ICCBH2013 Poster Presentations (1) (201 abstracts)
1Complex NF1 service, St Marys Hospital, Manchester, UK; 2MRC, Human Nutrition Research, Cambridge, UK; 3Radiology, Central Manchester University Hospitals NHS Foundation Trust, University of Manchester, Manchester, UK; 4Department of Paediatric Endocrinology, Royal Manchester Childrens Hospital, Manchester, UK.
Aim: Scoliosis is a common skeletal problem affecting 1030% of patients with neurofibromatosis type 1 (NF1). NF1 patients have been shown to have reduced bone mineral density (BMD) which may play a role in the pathogenesis or progression of scoliosis. Our centre is one of four international centres currently evaluating the efficacy of various spinal imaging techniques and BMD as predictors for scoliosis in NF1. In our cohort we measured the lumbar spine (LS) BMD both by dual energy absorptiometry (DXA) and quantitative computed tomography (QCT).
Methods: Clinical examination, spinal x-ray and bone densitometry was undertaken in 22 children with NF1 aged 69 years (12 females). This was repeated at year 4. BMD of L1L4 was measured by DXA; data was expressed as bone mineral apparent density (BMAD; g/cm3) and values transformed to Z-scores using previously published normative data (ADC 2007 92 (1) 5359). Volumetric trabecular BMD (TBMD; mg/cm3) of L1L3 was also measured using QCT; values transformed to Z-scores using the Mindways Software (Austin, TX, USA). The mean difference between years 1 and 4 was calculated using a paired T-test.
Results: Year 1 mean Z-score LSBMAD (−0.62±1.1; P=0.01) and TBMD (−0.86±0.7; P<0.001) were <0. Initial data for year 4 mean Z-score LSBMAD (−0.75±1.3; P=0.01) and TBMD (−1.07±0.94; P<0.001) were also <0. Mean difference in LSBMAD between years 1 and 4 is (−0.07±0.64; P=0.58) and for TBMD (−0.21±0.5; P=0.07).
Conclusions: Children with NF1 had reduced LS BMD which was more marked in the trabecular compartment. Furthermore this persisted during the period of follow-up.
K Ward is funded by Medical Research Council Grant Code U105960371.