Mineral and Bone Disorder Is Temporary in Patients Treated With Early Rapid Corticosteroid Reduction After Kidney Transplantation: A Single-Center Experience

Impact of corticosteroid withdrawal on bone mineral density after kidney transplantation

BACKGROUND

Bone abnormalities are common after kidney transplantation (KTx) and are associated with an increased risk of fractures. The pathophysiology of post-KTx bone disorders is multifactorial, with corticosteroid (CS) therapy being a contributor to the loss of bone mineral density (BMD). This study aimed to evaluate the impact of CS withdrawal versus continued CS therapy on BMD evolution in a kidney transplant recipients (KTRs) cohort.

METHODS

We retrospectively analyzed BMD data from 132 patients who underwent KTx between 2005 and 2021. BMD was assessed using dual-energy X-ray absorptiometry at the time of KTx (T0) and two-years post-KTx (2yT). Patients were categorized into two groups: those who discontinued CS (CS-) within the first-year post KTx and those who continued CS therapy (CS+).

RESULTS

The mean age at KTx was 52.2 (± 12.6) years, and 62.1% of the patients were male. Overall, BMD increased significantly at the lumbar spine (LS) but decreased at the radius at 2yT, while BMD at the hip site remained stable. CS was discontinued in 44.7% of patients between T0 and 2yT, with an average discontinuation time of 6.3 (± 4.9) months post-KTx. The CS- group showed significant BMD improvements at LS and hip sites. In a multivariate analysis, a higher cumulative CS dose was independently associated with a larger BMD decline.

CONCLUSIONS

CS withdrawal after KTx positively impacts BMD, while higher cumulative CS doses are associated with a greater BMD loss. These findings underscore the importance of minimizing CS exposure to preserve bone health in KTRs.

Fracture Risk in Dialysis and Kidney Transplanted Patients: A Systematic Review

Chronic kidney disease is associated with an increased risk of fracture and cardiovascular mortality. The risk of fracture in hemodialysis (HD), peritoneal dialysis (PD) and kidney transplant (KT) patients is higher when compared with the general population. However, there exists a knowledge gap concerning which group has the highest risk of fracture. We aimed to compare the risk of fracture in HD, PD, and KT populations. We conducted a systematic review of observational studies evaluating the risk of fracture in HD, PD, or KT patients. Eligible studies were searched using MEDLINE, Embase, Web of Science, and Cochrane Library from their inception to January 2016, and in grey literature. Incidences (cumulative and rate) of fracture were described together using the median, according to fracture sites, the data source (administrative database or cohort and clinical registry), and fracture diagnosis method. Prevalence estimates were described separately. We included 47 studies evaluating the risk of fracture in HD, PD, and KT populations. In administrative database studies, incidence of hip fracture in HD (median 11.45 per 1000 person-years [p-y]), range: 9.3 to 13.6 was higher than in KT (median 2.6 per 1000 p-y; range 1.5 to 3.8) or in PD (median 5.2 per 1000 p-y; range 4.1 to 6.3). In dialysis (HD+PD), three studies reported a higher incidence of hip fracture than in KT. Prevalent vertebral fracture (assessed by X-rays or questionnaire) reported in HD was in a similar range as that reported in KT. Incidence of overall fracture was similar in HD and KT, from administrative databases studies, but lower in HD compared with KT, from cohorts or clinical registry studies. This systematic review suggests an important difference in fracture risk between HD, PD, and KT population, which vary according to the diagnosis method for fracture identification. © 2018 The Authors. JBMR Plus published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research.

Maintenance low dose systemic glucocorticoids have limited impact on bone strength and mineral density among incident renal allograft recipients: A pilot prospective cohort study

Soon after kidney transplant (KT), a decrease in parathormone and bone mineral density (BMD) occur, but little is known on the impact of KT on novel bone quality parameters including trabecular bone score (TBS) and bone material strength index (BMSi). We aimed to study BMD, TBS and BMSi in the first year after KT, in patients not treated with any bone therapy. A cohort including 36 patients underwent KT on a low-glucocorticoid-dose protocol (5 mg daily-prednisone from post-operative-day 42 onwards) and was observed for 12 months prospectively. At 3 months, phosphorus and parathormone decreased, while calcium increased. We also observed at 3 months a transient mild 2.9% bone loss at femoral neck (BMD change 0.752 ± 0.15 vs 0.730 ± 0.15; p = 0.004), but no change at either spine or total hip. Both TBS and BMSi remained stable. At 12 months, lumbar (but not total hip or femoral neck) BMD slightly decreased by 2.1% vs baseline (0.950 ± 0.15 vs 0.930 ± 0.5; p = 0.046), while TBS and BMSi remained unmodified. In KT patients on low-dose glucocorticoids and no bone therapy, there were small BMD decreases at femoral neck (at 3 months) and lumbar spine (at 12 months), but no change in either TBS or BMSi. Low-dose post-KT glucocorticoid treatment shows limited impact on bone, supporting steroid-restrictive protocols.

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.

Fracture risk in dialysis and kidney transplanted patients: a protocol for systematic review and meta-analysis

BACKGROUND

Chronic kidney disease (CKD) is associated with an increased risk of fracture and cardiovascular mortality. The risk of fracture in hemodialysis (HD), peritoneal dialysis (PD), and kidney transplantation (KT) is higher when compared to the general population. However, uncertainties remain about which group has the highest risk of fracture. We aim to identify the risk of fracture and cardiovascular mortality post-fracture in HD compared to PD or KT and in PD compared to KT population.

METHODS

We will conduct a systematic review of observational studies and randomized control trials on patients with CKD. Eligible studies will be searched on MEDLINE, Embase, Web of Science, Cochrane Library, and in gray literature. Two independent reviewers will screen all identified references in order to include studies reporting the risk of fracture without a comparator or comparing that risk in HD vs KT, PD vs KT, or HD vs PD. Studies comparing the risk of fracture in a renal replacement therapy group to general population or to non-dialyzed CKD patients will also be included. Data on study settings, population characteristics, intervention, comparator, and outcomes will be extracted. Study data will be summarized and analyzed in RevMan and SAS. Risk of bias in cohort design studies will be assessed with an adapted version of the ROBINS-I tool and by the Cochrane handbook tool for RCTs. The quality of evidence and strengths of recommendations will be evaluated by the Grading of Recommendations Assessment, Development and Evaluations (GRADE) tool. We will pool relative risks with random-effect models and Mantel-Haenszel methods. Subgroup and sensitive analysis are planned according to the intervention and comparator, study design, and type of fracture.

DISCUSSION

This review will provide new pooled data about fracture risk in dialysis and KT patients. Our results should guide the implementation of future preventive strategies targeting patients with the highest fracture risk. A pooled analysis of observational studies could be limited by a probable considerable heterogeneity among these studies.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42016037526.