Low bone density, vertebral fracture and FRAX score in kidney transplant recipients: A cross-sectional cohort study.

Melis Sevil Karapinar,Burcu Kaya,Serhan Tuglular,Arzu Velioglu,Ebru Asicioglu,Stanislaw Stepkowski,Dilek Gogas Yavuz,Bige Ozkan,Onur Bugdaycı,Basar Aykent,Hakki Arikan

doi:10.1371/journal.pone.0251035

Abstract

BackgroundKidney transplantation (KT) recipients are at increased risk of low bone density (LBD) and fractures. In this retrospective study, we investigated bone mineral density (BMD), vertebral fractures, calculated risk for major osteoporotic fractures (MOF), and hip fractures in the KT recipients.Patients-methodPatients who completed at least one year after KT were included in the analysis. Demographic, clinical, and laboratory data were recorded. Measurements of BMD were performed by dual-energy X-ray absorptiometry. Vertebral fractures were assessed using semi-quantitative criteria with conventional radiography. The ten-year risk for MOF and hip fracture were calculated using the FRAX@ tool with BMD.ResultsOne hundred fifty-three KT recipients were included in the study. The population included 77 women. The mean age at evaluation was 46,5±11,9 years. Seventy-eight (50.9%) patients had normal femoral neck BMD while osteoporosis and osteopenia at the femoral neck were present in 12 (7.8%) and 63 (41.1%) of the patients, respectively. Age at evaluation was the risk factor for LBD (OR 1.057; 95% CI 1.024–1.091; p = 0.001). In female KT recipients, LBD was principally affected by menopausal status whereas in males, mammalian target of rapamycin (mTOR) inhibitor use and lower BMI levels were the risk factors. The prevalent vertebral fracture was found in 43.4% of patients. In multivariate analysis, only steroid use (OR 0.121; 95% CI 0.015–0.988; p = 0.049) was found to be associated with prevalent fracture. Among all KT recipients, 1.9% had a high MOF probability (≥20% risk of fracture), and 23.5% had high hip fracture probability (≥3% risk of hip fracture) according to FRAX.ConclusionExploring the prevalence of LBD and vertebral fracture and the risk factors would help clinicians to modify long-term follow-up strategies. Furthermore, the high hip fracture risk probability in our cohort suggested that there is a need for longitudinal studies to confirm the validity of the FRAX tool in the transplant population.

Highlights

Mineral and bone disease in kidney transplant patients is a major cause of morbidity and mortality in early and late post-transplant period
In female Kidney transplantation (KT) recipients, low bone density (LBD) was principally affected by menopausal status whereas in males, mammalian target of rapamycin inhibitor use and lower body mass index (BMI) levels were the risk factors
The high hip fracture risk probability in our cohort suggested that there is a need for longitudinal studies to confirm the validity of the FRAX tool in the transplant population

Summary

Introduction

Mineral and bone disease in kidney transplant patients is a major cause of morbidity and mortality in early and late post-transplant period. Kidney Disease: Improving Global Outcomes (KDIGO) guidelines published in 2017 with a special section on the management of CKD-MBD in transplant patients recommends Bone Mineral Density (BMD) evaluation to predict fracture risk in kidney transplant recipients especially in the first three months after transplantation [1]. This evaluation is especially important to detect patients eligible for treatment for osteoporosis with a perspective to prevent fractures. The ten-year risk for MOF and hip fracture were calculated using the FRAX@ tool with BMD

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