Ausencia de diferencias relacionadas con el sexo en los valores de los cambios mínimos significativos para composición corporal por DXA en sujetos adultos / Absence of sex-related differences in the values of minimum significant changes for body composition by DXA in adult subjects

Para la evaluación longitudinal de la composición corporal por DXA se deben calcular los cambios mínimos significativos (CMS). No está claro si hay diferencias de género para los CMS de adultos. Con consentimiento informado se realizaron 2 escaneos DXA de cuerpo completo consecutivos, con reposicionamiento entre ellos, en 40 varones y 40 mujeres (rango de edad de 22 a 85 años), con un equipo GE Lunar Prodigy Advance®, siguiendo las pautas de la International Society for Clinical Densitometry (ISCD). Todos los escaneos fueron obtenidos por la misma técnica experta. Los CMS se calcularon de acuerdo con el método propuesto por la ISCD. Los resultados se analizaron con GraphPad® para Windows 6.0, con una significancia fijada en p < 0,05. No hubo diferencias de género para la edad (p = 0,846) o el índice de masa corporal (p = 0,802). La altura, la masa corporal, la masa magra y el contenido mineral óseo (CMO) fueron mayores en los varones (todos p < 0,0001), mientras que la masa grasa fue mayor en las mujeres (p = 0,0036). No hubo diferencias significativas entre géneros para los coeficientes de variación de masa grasa (p = 0,0698), masa magra (p = 0,1483) o CMO (p = 0,5254). Los CMS (para IC de 95%) para la masa grasa fueron 1,780 kg (varones), 1,671 kg (mujeres) y 1,727 kg (ambos sexos); para masa magra, 1,658 kg (varones), 1,644 kg (mujeres) y 1,651 (ambos sexos); y para CMO, 112,2 g (varones), 109,4 (mujeres) y 110,8 g (ambos sexos). Los resultados sugieren que los CMS para la composición corporal de su-jetos adultos pueden calcularse a partir de una muestra de cualquier género o una que incluya sujetos de ambos sexos. (AU)

Lack of gender-related differences in least significant changes for DXA body composition analysis in adult subjectsFor longitudinal assessment of body composition by DXA, least significant changes (LSCs) should be calculated. It is unclear if there are gender differences for adult LSCs. With informed consent, 2 consecutive total-body DXA scans, with repositioning between them, were performed on 40 males and 40 females (age range 22 to 85 years) with a GE Lunar Prodigy Advance scanner, following the guidelines of the International Society for Clinical Densitometry (ISCD). All scans were obtained by the same skilled technologist. The LSCs were calculated according to the method proposed by the ISCD. Results were analyzed with GraphPad for Windows 6.0, with significance set at p < 0.05. There were no gender differences for age (p = 0.846) or body mass index (p = 0.802). Height, body mass, lean mass, and bone mineral content (BMC) were higher in males (all p < 0.0001), whereas fat mass was higher in females (p = 0.0036). There was no significant difference between genders for the coefficients of variation of fat mass (p = 0.0698), lean mass (p = 0.1483), or BMC (p = 0.5254). The LSCs (for a 95% CI) for fat mass were 1.780 kg (men), 1.671 kg (women), and 1.727 kg (both genders); for lean mass, 1.658 kg (men), 1.644 kg (women) and 1,651 (both genders); and for BMC, 112.2 g (men), 109.4 (women), and 110.8 g (both genders). These results suggest that LSCs for body composition of adult subjects can be calculated from either a sample of each gender or one that includes subjects of both genders. (AU)

Effect of Maternal Supplementation With Two Different Doses of Vitamin D During Lactation on Vitamin D Status, Anthropometry and Bone Mass of Infants: A Randomized Controlled Trial

Background: There is a high prevalence of vitamin D deficiency (VDD) in exclusively breast-fed infants in the absence of appropriate vitamin D supplementation. Objective: To evaluate the efficacy of two doses of maternal vitamin D supplementation on vitamin D levels of mother-infant pairs and to assess its effect on growth parameters (weight, length and head circumference) and bone mass of infants. Study design: Randomized controlled trial. Participants: Lactating mother-infant pairs (n=220). Intervention: Maternal oral vitamin D supplementation in two doses (group 1: 1,20,000 IU/month and group 2: 12,000 IU/month) for 12 months. Main outcomes: Maternal and infant serum 25OHD levels, and infants’ growth and bone mass. Results: There was high prevalence of VDD at baseline in mothers (94%) as well as infants (98.5%), which was reduced to 43.1% in (mothers) and 46.5% in infants after 12 months. Significantly higher median (IQR) serum 25OHD levels (ng/mL) were observed among mothers in group 1 compared to group 2 [46 (17-159) vs 18 (6-64); P<0.01] and in infants [36.5 (15-160) vs 17 (7-32); P<0.01]. No significant association was observed between growth parameters or bone mass and serum 25OHD levels of mother or infant between the two groups. Four mothers (3.6%) and two infants (1.8%) in group I had serum 25OHD>100 ng/mL, but without hypercalciuria or hypercalcemia. Conclusion: Bolus vitamin D supplementation in the dose of 1,20,000 IU/month was more efficacious in improving maternal and infant vitamin D status at 12 months, as compared to 12,000 IU/month.

Valores de referencia de la densidad mineral ósea por densitometría tipo DXA en una población adulta sana de Bogotá / Bone mineral density reference values by densitometry (DXA) in a healthy adult population of Bogota

RESUMEN Introducción: La actual definición de osteoporosis es basada en la absorciometría de energía dual de Rx (DXA, por sus siglas en inglés), lo cual representa la principal técnica para la cuantificación de la densidad mineral ósea (DMO) y la evaluación del riesgo de fractura. El objetivo de este estudio fue determinar la DMO en columna lumbar y cuello femoral de adultos sanos desde el punto de vista metabólico óseo en una población de Bogotá-Colombia. Métodos: Se realizó un estudio observacional, analítico, de corte transversal, basado en un cuestionario aplicado a la población de estudio. Las medidas densitométricas fueron realizadas con un equipo compacto de alto rendimiento de la General Electric, modelo iDXA, por el mismo tecnólogo en los sitios esqueléticos de interés, columna lumbar L1, L2, L3, L4 y L1-4 en proyección anteroposterior y en cuello femoral. El cálculo del tamaño de muestra se realizó teniendo en cuenta la estratificación por sexo y 2 grupos de edad: 20 a 29 años y 30 a 39 años. Se encuestó a 805 individuos y 432 se realizaron la densitometría ósea. Resultados: Los valores encontrados en columna lumbar para cada uno de los grupos de nuestra población, fueron: 1,150 g/cm2 (DE: 0,11), 1,180 g/cm2 (DE: 0,10), para mujeres y hombres de 20 a 29 años, y 1,169 g/cm2 (DE: 0,10), 1,209 g/cm2 (DE: 0,10) para mujeres y hombres de 30 a 39 años, respectivamente. A nivel del cuello femoral, 0,991 g/cm2 (DE: 0,10), 1,119 g/cm2 (DE: 0,13), para mujeres y hombres de 20 a 29 años, y 0,970 g/cm2 (DE: 0,11), 1,079 g/cm2 (DE: 0,13) para mujeres y hombres de 30 a 39 años, respectivamente. Conclusión: Este estudio pudo demostrar el comportamiento de la DMO en nuestra población, la cual es inferior a la detectada en otras latitudes y a las utilizadas como valores de referencia en nuestros equipos. Adicionalmente, se determinó el valor máximo de masa ósea en cada una de las regiones de interés para los rangos de edad de la población de nuestro estudio.

ABSTRACT Introduction: The current definition of osteoporosis is based on the dual energy X-ray absorptiometry (DXA), which represents the main technique for the quantification of bone mineral density (BMD) and the evaluation of fracture risk. The objective of this study was to determine the BMD in the lumbar spine and femoral neck of healthy adults from a bone metabolism point of view in a population of Bogotá-Colombia. Method: An observational, analytical, cross-sectional study was conducted based on a questionnaire completed by the study population. The densitometric measurements were carried out using a high-performance compact equipment of the General Electric, iDXA model, by the same technologist at the skeletal sites of interest, lumbar spine L1, L2, L3, L4 and L1-4 in anteroposterior projection, and in femoral neck. The sample size calculation was performed taking into account stratification by gender and 2 age groups: 20 to 29 years, and 30 to 39 years. A total of 805 individuals were surveyed, and 432 bone densitometries were performed. Results: The values found in the lumbar spine for each of the groups in our population were: 1.150 g/cm2 (SD: 0.11), 1.180 g/cm2 (SD: 0.10), for women and men aged 20 to 29 years, and 1.169 g/cm2 (SD: 0.10), 1.209 g/cm2 (SD: 0.10) for women and men aged 30 to 39, respectively. At the level of the femoral neck, 0.991 g/cm2 (SD: 0.10), 1.119 g/cm2 (SD: 0.13), for women and men aged 20 to 29 years, respectively, and 0.970 g/cm2 (SD: 0.11), 1.079 g/cm2 (SD: 0.13) for women and men aged 30 to 39, respectively. Conclusion: This study was able to demonstrate the behaviour of BMD in our population, which is lower than that detected in other latitudes and those used as reference values in our equipment. Additionally, the maximum bone mass value was determined in each of the locations of interest for the age ranges of the population in our study.

Diagnostic accuracy of Lumbar Spine Bone Mineral Density (BMD) measurements via Quantitative Computed Tomography (QCT) in the assessment of osteoporosis in Filipino women diagnosed with breast cancer using Dual-Energy X-ray Absorptiometry (DXA) as gold standard

Background@#Breast cancer, chemotherapy and endocrine treatment are risk factors for osteoporosis. Dual-energy x-ray absorptiometry (DXA) remains the gold standard in the diagnosis of osteoporosis. A quantitative computed tomography (QCT) with a bone mineral density analysis software on the whole abdomen CT may be used for screening osteoporosis without additional radiation exposure or cost.@*Objective@#To determine the accuracy of QCT in detecting osteoporosis among breast cancer patients using DXA as gold standard. @*Methods@#This is a cross-sectional analytic study of 76 Filipino women with breast cancer who underwent both DXA and whole abdomen CT scans. The DXA measurements were obtained using Lunar iDXA manufactured by GE Healthcare while the QCT measurements were made using the BMD analysis software available in the Philips Extended Brilliance Workspace post-processing system.@*Results@#Out of the 76 Filipino women with breast cancer, 92% were menopausal women with mean age of 58.9 (SD 8.7) years, 69.7% had IDCA and 94.7% had mastectomy. Majority had normal BMD (44.7%), 34.2% had osteopenia and 21.1% had osteoporosis based on DXA. QCT has 90% (95% CI: 55.5-99.8) sensitivity, 63.6% (95% CI: 30.1- 89.1) specificity, 69.2% (95% CI: 50.1-83.5) PPV, 87.5 (95% CI:50.8-97.9) NPV, 2.5 (95% CI:1.1-5.6) LR(+) and 0.16 (95% CI:0.02-1.06) LR (-).@*Conclusion@#The prevalence of osteoporosis and osteopenia among Filipino women with breast cancer was 21.1% and 34.2%. The sensitivity and specificity of QCT in detecting osteoporosis was 90% and 63.6%.

Comparative Study Between Periostin And Osteocalcin As Biomarkers For Osteoporosis And Fracture Risk In Egyptian Postmenopausal Women

Objective: This study aimed to compare between periostin and osteocalcin as biomarkers in Egyptian postmenopausal women with osteoporosis and to explore their possible relationship with fracture risk. Methods: This study included 90 postmenopausal females recruited from Al-Hussein University Hospital, Cairo, Egypt; divided into three groups; 35 postmenopausal osteoporotic females with low fracture risk (group I), 35 postmenopausal osteoporotic females with high fracture risk (group II), and 20 apparently healthy controls. Serum periostin, osteocalcin, and estrogen were measured by Enzyme Linked Immunosorbent Assay (ELISA). Fracture risk assessment was calculated. Alkaline phosphatase (ALP), total and ionized calcium, Aspartate transaminase (AST), and Alanine transaminase (ALT) were measured spectrophotometrically. Results: The diagnostic performance of periostin for discriminating high fracture risk from low fracture risk groups showed the specificity of (68.6 %) and sensitivity of (100 %), while for osteocalcin the specificity was (51.4 %) and the sensitivity was (68.6 %) respectively. Moreover, the multi Receiver Operating Characteristics (multi-ROC) curve for periostin and osteocalcin together revealed improved specificity and sensitivity of (100 %) each. Conclusion: Periostin was superior to osteocalcin in discriminating high fracture risk from low fracture risk postmenopausal osteoporotic groups. Moreover, dual use of both markers gave the highest discriminative power between low and high fracture risk groups with 100 % specificity and sensitivity.

A study on patients with coronary artery disease with special reference to bone mineral density

Background: Osteoporosis and Coronary artery disease are known to share common risk factors, like inflammation, but a direct relationship between the two has not been established. Some of the previous studies showed low BMD (osteoporosis and/orosteopenia) as an independent predictive factor for coronary artery disease in ambulatory patients. However, some reports have failed to demonstrate a direct relationship between low bone mineral density (BMD) and CAD or cardiovascular risk factors. This study was carried out to estimate bone mineral density (BMD) in patients with coronary artery disease (CAD) and also to evaluate the association between bone mineral density and coronary artery disease.Methods: Hospital based prospective observational study, involving 96 consecutive patients who were referred for coronary angiography for the evaluation of established or suspected CAD and also patients who had acute coronary syndrome (ACS) are enrolled in this study. BMD was determined for the lumbar spine (L2-L4) and femoral neck using DXA scan.Results: The total number of subjects was 96. Out of 96, 24 (25%) patients were females and remaining 72 (75%) were males. Coronary angiography was carried out in all patients. 42 patients from the total had coronary angiography proven single vessel disease (SVD), 33 patients had double vessel disease (DVD) and 21 patients had triple vessel disease (TVD). DXA scan was carried out in all patients. T- score of neck of femur region and lumbar spine was calculated. Neither the presence of significant coronary stenoses ≥50% in two or more coronary vessels nor the prevalence of severe coronary stenoses ≥70% differed significantly between patients with normal bone density, osteopenia, or osteoporosis (p<0.05, respectively).Conclusions: The result of this study suggests that in patients undergoing coronary angiography for the evaluation of CAD, the prevalence of low BMD is high; however, there is no statistically significant relationship between osteoporosis, osteopenia and coronary artery disease state.

Salud ósea en personas transgénero / Bone health in transgender subjects

Una persona transgénero es aquella en la cual el género autopercibido difiere del asignado al nacer, mientras que el término cisgénero es utilizado en aquellos individuos no trans. El tratamiento hormonal cruzado (THC) constituye una opción para lograr caracteres sexuales secundarios deseados. Es conocido que los esteroides sexuales desempeñan un rol fundamental en la adquisición de la densidad mineral ósea (DMO) durante la pubertad. Por lo tanto, el impacto del THC sobre la masa ósea se ha convertido en materia de estudio. En estadios puberales tempranos, los análogos de la hormona liberadora de gonadotrofinas (GnRH) son utilizados con un efecto reversible. Si bien la DMO parece mantenerse estable, cuando se compara con una población de referencia del mismo sexo biológico y edad, el Z-score se encuentra por debajo de lo esperado. En adultos, durante el THC no se informaron disminuciones en la DMO. Está reportado que las mujeres trans antes del inicio del TH presentan características densitométricas diferentes de los hombres cisgénero. Hasta el momento, la carga de datos para los calculadores del riesgo de fractura y el software del equipo DXA se basan en el sexo biológico y no en identidad de género. Recientemente, la International Society for Clinical Densitometry (ISCD) emitió sus recomendaciones para la evaluación de la masa ósea en personas transgénero y en aquellos individuos no conformes con el género. Si bien la ISCD sugiere realizar la evaluación únicamente en aquellos pacientes con factores de riesgo, es de importancia realizar DXA basal, sobre todo en mujeres transgénero, para determinar el riesgo inicial de dicha población. En este artículo se revisa la evidencia disponible sobre el impacto del THC en la salud ósea de personas transgénero. (AU)

Cross sex hormone therapy (CSHT) in transgender women (TW) it is an option to achieve desired secondary sexual characteristics. It is known that sex steroids play a fundamental role in the acquisition of bone mineral density during puberty, in addition to determining a different characteristic bone pattern between both biological sexes. So the impact of affirming HT on bone is it has become in subject of study. In early pubertal stages, GnRH analogs are used with a reversible effect. Although bone mineral density (BMD) seems to remain stable, when compared with a reference population of the same biological sex and age, the Z-score is lower than expected. In adults, during CSHT no decreases in BMD were reported. However, it was reported that TW prior to starting CSHT present different densitometric characteristics than cisgender men. So far, the data load for the fracture risk calculators and DXA software is based on biological sex and not gender identity. Recently the ISCD issued its recommendations for the evaluation of bone mass in transgender subjects and in those non-conforming to gender. Although the ISCD suggests performing the evaluation only in those patients with risk factors, our group recognizes that baseline DXA, especially in TW, constitutes a useful tool to determine the initial risk of this population. Our proposal arises from our own experience and from that compiled in the international literature, where it is observed that even without starting CSHT, transgender women have lower BMD. DXA. This article reviews the available evidence regarding the effect of CSHT on health bone in transgender people. (AU)

Arthroscopic repair for osteoporosis in the greater tuberosity of patients with rotator cuff tear due to chronic moderate to severe tendon retraction / 中国组织工程研究

BACKGROUND: Rotator cuff injury is the most common type of shoulder joint injury. So far, there are few studies on the relationship between local osteoporosis of the greater tuberosity of the humerus and rotator cuff tears in China. The bone mineral density (BMD) in the footprint area is a key factor affecting the intraoperative anchor placement. The recovery of BMD after operation is worth further study. OBJECTIVE: To compare preoperative and postoperative BMD of the bilateral greater tuberosity of the humerus and analyze the improvement of BMD after arthroscopic rotator cuff suture. METHODS: Data of 37 patients with unilateral rotator cuff injury who received arthroscopic suture in the Department of Joint Surgery of the Affiliated Hospital of Chengde Medical College were retrospectively analyzed. There were 16 males and 21 females. The average age was 55.8 years (age range: 35-73 years). Rotator cuff injuries were classified according to Patte’s degree of tendon retraction: mild retraction in 17 cases, moderate and severe retraction in 20 cases. BMD of the bilateral greater tuberosity of the humerus measured by dual-energy X-ray absorptiometry was collected, and the relationship between the course of disease, tendon retraction and the difference of BMD before and 1 year after surgery was analyzed. RESULTS AND CONCLUSION: The BMD difference of the bilateral greater tuberosity of the humerus in the mild retraction group was significantly lower than that in the moderate and severe retraction group (P < 0.05), and the BMD difference in the acute mild retraction group was significantly lower than that in the chronic moderate and severe retraction group (P < 0.05). The local osteoporosis of the greater tuberosity was severer in the patients with chronic moderate and severe retraction. During 1-year follow-up after surgery, the BMD difference of the 37 patients was significantly lower than that before surgery (P < 0.05). The BMD difference had no significant difference in the mild retraction group before and after surgery, while in the moderate and severe retraction group, the BMD difference was significantly lowered after surgery (P < 0.05). The BMD difference in the chronic moderate and severe retraction group was significantly lowered after surgery (P < 0.05). At the last follow-up, imaging examination showed no re-tears in all the enrolled patients. To conclude, local osteoporosis of the greater tuberosity is the most obvious in rotator cuff injury with chronic moderate to severe tendon retraction. Arthroscopic repair of rotator cuff injury under shoulder arthroscopy can restore local bone substance to a certain extent, regardless of the course of the disease.

Handball practice on bone health of female adolescents: evaluation of an eight-month competitive period / Prática de handebol e a densidade óssea de adolescentes do sexo feminino: avaliação de uma etapa competitiva de oito meses

A strategy to prevent bone loss diseases (i.e., osteoporosis) would be to enhance the increase of bone mass during childhood and adolescence. The purpose of this study was to compare bone mineral den-sity (BMD) and bone mineral content (BMC) between female adolescent handball players and peers who did not play (control group), and to assess the changes in BMD and BMC after eight-months of competitive period. Fifty-eight female adolescents (12­17 years old) were allocated into two groups: handball players (HG: n = 27) and control group (CG: n = 31). BMC and BMD were measured using dual-energy X-ray absorptiometry, and z-scores were calculated. Sexual maturity, menarche, peak height velocity (PHV ), sun exposure and calcium intake were assessed. At baseline, the handball players showed greater BMC and BMD than control group (p < 0.05). These differences between groups disappeared after adjusting for weight, BMI, menarche and lean soft tissue. After competitive period, significant time-effects for BMC and BMD of total TBLH and lumbar spine (p < 0.01) were observed in the handball players. HG increased BMC and BMD of total body and lumbar spine after eight-month. The Z-score analysis showed significant group effects with greater BMD of total body, lumbar spine, femur and hip than control group. The results showed that after eight-month compet-itive handball period, there was an increase in BMD of total body for handball players

Uma estratégia para prevenir doenças relacionadas a baixa densidade óssea, como a osteoporose, é aumentar o incremento da massa óssea durante a infância e a adolescência. O objetivo deste estudo foi comparar a densidade mineral óssea (DMO) e o conteúdo mineral ósseo (CMO) de adolescentes jogadoras de handebol com adolescentes da mesma idade que não jogavam (grupo controle) e avaliar a resposta da DMO e CMO ao longo de oito meses de temporada competitiva de handebol. Um grupo de 58 adolescentes do sexo feminino (12 a 17 anos de idade) foram alocadas em dois grupos: jogadoras de handebol (HG: n = 27) e grupo controle (GC: n = 31). O BMC e o BMD e respectivo escore-Z foram medidos pela absorciometria por raios X de dupla energia. Maturidade sexual, menarca, pico de velocidade de crescimento (PHV ), exposição ao sol e ingestão de cálcio foram avaliados. No início, as jogadoras de handebol apresentaram maior CMO e DMO do que o grupo controle (p < 0.05). Essas diferenças entre os grupos desapareceram após ajuste para peso, IMC, menarca e massa magra. O HG aumentou a CMO e a DMO do corpo total e da coluna lombar após oito meses. A análise do escore Z mostrou maior DMO do corpo total, coluna lombar, fêmur e quadril no HG do que no CG. Os resultados mostraram que, após um período competitivo de handebol de oito meses, houve um aumento na DMO do corpo total das jogadoras de handebol. Os resultados mostram que oito meses de temporada competitiva no handebol pode induzir um aumento no crescimento ósseo quando comparado a adolescentes do sexo feminino que tinham valores similares de BMD e BMC no início do estudo

Prediction of bone mass changes after successful parathyroidectomy using biochemical markers of bone metabolism in primary hyperparathyroidism: is it clinically useful?

ABSTRACT Objective To measure type 1 serum amino-terminal propeptide procollagen (P1NP) and type 1 cross-linked C-terminal telopeptide collagen (CTX) before parathyroidectomy (PTX) in PHPT patients, correlating these measurements with bone mineral density (BMD) changes. Subjects and methods 31 primary hyperparathyroidism (HPTP) were followed from diagnosis up to 12-18 months after surgery. Serum levels of calcium, parathyroid hormone (PTH) vitamin D, CTX, P1NP, and BMD were measured before and 1 year after surgery. Results One year after PTX, the mean BMD increased by 8.6%, 5.5%, 5.5%, and 2.2% in the lumbar spine, femoral neck (FN), total hip (TH), and distal third of the nondominant radius (R33%), respectively. There was a significant correlation between BMD change 1 year after the PTX and CTX (L1-L4: r = 0.614, p < 0.0003; FN: r = 0.497, p < 0.0051; TH: r = 0.595, p < 0.0005; R33%: r = 0.364, p < 0.043) and P1NP (L1-L4: r = 0,687, p < 0,0001; FN: r = 0,533, p < 0,0024; TH: r = 0,642, p < 0,0001; R33%: r = 0,467, p < 0,0079) preoperative levels. The increase in 25(OH)D levels has no correlation with BMD increase (r = -0.135; p = 0.4816). On linear regression, a minimum preoperative CTX value of 0.331 ng/mL or P1NP of 37.9 ng/mL was associated with a minimum 4% increase in L1-L4 BMD. In TH, minimum preoperative values of 0.684 ng/mL for CTX and 76.0 ng/mL for P1NP were associated with a ≥ 4% increase in BMD. Conclusion PHPT patients presented a significant correlation between preoperative levels of turnover markers and BMD improvement 1 year after PTX.

Body composition indices in Brazilian adults: age-specific and sex-specific percentile curves

ABSTRACT Objective To establish percentile curves for measures and indices of body composition by age and sex and compare them with data from other ethnic groups. Subjects and methods Cross-sectional, population-based study with adults aged 20-59 years (n = 689). Percentile curves adjusted by a third degree polynomial function were constructed for skeletal mass index (SMI), fat mass index, body fat, and load-capacity metabolic indices (LCMI) based on dual-energy X-ray absorptiometry (DXA). Results SMIweight and SMIBMI showed decline from the third decade of life in both sexes, whereas SMIheight was not able to identify lean mass loss over the ages studied. There was a slight drop at the end of the fifth decade (50-59 years) in men. Among Americans and Chinese, the 50th percentile curve of SMIheight showed an earlier decline. The estimates of adiposity and LCMI curves peaked between 40-49 years and Americans and Chinese maintained an upward curve throughout adulthood. Conclusion The data and curves showed that the SMI adjusted for BMI and body weight were more adequate in detecting the decline of lean mass in adults due to aging. In contrast, SMIheight had a positive correlation with age and its curve increased throughout the evaluated age groups. The results contribute to the evaluation to the nutritional status of adults and to the prevention and treatment of outcomes related to adiposity and deficit lean mass.

Evaluation of iNSiGHT VET DXA (Dual-Energy X-ray Absorptiometry) for assessing body composition in obese rats fed with high fat diet: a follow-up study of diet induced obesity model for 8 weeks / 한국실험동물학회지

We examined the precision, accuracy, and capability of detecting changes of Dual-Energy X-ray Absorptiometry (DXA) for the measurements of total-body weight (TBW), total-body fat weight (TBFW), and total-body lean weight (TBLW) in an 8-week follow-up study of rats. Twenty male rats (4-week) were divided into 2 diet groups. For 8 weeks, we measured body composition (TBW, TBFW, TBLW) by DXA and TBW by an electronic scale once a week. In week 8, we measured body composition 5 times by DXA and TBFW by dissecting experiment (EXP) of euthanized rats (12-week). Total-body fat ratio (TBFR) was defined as TBFW/(TBFW+TBLW). The precision of DXA was evaluated by measuring the coefficient of variation (CV) and accuracy was evaluated by comparing DXA-derived data with EXP data. The capability of detecting changes of DXA in follow-up study was verified by analyzing the trend of DXA-derived values over the 8 weeks. For TBW, TBFW, TBLW of DXA, CVs were 0.02 ± 0.01, 0.10 ± 0.05, 0.03 ± 0.02 and errors were − 6.996 ± 3.429 (r = 0.999), + 14.729 ± 3.663 (r = 0.982), − 21.725 ± 4.223 (r = 0.991), respectively. Prediction models were [EXP TBW = − 31.767 + 1.085 (DXA TBW), R2 = 0.998, root mean square error (RMSE) = 1.842] and [EXP TBFR = − 0.056 + 1.177 (DXA TBFR), R2 = 0.948, RMSE = 0.007]. Over 8 weeks, DXA TBW and DXA TBLW steadily increased, DXA TBFW steadily increased followed by saturation or declination, difference of DXA TBFW between 2 diet groups steadily increased. In conclusion, our study verified that DXA (iNSiGHT VET DXA, OsteoSys, Korea) is accurate and precise enough to measure body composition of rats. Additionally, we confirmed the possibility that DXA could be used for the long-term follow-up studies.

Las diferencias antropométricas entre sexos de la columna lumbar, medidas por dxa, no afectan a todas las vértebras en forma uniforme: probable implicancia en la incidencia de fracturas / Gender anthropometric differences of the lumbar spine, measured by dxa, do not involve all vertebrae uniformly: probable implication in the incidence of fractures

Las fracturas vertebrales osteoporóticas son más frecuentes en la mujer. El segmento toracolumbar es el preferentemente comprometido, en especial las vértebras D11 a L2, mientras que L4 contribuye en una proporción mínima a este evento. El objetivo del presente estudio fue investigar si el menor tamaño de las vértebras lumbares en las mujeres con respecto a los varones, involucra a todas las vértebras por igual o solamente a las que con más frecuencia se fracturan. Se analizaron en forma aleatoria las densitometrías óseas (DXA) de la región lumbar de 48 mujeres y 45 varones adultos. Se consideró el ancho del segmento L1-L2 (S L1-L2) y de L4 como un subrogado del área de sus cuerpos vertebrales. Resultados: ancho S L1-L2 Hombres: 4,32 ± 0,33 cm; Mujeres: 3,78 ± 0,23 cm, p < 0,001. Ancho L4 Hombres: 5 ± 0,37 cm; Mujeres: 4,66 ± 0,38 cm, p < 0,001. Diferencia de L4 menos S L1-L2: Hombres: 0,69 ± 0,25 cm, Mujeres: 0,88 ± 0,27 cm p < 0,001. Ancho relativo (S L1-L2/L4): Hombres: 0,86 ± 0,04, Mujeres 0,81 ± 0,04 p <0,001. Conclusiones: en el presente estudio observamos, en consonancia con lo ya conocido, que las mujeres tienen en promedio vértebras más pequeñas que los hombres. La diferencia de tamaño no es uniforme en las vértebras lumbares, siendo el segmento L1-L2 particularmente menor comparado con L4. Estas diferencias estructurales entre mujeres y hombres deben ser consideradas para explicar, dentro del contexto multifactorial de las fracturas vertebrales, la mayor incidencia de éstas en el sexo femenino, en particular de L1 y L2. (AU)

Vertebral fractures occur most frequently in thoracolumbar region, especially D11- L2, while L4 contributes minimally to this event. That cannot be explained by differences in loading during daily activities or bone quality between vertebrae. Differences exist in vertebral size. The aim of the study was to evaluate in female lumbar spines if vertebrae which most frequently fracture are smaller than L4. We analyzed BMD (DXA) of 48 women (W) and 45 men (M). The width of the segment L1-L2 (S L1-L2) and of L4 was considered a surrogate of vertebral bodies Results: Width S L1-L2: Men: 4,32 ± 0,33 cm; Women: 3,78 ± 0,23 cm, p < 0,001. Width L4: Men: 5 ± 0.37; Women: 4,66 ± 0,38 cm, p < 0,001. Difference between L4 and S L1-L2: Men: 0,69 ± 0,25cm, Women: 0,88 ± 0,27 cm p < 0,001. Relative width (S L1-L2/L4) Men: 0,86 ± 0,04 Women: 0,81 ± 0,04 p <0,001. Conclusions: the study shows, as already known, that women have smaller vertebrae than men. The differences are not uniform in the lumbar spine, L1 and L2 being particularly smaller compared to L4. These structural differences between women and men should be considered to explain, within the multifactorial context of vertebral fractures, the greater incidence in female, particularly L1 and L2. (AU)

Validation of anthropometric models in the estimation of appendicular lean soft tissue in young athletes / Validação de modelos antropométricos na estimação da massa isenta de gordura e osso apendicular em jovens atletas

Abstract Magnetic resonance imaging and Computer tomography are gold standards in the measurement of muscle tissue (MT), but are expensive. Dual Energy X-Ray Absorptiometry (DXA) is also costly but safer and allows for the measurement of Appendicular Lean Soft Tissue (ALST), a strong predictor of MT. Alternatively, there are anthropometric models that predict the ALST of Portuguese athletes with low cost/risk that have not been validated in other populations. The aim of this study was to validate anthropometric Portuguese models that predict ALST in young athletes or, if the validation fails, to propose new models. The ALSTDXA of 174 young athletes was determined by DXA. Two anthropometric models (ALSTmod1 and ALSTmod2) measuring ALST among Portuguese athletes were tested. To validate the coefficient of determination, the difference (bias) and concordance correlation coefficient between predicted and actual values were computed. Finally, association between mean and difference of methods was verified. Validation failed and, for this reason, new multiple regression models were proposed and validated using PRESS statistics. The Portuguese models explained ~96% of the ALSTDXA variability. The difference between ALST (-0.7kg) was less than that found for the ALSTmod2 and ALSTDXA limits of agreement from 3.6 to -2.1 and from 6.1 to -1.5kg, respectively. The new models included three predictive equations for ALST. Only ASLTmod1was valid; however, it was prone to bias, depending on the magnitude of ALST values. The newly proposed models present validity with greater concordance (r2PRESS=0.98), lower standard error of estimate (SEEPRESS [kg]=0.91) and more homogeneous predicted extreme values.

Resumo Ressonância magnética e tomografia computadorizada são referências para medir o tecido muscular (TM), porém apresentam custo elevado. A Absorciometria Radiológica de Dupla Energia (DXA) é segura, embora ainda dispendiosa, permite medir a Massa Isenta de Gordura e Osso apendicular (MIGOap), forte preditor do TM. Alternativamente, existem modelos antropométricos preditivos da MIGOap de atletas portugueses com baixo custo/risco, porém sem validação para outras populações. Objetivou-se validar modelos antropométricos portugueses preditivos da MIGOap em jovens atletas ou propor novos modelos, caso a validação falhe. A determinação da MIGOapDXA de 174 jovens atletas foi realizada por DXA. Dois modelos antropométricos (MIGOapmdJ1 e MIGOapmd2) de atletas portugueses foram testados para predizer MIGOap. Para validação o coeficiente de determinação, a diferença (viés) e a concordância entre valores medidos e preditos foram calculados. Finalmente, a associação entre média-e-diferença dos métodos foi calculada. A validação falhou, assim foram propostos novos modelos de regressão múltipla validados por estatística PRESS. Os modelos portugueses explicaram ~96% da variabilidade da MIGOapDJAf A diferença entre MIGOapmod1 e MIGOapDXA (-0,7kg) foi menor do que MI-GOapmod2 (-2,3kg), com limites de concordância de3,6 a -2,1 e de 6,1 a -1,5kg, respectivamente. Os novos modelos incluíram três equaçõespreditivaspara MIGOap. Somente MIGOapmd1foi válido, todavia mostrou grande tendência a vieses, conforme magnitude dos valores de MIGOap. Os novos modelos propostos mostraram validade com maior concordância (r2PRESS=0,98), menores erros de estimativa (EPEPRESS =0,91) e valores preditos mais homogêneos para casos extremos.

Are traditional body fat equations and anthropometry valid to estimate body fat in children and adolescents living with HIV?

Abstract The aim of this study was to assess the validity of traditional anthropometric equations and to develop predictive equations of total body and trunk fat for children and adolescents living with HIV based on anthropometric measurements. Forty-eight children and adolescents of both sexes (24 boys) aged 7-17 years, living in Santa Catarina, Brazil, participated in the study. Dual-energy X-ray absorptiometry was used as the reference method to evaluate total body and trunk fat. Height, body weight, circumferences and triceps, subscapular, abdominal and calf skinfolds were measured. The traditional equations of Lohman and Slaughter were used to estimate body fat. Multiple regression models were fitted to predict total body fat (Model 1) and trunk fat (Model 2) using a backward selection procedure. Model 1 had an R2 = 0.85 and a standard error of the estimate of 1.43. Model 2 had an R2 = 0.80 and standard error of the estimate = 0.49. The traditional equations of Lohman and Slaughter showed poor performance in estimating body fat in children and adolescents living with HIV. The prediction models using anthropometry provided reliable estimates and can be used by clinicians and healthcare professionals to monitor total body and trunk fat in children and adolescents living with HIV.

Evaluación de score de hueso trabecular (TBS) en pacientes menopáusicas con fracturas y sin ellas / Trabecular bone score evaluation in postmenopausal women with or without fractures

El score de hueso trabecular (TBS, Trabecular Bone Score) es una medición de la textura de los grises derivada de la evaluación del raquis por DXA y proporciona un índice de la microarquitectura ósea. Se ha demostrado que los valores bajos presentan capacidad para predecir fracturas. Nuestro objetivo fue evaluar si existían diferencias entre los valores de TBS de pacientes con fracturas frente a no fracturadas. Materiales y métodos: se revisaron 159 historias clínicas de mujeres menopáusicas que consultaron para evaluación de su salud ósea. Se consideraron los antecedentes autorreferidos de fracturas (Fx), la DMO de raquis, cuello femoral y fémur total y TBS. Resultados: treinta pacientes (18,9%) presentaron fracturas y en ellas se observó menor TBS (con Fx: 1,295±83 vs. sin Fx: 1,366±84, p<0,0001), menor índice de masa corporal (IMC) (con Fx: 23,7±1,9 vs. sin Fx: 25,7±4,2, p=0,02), sin diferencias en la edad (p=0,39), ni en valores de DMO (L1-L4 p=0,11, cuello femoral p=0,20 y fémur total p= 0,12). Muchas de las fracturas ocurrieron en pacientes sin osteoporosis por DXA. Conclusiones: el TBS aumentaría la capacidad de DXA para identificar a mujeres argentinas en riesgo de padecer fracturas sin tener osteoporosis densitométrica. Este es el primer trabajo realizado en la Argentina con medición de TBS. (AU)

Trabecular Bone Score (TBS) is a measure of the grey scale derived from DXA lumbar image and provides information about microarchitecture. It has been shown that low TBS values can predict fractures. Our objective was to evaluate if there are any differences between the TBS values in patients with fractures vs. non-fractures. Materials and methods: We reviewed 159 medical records of menopausal women who consulted for evaluation of their bone health. Self-reported fractures (Fx), spine BMD, femoral neck and total femur and TBS were evaluated. Results: thirty patients (18.9%) presented fractures and they showed lower TBS (with Fx: 1,295±0,083 vs. without Fx: 1,366±0,084, p<0.0001), lower body mass index (BMI) (with Fx: 23.7±1.9 vs. without Fx 25.7±4.2, p=0.02), without differences in ages (p=0.39) or in BMD values (L1-L4 p=0.11, femoral neck p=0.20 and total femur p=0.12). Some fractures occurred in patients without osteoporosis, as determined by DXA. Conclusions: TBS would increase the ability of DXA to identify Argentine women at risk for fractures without densitometric osteoporosis. This is the first work done in Argentina with TBS measurement. (AU)

Bone mineral density in children with idiopathic nephrotic syndrome / Densidade mineral óssea em crianças com síndrome nefrótica idiopática

Abstract Objectives: To assess bone mineral density (BMD) in children with idiopathic nephrotic syndrome (NS) and normal glomerular filtration rate (GFR). Methods: Cross-sectional case-control study carried out on 50 children: 25 cases of NS (16 steroid-sensitive [SSNS] and nine steroid-resistant [SRNS] under follow up in the pediatric nephrology unit of Menoufia University Hospital, which is tertiary care center, were compared to 25 healthy controls with matched age and sex. All of the participants were subjected to complete history taking, thorough clinical examination, laboratory investigations (serum creatinine, blood urea nitrogen [BUN], phosphorus [P], total and ionized calcium [Ca], parathyroid hormone [PTH], and alkaline phosphatase [ALP]). Bone mineral density was measured at the lumbar spinal region (L2-L4) in patients group using dual-energy X-ray absorptiometry (DXA). Results: Total and ionized Ca were significantly lower while, serum P, ALP, and PTH were higher in SSNS and SRNS cases than the controls. Osteopenia was documented by DXA scan in 11 patients (44%) and osteoporosis in two patients (8%). Fracture risk was mild in six (24%), moderate in two (8%), and marked in three (12%) of patients. Conclusion: Bone mineralization was negatively affected by steroid treatment in children with NS.

Resumo Objetivos: Avaliar a densidade mineral óssea (DMO) em crianças com síndrome nefrótica idiopática (SNI) e com taxa de filtração glomerular (TFG) normal. Métodos: O estudo transversal de caso-controle foi feito com 50 crianças: 25 casos de SNI [16 sensíveis a esteroides (SNSE) e nove resistentes a esteroides (SNRE) com acompanhamento na unidade de nefrologia pediátrica do hospital da Menoufia University, centro de cuidados terciário] foram comparados com 25 controles saudáveis do grupo de controle com idade e sexo equivalentes. Todos os participantes foram submetidos a anamnese completa, exame clínico completo, exames laboratoriais [creatinina sérica, nitrogênio ureico no sangue (BUN), fósforo (P), cálcio (Ca) total e ionizado, paratormônio (PTH) e fosfatase alcalina (ALP)]. A densidade mineral óssea foi mensurada na região da coluna lombar (L2-L4) no grupo de pacientes com a absorciometria por raios X de dupla energia (DXA). Resultados: Os níveis de cálcio total e ionizado eram significativamente menores, ao passo que o fósforo sérico, a FA e o PTH eram maiores em casos de SNSE e SNRE do que nos controles. A osteopenia foi documentada pelo exame DXA em 11 pacientes (44%) e a osteoporose em dois (8%). O risco de fratura era leve em seis (24%), moderado em dois (8%) e acentuado em três (12%). Conclusão: A mineralização dos ossos foi afetada negativamente pelo tratamento com esteroides em crianças com SNI.

Bone mineral density and content are differentially impacted by aerobic and resistance training in the colon-26 mouse model of cancer cachexia

Background: Cancer cachexia is a debilitating paraneoplastic syndrome featuring unintended weight loss and skeletal muscle atrophy. Evidence suggests that bone health may also be compromised, further limiting mobility and quality of life. Aerobic and resistance training was recently reported to differentially affect skeletal muscle adaptations in cancer cachectic mice. The purpose of this investigation was to assess the effects of aerobic and resistance training on bone mineral density (BMD) and bone mineral content (BMC) in mice with colon-26 (C26) tumor-induced cachexia. Methods: Twelve-month old Balb/c mice were aerobic-trained (wheel running 5 days/week) or resistance-trained (weighted ladder climbing 3days/week) for 8 weeks prior to C26 cell injection, followed by an additional three weeks of exercise. BMD and BMC were assessed pre- and post-training by dual-energy x-ray absorptiometry. Results: Resistance-trained C26 mice lost total BMD by 7% (p = 0.06), which did not occur in aerobic-trained C26 mice. In terms of pelvic bone, both resistance- and aerobic-trained C26 mice had significantly lower BMD values (−12%, p = 0.01 and −6%, p = 0.04, respectively), albeit to a lesser degree in aerobic-trained C26 mice. Furthermore, resistance-trained C26 mice tended to lose total BMC (−12%), whereas aerobic-trained C26 mice maintained total BMC. In mice without C26 tumors, resistance training significantly increased total BMD (+13%, p = 0.001). Conclusions: Aerobic and resistance training may differentially affect bone status in C26 cancer cachexia, with high resistance loading possibly being detrimental to total and pelvis BMD, a region expected to bear significant loading stress and contribute substantially to overall mobility. Because resistance training improved BMD in tumor-free mice, the C26 tumor burden appeared to impair the beneficial effect of resistance training on bone mass (AU)

Assessment of radiation dose in dual energy X-ray absorptiometry scanner / 中华放射医学与防护杂志

Objective To evaluate the radiation dose from a dual energy X-ray absorptiometry (DXA) study. Methods A Radcal multifunctional dosimeter (1800 cc ionization chamber, USA) was used, for purpose of comparison, to measure the entrance surface doses (ESD) from Norland XR-800 DXA ( pencil beam scan, 100/46. 8 kVp, 1. 3 mA) and from Hologic Discovery A DXA ( fan beam scan, 140/100 kVp, 5. 0 mA) . Ambient dose equivalent rate at 1 m away from studied phantom center and at 1 m above floor was measured using the US 451P ionizaion chamber survey meter ( Fluke, USA). Results The ESD measured using a Radcal dosimeter for Norland XR-800 DXA was 0. 43 μGy in high speed mode and 0. 73 μGy in standard mode ( AP spine ) , 1. 93 μGy ( hip ) , 0. 40 μGy ( wrist ) and 1. 06 μGy ( mandible) . The ESD measured for Hologic Discovery A DXA was 65. 6 μGy ( AP spine) and 63. 9 μGy ( hip) . The ESD measured for Norland XR-800 at different scan types and scan speeds was <2 μGy while Hologic Discovery A DXA showed a result of <66 μGy ( AP spine and hip scan ) , which were both consistent with the data given in their own respective operational manual. A comparison of DXA scanners with fan beam and pencil beam indicated that ambient equivalent dose rate, measured with 451P survey meter, from fan beam scan was 65 times that from pencil beam scan. Conclusions Compared with other medical X-ray studies, the ESD to the phantom undergoing a DXA study is relatively low. DXA pencil beam scan doses to lumbar spine and hip were about 1/153-1/33 of those from DXA fan beam scan. Pencil beam scan dose to DXA staff was negligible and fan beam scan dose to DXA staff was lower than the personal dose limits of 20 mSv per year.