006801:Humans; D006961:Hyperparathyroidism / Q000453:epidemiology* / Q000209:etiology / Q000503:physiopathology; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D007676:Kidney Failure, Chronic / Q000150:complications / Q000601:surgery; D016030:Kidney Transplantation / Q000009:adverse effects* / Q000502:physiology; D008297:Male; D008875:Middle Aged; D010024:Osteoporosis / Q000453:epidemiology* / Q000209:etiology / Q000503:physiopathology; D015995:Prevalence
D015415:Biomarkers; D007166:Immunosuppressive Agents; D002118:Calcium