RESUMO
To date, the only published reports of bone mineral density (BMD) in MPS IV involve patients with MPS IVA; no reports exist describing BMD for MPS IVB. In this prospective study of BMD in three patients with MPS IVB, BMD was acquired by dual-energy X-ray absorptiometry (DXA) at whole body (WB), lumbar spine (LS), and lateral distal femur (LDF). Functional abilities, ambulatory status, medical history, and height z-score were evaluated. Three patients with MPS IVB (two females), aged 17.7, 31.4 and 31.7 years, were evaluated. Every patient was ambulatory and one sustained two fractures caused by trauma. Whole body and hip DXA scans were technically invalid in every patient due to the presence of prosthetic hip hardware. Lumbar spine was valid in only 1 patient due skeletal abnormalities, and was normal (Z-score of - 0.8). The LDF was valid in every patient and was low at all three regions of interest: average LDF z-scores were - 3.1 (range, - 2.9 to - 3.6), - 2.3 (range, - 2.0 to - 2.5), and - 2.1 (range, - 2.0 to - 2.3) for region 1-region 3, respectively. Patients with MPS IVB have low BMD of the lower extremities even with full-time ambulation. Routine body sites to measure by DXA were problematic; hip and WB were invalid due to artifact, and LS had limited utility. The LDF was the only body site consistently available on all patients. Patients did not experience low-energy fractures despite low BMD.
RESUMO
UNLABELLED: This study compared the effects of pediatric acne treatment with two isotretinoin formulations on bone mineral density. We demonstrated no difference in the effect of the two formulations. No effect on pediatric bone mineral density was identified for either formulation. INTRODUCTION: Isotretinoin (13-cis-retinoic acid) is a treatment for recalcitrant nodular acne with a purported effect on bone mineral density (BMD). The side effects of isotretinoin on vertebral bone were evaluated to assess the safety of a new FDA-approved isotretinoin formulation: Lidose-isotretinoin (Cip-Iso). METHODS: This double-blind, randomized, phase III, active control, parallel-group, multicenter study compared the safety, efficacy, and non-inferiority of CIP-Iso to a marketed reference product, Accutane®, in severe recalcitrant nodular acne subjects. Three hundred fifty-eight pediatric male and female subjects aged between 12 and 17 years underwent 20 weeks of treatment with PA lumbar spine dual X-ray absorptiometry (DXA) measurements obtained for bone mineral density (BMD) and Z-scores, 5.5 months apart on visits 1 and 8. One hundred sixty-eight of 358 subjects had height adjusted Z-scores (HAZ) calculated. RESULTS: There was no difference in the least squares (LS) mean Z-score or HAZ of the two drugs at visit 1 or 8. The mean and LS mean Z-score and HAZ were greater than zero at visits 1 and 8 for both drugs. The change in the LS mean spine Z-score, but not HAZ, between visits, was statistically significant for both drugs. There was a mean increase in BMD (g/cm(2)) for both products between visits. CONCLUSIONS: There is no difference in the effect of two formulations of isotretinoin on spine bone density after 6 months of treatment. BMD increased and the small change in spine Z-score over treatment disappeared after height adjustment. Mean positive Z-scores and HAZ in the study were likely due to the exclusion of low and inclusion of high Z-score subjects.