Background Renal transplant patients may have bone loss related to the drugs taken but also to their past history of chronic kidney disease.

Objectives The objective of the present work was to study changes in BMD 2 years after the first assessment.

Methods This longitudinal study included patients who underwent renal transplantation realized between 2005 and 2011 and followed at the University-Hospital of Lille. Patients were included if they had a first bone evaluation (including bone densitometry, spine X-rays and biological assessment) and at least another BMD assessment. The first assessment was done on average 9 months after transplantation and 2 years later.

Results 259 patients satisfied to the inclusion criteria, (96 women) with a mean age of 49.7±12.1 years at transplantation. The mean duration of dialysis was 3.2±3.3 years. 75 patients (29.0%) withdrew corticosteroid 7 days after transplantation without new introduction during follow-up. Vertebral fractures were found in 28 patients (10.8%). According to the WHO classification, 101 patients had osteoporosis and 125 had osteopenia at the first evaluation (at least at one site). Osteoporosis treatment with bisphosphonates (alendronate or risedronate) was initiated for 95 patients. In all patients, BMD gains compared with baseline were significant: 3.9±6.6%, 2.6%±7.6, 3.0±7.2% at the lumbar spine, femoral neck and the total hip respectively (p<0.0001). The gains were significant for patients treated with bisphosphonates compared with patients not treated: 5.0% (p<0.0001), 2.5% (p=0.01) and 2.7% (p<0.01) respectively at the lumbar spine, femoral neck and total hip. There was no difference in terms of BMD gains between alendronate and risedronate (p=0.6). The patients who withdrew corticosteroids early had higher gains in BMD than patients with more prolonged corticosteroid therapy: difference between groups was 2.1% for the lumbar spine (p=0.02) and 2.0% for the total hip (p=0.04). The stepwise regression analysis (patients without bisphosphonates) showed associations between BMD changes (femoral neck) and the duration of corticosteroid therapy, the level of bone alkaline phosphatase at baseline, the lack of vertebral fracture. No correlation was found between the change in BMD and the duration of dialysis or renal function.

Conclusions Kidney transplant recipients have a pre-existing increased bone fragility. Bisphosphonates and early corticosteroid withdrawal can improve BMD.

Disclosure of Interest None declared