Evaluation of bone mineral disorders in pediatric kidney transplant recipients

Objective: This study aimed to evaluate post-transplant bone mineral disorder in pediatric kidney transplant patients. Specifically, it sought to determine the frequency and severity of the disorder, reveal the clinical, biochemical, and treatment-related factors involved, and identify modifiable risk factors. Materials and Methods: The study included 111 patients under the age of 18 who received kidney transplants at Akdeniz University Hospital Pediatric Nephrology Clinic between 2014 and 2024 and underwent bone mineral density (BMD) monitoring during follow-up. Demographic data, primary disease and transplant characteristics, anthropometric measurements, laboratory parameters, treatments, and DEXA-derived BMD measurements were retrospectively evaluated. The prevalence of osteoporosis and associated risk factors were investigated. Results: Evaluation of post-kidney transplant DEXA measurements based on vertebral height age showed an osteoporosis frequency ranging from 22% to 29% at various intervals. In contrast, when evaluated based on chronological age, the frequency was higher, ranging from 36% to 48%. Vertebral and femoral BMD SDS values calculated by height age were significantly higher than those calculated by chronological age (p < 0.01). Patients' ages and BMI SDS at the time of transplant were identified as risk factors (OR=1.106, p=0,049 and OR=0.693, p=0,043, respectively). Conversely, variables such as sex, duration on dialysis, preemptive transplantation, vitamin D levels, and high-dose steroid use did not emerge as significant risk factors. At the initial assessment based on height age, 22.8% of patients had osteoporosis and 25.7% had osteopenia. Patients showing improvement by the second measurement were receiving vitamin D and calcium supplementation, while those progressing to osteoporosis were receiving high-dose steroids and exhibited poor adherence to supportive therapies. Conclusion: Following kidney transplantation, the prevalence of osteoporosis based on vertebral height age ranged from 22% to 29%. Patients' ages and BMI SDS at the time of transplant were associated with post-transplant osteoporosis, whereas sex, duration on dialysis, preemptive transplantation, vitamin D levels, and high-dose steroid use were not. Regular monitoring of bone mineral density is essential for early detection and prevention of progression.