BODPOD体成分测量仪中两种方法测量成年人身体成分的差异性及相关性研究

目的：研究在BODPOD体成分测量仪中，利用估计测量与直接测量两种方法测得的成年人身体成分结果是否存在显著性差异，探索估计测量方法的准确性；方法：利用BODPOD体成分测量仪测量35名爱试者的身体成分。分别采用估计测量和直接测量两种方法测得胸腔内气体体积，然后再分别计算出体脂率。比较估计测量和直接测量两种方法所得的体成分值的差异性与相关性；结果：两种方法所得的％BF值无显著性差异，而是存在高度相关性（r=0．954，P〈0．001）。结论：估计测量方法也是一种较为精确的测量体成分的方法。从长远采看，存在估计测量方法代替直接测量方法测量体成分的可能。     

身体成分测量与评价的理论和方法

身体成分评价是指体内各种成分的含量。常用各种物质的组成和比例表示。一旦机体内部各成分比例失衡。将会严重危险人类的健康。所以，关注身体成分的测量与评价已经成为世界性话题。多年的研究证实，身体成分评价的理论模型多见于“2-成分”模型和“多-成分”模型。现在较为流行的测量和评价方法包括水下称重法，皮褶厚度法、生物电阻抗法和双能量X吸收法等。     

DEXA在身体成分测量中的应用

作为骨量测量“金标准”的双能X线吸收测定法（DEXA），近几年已被国外研究学者作为身体成分测量的新标准．但在国内DEXA还没有得到广泛应用．本文综合有关文献，从DEXA测量身体成分的原理、研究进展及展望等方面对DEXA进行综述，以期促进DEXA在国内更广泛的应用。     

对我国高山滑雪运动员身体成分的研究

通过对我国现役的36名高山滑雪运动员身体成分的测量,并对测量结果进行了横向和纵向的对比分析,发现我国高山滑雪运动员身体成分特点身体比较强壮,充实度较高,营养状况良好,肌肉重量处于中等水平,上下肢左右肌力平衡.     

对评价大学生身体成分方法的研究

为研究在校大学生身体成分测量的最佳方法,采用皮褶法、生物电阻抗法(BAI)、身体质量指数(BMI)、腰臀比(WHR)和身高标准体重法,分别对随机抽取的220名大学生进行身体成分测试,并进行相关分析。结果发现:1.BAI、皮褶法、BMI和WHR可用来测量和评价大学生的身体成分,但其准确性依次是BAI>皮褶法>BMI>WHR;2.《标准》中身高标准体重不能客观有效地评价身体成分,故建议选用体脂百分比。     

用生物电阻抗法测量体育学院学生体成分及比较分析

目的:利用生物电阻抗技术测量90名体育学院大学生的身体成分,并将身体质量指数(BMI)、腰臀比(WHR)、体脂百分比(PBF)等指标做统计分析,探讨身体成分与运动之间的关系,为身体成分的优化提供科学依据。结果:不同组别之间的大学生身体成分存在显著差异,运动水平高的大学生身体成分相对具有优势。结论:身体成分与运动水平具有很高的相关性。     

对大学生身体成分的评价反应及其体育锻炼动机的调查

对128名大学生皮脂厚度进行测量，采用问卷的方式调查了学生对测量的情绪反应。结果显示，大多数学生认为身体成分的测量与评价是有意义的。皮脂厚度测量的重要作用在于测量促进了学生的自我训练意识和动机，特别是测量使肥胖者的自我锻炼意志、感情、自我练习动机得到了加强。     

体育专业与非体育专业学生体成分及骨密度的分析研究

应用体育测量与统计、文献资料和问卷调查等方法,对体育专业238名学生和非体育专业153名学生进行了体成分和骨密度的测量与分析,旨在探讨运动对处于青春发育末期和骨量缓慢增长期的大学生体成分和骨密度的作用及影响。研究结果表明运动对体成分有明显的改善作用;学生骨密度值都在正常范围值内,但体育专业学生骨密度值略低于非体育专业学生。研究提示,大学生在进行运动时,应选择适宜的运动方式,合理安排运动强度和运动量,并且在运动后及时补充人体各种营养物质。     

全身与四肢瘦体重3种测量方法结果间的一致性评价——以生存分析与一致性图谱法为例

目的:通过对18~56岁成年人使用生物电阻抗法(BCA I、BCA II)与双能X线吸收测定法(DEXA)测量全身瘦体重(LM)与四肢瘦体重(ALM),明确不同身体成分测量仪测量国人瘦体重分布特征时的差异,详述一致性界限与生存分析法在评价两种或多种方法测量结果间的一致性应用过程。方法:采用BCA I、BCA II与DEXA 3种设备测量163名成年人的身体成分,采用一致性界限与生存分析法评价3种设备测量LM与ALM结果的一致性。结果:男女受试者LM、ALM测量结果在3种测试方法中均具有较高的相关性(P<0.01),BCA I测量结果显著高于BCA II和DEXA,且都具有统计学意义(P<0.05),BCA II与DEXA的一致性程度较好。结论:生存分析与一致性图谱法可用于两种或多种方法测量结果间的一致性评价,两者可结合使用。相对于BCA I,BCA II与DEXA测量值一致性程度更好。     

高校健美操队员形态特征的研究

本文利用形态测量、数理统计等方法，对湖北省15所高等院校健美操队员进行了身体形态、身体成分的测量分析．试图探索健美操队员形体与动作技能能力的关系，以及健美操运动训练对人体形态的影响．研究结果显示：健美操队员的身体形态、身体成分形态指数对完成高质量的动作有重要影响，而且长期的健美探训练中可以增加瘦体重，改善身体成分，提高肌肉力量；使胸、腰、臀各个部分的比例趋于协调、合理，有利于形成健康健美的形体．     

The accuracy and precision of DXA for assessing body composition in team sport athletes

Abstract

This study determined the precision of pencil and fan beam dual-energy X-ray absorptiometry (DXA) devices for assessing body composition in professional Australian Football players. Thirty-six professional Australian Football players, in two groups (fan DXA, N = 22; pencil DXA, N = 25), underwent two consecutive DXA scans. A whole body phantom with known values for fat mass, bone mineral content and fat-free soft tissue mass was also used to validate each DXA device. Additionally, the criterion phantom was scanned 20 times by each DXA to assess reliability. Test–retest reliability of DXA anthropometric measures were derived from repeated fan and pencil DXA scans. Fat-free soft tissue mass and bone mineral content from both DXA units showed strong correlations with, and trivial differences to, the criterion phantom values. Fat mass from both DXA showed moderate correlations with criterion measures (pencil: r = 0.64; fan: r = 0.67) and moderate differences with the criterion value. The limits of agreement were similar for both fan beam DXA and pencil beam DXA (fan: fat-free soft tissue mass = ?1650 ± 179 g, fat mass = ?357 ± 316 g, bone mineral content = 289 ± 122 g; pencil: fat-free soft tissue mass = ?1701 ± 257 g, fat mass = ?359 ± 326 g, bone mineral content = 177 ± 117 g). DXA also showed excellent precision for bone mineral content (coefficient of variation (%CV) fan = 0.6%; pencil = 1.5%) and fat-free soft tissue mass (%CV fan = 0.3%; pencil = 0.5%) and acceptable reliability for fat measures (%CV fan: fat mass = 2.5%, percent body fat = 2.5%; pencil: fat mass = 5.9%, percent body fat = 5.7%). Both DXA provide precise measures of fat-free soft tissue mass and bone mineral content in lean Australian Football players. DXA-derived fat-free soft tissue mass and bone mineral content are suitable for assessing body composition in lean team sport athletes.     

Prediction of visceral fat area at the umbilicus level using fat mass of the trunk: The validity of bioelectrical impedance analysis

The aims of this study were to determine the validity of fat mass of the trunk as a predictor for visceral fat area at the umbilicus level and to develop equations to predict visceral fat mass at the umbilicus level using fat mass of the trunk measured by dual-energy X-ray absorptiometry (DXA) and bioelectrical impedance analysis (BIA). The participants were 121 normal Japanese adults (69 males, 52 females). Another 60 volunteer adults (34 males, 26 females) were recruited for examination of cross-validity. Altogether, 41 adults (15 males, 26 females) in the original group and 19 adults (7 males, 12 females) in the cross-validity group received BIA measurement. We measured fat mass by DXA and the BIA system, which was a single-frequency BIA with 8-point contact electrodes, and visceral fat area by computed tomography. We observed significant correlations for visceral fat area in waist circumference (0.56) and fat mass of the trunk measured by DXA (0.64). There was no significant difference in fat mass of the trunk between the DXA and BIA systems, but the BIA system tended to provide an underestimate compared with DXA. With combined fat mass of the trunk measured by DXA and waist circumference as predictors, visceral fat area was estimated by equation (1) (R = 0.87, R(2) = 0.76, standard error of the estimate = 20.9 cm(2)). When substituting fat mass of the trunk measured by BIA into equation (1), there was no significant difference in visceral fat area between the reference and predicted values. An equation using fat mass of the trunk measured by BIA (equation 2) was obtained (R = 0.89, R(2) = 0.78, standard error of the estimate = 20.7 cm(2)), but a systematic error was found for the males. There was cross-validity in both equations. In conclusion, fat mass of the trunk is an effective predictor for the visceral fat area at the umbilicus level. Fat mass of the trunk measured by BIA might be a valid method to predict visceral fat, although further studies with larger samples taking into account the extent and type of obesity are required.     

Bone mineral density and lean mass asymmetries are greater in cyclists than non-cyclists

ABSTRACT

Cyclists may be at greater risk of developing asymmetrical force and motion patterns than other ground-based athletes. However, functional asymmetries during cycling tend to be highly variable, making them difficult to assess. Dual-energy x-ray absorptiometry (DXA) measurements of areal bone mineral density (aBMD) and lean mass (LM) in the lower limbs may be a more sensitive and consistent method to identify asymmetries in cyclists. The goal of this study was to determine if competitive cyclists have greater levels of asymmetries in the lower body compared to non-cyclists using DXA. A secondary aim was to determine if aBMD and LM asymmetries change over the road cycling season. 17 competitive cyclists and 21 non-cyclist, healthy controls underwent DXA scans. Lower-body asymmetries were greater in cyclists compared to non-cyclists in aBMD and LM for all lower limb segments. However, these asymmetries did not tend to consistently favour a particular side, except for the pelvis having more LM on the dominant side. The were no longitudinal changes in aBMD or LM in the cyclists. Asymmetry analysis via DXA provides evidence that although functional asymmetries during cycling are variable, cyclists have increased lower body LM and aBMD asymmetries compared to non-cyclists.     

Determination of thigh volume in youth with anthropometry and DXA: Agreement between estimates

Abstract

This study examined the agreement between estimates of thigh volume (TV) with anthropometry and dual-energy x-ray absorptiometry (DXA) in healthy school children. Participants (n=168, 83 boys and 85 girls) were school children 10.0–13.9 years of age. In addition to body mass, height and sitting height, anthropometric dimensions included those needed to estimate TV using the equation of Jones & Pearson. Total TV was also estimated with DXA. Agreement between protocols was examined using linear least products regression (Deming regressions). Stepwise regression of log-transformed variables identified variables that best predicted TV estimated by DXA. The regression models were then internally validated using the predicted residual sum of squares method. Correlation between estimates of TV was 0.846 (95%CI: 0.796–0.884, S_y·x=0.152L). It was possible to obtain an anthropometry-based model to improve the prediction of TVs in youth. The total volume by DXA was best predicted by adding body mass and sum of skinfolds to volume estimated with the equation of Jones & Pearson (R=0.972; 95%CI: 0.962–0.979; R ²=0.945).     

Comparison of anthropometry to dual energy X-ray absorptiometry: a new prediction equation for women

The purpose of this study was to assess the accuracy of three recommended anthropometric equations for women and then develop an updated prediction equation using dual energy x-ray absorptiometry (DXA). The percentage of body fat (%BF) by anthropometry was significantly correlated (r = .896-.929; p < .01) with DXA, but each equation underestimated %BF (3.2-5.6 %BF; p < .01). The following DXA criterion (DC) equation was created: %BF= -6.40665 + 0.41946(S3SF) - 0.00126(S3SF)2 + 0.12515(hip) + 0.06473 (age); (S3SF = sum of triceps, suprailiac, thigh; hip = circumference in cm; age = years). The predicted residual sum of squares (PRESS) R2 was high (0.86), and the PRESS standard error of estimate (SEE) was low (2.5 %BF) for our sample of 150 women. The DC equation was further crosschecked on a separate sample of women (n = 25) and again showed excellent agreement. The DC equation appears to be a more accurate estimation of %BF in women.     

Prediction of visceral fat area at the umbilicus level using fat mass of the trunk: The validity of bioelectrical impedance analysis

Abstract

The aims of this study were to determine the validity of fat mass of the trunk as a predictor for visceral fat area at the umbilicus level and to develop equations to predict visceral fat mass at the umbilicus level using fat mass of the trunk measured by dual-energy X-ray absorptiometry (DXA) and bioelectrical impedance analysis (BIA). The participants were 121 normal Japanese adults (69 males, 52 females). Another 60 volunteer adults (34 males, 26 females) were recruited for examination of cross-validity. Altogether, 41 adults (15 males, 26 females) in the original group and 19 adults (7 males, 12 females) in the cross-validity group received BIA measurement. We measured fat mass by DXA and the BIA system, which was a single-frequency BIA with 8-point contact electrodes, and visceral fat area by computed tomography. We observed significant correlations for visceral fat area in waist circumference (0.56) and fat mass of the trunk measured by DXA (0.64). There was no significant difference in fat mass of the trunk between the DXA and BIA systems, but the BIA system tended to provide an underestimate compared with DXA. With combined fat mass of the trunk measured by DXA and waist circumference as predictors, visceral fat area was estimated by equation (1) (R = 0.87, R ² = 0.76, standard error of the estimate = 20.9 cm²). When substituting fat mass of the trunk measured by BIA into equation (1), there was no significant difference in visceral fat area between the reference and predicted values. An equation using fat mass of the trunk measured by BIA (equation 2) was obtained (R = 0.89, R ² = 0.78, standard error of the estimate = 20.7 cm²), but a systematic error was found for the males. There was cross-validity in both equations. In conclusion, fat mass of the trunk is an effective predictor for the visceral fat area at the umbilicus level. Fat mass of the trunk measured by BIA might be a valid method to predict visceral fat, although further studies with larger samples taking into account the extent and type of obesity are required.     

Estimating fat-free mass in elite youth male soccer players: cross-validation of different field methods and development of prediction equation

This study determined the most effective field method for quantifying fat-free mass (FFM) in elite youth male soccer players compared to dual X-ray absorptiometry (DXA) values and to develop prediction equations for FFM based on anthropometric variables. Forty-one male elite-standard youth soccer players, ages 16.2–18.0 years, undertook FFM assessments including bioelectrical impedance analysis, and different skinfold-based prediction equations. DXA provided a criterion measure of FFM. Correlation coefficients, bias, limits of agreement, and differences were used as validity measures, and regression analyses to develop soccer-specific prediction equations. Slaughter et al (1988), Durnin and Wormersley (1974), and Sarria et al (1998) equations showed the lowest biases, and no significant, standardized, and substantial differences against DXA. The new youth soccer-specific anthropometric equation explained 91% of the DXA-derived FFM variance using three circumferences, eight skinfolds, and one bone breadth. All field methods compared in this study may not be adequate for estimating FFM in elite youth male soccer players, except the equations of Slaughter et al (1988), Durnin and Wormersley (1974), and Sarria et al (1998). We recommend the use of the new soccer-specific equation proposed in this study as a valid alternative to DXA to quantify FFM among elite youth male players.     

An investigation of the accuracy and reliability of body composition assessed with a handheld electrical impedance myography device

The purpose of this study was to compare the body fat per cent (BF%) assessed with a unique handheld electrical impedance myography (EIM) device, along with other popular methods, to dual-energy X-ray absorptiometry (DXA). Participants included 33 males (aged 24.3?±?4.6 years) and 38 females (aged 25.3?±?8.9 years) who completed 2 visits separated by 24–72?h. The assessments included DXA, bioelectrical impedance analysis (BIA), skinfold measures (SKF), and three separate EIM measurements. No significant differences in BF% (P?>?0.05) were found between all EIM assessments when compared against DXA for both males and females for each visit. All methods showed no significant differences in BF% (P?>?0.05) between days within themselves. Across both days, the standard error of the estimate (SEE) for the EIM measurements ranged from 2.66% to 3.15%, the SEE for BIA was 2.80 and 2.85, and for SKF was 2.90 and 2.82. The 95% limits of agreement ranged from ±5.34% to ±6.38% for EIM measurements and were highest for SKF (±7.42% and ±7.47%). The total error for both days was largest for SKF (5.20% and 5.35%) and lowest for the EIM measurements (2.48–3.24%). This investigation supports use of a handheld EIM device as an accurate and reliable method of estimating BF% compared to DXA in young, apparently healthy individuals with BF% in the range of 10–22% for males and 20–32% in females and suggests this EIM device be considered a viable alternative to other established field measurements in this population.     

Assessing Fat Mass of Adolescent Swimmers Using Anthropometric Equations: A DXA Validation Study

Purpose: The aim of the present study was to determine which of the published anthropometric equations is the most appropriate to estimate body-fat percentage (BF_%) in adolescent swimmers. Method: Eighty-eight swimmers (45 boys, 43 girls) participated in this study. Following the recommendations of the International Society of the Advancement of Kinanthropometry, biceps, triceps, subscapular, iliac-crest, supraspinale, front-thigh, and medial calf skinfold thicknesses were measured. Waist, hip, midthigh, calf, relaxed arm, and arm flexed and tensed girths were also registered. BF_% was measured with dual-energy X-ray absorptiometry (DXA) to obtain the reference value. Existing anthropometric equations were applied, and BF_% results obtained from anthropometric equations were compared to DXA BF_% results with the modified Bland-Altman. Results: The Flavel, Durnin-Rahaman-Siri, and Durnin-Rahaman-Brozek were the only equations that did not demonstrate statistically significant differences when compared with DXA. Conclusion: The present study showed that the best anthropometric equation from existing literature to estimate BF_% in swimmers is that proposed by Durnin-Rahaman (independently of applying the Siri or Brozek equation).     

Agreement between bioelectrical impedance and dual energy X-ray absorptiometry in assessing fat,lean and bone mass changes in adults after a lifestyle intervention

We aimed to assess the agreement of a commercially available bioelectrical impedance analysis (BIA) device in measuring changes in fat, lean and bone mass over a 10-week lifestyle intervention, with dual energy X-ray absorptiometry (DXA) as reference. A sample of 136 volunteers (18–66 years) underwent a physical activity intervention to enhance lean mass and reduce fat mass. BIA (Tanita BC545) and DXA (Hologic Explorer) measures of whole-body composition were taken at baseline and at the end of the intervention. After an average of 74 ± 18 days intervention, DXA showed significant changes in 2 of 3 outcome variables: reduced fat mass of 0.802 ± 1.092 kg (P < 0.001), increased lean mass of 0.477 ± 0.966 kg (P < 0.001); minor non-significant increase of 0.007 ± 0.041 kg of bone mass (P = 0.052). The respective changes in BIA measures were a significant reduction of 0.486 ± 1.539 kg fat (P < 0.001), but non-significant increases of 0.084 ± 1.201 kg lean mass (P = 0.425), and 0.014 ± 0.091 kg bone (P = 0.074). Significant, but moderately weak, correlations were seen in absolute mass changes between DXA and BIA: 0.511 (fat), 0.362 (lean) and 0.172 (bone). Compared to DXA, BIA demonstrated mediocre agreement to changes in fat mass, but poor agreement to lean mass changes. BIA significantly underestimated the magnitude of changes in fat and lean mass compared to DXA.