Bone Abstracts

Background: Hypophosphatasia (HPP) is caused by inactivating mutation(s) in the gene for tissue non-specific alkaline phosphatase. Extracellular accumulation of inorganic pyrophosphate can lead to profound hypomineralization resulting in limb and chest deformity, respiratory complications and vitamin B6-dependent seizures in the severe forms of HPP. The natural history of HPP is poorly understood, but the perinatal and infantile forms are often considered lethal.<p class="...

Objectives: Hypophosphatasia (HPP) is the rare inherited metabolic disease caused by low tissue nonspecific alkaline phosphatase activity. HPP manifests a wide spectrum of complications, which may include HPP-related rickets and compromised physical function in children.Methods: We report on clinical gait assessments based on archival video recordings of six children with onset of HPP symptoms at ≧6 months and documented HPP-related skeletal abnor...

Objective: Mobility is an important endpoint in patient care with implications for activities of daily living, community participation, and quality of life. We adapted the performance-oriented mobility assessment (POMA-G),1 a widely used and validated clinical gait assessment tool for adults, to use in children with hypophosphatasia (HPP). HPP is the rare metabolic disease caused by loss-of-function mutation(s) in the gene encoding tissue non-specific alkaline phosp...

Morbidity and mortality are associated with osteoporosis and sarcopenia. There are few data describing the associations between functional measures of muscle and bone. Therefore, the aim of this study was to examine the associations of muscle strength and tibial bone outcomes in ageing men.Men (n=301) aged 40–85 years were recruited in UK (201-White, 43-Black, 57-South-Asian). pQCT was performed at the 38 and 66% tibia with the outcome meas...

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Previous studies demonstrated a negative influence of the growth- and differentiation factor midkine (MDK) on bone formation during bone remodeling and fracture healing. Additionally, MDK-deficiency protected mice from a loss of trabecular bone mass after ovariectomy (OVX). Therefore, we hypothesized that MDK may also be involved in the pathogenesis of delayed, osteoporotic fracture healing after OVX in mice. Thus, we analyzed the expression of MDK during bone regeneration and...

Breastfeeding women resorb trabecular bone to supply much of the calcium content of milk. Few studies have examined the speed and extent of BMD recovery after weaning, or the factors that predict a greater post-lactation increase in BMD. We hypothesize that weight-bearing, nutrition, hormones, and other factors facilitate bone formation after lactation.The aims of the Factors Affecting Bone Formation After Breastfeeding Pilot Study (FABB-Pilot) were to d...

Tenofovir disoproxil fumarate (TDF) is a critical component of first-line antiretroviral regimens for HIV worldwide. However, TDF-containing regimens have been associated with decreased bone mineral density and increased fracture risk, which may in part be mediated through secondary elevations in parathyroid hormone (PTH). Prior cross-sectional data suggest vitamin D binding protein (DBP) levels may increase with TDF exposure leading to a functional vitamin D deficiency, which...

Objectives: XLH features renal phosphate (Pi) wasting, hypophosphatemia, rickets, and skeletal deformities from elevated circulating levels of fibroblast growth factor 23 (FGF23). KRN23, an investigational fully human monoclonal antibody, binds FGF23 and inhibits its action. Our Phase 2 study of KRN23 in XLH children (ages 5–12 years) is demonstrating improvements in serum Pi and rickets. Here we present our Phase 2 trial evaluating the efficacy and safety of KRN23 in you...