Total Body Dual-energy X-ray Research Articles

Relationship Between Physiologic Tests, Body Composition Changes, and On-Ice Playing Time in Canadian Collegiate Hockey Players.

Delisle-Houde, P, Chiarlitti, NA, Reid, RER, and Andersen, RE. Relationship between physiologic tests, body composition changes, and on-ice playing time in canadian collegiate hockey players. J Strength Cond Res 32(5): 1297-1302, 2018-Hockey player's body composition and physical fitness are suggested to influence coaching decisions regarding on-ice playing time. The purpose of this study was to explore the relationship between seasonal body composition changes, off-ice preseason testing, and on-ice metrics. Twenty-one Canadian collegiate hockey players (22.70 ± 1.30 years old, 181.0 ± 5.92 cm, 86.52 ± 6.41 kg) underwent off-ice physical testing at the beginning of their season and had one total body dual energy x-ray absorptiometry scan at the beginning and end of the season. The team's statistician tracked all on-ice metrics. Pearson correlations were used to explore relationships between off-ice tests (long jump, vertical jump, beep test, and Wingate test), change in body composition (body fat percentage, visceral adiposity, and total lean tissue mass), and on-ice performance (average time on ice, average shift length, power play time, penalty kill time, and shot differential). Long jump was correlated with shot differential (r = -0.532, p ≤ 0.05) and average shift length (r = -0.491, p ≤ 0.05) while fatigue index was correlated with average ice time (r = -0.476, p ≤ 0.05). Hockey performance is a complex interaction of player's body compositions and skeletal fitness that interact to affect on-ice playing metrics.

The Association Among Body Composition, Explosive Leg Power and Aerobic Capacity in Male Varsity Hockey Players

Fitness testing and body composition assessments in sports are ubiquitous and rapidly becoming an indispensible resource for strength and conditioning coaches. Previous research has shown that higher amounts of lean tissue mass have been associated with increased power outputs and lower levels of body fat percentage have been associated with improved aerobic fitness. PURPOSE: To examine the relationship between body composition and lower body power and aerobic fitness in elite collegiate hockey players. METHODS: Sixteen elite male Canadian university hockey players (age = 22.194 ± 0.99 years, weight = 85.74 ± 5.80 kg, height = 182.25 ± 6.67 cm), participated in the study at the beginning of their hockey season. All participants completed the long jump and the beep-test and a day after testing, one total body dual energy x-ray absorptiometry scan to measure body composition. Simple linear regression was used to explore the relationship between body fat percentage, visceral adipose tissue, and abdominal adipose tissue with aerobic fitness evaluations and leg lean with lower body power. RESULTS: On average body fat percentage was 16.6 ± 3.0%, fat mass 13.7 ± 2.8 kg, abdominal adipose tissue 0.9 ± 0.3 kg, leg lean mass 23.8 ± 1.97 kg, long jump 2.67 ± 0.16 m, beep test 12.8 ± 1.32 min. Visceral adipose tissue explained 24.5% of the variance in the test of aerobic fitness (p .05), while other adiposity measures were non-significant. Body fat percentage and lower lean mass did not significantly contribute to aerobic fitness and lower body power respectively (all p> .05). CONCLUSIONS: Despite a lack of inter-relationships among field tests and body composition, these variables should remain part a test battery to allow strength and conditioning coaches to better tailor training programs for elite hockey players. Keywords: body composition, hockey, Fitness testing

The Prediction of Body Composition in African Americans From Spine and Hip Dual-Energy Absorptiometry

Body composition, the makeup of the body's fat and lean tissue, is associated with important health outcomes and provides useful clinical information. Although body composition can be measured with total body dual-energy X-ray absorptiometry (DXA), this is rarely performed. As an alternative to total body DXA measurement, methods for estimation of body composition have been developed. These methods use soft tissue measures from spine and hip DXA to predict body composition and include prediction equations previously published by Leslie and proprietary equations within General Electric densitometry software. However, these estimates have not been tested in African Americans (AA), an ethnicity with a different distribution of fat than Caucasians (CA). Therefore, we examined the performance of the existing models in 99 CA and 162 AA subjects over the age of 40 who had total body, spine, and hip DXA measurements. We observed that existing models estimated body composition well in CA but underestimated fat mass and overestimated lean mass in AA. AA subjects were then randomly divided into 2 equal-sized subgroups—the first to develop new prediction equations and the second to independently validate them. We found that body composition can be more accurately estimated using either a new model that we derived in AA subjects using backward stepwise elimination or by adding a fixed offset for AA to the previously published model. Our results demonstrate that body composition estimates from spine and hip DXA require consideration of race/ethnicity.

P.120 - Segmental body composition in young children with SMA type 2: Correlation with motor function abilities

The aim of the present study was to investigate the correlation between fat mass (FM) and fat-free mass (FFM), measured by total and segmental body dual energy x-ray absorptiometry (DEXA), and the Hammersmith Functional Motor Scale Expanded (HFMSE) and the Upper limb module (ULM). 40 children with SMA type 2 (mean age 4.07 ± 1.90 years) were included in the study. Total FFM and FM were not correlated with HFMSE scores. However, when we investigated the correlation of segmental FFM and FM with motor function scores, we found that lower limbs FFM was significantly correlated with HFMSE scores (r = 0.375; p = 0.017), while no correlations were found between upper limbs FFM and HFMSE (r = 0.050; p = 0.756) or ULM (r = 0,154; p = 0,392). When we divided the whole cohort into Low-Functioning (HFMSE < 12) and High-Functioning (HFMSE > 12) children, we found that the Low-Functioning group had lower upper and lower limbs FFM, and higher upper and lower limbs FM, compared to the High-Functioning group. To our knowledge this is the first study investigating the correlation between total and segmental body composition and motor function in young children with SMA 2. The present study demonstrated that segmental lean mass at the lower limbs was correlated with global motor function abilities, as assessed by the HFMSE, and that segmental lean and fat mass was significantly different when children were stratified by level of functional abilities. These data further highlight the validity of HFMSE as an outcome measure in SMA, and may be helpful in monitoring the effects of therapeutic strategies.

Prediction of whole-body fat percentage and visceral adipose tissue mass from five anthropometric variables.

BackgroundThe conventional measurement of obesity utilises the body mass index (BMI) criterion. Although there are benefits to this method, there is concern that not all individuals at risk of obesity-associated medical conditions are being identified. Whole-body fat percentage (%FM), and specifically visceral adipose tissue (VAT) mass, are correlated with and potentially implicated in disease trajectories, but are not fully accounted for through BMI evaluation. The aims of this study were (a) to compare five anthropometric predictors of %FM and VAT mass, and (b) to explore new cut-points for the best of these predictors to improve the characterisation of obesity.MethodsBMI, waist circumference (WC), waist-to-hip ratio (WHR), waist-to-height ratio (WHtR) and waist/height0.5 (WHT.5R) were measured and calculated for 81 adults (40 women, 41 men; mean (SD) age: 38.4 (17.5) years; 94% Caucasian). Total body dual energy X-ray absorptiometry with Corescan (GE Lunar iDXA, Encore version 15.0) was also performed to quantify %FM and VAT mass. Linear regression analysis, stratified by sex, was applied to predict both %FM and VAT mass for each anthropometric variable. Within each sex, we used information theoretic methods (Akaike Information Criterion; AIC) to compare models. For the best anthropometric predictor, we derived tentative cut-points for classifying individuals as obese (>25% FM for men or >35% FM for women, or > highest tertile for VAT mass).ResultsThe best predictor of both %FM and VAT mass in men and women was WHtR. Derived cut-points for predicting whole body obesity were 0.53 in men and 0.54 in women. The cut-point for predicting visceral obesity was 0.59 in both sexes.ConclusionsIn the absence of more objective measures of central obesity and adiposity, WHtR is a suitable proxy measure in both women and men. The proposed DXA-%FM and VAT mass cut-offs require validation in larger studies, but offer potential for improvement of obesity characterisation and the identification of individuals who would most benefit from therapeutic intervention.

A pilot study of brisk walking in sedentary combination antiretroviral treatment (cART)- treated patients: benefit on soluble and cell inflammatory markers

BackgroundChronic HIV infection is associated with low-level inflammation and increased risk of chronic diseases and mortality. The objective was to assess the effects of moderate intensity exercise on metabolic and inflammatory markers in HIV-infected treated persons.MethodsThis was a pilot study enrolling cART-treated, sedentary persons with metabolic complications in a 12-week protocol, consisting of three sessions per week of 60 min brisk walking with (strength-walk group) or without (walk group) 30 min circuit-training. Assessments at baseline and week 12 (W12) included body morphometrics and total body dual-energy X-ray absorptiometry; lipid and glucose blood profile; plasma level of high sensitivity C-reactive protein (hsCRP), interleukin-6 (IL-6), D-dimer, interleukin-18 (IL-18), soluble CD14, and CD38 and HLA-DR expression on CD4+ and CD8+ T-cells.ResultsForty-nine patients were included and 35 (71%) completed the program: 21 in the walk and 14 in the strength-walk group. At W12, significant improvements were observed of body mass index, waist and hip circumference, and total cholesterol both overall and in the walk group, and of LDL cholesterol in both training groups. In the whole group, significant reductions were observed in hsCRP, IL-6, D-dimer, IL-18, and of CD8+/CD38+/HLA-DR+ cell frequencies. HsCRP and CD8+/CD38+/HLA-DR+ frequency decreased significantly in both training groups when examined separately whereas IL-6 and D-dimer in the walk group only.ConclusionsBrisk walking, with or without strength exercise, could improve lipid profile and inflammatory markers in chronic HIV infection.Trial registrationACTRN12615001258549, registered 17 November 2015, “retrospectively registered” Web address of trial: http://www.ANZCTR.org.au/ACTRN12615001258549.aspx

Ethnic Differences in Osteoporosis After Cardiac Transplantation

Cardiac transplantation is associated with a high risk of fracture. African Americans (AAs) are believed to have a lower risk of osteoporosis than Caucasians, but it is not clear whether they are also protected from osteoporosis resulting from the use of glucocorticoids and/or organ transplantation. We examined possible ethnic differences in 33 cardiac transplant recipients (16 AAs) in a cross-sectional analysis. In addition to bone mineral density and vertebral fracture assessment, we also compared biochemical variables, trabecular bone score, total body dual-energy X-ray absorptiometry, and disability. Overall fracture rates were low in both groups, with only 6 total subjects with fractures on vertebral fracture assessment or history of fracture. While T-scores were similar between groups, Z-scores were lower in AA with the difference reaching statistical significance when controlling for important covariates. The trabecular bone score was also lower in AAs than in Caucasians even when adjusting for age and tissue thickness (1.198 ± 0.140 vs 1.312 ± 0.140, p = 0.03).While AAs are generally thought to be protected from osteoporosis, our study instead suggests that AAs may be at higher risk of bone deterioration after cardiac transplantation and may need to be managed more aggressively than suggested by current guidelines.

Hyperandrogenism Accompanies Increased Intra-Abdominal Fat Storage in Normal Weight Polycystic Ovary Syndrome Women.

Normal weight polycystic ovary syndrome (PCOS) women may have altered adipose structure-function underlying metabolic dysfunction. This study examines whether adipose structure-functional changes exist in normal weight PCOS women and correlate with hyperandrogenism and/or hyperinsulinemia. This is a prospective cohort study. The setting was an academic medical center. Six normal weight PCOS women and 14 age- and body mass index-matched normoandrogenic ovulatory (NL) women were included. All women underwent circulating hormone and metabolic measurements; frequently sampled intravenous glucose tolerance testing; total body dual-energy x-ray absorptiometry; abdominal magnetic resonance imaging; and SC abdominal fat biopsy. Circulating hormones and metabolites, body fat and its distribution, and adipocyte size were compared between PCOS and NL women, and were correlated with each other in all women. Circulating LH and androgen levels were significantly greater in PCOS than NL women, as were fasting insulin levels, pancreatic β-cell responsiveness to glucose, and total abdominal fat mass. Intra-abdominal fat mass also was significantly increased in PCOS women and was positively correlated with circulating androgen, fasting insulin, triglyceride, and non-high-density lipoprotein cholesterol levels in all women. SC abdominal fat mass was not significantly increased in PCOS women, but contained a greater proportion of small SC abdominal adipocytes that positively correlated with serum androgen levels in all women. Hyperandrogenism in normal weight PCOS women is associated with preferential intra-abdominal fat deposition and an increased population of small SC abdominal adipocytes that could constrain SC adipose storage and promote metabolic dysfunction.

ABCD: Anthropometry, Body Composition, and Crohn Disease.

Young individuals with Crohn disease (CD) are at risk of poor bone mineral density (BMD) and reduced lean tissue mass (LTM). The importance of LTM for maintaining skeletal health, in both incident and established CD, is evidenced. We used dual-energy x-ray absorptiometry assessment to identify areal BMD and LTM in individuals with CD. In 57 patients with CD (15F; 12.99-14.16 years) anthropometric, disease activity, bone age assessment, and total body dual-energy x-ray absorptiometry measurements were acquired. A 4-step algorithm was used to assess simultaneous bone and body composition data: areal BMD and height z scores, and LTM for height and bone mineral content (BMC) for LTM z scores were calculated. Low z score cut-off values were defined as ≤1 standard deviations below the population means. The CD cohort showed: low areal BMD z scores (P = 0.00); and low LTM for height (P = 0.00) according to defined cut-off values. BMC appeared to be adapting for the lower amount of LTM. Correcting for bone age eliminated the low areal BMD z scores. As expected, LTM for height and BMC for LTM z scores remained unchanged. We present a useful clinical algorithm to show significant LTM for height deficits, regardless of chronological or bone age, in this CD cohort. BMC seemed to adapt to the reduced LTM, indicating clinically "normal" areal BMD for age when considered for height. The ongoing deficits in LTM may, however, create chronic long-term consequences for bone health. Improving LTM should be a focus of clinical treatment in individuals with CD.

Three-Compartment Body Composition Changes in Professional Rugby Union Players Over One Competitive Season: A Team and Individualized Approach

The purpose of this study was to investigate the longitudinal body composition of professional rugby union players over one competitive season. Given the potential for variability in changes, and as the first to do so, we conducted individual analysis in addition to analysis of group means. Thirty-five professional rugby union players from one English Premiership team (forwards: n = 20, age: 25.5 ± 4.7 yr; backs: n = 15, age: 26.1 ± 4.5 yr) received one total-body dual-energy X-ray absorptiometry scan at preseason (August), midseason (January), and endseason (May), enabling quantification of body mass, total and regional fat mass, lean mass, percentage tissue fat mass (%TFM), and bone mineral content (BMC). Individual analysis was conducted by applying least significant change (LSC), derived from our previously published precision data and in accordance with International Society for Clinical Densitometry guidelines. Mean body mass remained stable throughout the season (p > 0.05), but total fat mass and %TFM increased from pre- to endseason, and from mid- to endseason (p < 0.05). There were also statistically significant increases in total-body BMC across the season (p < 0.05). In both groups, there was a loss of lean mass between mid- and endseason (p < 0.018). Individual evaluation using LSC and Bland–Altman analysis revealed a meaningful loss of lean mass in 17 players and a gain of fat mass in 21 players from pre- to endseason. Twelve players had no change and there were no differences by playing position. There were individual gains or no net changes in BMC across the season for 10 and 24 players, respectively. This study highlights the advantages of an individualized approach to dual-energy X-ray absorptiometry body composition monitoring and this can be achieved through application of derived LSC.

Associations of breast-feeding patterns and introduction of solid foods with childhood bone mass: The Generation R Study.

Breast-feeding has been associated with later bone health, but results from previous studies are inconsistent. We examined the associations of breast-feeding patterns and timing of introduction of solids with bone mass at the age of 6 years in a prospective cohort study among 4919 children. We collected information about duration and exclusiveness of breast-feeding and timing of introduction of any solids with postnatal questionnaires. A total body dual-energy X-ray absorptiometry scan was performed at 6 years of age, and bone mineral density (BMD), bone mineral content (BMC), area-adjusted BMC (aBMC) and bone area (BA) were analysed. Compared with children who were ever breast-fed, those never breast-fed had lower BMD (-4·62 mg/cm2; 95 % CI -8·28, -0·97), BMC (-8·08 g; 95 % CI -12·45, -3·71) and BA (-7·03 cm2; 95 % CI -12·55, -1·52) at 6 years of age. Among all breast-fed children, those who were breast-fed non-exclusively in the first 4 months had higher BMD (2·91 mg/cm2; 95 % CI 0·41, 5·41) and aBMC (3·97 g; 95 % CI 1·30, 6·64) and lower BA (-4·45 cm2; 95 % CI -8·28, -0·61) compared with children breast-fed exclusively for at least 4 months. Compared with introduction of solids between 4 and 5 months, introduction <4 months was associated with higher BMD and aBMC, whereas introduction between 5 and 6 months was associated with lower aBMC and higher BA. Additional adjustment for infant vitamin D supplementation did not change the results. In conclusion, results from the present study suggest that ever breast-feeding compared with never breast-feeding is associated with higher bone mass in 6-year-old children, but exclusive breast-feeding for 4 months or longer was not positively associated with bone outcomes.

The Qatar Biobank: background and methods.

BackgroundThe Qatar Biobank aims to collect extensive lifestyle, clinical, and biological information from up to 60,000 men and women Qatari nationals and long-term residents (individuals living in the country for ≥15 years) aged ≥18 years (approximately one-fifth of all Qatari citizens), to follow up these same individuals over the long term to record any subsequent disease, and hence to study the causes and progression of disease, and disease burden, in the Qatari population.MethodsBetween the 11th-December-2012 and 20th-February-2014, 1209 participants were recruited into the pilot study of the Qatar Biobank. At recruitment, extensive phenotype information was collected from each participant, including information/measurements of socio-demographic factors, prevalent health conditions, diet, lifestyle, anthropometry, body composition, bone health, cognitive function, grip strength, retinal imaging, total body dual energy X-ray absorptiometry, and measurements of cardiovascular and respiratory function. Blood, urine, and saliva were collected and stored for future research use. A panel of 66 clinical biomarkers was routinely measured on fresh blood samples in all participants. Rates of recruitment are to be progressively increased in the coming period and the recruitment base widened to achieve a cohort of consented individuals broadly representative of the eligible Qatari population. In addition, it is planned to add additional measures in sub-samples of the cohort, including Magnetic Resonance Imaging (MRI) of the brain, heart and abdomen.ResultsThe mean time for collection of the extensive phenotypic information and biological samples from each participant at the baseline recruitment visit was 179 min. The 1209 pilot study participants (506 men and 703 women) were aged between 28–80 years (median 39 years); 899 (74.4 %) were Qatari nationals and 310 (25.6 %) were long-term residents. Approximately two-thirds of pilot participants were educated to graduate level or above.ConclusionsThe pilot has proven that recruitment of volunteers into the Qatar Biobank project with intensive baseline measurements of behavioural, physical, and clinical characteristics is well accepted and logistically feasible. Qatar Biobank will provide a powerful resource to investigate the major determinants of ill-health and well-being in Qatar, providing valuable insights into the current and future public health burden that faces the country.

Identification of a dietary pattern prospectively associated with bone mass in Australian young adults

Relatively little is known about the relations between dietary patterns and bone health in adolescence, which is a period of substantial bone mass accrual. We derived dietary patterns that were hypothesized to be related to bone health on the basis of their protein, calcium, and potassium contents and investigated their prospective associations with bone mineral density (BMD), bone area, and bone mineral content (BMC) in a cohort of young adults. The study included 1024 young adults born to mothers who were participating in the Western Australian Pregnancy Cohort (Raine) Study. Dietary information was obtained from food-frequency questionnaires at 14 and 17 y of age. Dietary patterns were characterized according to protein, calcium, and potassium intakes with the use of reduced-rank regression. BMD, bone area, and BMC were estimated with the use of a total body dual-energy X-ray absorptiometry scan at 20 y of age. We identified 2 major dietary patterns. The first pattern was positively correlated with intakes of protein, calcium, and potassium and had high factor loadings for low-fat dairy products, whole grains, and vegetables. The second pattern was positively correlated with protein intake but negatively correlated with intakes of calcium and potassium and had high factor loadings for meat, poultry, fish, and eggs. After adjustment for anthropometric, sociodemographic, and lifestyle factors, a higher z score for the first pattern at 14 y of age was positively associated with BMD and BMC at 20 y of age [differences: 8.6 mg/cm(2) (95% CI: 3.0, 14.1 mg/cm(2)) and 21.9 g (95% CI: 6.5, 37.3 g), respectively, per SD increase in z score]. The z score for this same pattern at 17 y of age was not associated with bone outcomes at 20 y of age. The second pattern at 14 or 17 y of age was not associated with BMD, BMC, or bone area. A dietary pattern characterized by high intakes of protein, calcium, and potassium in midadolescence was associated with higher BMD and BMC at 20 y of age. Our results indicate that high consumption of low-fat dairy products, whole grains, and vegetables in adolescence are associated with beneficial effects on bone development.

Effect of vitamin D supplementation alone on muscle function in postmenopausal women: a randomized, double-blind, placebo-controlled clinical trial.

The present study investigates the effects of vitamin D on muscle function in postmenopausal women. It has been shown that vitamin D supplementation in postmenopausal women with hypovitaminosis D provides significant protective factor against sarcopenia, with significant increases in muscle strength and control of progressive loss of lean mass. We aimed to evaluate the effect of supplementation of vitamin D (VITD) alone on muscle function in younger postmenopausal women. In this double-blind, placebo-controlled clinical trial, 160 Brazilian postmenopausal women were randomized into two groups: VITD group consisting of patients receiving vitamin D3 1000 IU/day orally (n = 80) or placebo group (n = 80). Women with amenorrhea for more than 12 months and age 50-65 years, with a history of falls (previous 12 months), were included. The intervention time was 9 months, with assessments at two points, start and end. Lean mass was estimated by total-body dual-energy X-ray absorptiometry (DXA) and muscle strength by handgrip strength and chair rising test. The plasma concentrations of 25-hydroxyvitamin D [25(OH)D] were measured by high-performance liquid chromatography (HPLC). Statistical analysis was by intention to treat (ITT), using ANOVA, Student's t test, and Tukey's test. After 9 months, average values of 25(OH)D increased from 15.0 ± 7.5 to 27.5 ± 10.4 ng/ml (+45.4%) in the VITD group and decreased from 16.9 ± 6.7 to 13.8 ± 6.0 ng/ml (-18.5%) in the placebo group (p < 0.001). In the VITD group, there was significant increase in muscle strength (+25.3%) of the lower limbs by chair rising test (p = 0.036). In women in the placebo group, there was considerable loss (-6.8%) in the lean mass (p = 0.030). The supplementation of vitamin D alone in postmenopausal women provided significant protective factor against the occurrence of sarcopenia, with significant increases in muscle strength and control of progressive loss of lean mass.

Relationships Between Changes In Performance And Body Composition Variables After A Ten-week Resistance Training Intervention

Changes in body composition variables as well as strength and power performance are both apparent after resistance training interventions. PURPOSE: To compare multiple body composition variables and how they relate to changes in strength and power. METHODS: Eighteen trained men (25.8 ± 4.3y; 176.7 ± 5.0cm; 80.4 ± 12.0kg) completed a 10 week resistance training program. The first 8 weeks consisted of daily undulating periodized resistance training 3 days per week, focusing on either muscular hypertrophy, power, or strength. The final 2 weeks featured an overreach and taper phase. Tests consisted of 1RM strength of the bench press and leg press, a 30s Wingate, bench press peak power and velocity, and vertical jump height, peak power, and peak velocity. Body composition variables include total body and segmental Dual-Energy X-Ray Analysis (DXA), multi-frequency bioelectrical impedance (MFBIA), Single Frequency BIA (SFBIA), Bioimpedance Spectroscopy (BIS), Skinfold thicknesses, limb circumferences, and diagnostic ultrasound (US). RESULTS: With the exception of Wingate variables (p > 0.09), significant increases in strength and power were observed for all performance measurements (p < 0.01). Significant positive relationships were observed for MFBIA fat mass (FM) and MFBIA percent fat (%Fat) (r > 0.50, p < 0.03) for bench press velocity as well as for DXA trunk lean mass and leg press 1RM (r = 0.576, p = 0.012). Significant negative relationships were discovered for skinfold thicknesses of the suprailliac and vertical jump height (r = -0.507, p = 0.032) as well as US fat thickness and leg press 1RM (r = -0.711, p = 0.001). CONCLUSION: Changes in body composition variables (FM, FFM, %Fat, etc.) measured by different methods appear to produce varying relationships with performance variables after resistance training. An increase in fat measured by MFBIA appears to be associated with an increase in bench press velocity and an increase in trunk lean mass measured by DXA may predict an increase in leg strength. Also, a loss in subcutaneous hip (Skinfold) and thigh (US) fat may increase both vertical jump height and lower body strength, respectively. Thus, relationships between changes in body composition and performance after a resistance exercise intervention are dependent on both the method used as well as the variables being analyzed.

Concurrent validity of the Sahara Portable Bone Sonometer

Osteoporosis is a contemporary health issue in today’s society. Bone mineral density tests have the ability to detect low bone density before a fracture occurs. Presently dual-energy X-ray absorptiometry (DXA) is common method used to measure bone mineral density. In recent years, quantitative ultrasonography (ultrasound) has been used as a screening device at health fairs and other venues to estimate bone mineral density. The use of ultrasound offers several advantages: it exposes individuals to no radiation, it is inexpensive, and requires less tester skill and oversight than DXA. PURPOSE: To assess the accuracy of calcaneal ultrasound as a screening method compared to total body dual-energy X-ray absorptiometry. METHODS: A total of 44 men between the ages of 18-25 years (21.6 + 1.41) completed both a total body dual-energy X-ray absorptiometry (DXA) (GE Lunar) scan and an ultrasound (Hologic Sahara) calcaneus scan in a single visit. Correlation coefficients were calculated to determine the relationship between the two devices. Independent sample t-tests were used to determine if the two devices produced significantly different raw values. Bland-Altman plots were used to visually display agreement between devices. RESULTS: The ultrasound device had a weak relationship to the DXA (r = 0.514, p < 0.01). Comparing the absolute agreement between the two devices, the ultrasound device was consistently conservative. It provided mean values 0.689 g/cm2 less than the DXA. It produced values that were significantly lower (1.31 + 0.13 g/cm2 vs 0.62 + 0.14 g/cm2, p < 0.01). CONCLUSIONS: In this study, the ultrasound device produced values significantly lower than the values produced by the DXA. Ultrasound should not be used for individuals requiring high amounts of precision in their measurements. It however could be useful as a device in the screening and estimating of bone mineral density.

Infant dietary patterns and bone mass in childhood: the Generation R Study.

SummaryEarly life nutrition affects peak bone mass attainment. In this prospective cohort study, children with high adherence to a “dairy and whole grains” pattern in infancy had higher bone mineral density at the age of 6 years. Although the observed effects are small, our study provides insight into mechanisms linking early nutrition to bone acquisition in childhood.IntroductionNutrition in early life may affect peak bone mass attainment. Previous studies on childhood nutrition and skeletal health mainly focused on individual nutrients, which does not consider the cumulative effects of nutrients. We investigated the associations between dietary patterns in infancy and childhood bone health.MethodsThis study included 2850 children participating in a population-based prospective cohort study. Dietary information was obtained from a food frequency questionnaire at the age of 13 months. Using principal component analysis, three major dietary patterns were extracted, explaining in total 30 % of the variation in dietary intake. At the age of 6 years, a total body dual-energy X-ray absorptiometry (DXA) scan was performed, and bone mineral density (BMD), bone mineral content (BMC), area-adjusted BMC (aBMC), and bone area (BA) were analyzed.ResultsHigher adherence score to a “dairy and whole grains” pattern was positively associated with BMD and aBMC, but not with BMC and BA. Accordingly, children in the highest quartile of the “dairy and whole grains” pattern had higher BMD (difference 3.98 mg/cm2, 95 % confidence interval (CI) 0.36 to 7.61) and aBMC (difference 4.96 g, 95 % CI 1.27 to 8.64) than children in the lowest quartile. Stratification for vitamin D supplementation showed that the positive associations between the “dairy and whole grains” pattern and bone outcomes were only observed in children who did not receive vitamin D supplementation. A “potatoes, rice, and vegetables” and a “refined grains and confectionery” pattern were not consistently associated with bone outcomes.ConclusionsAn infant dietary pattern characterized by high intakes of dairy and cheese, whole grains, and eggs is positively associated with bone development in childhood. Further research is needed to investigate the consequences for bone health in later life.Electronic supplementary materialThe online version of this article (doi:10.1007/s00198-015-3033-1) contains supplementary material, which is available to authorized users.

Multiple Comparison of Age Groups in Bone Mineral Density under Heteroscedasticity.

Osteoporosis is a silent disease because individuals may not know that they have osteoporosis until their bones become so fragile. Bone mineral density (BMD) test helps to detect osteoporosis and determine the risk fractures. This study covers bone measurement data from total body dual energy X-ray absorptiometry scans for 28,454 persons who participated in the 1996–2006 National Health and Nutrition Examination Survey in USA Dual energy X-ray absorptiometry (DXA) method is known as the primary method for detecting osteoporosis because of its high precision and accuracy. Testing the equality of the means of normal populations when the variances are unknown and unequal is a fundamental problem in clinical trials and biomedical research. In this study we compare age groups based upon BMD in case of unequal variance being present among the groups. First we test equality of variances among the age groups by the Hartley test. And then Scott-Smith test is used to test equality of BMD means for the age groups. Finally, Tukey-Cramer confidence intervals are constructed to detect which groups start to differ from the reference group in which BMD reaches the peak level.

Obesity Increases Precision Errors in Total Body Dual-Energy X-Ray Absorptiometry Measurements

Total body (TB) dual-energy X-ray absorptiometry (DXA) is increasingly being used to measure body composition in research and clinical settings. This study investigated the effect of body mass index (BMI) and body fat on precision errors for total and regional TB DXA measurements of bone mineral density, fat tissue, and lean tissue using the GE Lunar Prodigy (GE Healthcare, Bedford, UK). One hundred forty-four women with BMI's ranging from 18.5 to 45.9 kg/m2 were recruited. Participants had duplicate DXA scans of the TB with repositioning between examinations. Participants were divided into 3 groups based on their BMI, and the root mean square standard deviation and the percentage coefficient of variation were calculated for each group. The root mean square standard deviation (percentage coefficient of variation) for the normal (<25 kg/m2; n = 76), overweight (25–30 kg/m2; n = 36), and obese (>30 kg/m2; n = 32) BMI groups, respectively, were total BMD (g/cm2): 0.009 (0.77%), 0.009 (0.69%), 0.011 (0.91%); total fat (g): 545 (2.98%), 486 (1.72%), 677 (1.55%); total lean (g): 551 (1.42%), 540 (1.34%), and 781 (1.68%). These results suggest that serial measurements in obese subjects should be treated with caution because the least significant change may be larger than anticipated.

Lean tissue mass and energy expenditure are retained in hypogonadal men with spinal cord injury after discontinuation of testosterone replacement therapy

ObjectiveTo determine whether favorable changes to lean tissue mass (LTM), resting energy expenditure (REE), and testosterone (T) that occurred with 12 months of physiological testosterone replacement therapy (TRT) were retained 6 months after discontinuing treatment.DesignProspective, open-label, controlled drug intervention trial.SettingMetropolitan area hospitals.SubjectsEugonadal (n = 11) and hypogonadal (n = 13) men with chronic spinal cord injury (SCI).InterventionsHypogonadal subjects received a 5 or 10 mg transdermal T patch daily for 12 months, with adjustment of the dose to normalize the serum T concentration; TRT was discontinued after 12 months (TRT-12M) and subjects were followed for an additional 6 months and re-evaluated (Post-TRT). Total body dual energy X-ray absorptiometry and blood draws were performed at baseline (BL) prior to TRT, TRT-12M, and Post-TRT. Eugonadal subjects did not receive treatment and were evaluated at comparable time points.ResultsThere were no significant differences between groups prior to TRT at BL for any of the study endpoints. In the hypogonadal group, a significant increase in LTM was observed from BL to TRT-12M (50.2 ± 7.4 vs. 52.9 ± 6.8 kg, P < 0.01), which persisted Post-TRT compared to BL (52.2 ± 7.8 kg, P < 0.05). The increase in REE from BL to TRT-12M (1283 ± 246 vs. 1410 ± 250 kcal/day) was also retained at Post-TRT (1393 ± 220 kcal/day). These sustained improvements in LTM and REE after termination of anabolic hormonal therapy may be associated with persistent beneficial effects on health and physical function of hypogonadal men with chronic SCI.