Dual X-ray absorptiometry has limited utility in detecting bone pathology in children with hypophosphatasia: A pooled post hoc analysis of asfotase alfa clinical trial data

Asfotase alfa is an enzyme replacement therapy approved for treatment of patients with pediatric-onset hypophosphatasia (HPP), a rare, inherited, systemic disease causing impaired skeletal mineralization, short stature, and reduced physical function in children. The role of dual X-ray absorptiometry (DXA) in the assessment of children with HPP has been insufficiently explored. This post hoc analysis included pooled DXA data from 2 open-label, multicenter studies in 19 children with HPP. The study population was aged ≥5 to <18 years and had received asfotase alfa for ≤6.6 years at enrollment (male: 79%; median age at enrollment: 10.4 y [range: 5.9–16.7]; treatment duration: 6.3 y [range: 0.1–6.6]. Baseline height Z-scores indicated short stature (median [min, max]: −1.26 [−6.6, 0]); mean [SD]: −2.30 [1.97]), thus requiring height adjustment of DXA Z-scores. At Baseline, few patients had height-adjusted bone mineral density (BMDht) Z-scores of −2 or less for whole body (n = 3) or lumbar spine (n = 5). In treated patients, mean whole body and lumbar spine BMDht Z-scores did not change over time, but whole body and lumbar spine height- adjusted bone mineral content (BMCht) Z-scores increased significantly from Baseline to Last Assessment (P ≤ 0.0056). Improvements in Radiographic Global Impression of Change (RGI-C) scale scores correlated significantly with increases in whole body and lumbar spine BMCht Z-scores (P < 0.05) but not BMDht Z-Scores. Improvements in Rickets Severity Score (RSS) correlated significantly with increases in lumbar spine BMDht Z-scores and whole body BMCht Z-scores (P < 0.05). No significant correlations were observed between any DXA and bone histomorphometry measure. These findings suggest that DXA BMD Z-scores, which are commonly used in clinical practice, have limited utility in assessing deficient bone mineralization in patients with HPP. Although BMCht Z-scores increased significantly over time with asfotase alfa therapy, the lack of significant changes in more than one DXA parameter suggests that this tool may not be useful in everyday clinical practice. Furthermore, the use of BMC as an independent metric is not typical or recommended by guidelines. Complementary measures, such as skeletal radiographs supplemented with age-appropriate functional assessments, should be considered.This work was supported by Alexion Pharmaceuticals, Inc., Boston, MA, USA

Impact of muscular symptoms and/or pain on disease characteristics, disability, and quality of life in adult patients with hypophosphatasia: A cross-sectional analysis from the Global HPP Registry

IntroductionHypophosphatasia (HPP) manifests in adults as fractures/pseudofractures, pain, muscle weakness, and other functional impairments. Better phenotypic disease characterization is needed to help recognize disability and treat patients with HPP.MethodsBaseline/pretreatment demographic, clinical characteristic, and patient-reported disability/health-related quality-of-life (HRQoL) data from adults (≥18 y) in the Global HPP Registry (NCT02306720) were stratified by presence of overt skeletal manifestations (skeletal group) versus muscular/pain manifestations without skeletal manifestations (muscular/pain group) and summarized descriptively. Disability was measured using the Health Assessment Questionnaire–Disability Index (HAQ-DI), and HRQoL using the 36-item Short Form Health Survey (SF-36v2).ResultsOf 468 adults, 300 were classified into the skeletal group and 73 into the muscular/pain group. The skeletal group had a higher median age at baseline (50.1 vs 44.4 y; P=0.047) but a lower median age at first HPP manifestation (12.3 vs 22.1 y; P=0.0473), with more signs and symptoms (median, 4 vs 3; P<0.0001) and involved body systems (median, 3 vs 2; P<0.0001) than the muscular/pain group. More patients in the skeletal group required any use of mobility aids (22.6% vs 3.5%, respectively; P=0.001). Six-Minute Walk test distances walked were similar between groups. SF-36v2 and HAQ-DI scores were similar between groups for physical component summary (n=238; mean [SD]: 40.2 [11.0] vs 43.6 [11.2]; P=0.056), mental component summary (n=238; mean [SD]: 43.6 [11.3] vs 43.8 [11.8]; P=0.902), and HAQ-DI (n=239; median [minimum, maximum]: 0.4 [0.0, 2.7] vs 0.3 [0.0, 2.1]; P=0.22).ConclusionAdults with HPP experience similar QoL impairment regardless of skeletal involvement.Registrationhttps://clinicaltrials.gov/ct2/show/NCT02306720 and https://www.encepp.eu/encepp/viewResource.htm?id=47907, identifier NCT02306720; EUPAS13514

The importance of socioeconomic factors in obesity studies. Authors reply

Este trabajo ha sido desarrollado con financiación procedente del CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn) y del Instituto de Salud Carlos III, FIS (FIS. PI09/91060; FIS 10/00747; FIS 13/01295 y FIS 16/00485)

Caracterización antropométrica y de las alteraciones metabólicas de la obesidad infanto-juvenil en relación con la restricción del crecimiento intrauterino del paciente y su alimentación infantil (lactancia materna y asistencia a comedor escolar)

OBJETIVOS: Estudiar la influencia de nacer con antropometría neonatal pequeña para la edad gestacional (PEG) y la influencia de la lactancia materna y asistencia al comedor escolar, sobre las características antropométricas y las comorbilidades metabólicas observadas en los niños y adolescentes obesos. PACIENTES y MÉTODOS: Estudio observacional retrospectivo, con evaluación de variables perinatales, antropométricas, bioquímicas, hormonales y nutricionales, en 1112 pacientes atendidos en el Servicio de Endocrinología del Hospital Infantil Universitario Niño Jesús de Madrid, con un IMC Z-score > +2 SDS para su edad y sexo en el periodo 2009-2013. RESULTADOS: El 6,3% fueron pacientes obesos nacidos PEG. En éstos, se observó una afectación más grave del metabolismo lipídico e hidrocarbonado que en aquellos pacientes que habían nacido con una antropometría adecuada a su edad gestacional (AEG) y sexo. El 78,7% de los pacientes recibieron lactancia materna. Aquellos que no habían recibido lactancia materna presentaban mayor IMC-SDS y niveles de VLDL, Triglicéridos, TSH y AUC de insulina. El 46,8% asistían al comedor escolar, y presentaban menores niveles de ácido úrico, VLDL, triglicéridos, índice triglicéridos/colesterol HDL, insulina basal, índice HOMA y mayores de HDL en comparación con los que no lo hacían. CONCLUSIONES: El antecedente de antropometría pequeña para la edad gestacional determina un mayor número e intensidad de las alteraciones metabólicas asociadas a la obesidad infanto-juvenil, al tiempo que la lactancia materna y la asistencia al comedor escolar durante la infancia parecen influenciarlas positivament

A proteomic approach to obesity and type 2 diabetes

The incidence of obesity and type diabetes 2 has increased dramatically resulting in an increased interest in its biomedical relevance. However, the mechanisms that trigger the development of diabetes type 2 in obese patients remain largely unknown. Scientific, clinical and pharmaceutical communities are dedicating vast resources to unravel this issue by applying different omics tools. During the last decade, the advances in proteomic approaches and the Human Proteome Organization have opened and are opening a new door that may be helpful in the identification of patients at risk and to improve current therapies. Here, we briefly review some of the advances in our understanding of type 2 diabetes that have occurred through the application of proteomics. We also review, in detail, the current improvements in proteomic methodologies and new strategies that could be employed to further advance our understanding of this pathology. By applying these new proteomic advances, novel therapeutic and/or diagnostic protein targets will be discovered in the obesity/Type 2 diabetes areaThis work is funded by Ministerio de Ciencia e Innovación (BFU2011–27492), Fondos de Investigación Sanitaria (PI1302195), Centro de Investigación Biomédica en Red Fisiopatología de Obesidad y Nutrición (CIBERobn), Instituto de Salud Carlos III and Fundación de Endocrinología y Nutrición. Dr. Elena López Villar is supported by ISCIII Spanish Health System (SNS BOE 2012) and she is Delegate of HUPO (Human Proteome Organization) supporting clinical proteomic studies at Hospital Niño Jesús of Madrid, Spain, to improve diagnosis and therapies via researc

Implication in Paediatrics of the First International Consensus Statement for the Diagnosis and management of pseudohypoparathyroidism and related disorders

Desde que en 1942 Albright y colaboradores describieran por primera vez el pseudohipoparatiroidismo como la existencia de hipocalcemia e hiperfosfatemia asociadas a resistencia tisular a la hormona paratiroidea (PTH) en presencia de una función renal normal, se han realizado grandes avances en la caracterización clínica y genética de los pacientes afectos de esta enfermedad. De hecho, no solo se han identificado las alteraciones moleculares responsables, sino que se ha podido establecer que variantes en otros genes de la misma vía de señalización, PTH/PTHrP a través de la proteína Gsα, son la causa de enfermedades que comparten determinadas manifestaciones clínicas con el pseudohipoparatiroidismo. En el ámbito pediátrico, los primeros síntomas o signos que deben hacernos pensar en alteraciones en esta vía son la presencia de osificaciones subcutáneas, la braquidactilia y/o la obesidad de inicio precoz, seguidas en el tiempo por la posible aparición de resistencia a la PTH. Esta sospecha clínica deberá ser confirmada mediante un diagnóstico molecular que permita el correcto seguimiento clínico coordinado y multidisciplinar. Entre los aspectos a tener en cuenta en la atención de estos pacientes se incluye la evaluación al diagnóstico y seguimiento de la eventual presencia de resistencia a la PTH y a la hormona tirotropa (TSH), deficiencia de hormona de crecimiento (GH), hipogonadismo, alteraciones esqueléticas, alteraciones de la salud dental, obesidad, resistencia a la acción de la insulina, intolerancia a la glucosa o diabetes mellitus tipo 2 e hipertensión, así como osificaciones ectópicas (subcutáneas o con afectación de tejidos más profundos) y alteración del desarrollo neurocognitivoSince Albright and co-workers described pseudohypoparathyroidism in 1942 as the combined presence of hypocalcaemia and hyperphosphataemia associated with the existence of tissue resistance to parathyroid hormone (PTH) action upon normal renal function, great advances have been made in the clinical and genetic profile of patients affected by this condition. Furthermore, not only have genetic bases of pseudohypoparathyroidism been unravelled, but also variants in other genes involved in the PTH/PTHrP signalling pathway through Gsα, have been identified as the cause of diseases that share clinical features with pseudohypoparathyroidism. In the paediatric setting, the first symptoms suggesting the impairment of this signalling pathway are the presence of subcutaneous ossifications, brachydactyly and/or early onset obesity, followed by the possible development of PTH resistance. This clinical suspicion should be confirmed by an accurate molecular diagnosis to allow for coordinated multidisciplinary clinical management. Among the features of this group of disorders, physicians should pay attention to evaluation of PTH and/or thyrotropin (TSH) resistance at diagnosis and throughout follow-up, as well as growth hormone deficiency, hypogonadism, skeletal deformities, dental impairment, obesity, insulin resistance, impaired glucose tolerance or type 2 diabetes mellitus and hypertension, as well as ectopic ossifications (either subcutaneous or affecting deeper tissues) and impairment of neurocognitive developmen

Adult height and long-term outcomes after rhIGF-1 therapy in two patients with PAPP-A2 deficiency

PAPP-A2 deficiency is a novel syndrome characterized by short stature due to low IGF bioactivity, skeletal abnormalities and decreased bone mineral density (BMD). Treatment with recombinant human IGF-1 (rhIGF-1) for 1 year demonstrated to increase growth velocity and BMD, without reported adverse effects, but data regarding the long-term efficacy and safety of rhIGF-1 administration in this entity has not yet been reported. Two Spanish siblings with short stature due to a homozygous loss-of-function mutation in the PAPP-A2 gene (p.D643fs25*) were treated with rhIGF-1 twice daily for six years. Growth velocity continued to increase and both patients achieved their target height. Free IGF-1 concentrations increased notably after rhIGF-1 administration, with serum IGFBP-3, IGFBP-5 and ALS levels also being higher during treatment. BMD was progressively normalized and an increase in lean mass was also noted during treatment. No episodes of hypoglycemia or any other adverse effects were documented. An increase in the growth of kidney and spleen length was observed in one of the patientsThis work was funded by the Spanish Ministry of Health with the help of European FEDER funding (FIS-PI19/00166

Ethnicity strongly influences body fat distribution determining serum adipokine profile and metabolic derangement in childhood obesity

Background: Body fat content and distribution in childhood is influenced by sex and puberty, but interethnic differences in the percentage and distribution of body fat also exist. The abdominal visceral/subcutaneous fat ratio has been the main feature of body fat distribution found to associate with the serum adipokine profile and metabolic derangement in adulthood obesity. This has also been assumed for childhood obesity despite the known singularities of this disease in the pediatric age in comparison to adults. Objective: We aimed to investigate the effect of ethnicity, together with sex and pubertal status, on body fat content and distribution, serum adipokine profile, metabolic impairment and liver steatosis in children and adolescents with obesity. Patients and Methods: One hundred and fifty children with obesity (50% Caucasians/50% Latinos; 50% males/50% females) were studied. Body fat content and distribution were studied by whole body DXA-scan and abdominal magnetic resonance, and their relationships with liver steatosis (as determined by ultrasonography), glycemia, insulinemia, lipid metabolism, uric acid, total and HMW-adiponectin, leptin, leptin-receptor, and sex steroid levels were explored. Results: Latino patients had more severe truncal obesity (higher trunk/lower limb fat ratio, odds ratio 10.00; p < 0.05) and higher prevalence of liver steatosis than Caucasians regardless of sex or pubertal status, but there were no difference in the visceral/subcutaneous abdominal fat ratio, except for pubertal females. A higher trunk/lower limb fat ratio, but not the visceral/subcutaneous abdominal fat ratio, was associated with adipokine profile impairment (higher free leptin index and lower adiponectin levels), insulin resistance and dyslipidemia, and was further enhanced when liver steatosis was present (p < 0.05). A higher abdominal visceral/subcutaneous fat ratio was observed in prepubertal children (p < 0.01), except for Latino females, whereas predominant subcutaneous fat deposition was observed in adolescents. Conclusion: Ethnicity is one of the main determinants of increased trunk body fat accumulation in Latino children with obesity, which is best estimated by the trunk/lower limb fat ratio and related to the development of metabolic derangement and liver steatosis.This work was supported by CIBER Fisiopatología de la Obesidad y Nutrición (CIBEROBN) and the Instituto de Salud Carlos III, FIS (FIS grant numbers PI09/91060; FIS 10/00747; FIS 13/01295; and FIS 16/00485

Bone mineral density, body composition, and metabolic health of very low birth weight infants fed in hospital following current macronutrient recommendations during the first 3 years of life

The present study longitudinally evaluated growth, bone mineral density, body composition, and metabolic health outcome in very low birth weight (VLBW) infants whose in-hospital target nutrient intake was within recent recommendations. From six months to three years, bone mineral density (dual-energy X-ray absorptiometry, DXA), body composition, and metabolic health outcome were compared with a reference group of term infants. The aim was to test whether in-hospital achieved weight gain until 36 weeks of gestation (light or appropriate for term equivalent age; LTEA or ATEA) predicts later growth, bone mineral density (BMD), abdominal obesity, or metabolic health outcomes such as insulin resistance, relative to term infants, during the first three years of life. Target in-hospital energy and protein intake was not achieved. Growth in weight, length and head circumference, mid arm circumference, adiposity, fat free mass (FFM), and bone mineralization in VLBW infants was less than those in term infants and influenced by nutritional status at discharge. Preterm infants had poorer motor and cognitive outcomes. Post-discharge body composition patterns indicate FFM proportional to height but lower fat mass index in LTEA preterm infants than term infants, with no evidence of increased truncal fat in preterm infants. The hypothesis of early BMD catch-up in VLBW infants after discharge was not supported by the present data. The clinical significance of these findings is unclear. The data may suggest a reduced obesity risk but an increased osteoporosis risk. Since postnatal growth restriction may have permanent negative health effects, LTEA VLBW infants would especially appear to benefit from targeted preventive interventions. Further follow-up of the infants is required.This research was partially funded by the ‘Fondo de Investigación Sanitaria’ (grant number PI041631