Whole-Body Computed Tomography-Based Body Mass and Body Fat Quantification: A Comparison to Hydrostatic Weighing and Air Displacement Plethysmography

How reliably can ultrasound help determine muscle and adipose tissue thickness in clinical settings? An assessment of intra- and inter-examiner reliability in the USVALID study

BACKGROUND/OBJECTIVES

Ultrasound is used to measure muscle and adipose tissue thickness at the bedside. This study was aimed at determining the intra- and inter-examiner reliability for marking points to measure adipose tissue and muscle thickness and assessing it in terms of the performance and evaluation of the corresponding ultrasound scans.

SUBJECTS/METHODS

Intra- and inter-examiner reliability was tested in 120 patients. Limb lengths were measured to mark three and two measuring points on both the thighs and upper arms, respectively. Ultrasound scans were performed at each measuring point to evaluate muscle and adipose tissue thickness.

RESULTS

Regarding the marking of the measuring points, intra- and inter-examiner reliability were high to very high, with correlation coefficients ranging from 0.74 to 0.96. In the performance and evaluation of adipose tissue thickness, all measuring points showed a high to very high reliability, with correlation coefficients ranging from 0.70 to 0.97. In the performance and evaluation of muscle thickness, the ventral measuring point on the thigh and the anterior measuring point on the upper arm showed the best reliability, with high to very high correlation coefficients ranging from 0.77 to 0.93.

CONCLUSIONS

In terms of intra- and inter-examiner reliability, the ventral measuring point on the thigh and the anterior measuring point on the upper arm can be strongly recommended for ultrasound measurements of muscle and adipose tissue thickness.

Come Back Skinfolds, All Is Forgiven: A Narrative Review of the Efficacy of Common Body Composition Methods in Applied Sports Practice

Whilst the assessment of body composition is routine practice in sport, there remains considerable debate on the best tools available, with the chosen technique often based upon convenience rather than understanding the method and its limitations. The aim of this manuscript was threefold: (1) provide an overview of the common methodologies used within sport to measure body composition, specifically hydro-densitometry, air displacement plethysmography, bioelectrical impedance analysis and spectroscopy, ultra-sound, three-dimensional scanning, dual-energy X-ray absorptiometry (DXA) and skinfold thickness; (2) compare the efficacy of what are widely believed to be the most accurate (DXA) and practical (skinfold thickness) assessment tools and (3) provide a framework to help select the most appropriate assessment in applied sports practice including insights from the authors' experiences working in elite sport. Traditionally, skinfold thickness has been the most popular method of body composition but the use of DXA has increased in recent years, with a wide held belief that it is the criterion standard. When bone mineral content needs to be assessed, and/or when it is necessary to take limb-specific estimations of fat and fat-free mass, then DXA appears to be the preferred method, although it is crucial to be aware of the logistical constraints required to produce reliable data, including controlling food intake, prior exercise and hydration status. However, given the need for simplicity and after considering the evidence across all assessment methods, skinfolds appear to be the least affected by day-to-day variability, leading to the conclusion 'come back skinfolds, all is forgiven'.

Diet-induced rodent models of obesity-related metabolic disorders-A guide to a translational perspective

Diet is a critical element determining human health and diseases, and unbalanced food habits are major risk factors for the development of obesity and related metabolic disorders. Despite technological and pharmacological advances, as well as intensification of awareness campaigns, the prevalence of metabolic disorders worldwide is still increasing. Thus, novel therapeutic approaches with increased efficacy are urgently required, which often depends on cellular and molecular investigations using robust animal models. In the absence of perfect rodent models, those induced by excessive consumption of fat and sugars better replicate the key aspects that are the root causes of human metabolic diseases. However, the results obtained using these models cannot be directly compared, particularly because of the use of different dietary protocols, and animal species and strains, among other confounding factors. This review article revisits diet-induced models of obesity and related metabolic disorders, namely, metabolic syndrome, prediabetes, diabetes and nonalcoholic fatty liver disease. A critical analysis focused on the main pathophysiological features of rodent models, as opposed to the criteria defined for humans, is provided as a practical guide with a translational perspective for the establishment of animal models of obesity-related metabolic diseases.

Reliability and validity of various laboratory methods of body composition assessment in young adults

Accurate measures of body composition (BC) are essential for performance and health. In addition to accuracy, BC measures should be practical and be minimally invasive to maximize their utility. The purpose of the present study was to compare the day-to-day variability and validity of four common laboratory-based body composition assessments to a criterion four-compartment model. Dual x-ray absorptiometry (DXA), air displacement plethysmography (BP), multi-frequency bioelectrical impedance (MF-BIA) and underwater weighing (UWW) were performed twice in a sample of 32 young men and women. Participants were assessed in a fasted, euhydrated state 2-7 days apart. All methods were compared to a criterion four-compartment model using BP-derived body volume, DXA-derived bone mineral content and MF-BIA-derived total body water (4C_BP ). Additional four-compartment models using UWW- and DXA-derived body volume were also examined (4C_UWW ) and (4C_DXA ). Validity results were conducted with paired t-tests and Bland-Altman analysis. Reliability was determined using intraclass correlations (ICC), coefficients of variation (CV) and standard error of the measurement (SEM). Validity analysis revealed that all methods overestimated per cent body fat and fat mass, and underestimated fat-free mass when compared with 4C_BP , but only DXA and BP were significantly different (P<0·008). All measures were highly reliable across days (ICCs > 0·9, CVs < 12%). Results of the present study indicate that typical laboratory-based methods of body composition are valid and reliable. However, we caution that results should not be translated between methods and assessments should be performed with the same instrument when the goal is to monitor changes in body composition over time.

Correlation of Subcutaneous Fat Measured on Ultrasound with Body Mass Index

BACKGROUND

Body mass index (BMI) is used for the assessment of obesity and overweight worldwide. When body fat is increased BMI is also increased. Ultrasound is a reliable method to assess body fat. We have selected only one suprapubic region for the assessment of fat which is very easy to measure even in routine pelvic and abdominal ultrasound examination. During our routine examination, we can measure abdominal fat and inform the patient about his/her health state regarding obesity. It was a hypothesis that increases in abdominal subcutaneous fat will increase in BMI.

OBJECTIVE

The objective is to correlate subcutaneous fats measured on ultrasound with BMI.

MATERIALS AND METHODS

It was a cross-sectional study, which was performed in Gilani ultrasound center, Lahore, Pakistan. A total of 384 participants were included with simple random sampling technique. Individuals of 16-60 years age of both genders were included in that study. Pregnant ladies, athletes, children, and elderly participants were not included in that study. Toshiba (Xario) and Mindray (Z5) ultrasound machine were used for subcutaneous fats measurement. Participants were scanned in the supine position. Subcutaneous fats were measured on the suprapubic region in three different trials. Compression was avoided. Compression artifacts were avoided by applying more quantity of gel between transducer and skin. Stadiometer was used for the measurement of weight and height. To calculate BMI, Quetelet index was used. BMI was calculated with that formula BMI = weight (kg) divided by height (m2).

RESULTS

The result was made by calculation of mean and standard deviation. We calculated Pearson correlation between BMI and subcutaneous fats measured on ultrasound at the suprapubic region. It showed a significant high correlation between BMI and subcutaneous fat (P = 0.0000 which is < 0.001).

CONCLUSION

There is a significantly high correlation between BMI and subcutaneous fat measured on ultrasound. Ultrasound is a reliable method to assess subcutaneous fat. It can be a predictor of obesity like BMI.

Percent of body fat, fat-mass, fat-free mass and assessment of body composition among rural school-going children of Eastern-India

Percent of body fat (PBF), fat mass (FM) and fat free mass (FFM) are useful indicators for the assessment of body composition. The present study was conducted among 1351 children (boys: 660; girls: 691) aged 5–12 years residing in West Bengal, Eastern-India. The children were selected using a stratified random sampling method. Anthropometric measurements of height, weight, triceps skinfold (TSF) and sub-scapular skinfold (SSF) were recorded using standard procedures. The PBF, PBF-for-age z-score (PBFZ) and body mass index (BMI) were subsequently calculated. Body composition was assessed using FM, FFM, fat mass index (FMI) and fat free mass index (FFMI). Age-specific mean values of FM ranged from 2.12–4.00 kg (boys) and 2.16–4.40 kg (girls). Age-specific mean values of FFM ranged from 14.45–23.93 kg (boys) and 14.01–23.03 kg (girls). Sex-specific mean differences between sexes were statistically significant in weight, height, TSF, SSF, PBF, PBFAZ, FM, FFM, FMI and FFMI (p<0.05), except in BMI (p>0.05). These results are important for future investigations in clinical and epidemiological settings so as to accurately identify the risk of lower or higher adiposity and body composition using PBF, FM and FFM.