Body composition in the elderly: Total body water and anthropometry

Body composition measured with isotopic dilution was compared with anthropometric measurements. The study was carried out in 47 subjects from both sexes, 65 to 92 years old. Total body water (TBW), anthropometric measurements, and dynamometry were assessed. TBW was significatively higher in men than women and decreased with age. Dynamometry and fatfree mass were well correlated (r=0.73 in males and r=0.58 in females) and significantly different between sexes. A negative correlation was found for dynamometry with age, being significant for women. Linear regression equations to predict TBW from anthropometric measurements in males and females were obtained: Males: TBW(I)=19.349+0.617 weight(kg) — 0.931 mid-arm circumference(cm)+0.122 dynamometry (kg) Females: TBW(l)=−5.531+0.343 weight(kg)-0.213 triceps skinfold (mm)+ 0.148 dynamometry(kg) + 3.424 wrist diameter (cm). This simple model is proposed for use in epidemiological and field studies where other more sophisticated methods can not be applied.     

The oral contraceptive containing 30 microg of ethinylestradiol plus 3 mg of drospirenone is able to antagonize the increase of extracellular water occurring in healthy young women during the luteal phase of the menstrual cycle: an observational study

PURPOSE: This nonrandomized study aimed to evaluate body weight and composition during the menstrual cycle and during oral contraception with 30 microg of ethinylestradiol plus 3 mg of drospirenone (EE+DRSP). DESIGN: Multifrequency bioelectrical impedance analysis was carried out in 38 normally cycling women (mean age, 25.5 years) at baseline during the follicular phase (FP) and the luteal phase (LP) of the menstrual cycle and after three and six cycles of EE+DRSP to evaluate total body water (TBW), intracellular water (ICW), extracellular water (ECW), fat mass and fat-free mass. Body weight, waist-to-hip ratio, blood pressure and the plasma concentrations of electrolytes were also determined at each visit. RESULTS: TBW and ECW increased in the LP. During EE+DRSP, TBW and ECW were significantly lower than in the LP but similar to the values measured in the FP. No significant variations in ICW or in the other parameters were observed. CONCLUSION: EE+DRSP maintains the same concentrations in TBW and ECW observed in the FP. This effect is likely due to the antimineralocorticoid activity of DRSP, which counteracts the water retention elicited by estrogen.     

Estimation of total body water from bioelectrical impedance spectroscopy in oncology outpatients receiving radiotherapy and agreement with three prediction equations

Background: Bioelectrical impedance spectroscopy (BIS) may be more accurate in determining total body water (TBW) than bioelectrical impedance analysis (BIA). The present study compared the agreement between three TBW prediction equations developed using BIA and BIS‐derived TBW in oncology outpatients. Methods: A cross‐sectional, observational study was conducted in 37 outpatients receiving radiotherapy (27 males/10 females, aged 68.3 ± 10.2 years). TBW was estimated by BIS (TBW_BIS) and three BIA TBW prediction equations (TBW_ca‐u: underweight cancer patients; TBW_ca‐n: normal‐weight cancer patients; and TBW_rad: patients receiving radiotherapy). Bland–Altman analyses determined agreement between methods. BIS‐derived TBW using new resistivity constants was calculated. Results: The mean ± SD of TBW estimated by BIS was 39.8 ± 8.3 L, which was significantly different from the prediction equations; TBW_rad 35.1 ± 7.9 L, TBW_ca‐u 33.1 ± 7.5 L and TBW_ca‐n 32.3 ± 7.3 L, (P < 0.001). Using new resistivity constants, TBW was 36.2 ± 8.1 L but this still differed from the equations (P < 0.001). Bias between TBW_BIS and that predicted by the equations was in the range 4.7–7.4 L or 1.1–3.9 L using new resistivity constants. Conclusions: TBW estimated by BIS cannot be directly compared with oncology‐specific BIA equations, suggesting that BIS cannot be used at the group level in outpatients receiving radiotherapy. There was a reduced bias with BIS using new resistivity constants; however, further research should determine any advantage of BIS over BIA in this population.     

Accuracy of direct segmental multi-frequency bioimpedance analysis in the assessment of total body and segmental body composition in middle-aged adult population

Background & aims

Body composition measurement is a valuable tool for assessing nutritional status and physical fitness in a variety of clinical settings. Although bioimpedance analysis (BIA) can easily assess body composition, its accuracy remains unclear. We examined the accuracy of direct segmental multi-frequency BIA technique (DSM-BIA) in assessing different body composition parameters, using dual energy X-ray absorptiometry (DEXA) as a reference standard.

Methods

A total of 484 middle-aged participants from the Leiden Longevity Study were recruited. Agreements between DSM-BIA and DEXA for total and segmental body composition quantification were assessed using intraclass correlation coefficients and Bland–Altman plots.

Results

Excellent agreements were observed between both techniques in whole body lean mass (ICC female = 0.95, ICC men = 0.96), fat mass (ICC female = 0.97, ICC male = 0.93) and percentage body fat (ICC female = 0.93, ICC male = 0.88) measurements. Similarly, Bland–Altman plots revealed narrow limits of agreements with small biases noted for the whole body lean mass quantification but relatively wider limits for fat mass and percentage body fat quantifications. In segmental lean muscle mass quantification, excellent agreements between methods were demonstrated for the upper limbs (ICC female≥0.91, ICC men≥0.87) and lower limbs (ICC female≥0.83, ICC male≥0.85), with good agreements shown for the trunk measurements (ICC female = 0.73, ICC male = 0.70).

Conclusions

DSM-BIA is a valid tool for the assessments of total body and segmental body composition in the general middle-aged population, particularly for the quantification of body lean mass.     

Estimation of total body water from foot-to-foot bioelectrical impedance analysis in patients with cancer cachexia – agreement between three prediction methods and deuterium oxide dilution

INTRODUCTION: Bioelectrical impedance analysis (BIA) is a useful bedside measure to estimate total body water (TBW). The aim of this study was to determine the agreement between three equations for the prediction of TBW using BIA against the criterion method, deuterium oxide dilution, in patients with cancer cachexia. METHODS: Eighteen measurements of TBW using foot-to-foot BIA in seven outpatients with cancer cachexia (five male and two female, age 56.4 +/- 6.7 years) at an Australian hospital. Three prediction formulae were used to estimate TBW - TBW(ca-radiotherapy) developed in patients with cancer undergoing radiotherapy, TBW(ca-underweight) and TBW(ca-normal weight) developed in underweight and normal weight patients with cachexia. TBW was measured using the deuterium oxide dilution technique as the gold standard. RESULTS: Mean measured TBW was 39.5 +/- 6.0 L. There was no significant difference in measured TBW and estimates from prediction equations TBW(ca-underweight) and TBW(ca-radiotherapy). There was a significant difference in measured TBW and TBW(ca-normal weight). All prediction equations overestimated TBW in comparison with measured TBW. The smallest bias was observed with TBW(ca-underweight) (0.38 L). The limits of agreement are wide (>7.4 L) for each of the prediction equations compared with measured TBW. CONCLUSIONS: At a group level, TBW(ca-underweight) is the best predictor of measured TBW in patients with cancer cachexia. For an individual however, the limits of agreement are wide for all prediction equations and are unsuitable for use. Practitioners need to be aware of the limitations of using TBW prediction equations for individuals.     

老年人体质量指数、体脂总量及分布与血脂异常的相关性

目的 观察老年人体质量指数、总体脂肪及分布与血脂异常的相关性.方法 连续定点抽取2013年10月至2014年3月在北京协和医院接受年度体检的395名健康老年人进行调查.采用多频生物电阻抗测定体质量、总体脂肪(TBF)、腹部脂肪(AF)、内脏脂肪(VF)、内脏脂肪面积(VFA)和腰臀围比值(WHR),并测定血清三酰甘油(TG)、总胆固醇(TC)、高密度脂蛋白胆固醇(HDL-C)和低密度脂蛋白胆固醇(LDL-C).分析体质量指数(BMI)、TBF及分布与血脂异常的相关性.结果 老年男性肥胖(17.8％比9.6％,P=0.036)、超重(49.6％比30.4％,P=0.000)和血脂异常(67.0％比44.8％,P=0.000)发生率均显著高于女性.女性表现为TBF％显著增高(60.0％比41.1％,P=0.001).TC分别与TBF (P =0.020)、AF (P =0.018)、VF (P=0.015)和VFA (P =0.017)呈正相关;TG分别与BMI(P=0.000)、TBF(P=0.000)、WHR(P=0.000)、AF(P=0.000)、VF (P =0.000)和VFA (P=0.000)呈正相关;LDL-C分别与BMI (P =0.049)、TBF (P =0.005)、AF(P=0.004)、VF (P=0.003)和VFA (P=0.004)呈正相关,而HDL-C分别与BMI(P=0.000)、TBF(P=0.020)、WHR(P=0.000)、AF (P=0.021)、VF (P=0.024)和VFA (P=0.022)呈负相关.BMI、TBF、WHR、AF、VF和VFA预测血脂异常风险的受试者工作特征曲线均在参考线上方.超重和肥胖组TBF(P=0.000)、WHR(P=0.000)、AF (P=0.000)、VF (P=0.000)、VFA (P=0.000)、TG (P =0.000)和LDL-C(女性:P=0.021)均显著高于体质量正常组.结论 肥胖/超重和体脂总量超标及腰围增大,可增加老年人血脂异常的发生风险.     

Effects of two different oral contraceptives on total body water: a randomized study

Purpose

This open-label, randomized study evaluated the effect of two different oral contraceptives on body weight and composition during one cycle of treatment.

Method

Eighty women (mean age, 24.6 years) were randomized into three groups and given one of the following contraceptive methods: ethinylestradiol 15 μg/gestodene 60 μg (EE/GST, n=25), ethinylestradiol 30 μg/drospirenone 3 mg (EE/DRS, n=29) or male condom (control group, n=26). Bioelectric impedance analysis (BIA) was carried out on the first, 10th and 21st days during the use of oral contraceptives or in the menstrual cycle (control group), and total body water (TBW), fat mass (FM) and fat-free mass (FFM) were measured.

Results

No significant variations in TBW, FM or FFM were observed in the three groups during the cycle. Intergroup analysis showed no differences in TBW or FM; however, users of EE/GST showed a statistically significant increase in FFM compared to the control group.

Conclusion

The different doses of ethinylestradiol associated with gestodene or drospirenone showed no statistically significant effects on TBW or FM during one cycle of observation.     

生物电阻抗法测量7～10岁儿童总体水含量和去脂体重的预测模型

目的利用生物电阻抗方法测量儿童的体成分,建立适合我国儿童体成分的预测方程。方法在北京市采用目的抽样法选取409名7～10岁的儿童（男生220名,女生189名）,测量身高和体重,采用生物电阻抗仪测量全身电阻抗和电容抗,采用单标水法测量的总体水（totalbodywater,TBW）和去脂体重（fat—freemass,FFM）作为标准,用多元线性逐步回归法建立回归方程,并采用纯误差和Bland—Altman分析法来判断预测方程的准确度。结果TBW的预测方程=-6．893＋0．410x性别（男：1,女=0）＋0．273×年龄（岁）＋0．174x体重（k）＋0．081×身高（cm）＋0．206x阻抗指数（cm2/Ω）（R2=0．90,均方根误差=1．2kg）;FFM的预测方程=-9．742＋0．784x性别（男=1,女=0）＋0．429x年龄（岁）＋0．227×体重（kg）＋0．104x身高（cm）＋0．269×阻抗指数（cm2／Ω）（R2=0．90,均方根误差=1．6kg）。TBW和FFM的预测值与测量值间差异均无统计学意义,纯误差分别是1．4、1．8kg。TBW和FFM的测量值与预测值的差值与均值之间存在显著正相关性（相关系数分别为0．24、0．23,P〈0．01）。不同BMI分组的测量值与预测值间差异均无统计学意义。结论推导的预测方程有较高的精确度和准确度,能有效准确地预测我国7～10岁儿童的体成分。     

Percentage of body fat in adolescents with Down syndrome: Estimation from skinfolds

Background

Adolescents with Down syndrome (DS) have a unique morphology and body shape, and this needs to be taken into account when assessing body fat percentage (BF%).