Dataset Information

Limitations of Fat-Free Mass for the Assessment of Muscle Mass in Obesity.

ABSTRACT:

Background

A high amount of adipose tissue limits the accuracy of methods for body composition analysis in obesity.

Objectives

The aim was to quantify and explain differences in fat-free mass (FFM) (as an index of skeletal muscle mass, SMM) measured with bioelectrical impedance analysis (BIA), dual energy X-ray absorptiometry (DXA), air displacement plethysmography (ADP), and deuterium dilution in comparison to multicompartment models, and to improve the results of BIA for obese subjects.

Methods

In 175 healthy subjects (87 men and 88 women, BMI 20-43.3 kg/m2, 18-65 years), FFM measured by these methods was compared with results from a 3- (3C) and a 4-compartment (4C) model. FFM4C was compared with SMM measured by magnetic resonance imaging.

Results

BIA and DXA overestimated and ADP underestimated FFM in comparison to 3C and 4C models with increasing BMI (all p < 0.001). -Differences were largest for DXA. In obesity, BIA results were improved: valuecorrected = -valueuncorrected - a(BMI - 30 kg/m2), a = 0.256 for FFM and a = 0.298 for SMM. SMM accounts for 45% of FFM in women and 49% in men.

Conclusions

In obesity, the use of FFM is limited by a systematic error of reference methods. In addition, SMM accounts for about 50% of FFM only. Corrected measurement of SMM by BIA can overcome these drawbacks.

SUBMITTER: Jensen B

PROVIDER: S-EPMC6696776 | biostudies-literature | 2019

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Limitations of Fat-Free Mass for the Assessment of Muscle Mass in Obesity.

Jensen Björn B Braun Wiebke W Geisler Corinna C Both Markus M Klückmann Kristin K Müller Manfred J MJ Bosy-Westphal Anja A

Obesity facts 20190527 3

<h4>Background</h4>A high amount of adipose tissue limits the accuracy of methods for body composition analysis in obesity.<h4>Objectives</h4>The aim was to quantify and explain differences in fat-free mass (FFM) (as an index of skeletal muscle mass, SMM) measured with bioelectrical impedance analysis (BIA), dual energy X-ray absorptiometry (DXA), air displacement plethysmography (ADP), and deuterium dilution in comparison to multicompartment models, and to improve the results of BIA for obese s ...[more]

PMID: 31132777

Similar Datasets

Project description:IntroductionChildhood adiposity markers can be standardised for height in the form of indices (marker/heightp) to make meaningful comparisons of adiposity patterns within and between individuals of differing heights. The optimal value of p has been shown to differ by birth year, sex, age, and ethnicity. We investigated whether height powers for childhood weight and fat mass (FM) differed by birth year, sex, or age over the period before and during the child obesity epidemic in Copenhagen.Setting/methodsPopulation-based cross-sectional study of 391,801 schoolchildren aged 7 years, 10 years and 13 years, born between 1930 and 1996, from the Copenhagen School Health Records Register. Sex- and age-specific estimates of the height powers for weight and FM were obtained using log-log regression, stratified by a decade of birth.ResultsFor weight, amongst children born 1930-39, optimal height powers at 7 years were 2.20 (95% CI: 2.19-2.22) for boys and 2.28 (95% CI: 2.26-2.30) for girls. These increased with birth year to 2.82 (95% CI: 2.76-2.87) and 2.92 (95% CI: 2.87-2.97) for boys and girls born in 1990-96, respectively. For FM, amongst those born 1930-39, powers at 7 years were 2.46 (95% CI: 2.42-2.51) and 2.58 (95% CI: 2.53-2.63) for boys and girls, respectively, and increased with birth year reaching 3.89 (95% CI: 3.75-4.02) and 3.93 (95% CI: 3.80-4.06) for boys and girls born 1990-96, respectively. Powers within birth cohort groups for weight and FM were higher at 10 years than at 7 years, though similar increases across groups were observed at both ages. At 13 years, height powers for weight and FM initially increased with the birth year before declining from the 1970s/80s.ConclusionDue to increases in the standard deviation of weight and FM during the obesity epidemic, optimal height powers needed to standardise childhood weight and FM varied by birth year, sex, and age. Adiposity indices using a uniform height power mean different things for different birth cohort groups, sexes, and ages thus should be interpreted with caution. Alternative methods to account for height in epidemiological analyses are needed.

Project description:A single nucleotide polymorphism (SNP) in the fat mass and obesity-associated (FTO) gene is a strong predictor of obesity in humans. The FTO SNP (rs1421085) results in a T to C nucleotide substitution that may result in an increased risk for obesity in individuals who carry at least one C allele. The purpose of this investigation was to characterize the FTO genotype in a cohort of exercise-trained men and women.We tested 108 exercise-trained individuals that included professional mixed martial arts fighters, competitive distance runners, collegiate swimmers, stand-up paddlers as well as a cohort of recreational bodybuilders. Body composition was assessed via dual-energy x-ray absorptiometry (DXA). Saliva samples were collected in order to genotype participants and quantify cortisol levels.The physical characteristics of the subjects were as follows (mean±SD): body weight 74.5±15.6 kg; height 171.5±9.5 cm; bone mineral content 2.8±0.7 kg; fat mass 15.7±5.5 kg; lean body mass 55.9±14.4 kg; % body fat 21.6±7.0. Independent samples t tests showed that C allele carriers (n =?54) had significantly higher fat mass t(106)?=?3.13, p <?0.01 and body fat percentage t(106)?=?2.68, p?<?0.01, relative to the TT group (n?=?54) (i.e., fat mass: C/-?17.3 ±5.6 kg, TT 14.2±4.6 kg; body fat percentage: C/- group 23.4±7.4%, TT group 19.9±6.2). No other measures of body composition were associated with the FTO genotype (i.e., body mineral density, bone mineral content, or lean body mass). Moreover, cortisol levels were significantly higher in the TT group relative to the C allele carriers t(106)?=?2.37, p =?0.02 (i.e., TT 0.35 ±0.35 ?g/dL, C/-?0.22±0.16 ?g/dL).Our findings demonstrate a relationship between C allele carriers on the FTO gene and a predisposition to a higher fat mass and body fat percentage. In addition, we found no relationship between cortisol and fat mass. However, due to the cross-sectional nature of this investigation, we cannot infer causality regarding the FTO gene and body composition.

Dataset Information

Limitations of Fat-Free Mass for the Assessment of Muscle Mass in Obesity.

Background

Objectives

Methods

Results

Conclusions

Publications

Limitations of Fat-Free Mass for the Assessment of Muscle Mass in Obesity.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets