Body Composition, Bone Health, and Dietary Intake in Children After Allogeneic Hematopoietic Stem Cell Transplantation

Background/Objectives: This study describes body composition, bone mineral density (BMD), and dietary intake in pediatric patients undergoing allogeneic hematopoietic stem cell transplantation compared to healthy children. Methods: In this prospective observational study, dual-energy X-ray absorptiometry was used to assess appendicular lean mass index (ALMI), fat mass index (FMI), fat mass percentage (FM%), and BMD, and a 4-day dietary record was used to assess dietary intake at 3 months and 1 year post-transplant. Healthy children were assessed once by the same methods. Results: We included 28 patients (mean 10.3 years, SD 4.0) and 50 healthy children (mean 10.0 years, SD 3.6). At 1 year, median Z-scores were lower for ALMI (−1.34 vs. 0.40, p < 0.001), higher for FMI (0.34 vs. −0.33, p < 0.012) and FM% (0.59 vs. −0.98, p < 0.001), lower for BMD total body less head (−1.0 vs. 0.3, p = 0.006), but similar for BMD spine compared to healthy children. At 1 year, 9/15 (60%) had ALMI Z-score ≤ −1, 6/15 (40%) had FMI Z-score ≥ 1, 5/15 (33%) had FM% Z-score ≥ 1, and 8/18 (53%) had BMD total body less head Z-score ≤ −1, and 3/15 (20%) had BMD spine Z-score ≤ −1. Dietary intake improved, and at 1 year, energy and protein intakes were comparable, fat, calcium, and vitamin D intakes were higher, but fiber intake remained lower in patients than in healthy children. Conclusions: Patients had a more unfavorable body composition and bone health. Dietary intake improved from 3 months to 1 year post-transplant. However, the results indicate a need for nutritional follow-up, particularly targeting protein, fat, fiber, calcium, and vitamin D.