Bone Age Reading by DXA Images should not Replace Bone Age Reading by X-ray Images.

X-ray image of the hand is the most used technique to estimate bone age in children. For the analysis of bone mineral density using DXA in children, bone age may help to adjust such measurement in some cases. During image acquisition in DXA, an anteroposterior image of the hand may be acquired and used to evaluate bone age but few studies have evaluated the agreement between conventional X-ray and DXA images. The aim of the study was to determine bone age estimation agreement between conventional X-ray images and DXA in children and adolescents aged 5 to 16 years of age. We performed an analytical cross-sectional study of 711 healthy subjects. Subject´s bone age, both in conventional X-ray, and DXA images were read independently by two expert evaluators blinded for chronological age. Intraobserver and inter-observer reproducibility were evaluated using Intraclass Correlation Coefficient (ICC), and the agreement between bone age estimations made by both evaluators was analyzed using ICC and Bland-Altman analysis. General agreement between techniques measured through ICC was 0.99 with a mean difference of 6 months between techniques being older the ages obtained by DXA. The agreement limits were around ±2 years, which means that 95% of all differences between techniques were covered within this range. We found a high level of ICC agreement in bone age readings from X-ray and DXA images although we observed overestimation of bone age measurements in DXA. Differences between techniques were greater in women than in men, especially at the ages corresponding to puberty. Bone age measurement in DXA images appears not to be reliable; hence it should be suggested to perform conventional radiography of the hand to assess bone age taking into account that X-ray images have better resolution.

Description of Normative Spine TBS Data for Men and Women in Mexican Population.

Trabecular Bone Score (TBS) has proven its usefulness to improve areal Bone Mineral Density in diagnosing fracture risk and bone status evaluation. For it to be better interpreted, local reference values are recommended to account for population differences and, if possible, both in women and men, the former being scarcer. Using TBS, we reanalyzed data obtained from the Mexican population included in the Latin American Vertebral Osteoporosis Study and the Mexican Vertebral Study in men that included a random probability sample of 408 women and 414 men aged 50 and older without fractures. Data was used to obtain reference curves in such a population. Mean TBS in women ranged from an average of 1.359 ± 0.118 standard deviation (SD) 50 to 59 and decreased down to 1.211 ± 0.128 SD in women 80 and above. In men ranged from 1.382 ± 0.116 SD in the first group down to 1.315 ± 0.118 SD in the latter with little differences in age groups. Mean values in women are lower than previously suggested cutoff points to establish microarchitecture status using TBS: 1.350 and above normal, 1.200 to 1.349 partially degraded and 1.199 and below, degraded. Our TBS data have the strength of being a random sample drawn from the population, although limited in its extent to one city in Mexico. The means and curves may be used to diagnose bone status with better sensibility and specificity, although these values are yet to be evaluated.

Bone age as a correction factor for the analysis of trabecular bone score (TBS) in children.

Trabecular bone score (TBS) is a tool to improve evaluation of DXA scans, barely used in children. We proposed to evaluate TBS with bone age (BA) compared to chronological age (CA). In girls, TBS value using BA is constant until age 8, and in boys until age 10, and then starts to increase steadily. This data may help widen TBS use in pediatric populations. INTRODUCTION: Trabecular bone score (TBS) is a software-based tool for the analysis of DXA images to assess bone microarchitecture in the lumbar region. It is used widely in adults to improve evaluation of fracture risk, yet it has been rarely studied in children and no normal curves have been developed for pediatrics. The purpose of this study was to evaluate bone (skeletal) age compared to chronological age to determine which is better in the pediatric population since both bone age (BA) and trabecular density are equally susceptible to change in response to similar factors. METHODS: Total body, lumbar region, and non-dominant hand scans were obtained with an iDXA device in all participants. DXA scans of lumbar region for TBS analysis and AP images of non-dominant hand-for-BA were obtained for 565 children (269 female) aged 4to 19. RESULTS: Simple correlation was calculated and r2 values for TBS and chronological age were obtained by linear regression, with low correlations (0.36 for boys and 0.38 for girls), and then we created Loess curves to show the change for consecutive ages. In girls, the curve forms a U shape with a nadir point at approximately age 10. We then replaced chronological age with BA, and significant change was seen in the girls' curve, where a turning point is seen at age 8. In boys, a similar trend shows a turning point at age 10. Finally, BA-corrected TBS curves were constructed using LMS, obtaining curves with percentiles. CONCLUSIONS: The use of BA in the analysis and interpretation of TBS may help widen its use in pediatric populations by enabling the appearance of normative data, but more information is needed to confirm this finding.

Vitamin D, not iron, is the main nutrient deficiency in pre-school and school-aged children in Mexico City: a cross-sectional study.

INTRODUCTION: In 2012, the Mexican National Health Survey showed a moderate prevalence rate of vitamin D deficiency, around 16%, in a national representative sample of children. A decreasing prevalence of anemia during the last 15 years has been observed in Mexico. The aim of this study was to determine the levels of vitamin D in children 3-8 years old in four different locations within the metropolitan area of Mexico City and to compare them to levels of iron and zinc as references of nutritional status. METHODS: One hundred and seventeen healthy children aged 3-8 years attending four hospitals in Mexico City were invited to participate. All children received medical and nutritional evaluation, and blood samples were obtained. RESULTS: Children were selected in the four hospitals between April and August 2008. More than half (51.3%) were boys; their average age was 5.5 ± 1.6 years. The mean height and weight of the children were 112.1 ± 11.2 cm and 20.2 ± 4.9 kg respectively, with a body mass index [BMI] of 15.8 ± 1.7 kg/m². The mean Z-score (BMI) was 0.007 ± 0.999. The prevalence of subjects with deficient levels of 25-OH-vitamin D (<50 nmol/l) was 24.77%. None of the children had haemoglobin levels below the anaemia threshold, and zinc determination revealed 8.26% of individuals with deficient levels (<65 µg/dL). These data confirm the findings reported in the latest National Nutrition Survey (ENSANUT 2012) about the sustained reduction of anaemia prevalence among preschool and schoolchildren since 1999 and the rising rates of vitamin D deficiency in the same population. Similar to other studies, we found a link between socioeconomic status and the deficiency of micronutrients, these being markers of better nutrition, and vitamin D is remarkably related to the quality of the diet. This finding has not been considered in our population before. CONCLUSIONS: There is evidence of a sustained decrease of anaemia in Mexican children due to general enrichment of foods and focus on vulnerable populations, while vitamin D deficiency seems to have increased. More studies are needed to obtain more information on vitamin D levels at different ages and definition of susceptible groups in order to investigate the possibility of general population measures such as enrichment, which have proven to be effective.

Vitamin D, not iron, is the main nutrient deficiency in pre-school and school-aged children in Mexico City: a cross-sectional study / La vitamina D, y no el hierro, es la principal deficiencia nutricional en niños preescolares y escolares en la ciudad de México: un estudio transversal

Introduction: In 2012, the Mexican National Health Survey (ENSANUT 2012) showed a moderate prevalence rate of vitamin D deficiency, around 16%, in a national representative sample of children. A decreasing prevalence of anemia during the last 15 years has been observed in Mexico. The aim of this study was to determine the levels of vitamin D in children 3-8 years old in four different locations within the metropolitan area of Mexico City and to compare them to levels of iron and zinc as references of nutritional status. Methods: One hundred and seventeen healthy children aged 3-8 years attending four hospitals in Mexico City were invited to participate. All children received medical and nutritional evaluation, and blood samples were obtained. Results: Children were selected in four hospitals between April and August 2008. More than half (51.3%) were boys; their average age was 5.5 ± 1.6 years. The prevalence of subjects with deficient levels of 25-OH-vitamin D (< 50 nmol/L) was 24.77%. None of the children had haemoglobin levels below the anaemia threshold, and zinc determination revealed 8.26% of individuals with deficient levels (< 65 μg/dL). These data confirm the findings reported in ENSANUT about the sustained reduction of anaemia prevalence among preschool and schoolchildren and the rising rates of vitamin D deficiency in the same population. Similar to other studies, we found a link between socioeconomic status and micronutrient deficiency, these being markers of better nutrition, and vitamin D is remarkably related to the quality of the diet. This finding has not been considered in our population before. Conclusions: There is evidence of a sustained decrease of anaemia in Mexican children due to general enrichment of foods and focus on vulnerable populations, while vitamin D deficiency seems to have increased. More studies are needed to obtain more information on vitamin D levels at different ages and definition of susceptible groups in order to investigate the possibility of general population measures such as enrichment, which have proven to be effective (AU)

Introducción: en 2012 la Encuesta Nacional de Salud y Nutrición (ENSANUT) mostró una prevalencia moderada de deficiencia de vitamina D, alrededor del 16%, en una muestra de niños representativa del país. A su vez, la anemia carencial ha disminuido durante los últimos 15 años en México. El objetivo del presente estudio fue determinar los niveles de vitamina D en niños de 3 a 8 años de edad en cuatro diferentes regiones dentro del área metropolitana de la Ciudad de México y compararlos con los niveles de hierro y zinc como referentes del estado nutricional. Métodos: ciento diecisiete niños sanos de 3 a 8 años de edad que regularmente asisten a cuatro diferentes hospitales en la Ciudad de México fueron invitados a participar. Todos los niños recibieron una evaluación médica y nutricional, y se obtuvieron muestras de sangre. Resultados: se reclutaron niños en los cuatro hospitales entre abril y agosto del 2008. Más de la mitad (51,3% fueron niños, su edad promedio fue de 5,5 ± 1,6 años. La prevalencia de sujetos con niveles deficientes de 25-OH-vitamina D (< 50 nmol/l) fue de 24,77%. Ninguno de los niños tuvo niveles de hemoglobina por debajo del umbral de la anemia y la determinación de zinc reveló que 8,26% de los individuos tenían niveles deficientes (< 65 μg/dl). Estos datos confirman los hallazgos reportados en el ENSANUT acerca de la reducción sostenida en la prevalencia de anemia en escolares y preescolares, pero también muestran que se eleva la de deficiencia de vitamina D en esta población. De forma similar a otros estudios, encontramos un vínculo entre el estatus socioeconómico y la deficiencia de micronutrimentos en tanto que estos son marcadores de mejor estado nutricional y la vitamina D se relaciona notablemente con la calidad de la dieta. Estos hallazgos no se han considerado previamente en nuestra población. Conclusiones: existen datos que sugieren una disminución progresiva de la anemia en niños mexicanos debido a una fortificación general de los alimentos y el enfoque en población vulnerable, mientras que la deficiencia de vitamina D parece haber incrementado. Se requieren más estudios para obtener más información acerca de los niveles de vitamina D en distintos grupos de edad y definir a los grupos susceptibles para investigar la posibilidad de llevar a cabo medidas de impacto en la población general como enriquecimiento de alimentos, que ha probado ser efectiva en otros nutrimentos (AU)

Deficiencia de vitamina D en la edad pediátrica. Una oportunidad de prevención / Vitamin D deficiency in childhood: an opportunity for prevention

ResumenLa prevalencia de deficiencia de vitamina D en la población pediátrica ha incrementado en los últimos años y se considera que continúa subdiagnosticada y subtratada. De acuerdo con datos de la Encuesta Nacional de Salud y Nutrición 2006, en México se ha estimado una prevalencia del 16% en niños de 2 a 12 años. La vitamina D desempeña un papel fundamental en la formación y homeostasis del hueso, y consecuentemente en el crecimiento. Su deficiencia se asocia con enfermedades como raquitismo y osteomalacia, y se ha relacionado con otros padecimientos, como obesidad, síndrome metabólico, diabetes, cáncer, infecciones de vías respiratorias y problemas del sistema inmune. En la literatura se han descrito grupos específicos de riesgo para deficiencia de vitamina D en los que el suplemento pudiera ofrecer un beneficio. Actualmente aún hay controversia en definir los niveles séricos de suficiencia, así como la dosis de suplemento. En México, la ingesta diaria sugerida de vitamina D es de 5.6 µg/día (224 UI), que resulta significativamente menor a las recomendaciones en los Estados Unidos y Europa (entre 400 y 1,000 UI). Debido al aumento en la deficiencia de vitamina D en los últimos años y a la falta de consenso con respecto a los niveles de suficiencia de vitamina D (ya que los valores de corte varían de 20 a 30 ng/ml considerados por la asociación de endocrinología), el objetivo de esta revisión fue proporcionar un panorama general del problema en la población pediátrica, así como describir aquellos grupos en riesgo y analizar las recomendaciones vigentes para el suplemento de vitamina D.La deficiencia de vitamina D se ha considerado rara en México, y la falta de evidencia no ha permitido establecer las recomendaciones de ingesta diaria, de acuerdo con el Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán. Sin embargo, hoy debe reconocerse como un problema de salud, meritorio de atención y acción. Sugerimos que se lleven a cabo estudios prospectivos en nuestro país, donde se establezca la relación entre la deficiencia sérica de vitamina D y la pobre mineralización ósea.

AbstractThe prevalence of vitamin D deficiency in the pediatric population has increased in recent years and continues to be underdiagnosed and undertreated. According to data from the "ENSANUT 2006" (National Health and Nutrition Survey), the prevalence of vitamin D deficiency in Mexico was 16% in children aged 2-12 years. Vitamin D plays a critical role in the formation and bone homeostasis and consequently on growth. Its deficiency is clearly associated with diseases such as rickets and osteomalacia, and it has been linked to other diseases such as obesity, metabolic syndrome, diabetes, cancer, respiratory infections and immune system disease. Specific risk groups have been described in the medical literature for vitamin D deficiency in which supplementation may offer a benefit. Currently, there is still controversy in defining the serum levels of proficiency and dose supplementation. In Mexico, the daily suggested intake of vitamin D is 5.6 µg (224 IU), which is significantly lower than the recommendations in the U.S. and Europe (i.e., between 400 and 1000 IU/day).An increase in vitamin D deficiency has been reported in recent years. There is no consensus regarding the sufficiency levels of vitamin D. Cut-off values vary from 20 to 30 ng/ml. Therefore, the objective of this review was to provide an overview of the problem in the pediatric population and to describe the groups at risk, as well as to analyze the current recommendations for vitamin D supplementation.Vitamin D deficiency was considered rare in Mexico according to the National Institute of Medical Science and Nutrition Salvador Zubirán. Lack of evidence did not help to establish the international recommended daily intake. Currently, vitamin D deficiency must be recognized as a health problem, worthy of attention and action. We suggest that prospective studies are carried out in our country where the relationship between serum vitamin D deficiency and poor bone mineralization will be established.

[Vitamin D deficiency in childhood: an opportunity for prevention]. / Deficiencia de vitamina D en la edad pediátrica. Una oportunidad de prevención.

The prevalence of vitamin D deficiency in the pediatric population has increased in recent years and continues to be underdiagnosed and undertreated. According to data from the "ENSANUT 2006" (National Health and Nutrition Survey), the prevalence of vitamin D deficiency in Mexico was 16% in children aged 2-12 years. Vitamin D plays a critical role in the formation and bone homeostasis and consequently on growth. Its deficiency is clearly associated with diseases such as rickets and osteomalacia, and it has been linked to other diseases such as obesity, metabolic syndrome, diabetes, cancer, respiratory infections and immune system disease. Specific risk groups have been described in the medical literature for vitamin D deficiency in which supplementation may offer a benefit. Currently, there is still controversy in defining the serum levels of proficiency and dose supplementation. In Mexico, the daily suggested intake of vitamin D is 5.6µg (224 IU), which is significantly lower than the recommendations in the U.S. and Europe (i.e., between 400 and 1000 IU/day). An increase in vitamin D deficiency has been reported in recent years. There is no consensus regarding the sufficiency levels of vitamin D. Cut-off values vary from 20 to 30ng/ml. Therefore, the objective of this review was to provide an overview of the problem in the pediatric population and to describe the groups at risk, as well as to analyze the current recommendations for vitamin D supplementation. Vitamin D deficiency was considered rare in Mexico according to the National Institute of Medical Science and Nutrition Salvador Zubirán. Lack of evidence did not help to establish the international recommended daily intake. Currently, vitamin D deficiency must be recognized as a health problem, worthy of attention and action. We suggest that prospective studies are carried out in our country where the relationship between serum vitamin D deficiency and poor bone mineralization will be established.

Functional reorganization of visual cortex maps after ischemic lesions is accompanied by changes in expression of cytoskeletal proteins and NMDA and GABA(A) receptor subunits.

Reorganization of cortical representations after focal visual cortex lesions has been documented. It has been suggested that functional reorganization may rely on cellular mechanisms involving modifications in the excitatory/inhibitory neurotransmission balance and on morphological changes of neurons peripheral to the lesion. We explored functional reorganization of cortical retinotopic maps after a focal ischemic lesion in primary visual cortex of kittens using optical imaging of intrinsic signals. After 1, 2, and 5 weeks postlesion (wPL), we addressed whether functional reorganization correlated in time with changes in the expression of MAP-2, GAP-43, GFAP, GABA(A) receptor subunit alpha1 (GABA(A)alpha1), subunit 1 of the NMDA receptor (NMDAR1), and in neurotransmitter levels at the border of the lesion. Our results show that: (1) retinotopic maps reorganize with time after an ischemic lesion; (2) MAP-2 levels increase gradually from 1wPL to 5wPL; (3) MAP-2 upregulation is associated with an increase in dendritic-like structures surrounding the lesion and a decrease in GFAP-positive cells; (4) GAP-43 levels reach the highest point at 2wPL; (5) NMDAR1 and glutamate contents increase in parallel from 1wPL to 5wPL; (6) GABA(A)alpha1 levels increase from 1wPL to 2wPL but do not change after this time point; and (7) GABA contents remain low from 1wPL to 5wPL. This is a comprehensive study showing for the first time that functional reorganization correlates in time with dendritic sprouting and with changes in the excitatory/inhibitory neurotransmission systems previously proposed to participate in cortical remodeling and suggests mechanisms by which plasticity of cortical representations may occur.