Bone Abstracts

Background and objectives: X-linked hypophosphatemic rickets (XLH) is the most common form of inheritable rickets. The treatment of rickets is monitored via laboratory tests such as alkaline phosphatase (ALP), clinical features, and plain X-rays. The objectives of this study were to describe the MRI features in XLH and to look for correlations between those features and XLH activity.Study design: Twenty-seven patients (younger than 18 years with XLH due ...

Many of our assumptions concerning oral implant osseointegration are extrapolated from experimental models studying skeletal tissue repair in long bones rather than in oral bones. This discrepancy between clinical practice and experimental research hampers our understanding on how alveolar bone forms or resorbs around implants and how osseointegration of oral implants can be improved. To overcome this disconnect, we have developed a mouse model which mimics oral implant placem...

Mutations in the PHEX gene cause X-linked familial hypophosphatemic rickets (XLH) with severe bone (osteomalacia) and tooth abnormalities being the distinguishing features of this disease. The PHEX mutations lead to an increase in ASARM peptides (acidic serine- and aspartate-rich motif) and osteopontin fragments which inhibit bone extracellular matrix mineralization. MEPE-derived ASARM has been shown to accumulate in tooth dentin of patients with XLH where it may impair dentin...

Mutations in PHEX and specific missense mutations of FGF23 result in elevated circulating FGF23 and hypophosphatemic rickets, respectively X-linked hypophosphatemic rickets (XLHR) and autosomal dominant HR (ADHR). FGF23, secreted by osteoblasts and osteocytes, regulates phosphate handling and vitamin D metabolism through its action on kidney. Extra renal effects of FGF23, including bone, have been very recently suspected mainly from overexpression or underexpression of FGF23 i...

Background and aim: Burosumab is a monoclonal antibody against anti-FGF23, which has been recently approved for treatment of X-linked hypophosphatemia (XLH). Beyond clinical trials, little is known about its efficacy/safety in clinical practice which is the aim of study.Patients/Methods: 39 children with XLH were switched from conventional therapy to burosumab (starting dose 0.4 mg/kg), because of following indications: non-responder to conventional ther...

The childhood and adolescent years represent a critical period for bone acquisition. Extrinsic factors such as diet and physical activity represent modifiable variables that may have a significant impact on a young adult’s peak bone mass. This lecture will consider dietary supplementation with specific nutrients as a strategy to augment bone density during the childhood and teenage years. An overview will be provided, as well as data reviewed from supplementation trials i...

Biographical DetailsCatherine M Gordon, MD, MSc is a Professor of Pediatrics at the Alpert Medical School of Brown University and is Director of the Division of Adolescent Medicine at Hasbro Children’s Hospital. She is board-certified in adolescent medicine and pediatric endocrinology. She is on the Board of Directors for the International Society for Clinical Densitometry, and direc...

Vascular calcification is a ubiquitous pathology in the aged and diseased vasculature occurring at two sites in the vessel wall; in the intima in association with atherosclerosis and in the media in association with ageing, diabetes, and end-stage renal disease. Calcification at either site is associated with adverse cardiovascular outcomes including increased risk of myocardial infarction and arterial stiffness. Numerous studies have observed that vascular calcification and c...

Gross motor development is positively associated with bone mineral density in teenagers and is thought to be mediated by lean mass. Age at walking is an accepted milestone in motor development, achieved by 50% of infants by 12 mo of age according to the WHO Motor Development Study.Objective: To examine if walking within 12 mo of age is related to bone mineral density (BMD) and if this relationship is mediated by lean mass.Methods: ...

The relationship between vitamin D status and lean mass accretion in young children is not well understood.Objective: To explore vitamin D status in relation to lean mass outcomes over 12 mo in children 2–8 years.Methods: This was a secondary analysis of trial data (clinicaltrials.gov: NCT02097160, NCT02387892) in Montreal, Canada. Children consumed their normal vitamin D intake for 6 mo (Apr–Oct 2014, n=39) and ...