Quantitative magnetic resonance (QMR) has previously been shown to both overestimate and underestimate average fat mass (FM) in humans. Eight-electrode bioelectrical impedance analysis (BIA) has previously been found biased as well as successfully validated. We report cross-sectional accuracy of QMR and eight-electrode BIA evaluated with air displacement plethysmography (ADP) as reference method.
Fat mass and fat free mass (FFM) by QMR and eight-electrode BIA were evaluated against ADP as reference in 38 normal weight and 30 obese women. Total body water estimates by QMR and eight-electrode BIA were compared.
To investigate the adequacy of food rations to supply energy needs in cold-temperature environments, caloric expenditure and intake and body composition changes were measured in a group of infantrymen during a 10-day field exercise in the Canadian Arctic. Energy expenditure was measured by the doubly labeled water method (n = 10), and caloric intake was measured by complete food intake records (n = 20). Body composition was determined by isotope dilution (n = 10) and bioelectrical impedence analysis (n = 20) on days 0 and 10. Baseline isotopic enrichment shifts due to geographical relocation were also monitored (n = 5). Mean body weight decreased 0.63 +/- 0.83 (SD) kg over the study period (P
To examine the association between aerobic performance and body composition changes by body mass index (BMI).
6-12 months' follow-up during military service.
Conscripts entering military service in 2005 in Sodankyl? Jaeger Brigade (Finland).
945 men (19 years, SD 1 years).
Height, weight, waist circumference, BMI, and aerobic performance (Cooper test) were recorded. Body composition was measured by bioelectrical impedance analysis (BIA). The measured parameters were fat mass (FM), fat free mass (FFM), and visceral fat area (VFA). All the measurements were performed at the beginning and end of service.
On average, the military training period improved the running distance by 6.8% (169 m, p
Cites: Am J Prev Med. 2000 Apr;18(3 Suppl):147-5510736551
Cites: Sports Med. 2010 Nov 1;40(11):907-2020942508
In this study, the bioelectrical impedance analysis (BIA), skinfold thickness measurement (STM) and dual-energy X-ray absorptiometry (DXA), as a reference method, were compared with each other in the assessment of body composition in elderly (62-72-year-old) Finnish women (n=93). BIA had better agreement with DXA in the assessment of fat free mass (FFM, R2=0.70, Sres=2.1) and fat mass (FM, R2=0.93, Sres=2.3) than the STM (FFM, R2=0.62, Sres=2.4; FM, R2=0.89,Sres=2.8). There was quite a large variation in the estimates when different BIA prediction equations were used. The equation developed in this study, FFM (kg)=-128.06 + 1.85 x BMI-0.63 x weight + 1.07 x height - 0.03 x resistance +10.0 x waist-hip ratio, yielded a small and unbiased error (0.5 +/- 1.6 kg), with a small residual standard deviation (R2=0.83, Sres=1.6). However, error associated with the estimate of FM was positively related to the degree of FM. BIA(Heitmann) equation yielded unbiased estimates of both FFM and FM (FFM, R2=0.77, Sres=1.8; FM, R2=0.95, Sres=1.9). Both the STM and BIA (manufacturer's equation) resulted in error which was statistically significant and positively correlated with FFM and FM. These results indicate that BIA prediction equations, chosen with care, can improve the performance of equations based upon anthropometric measurements alone in the assessment of body composition in elderly women.
The assessment of body composition is an important measure to monitor the process of healthy aging and detect early signs of disease. Dual X-ray absorptiometry (DXA) is considered a valid technique for the assessment of body composition but is confined to the clinical environment. Multi-frequency bio-electrical impedance analysis (MF-BIA) might be a versatile alternative to DXA. We aimed to assess whether a segmental MF-BIA scale can be an accurate and reliable tool for the monitoring of body composition in the elderly and whether the presence of metallic prostheses can influence the agreement between the two techniques.
Weight and height were measured in 92 healthy subjects (53 women) aged 80-81 years from the H70 Gerontological and Geriatric study in Gothenburg. Total and segmental fat mass (FM) and lean soft tissue (LST) were estimated by DXA (Lunar Prodigy, Scanex, Sweden) and segmental MF-BIA (MC-180MA, Tanita, Japan). Bland-Altman analyses were performed to assess the agreement between the two techniques. The prediction of DXA-FM by MF-BIA was compared to that of the body mass index (BMI).
MF-BIA showed a significant underestimation of FM and an overestimation of LST that was larger in men than in women. Smaller but significant deviations were found for appendicular LST and SMM. MF-BIA was not superior to BMI at predicting DXA-FM. The lack of agreement between MF-BIA and DXA was not due to the presence of metal prostheses or diagnoses such as hypertension and edema. The prediction equations applied by the device used in this study should be adapted to the elderly population and details about the reference population(s) should be disclosed.
This study evaluated to what extent dual-energy X-ray absorptiometry (DXA) and two types of bioimpedance analysis (BIA) yield similar results for body fat mass (FM) in men and women with different levels of obesity and physical activity (PA).
The study population consisted of 37-81-year-old Finnish people (82 men and 86 women). FM% was estimated using DXA (GE Lunar Prodigy) and two BIA devices (InBody (720) and Tanita BC 418 MA). Subjects were divided into normal, overweight, and obese groups on the basis of clinical cutoff points of BMI, and into low PA (LPA) and high PA (HPA) groups. Agreement between the devices was calculated by using the Bland-Altman analysis.
Compared to DXA, both BIA devices provided on average 2-6% lower values for FM% in normal BMI men, in women in all BMI categories, and in both genders in both HPA and LPA groups. In obese men, the differences were smaller. The two BIA devices provided similar means for groups. Differences between the two BIA devices with increasing FM% were a result of the InBody (720) not including age in their algorithm for estimating body composition.
BIA methods provided systematically lower values for FM than DXA. However, the differences depend on gender and body weight status pointing out the importance of considering these when identifying people with excess FM.
Low birth weight has been linked to lower lean body mass and abdominal obesity later in life, whereas high birth weight has been suggested to predict later obesity as indicated by high body mass index (BMI). We examined how birth weight was related to adult body size, body composition and grip strength.
Cross-sectional study on 928 men and 1075 women born in 1934-1944, with measurements at birth recorded.
Height, weight, waist and hip circumference and isometric grip strength were measured. Lean and fat body mass were estimated by bioelectrical impedance with an eight-polar tactile electrode system.
A 1 kg increase in birth weight corresponded in men to a 4.1 kg (95% CI: 3.1, 5.1) and in women to a 2.9 kg (2.1, 3.6) increase in adult lean mass. This association remained significant after adjustment for age, adult body size, physical activity, smoking status, social class and maternal size. Grip strength was positively related to birth weight through its association with lean mass. The positive association of birth weight with adult BMI was explained by its association with lean mass. Low birth weight was related to higher body fat percentage only after adjustment for adult BMI. Abdominal obesity was not predicted by low birth weight.
Low birth weight is associated with lower lean mass in adult life and thus contributes to the risk of relative sarcopenia and the related functional inability at the other end of the lifespan. At a given level of adult BMI, low birth weight predicts higher body fat percentage.
The aim of this study was to determine the level of agreement between body composition measurements by dual-energy X-ray absorptiometry (DXA), single-frequency bioelectrical impedance analysis (BIA) and multifrequency bioelectrical impedance spectroscopy (BIS). Fat-free mass (FFM), body fat mass and body fatness (percentage fat) were measured by DXA, BIA and BIS in 61 healthy children (37M, 24F, aged 10.9-13.9 y). Estimates of FFM, body fat mass and body fatness were highly correlated (r = 0.73-0.96, p
Body composition estimated by bioelectrical impedance in the Swedish elderly. Development of population-based prediction equation and reference values of fat-free mass and body fat for 70- and 75-y olds.
To develop a bioelectrical impedance (BIA) prediction equation for fat-free mass (FFM(BIA)) and present reference values of FFM and body fat (BF) for healthy Swedish elderly from population-based representative samples.
This study is based on 823 (344 males, 479 females) participants from two systematic samples of birth cohorts in Göteborg aged 70 (cohort H70V, 201 males and 299 females) and 75 (cohort NORA75, 143 males and 180 females).
Body composition was measured with BIA (BIA-101, RJL system, Detroit) in both cohorts and was estimated by a four-compartment (4C) model from total body water (TBW) and total body potassium (TBK) in a sub-sample of the NORA75 cohort. The FFM(BIA) was validated against the FFM from the 4C model (FFM(4C)).
The FFM(BIA) correlated well with FFM(4C) (r=0.95, SEE=2.64 kg). The FFM(BIA) (kg) in 70-y-old males and females were 58.5+/-5.4 and 43.4+/-4.4, and for 75-y-old males and females were 56.1+/-4.7 and 42.5+/-4, respectively. The body fat in kg (FM) among 70-y-old males and females were 25.2+/-8.1 and 25.7+/-8.4, and for 75-y-old males and females were 21.7+/-7.1 and 22.8+7.2, respectively. The percent body fat (BF%) among 70-y-old males and females were 29.5+/-5.8 and 36.3+/-6.4, and for 75-y-old males and females were 27.3+/-6 and 34.1+/-6.1, respectively.
The FFM, FM and BF% from this study might be used as reference values for Swedish elderly aged 70 and 75 y.
OBJECTIVE: To describe body composition in patients with short bowel syndrome (SBS) by using bioelectric impedance spectroscopy (BIS), dual-energy X-ray absorptiometry (DXA) measurements and anthropometrical-derived estimates. SUBJECTS: In all, 19 patients were included, mean age 54 y, range 36-77 (F/M=11/8). Mean BMI was 21.5 kg/m(2). Eight patients were on home parenteral nutrition (HPN). METHODS: Total body water (TBW), intracellular water and extracellular water were assessed by BIS. TBW were derived from DXA. Fat-free mass (FFM) was assessed by BIS and DXA. TBW and FFM were predicted according to an empirical formula. Differences were analysed using the Bland-Altman method. RESULTS: The mean difference between TBW (DXA) and TBW (BIS) was -1.1 l in women and -1.8 l in men. For FFM, the mean difference between FFM (DXA) and FFM (BIS) was -1.7 kg in women and -2.5 kg in men. The mean difference between TBW (DXA) and TBW (BIS) for all patients was -1.2 l and limits of agreement were (-7.80-5.40). Hydration of FFM assessed by BIS gave a mean of 0.75 (0.08). CONCLUSION: The limits of agreement (Bland-Altman) between DXA and BIS were wide, indicating that methods are not interchangeable, which limits its clinical utility. Most of our patients with SBS were maintained in a stable clinical condition within normal limits of body weight and BMI. FFM and TBW did not appear to be altered in ileostomates or those on HPN.