Bone Mineral Density Changes in Long-Term Kidney Transplant Recipients: A Real-Life Cohort Study of Native Vitamin D Supplementation

• Published in: Nutrients 2022-01, Vol.14 (2), p.323
• Main Authors: Battaglia, Yuri, Bellasi, Antonio, Bortoluzzi, Alessandra, Tondolo, Francesco, Esposito, Pasquale, Provenzano, Michele, Russo, Domenico, Andreucci, Michele, Cianciolo, Giuseppe, Storari, Alda
• Format: Article
• Language: English
• Subjects: Age; Biomedical materials; Bisphosphonates; Bone density; Bone Density - drug effects; Bone Density Conservation Agents - administration & dosage; Bone Density Conservation Agents - therapeutic use; Bone mineral density; bone mineral disease; Calciferol; Clinical medicine; Cohort analysis; Cohort Studies; Dietary Supplements; Dual energy X-ray absorptiometry; Female; femoral neck; Femur; Follow-Up Studies; Fractures; Humans; Kidney diseases; Kidney Transplantation; Kidney transplants; Kidneys; Male; Middle Aged; Osteopenia; Osteoporosis; Patients; Plasma levels; Standard deviation; Steroids; T-score; Time; Transplant Recipients - statistics & numerical data; Treatment Outcome; Vitamin D; Vitamin D - administration & dosage; Vitamin D - therapeutic use; Vitamin D Deficiency - prevention & control; Vitamin deficiency; Z-score
• ISSN: 2072-6643; 2072-6643
• DOI: 10.3390/nu14020323

Vitamin D insufficiency has been associated with reduced bone mineral density (BMD) in kidney transplant patients (KTRs). However, the efficacy of vitamin D supplementation on BMD remains poorly defined, especially for long-term KTRs. We aimed to investigate the effect of native vitamin D supplementation on the BMD of KTRs during a 2-year follow-up. Demographic, clinical, and laboratory data were collected. BMD was evaluated with standard DEXA that was performed at baseline (before vitamin D supplementation) and at the end of study period. BMD was assessed at lumbar vertebral bodies (LV) and right femoral neck (FN) by a single operator. According to WHO criteria, results were expressed as the T-score (standard deviation (SD) relative to young healthy adults) and Z-score (SD relative to age-matched controls). Osteoporosis and osteopenia were defined as a T-score ≤ -2.5 SD and a T-score < -1 and a > -2.5 SD, respectively. Based on plasma levels, 25-OH-vitamin D (25-OH-D) was supplemented as recommended for the general population. Data from 100 KTRs were analyzed. The mean study period was 27.7 ± 3.4 months. At study inception, 25-OH-D insufficiency and deficiency were recorded in 65 and 35 patients. At the basal DEXA, the percentage of osteopenia and osteoporosis was 43.3% and 18.6% at LV and 54.1% and 12.2% at FN, respectively. At the end of the study, no differences in the Z-score and T-score gains were observed. During linear mixed model analysis, native vitamin D supplementation was found to have a negative nitration with Z-score changes at the right femoral neck in KTRs ( < 0.05). The mean dose of administered cholecalciferol was 13.396 ± 7.537 UI per week; increased 25-OH-D levels were found ( < 0.0001). Either low BMD or 25-OH-vitamin D concentration was observed in long-term KTRs. Prolonged supplementation with 25-OH-D did not modify BMD, Z-score, or T-score.