Changes in bone mineral density after kidney transplantation: 2-year assessment of a French cohort.

INTRODUCTION: In renal transplant patients, bone loss may be related to the drugs patients are taking but also to their past history of chronic kidney disease. The purpose of this study was to assess changes in BMD 2 years after an initial assessment (performed 9 months post transplantation) and the factors associated with these changes. METHODS: This longitudinal study included patients who had undergone a renal transplantation between 2005 and 2011, and who were followed up at the Lille Regional University Hospital. 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 performed on average 9 months post transplantation. A second assessment was performed at 2 years. RESULTS: Two hundred fifty-nine out of 366 patients satisfied the inclusion criteria. The population included 96 women. Mean age at transplantation was 49.7 ± 12.1 years. Mean duration of dialysis was 3.2 ± 3.3 years. For 75 patients (29.0%), corticosteroid treatment was discontinued 7 days after transplantation without subsequent resumption during follow-up. Vertebral fractures assessed by X-rays at baseline were found in 28 patients (10.8%). According to the WHO classification, 106 patients (40.9%) patients had osteoporosis and 111 patients (42.8%) had osteopenia at the first assessment. Oral bisphosphonates were prescribed for 95 patients. The decision to prescribe bisphosphonates was taken jointly by rheumatologists and nephrologists based on BMD assessment, past history of fracture and corticosteroid management. In all patients, BMD gains at the second evaluation (2.2 ± 0.79 years) compared with baseline were significant (3.9 ± 6.6, 2.6% ± 7.6, 3.0 ± 7.2% at the lumbar spine, femoral neck and total hip respectively; p < 0.0001). The difference in gain between bisphosphonate-treated and untreated patients was significant (+ 5.0 ± 0.8% (p < 0.0001), + 2.5 ± 1.0% (p = 0.01) and + 2.7 ± 0.9% (p < 0.01) at the lumbar spine, femoral neck and total hip respectively. The patients who benefited early corticosteroid discontinuation had higher gains in BMD at the lumbar spine (+ 2.1 ± 0.9%; p = 0.02) and total hip (+ 2.0 ± 1.0%; p = 0.04) compared to those for whom corticosteroid therapy was maintained. Stepwise regression analysis (patients without bisphosphonates) showed associations between change in BMD (femoral neck) and duration of corticosteroid therapy, bone alkaline phosphatase level at baseline, and absence of vertebral fracture. No correlation was found between change in BMD and duration of dialysis or renal function. CONCLUSION: Kidney transplant recipients have an increased risk of bone fragility in the year following transplantation. Bisphosphonates and early corticosteroid discontinuation can improve BMD.

Bisphosphonate drug holidays in postmenopausal osteoporosis: effect on clinical fracture risk.

A cohort of 183 postmenopausal women, who had either discontinued or continued bisphosphonates (BPs) after first-line therapy, was used to investigate the relationships between "drug holiday" and clinical fracture. The risk of new clinical fractures was found to be 40% higher in women who had taken a BP "drug holiday." INTRODUCTION: BPs are the most widely used treatment for postmenopausal osteoporosis. The optimal treatment duration, however, remains unclear. The purpose of this study was to evaluate the fracture risk in postmenopausal women with osteoporosis after discontinuing BP treatment (BP "drug holiday"). METHODS: A retrospective analysis was performed at Lille University Hospital (LUH) on postmenopausal women with osteoporosis who had taken a "drug holiday" or continued treatment after first-line BP therapy (3 to 5 years). The occurrence of new clinical fractures during follow-up was also explored. Cox proportional hazards models were used to investigate the relationships between BP "drug holiday" and the occurrence of clinical fractures, while controlling for confounding factors. Survival without new clinical fractures was analyzed using Kaplan-Meier curves and log-rank tests. RESULTS: One hundred eighty-three women (mean age: 61.8 years; SD: 8.7) who had previously undergone BP treatment for 3 to 5 years were enrolled in our study. The patients had received alendronate (n = 81), risedronate (n = 73), zoledronic acid (n = 20), and ibandronate (n = 9). In 166 patients ("drug holiday" group: n = 31; continuous-treatment group: n = 135), follow-up ranged from 6 to 36 months (mean duration: 31.8 months; SD: 8.2). The incidences of new clinical fractures during follow-up were 16.1% (5/31) and 11.9% (16/135). After full adjustment, the hazard ratio of new clinical fractures among "drug holiday" patients was 1.40 (95% CI: 1.12-1.60; p = 0.0095). CONCLUSIONS: After first-line BP therapy in postmenopausal women with osteoporosis, the risk of new clinical fractures was 40% higher in subjects who took a bisphosphonate drug holiday.