Bone Mineral Density in Neurofibromatosis Type 1: A Systematic Review and Meta-Analysis

To assess BMD in patients with neurofibromatosis type 1 (NF1) using systematic review and meta-analysis technique. Potentially eligible studies were identified from Medline and EMBASE databases from inception to February 2023 using search strategy that comprised terms for "Bone mineral density" and Neurofibromatosis type 1 ''. Eligible study must include adult or pediatric patients with NF1. The study must report mean Z-score with variance of total body, lumbar spine, femoral neck or total hip BMD of the studied patients. Point estimates with standard errors were retrieved from each study and were combined using the generic inverse variance method. A total of 1,165 articles were identified. After systematic review, 19 studies were included. The meta-analysis revealed that patients with NF1 had negative mean Z-scores for total body BMD (pooled mean Z-score -0.808; 95%CI, -1.025 to -0.591) and BMD at lumbar spine (pooled mean Z-score -1.104; 95%CI, -1.376 to -0.833), femoral neck (pooled mean Z-score -0.726; 95%CI, -0.893 to -0.560) and total hip (pooled mean Z-score -1.126; 95%CI, -2.078 to -0.173). The subgroup meta-analysis in pediatric patients aged < 18 years revealed that patients with NF1 had negative mean Z-scores for lumbar spine BMD (pooled mean Z-score -0.938; 95%CI, -1.299 to -0.577) and femoral neck BMD (pooled mean Z-score -0.585; 95%CI, -0.872 to -0.298). The current meta-analysis found that patients with NF1 had low Z-scores although the degree of low BMD may not be of clinical significance. The results do not support the role of early BMD screening in children and young adults with NF1.