[Body composition: assessment and clinical value]

The determination of sarcopenia in older adults using a practical measure

BACKGROUND

Many older adults are at risk of sarcopenia, a gradual loss of muscle mass affecting muscle strength and physical function, which can lead to adverse health consequences deteriorating their independence. However, the detection could be delayed due to the requirement of many measures, including a complex imaging modality. Thus, an exploration for a practical community- or home-based measure would be helpful to identify at-risk older adults and begin the timely management.

OBJECTIVE

To explore the ability of the upper limb loading during a seated push-up test (ULL-SPUT) to determine the presence of sarcopenia in community-dwelling older adults.

METHODS

Older adults (n= 110; 62 females, average age approximately 77 years) were cross-sectionally assessed for sarcopenia using standard measures (handgrip strength, appendicular skeletal muscle mass, and walking speed) and the ULL-SPUT.

RESULTS

Data from standard measures indicated that 44 participants had sarcopenia. The ULL-SPUT index of < 16.9 kg/m2 for females (sensitivity = 86%, specificity = 78%, area under the receiver operating characteristic curve [AUC] = 0.85) and < 19.7 kg/m2 for males (sensitivity = 73%, specificity = 69%, AUC = 0.83) could optimally identify participants with sarcopenia.

CONCLUSION

The ULL-SPUT index could be used to screen and monitor older adults with sarcopenia in various clinical, community, and home settings. This practical measure may be accomplished using a digital bathroom scale on a hard, even surface. Outcomes would identify an adult who should undergo further confirmation of sarcopenia through standard measures or the initiation of timely management to promote treatment effectiveness.

C, C. H. GC. Concordance between dual indirect methods for assessing fat percentage

In the last decades there is a growing interest in the evaluation of human body composition for being an important part of the integral assessment of individuals. Its use has been extended to different disciplines associated with health care (medicine, nutrition, physiotherapy), and to sports and population fields. Specifically, fat percentage can be related to innumerable diseases. However, there are discrepancies in the results of fat percentage measurement measured by different methods.

Objective

To evaluate the concordance between two low-cost and easily accessible double indirect methods, which have been used indistinctly in different studies where access to more accurate methods is not available, and to determine fat percentage and its relationship with age, sex, body mass index (BMI), waist circumference, level of physical activity and sedentary hours.

Materials and Method

Twenty-four persons between 18 and 38 years and 28 between 39 and 59 years from a university community were evaluated. Calculations were made: BMI, fat % was estimated by anthropometry with a digital adipometer (Skyndex System I USA) and by Electrical Bioimpedance Analysis - BIA (Biody Expert ZM II FRA), physical activity level and sedentary hours were determined with the short IPAQ questionnaire. Pearson's correlation coefficient, Bland & Altman's graphical method and Lin's concordance correlation index were calculated. The significance level p<0.05 was estimated.

Results

The fat percentage by anthropometry was: 30.5% ±8.5 (18-38 years) 35.0% ±6.7 (39-59 years); by BIA 27.0% ±7.3 (18-38 years) and 29.2% ±7.0 (39-59 years). Both techniques showed good correlation, but low degree of concordance (Lin index less than 0.9) except for the group of young persons with moderate level of physical activity (0.95).

Conclusions

The doubly indirect methods used in the study showed strong correlation, but low concordance, so their use is not recommended indistinctly for the follow-up of a particular case. According to the study data for this specific population in young people with moderate physical activity, follow-up could be performed with either of the two methods.

[Body composition models based on anthropometry, systematic literature review]

Introduction

The body composition determination is carried out through measurement methods that require the use of specialized equipment that is difficult to acquire and manipulate. Therefore, different authors have developed mathematical models for its calculation. The target of this review was to analyze the work carried out on mathematical models of body composition variables from different anthropometric measurements, answering the following questions: what is the corporal variable that the model predicts?, what are the input variables for model development?, how is the patients typification in each model?, what data analysis method has been used?, and how has been the model evaluated? The search was limited to journals found in repositories in the areas of Medicine, Nursing, Biochemistry, Biology, Health, Pharmacology, Immunology, Engineering, and Mathematics. Four hundred and twenty-four articles were found, which were reduced to 30 by applying the systematic literature review process. The analyzed studies are oriented to the prediction of variables related to body fat mass. The evaluation results found for fat-free mass, fat mass and metabolic rate differ according to the comparison technique and the body segments analyzed. The evaluation is mainly based on the intraclass correlation, the Pearson correlation and the coefficient of determination (r2), and they present a good correlation for the population under study.

The Use of Practical Measures to Determine Body Composition of Older People

Background

Older adults frequently experience body composition changes-decreased lean body mass (LBM) and bone mineral content (BMC), along with increased body fat mass (FM)-which affect their health and independence. However, the need for standard complex and costly imaging modalities could delay the detection of these changes and retard treatment effectiveness. Thus, this study explored the ability of practical measures, including simple muscle strength tests and demographic data, to determine the body composition of older adults.

Methods

Participants (n = 111, with an average age of 77 years old) were cross-sectionally assessed for the outcomes of the study, including upper limb loading during a seated push-up test (ULL-SPUT), hand grip (HG) strength test and body composition.

Results

The ULL-SPUT significantly correlated with body composition (r or rs, = 0.370-0.781; P < 0.05), particularly for female participants and was higher than that found for the HG strength test (rs = 0.340-0.614; P < 0.05). The ULL-SPUT and HG strength test, along with gender and body mass index (BMI), could accurately determine the LBM and BMC of the participants up to 82%.

Conclusion

The ULL-SPUT along with gender and BMI can be used as a practical strategy to detect the LBM and BMC of older adults in various settings. Such a strategy would facilitate timely managements (i.e. standard confirmation or appropriate interventions) in various settings.

Body Composition Profiles of Applicants to a Physical Education and Sports Major in Southeastern Mexico

This study aimed to determine the body composition profile of candidates applying for a Physical Education and Sports major. 327 young adults (F: 87, M: 240) participated in this cross-sectional study. Nutritional status and body composition analysis were performed, and the profiles were generated using an unsupervised machine learning algorithm. Body mass index (BMI), percentage of fat mass (%FM), percentage of muscle mass (%MM), metabolic age (MA), basal metabolic rate (BMR), and visceral fat level (VFL) were used as input variables. BMI values were normal-weight although VFL was significantly higher in men (<0.001; η² = 0.104). MA was positively correlated with BMR (0.81 [0.77, 0.85]; p < 0.01), BMI (0.87 [0.84, 0.90]; p < 0.01), and VFL (0.77 [0.72, 0.81]; p < 0.01). The hierarchical clustering analysis revealed two significantly different age-independent profiles: Cluster 1 (n = 265), applicants of both sexes that were shorter, lighter, with lower adiposity and higher lean mass; and, Cluster 2 (n = 62), a group of overweight male applicants with higher VFL, taller, with lower %MM and estimated energy expended at rest. We identified two profiles that might help universities, counselors and teachers/lecturers to identify applicants in which is necessary to increase physical activity levels and improve dietary habits.

Comparison of Neck Circumference, Waist Circumference, and Skinfold Thickness in Measuring the Subcutaneous Fat Distribution and Their Association with Handgrip Strength: Cross-Sectional Study

Skinfold measurement (SKF) can accurately measure abdominal obesity and is regarded as a surrogate marker to predict non-communicable diseases. The objective of the present study was to observe the degree of association between neck circumference (NC), SKF and handgrip strength (HGS). Secondly, also to know the effects of smoking on NC, HGS and SKF. The mean and standard deviations and frequencies in percentage were analyzed, respectively. The degree of association between NC, anthropometric characters and HGS was also analyzed using the Pearson correlation. Furthermore, multiple linear regression models were used to study the degree of influence of independent variables on dependent variables. Correlation assessment for neck circumference with waist circumference and HGS revealed a weak association. While with SKF for four sites, a strong association was found. A significant regression was found among the smokers in the model (F (2, 7) = 5.2, p-value of 0.04 with an R2 of 0.598). The predictor variables, like waist and NC, can produce a variation of 59.8% in the dependent variable. Whereas, among non-smokers, an insignificant regression was seen. In conclusion, neck circumference is associated with SKF. However, a small sample size of young smokers revealed that NC and waist circumference influenced HGS.

Effect of baseline physical activity on the fat gain of adolescents in a 5-year cohort study in Ho Chi Minh City, Viet Nam

Differences in physical activity (PA) might lead to long-term weight control. Studies on inverse relations between PA and changes in fatness among adolescents are limited. This paper examined the effect of PA on adolescents' changing body fatness over 5 years in Ho Chi Minh City (HCMC). Two hundred thirty-five boys and 247 girls who have had skinfold thickness measurements in the baseline survey in 2004 were selected to follow yearly. We estimated PA as the average number of accelerometers' counts/h. Slopes of triceps, sub-scapular skinfolds and BMI were calculated and classified as increasing or stable/decreasing. To assess the effects of the low level of activity (i.e. below the median of the average number of counts) on the fat gain (i.e. increasing slopes), relative risk and 95 % CI were estimated using Poisson regression. The average number of counts/h in boys (7·8) was significantly higher than that in girls (5·0) (P < 0·001). On average, active girls still gained 0·51 mm in triceps skinfold (TSF) over 5 years, while active boys lost 0·12 mm. After controlling for baseline energy intake, baseline triceps and baseline age, inactive adolescents were 1·39 times higher than active ones to increase the slope of triceps (95 % CI 1·19, 1·63). The risk ratio was 1·62 for those with more body fat at baseline. In general, inactive students gained substantially more subcutaneous fat, especially in their TSF, than more active ones. Thus, strategies to prevent adolescent obesity in HCMC should consider the important role of PA to control this problem in adolescents effectively.

Clasificación funcional del paciente anciano en hemodiálisis y su influencia en la individualización del tratamiento

Introducción: La edad de los pacientes en hemodiálisis está aumentando, presentando mayor deterioro. Objetivos: Conocer la situación del paciente ancia­no en hemodiálisis categorizando nuestra población. Ana­lizar la relación entre las escalas de funcio­nalidad, desnutrición y comorbilidad. Material y Método: Estudio descriptivo transversal, pacien­tes 75-95 años. Se midieron: a) Comorbilidad-CHARLSON: alta (>6 puntos). b) Nutrición-MISS: extremadamente des­nutrido (<10 puntos.); desnutrición muy severa (>7-10 puntos); moderada-severa (>5-7 puntos); leve-moderada (>2-5 puntos); normonutrido (<2 puntos); c) Dependencia-BAR­THEL, independiente (100 puntos); dependencia leve (91-99 puntos); moderada (61-90 puntos.); severa (21-60 puntos.); total (<20 puntos). d) Fragilidad-FRAIL, no fragilidad (0 puntos); prefrágil (1-2 puntos); frágil (>3 puntos). Resultados: 60 pacientes, 68%(41) hom­bres, edad media 81,85±5,58 años y tiempo HD 49,88±40,29 meses. Etiología más prevalente, diabe­tes mellitus (28%). MIS: 6,01±3,80 puntos. clasificándose 8(13%) normonu­tridos, 24(40%) desnutrición leve-moderada, 10(17%) desnutrición moderada-severa, 13(22%) desnutrición muy severa y 5(8%) extremadamente desnutridos. BARTHEL: 88,16±18,59 puntos, clasificó 32(53%) independientes, 6(10%) dependencia leve, 17(28%) dependencia modera­da, 4(7%) dependencia severa, 1(2%) dependencia total. FRAIL: 1,98±1,32 puntos, clasificó 10(17%) no frágiles, 31(51%) prefrágiles y 19(32%) frágiles. CHARLSON: 10,01±2,20 puntos. Presentando 60(100%) alta comorbilidad. CHARLSON presentó diferencias entre sexo, mayor en hombres (p=0,002). Se encontró alta correlación entre Barthel y Frail (r=0,647,p<0,001), moderada entre MIS y Barthel (r=0,556, p<0,001) y MIS y Frail (r=0,455,p<0,001). Charlson obtuvo peor correlación. Conclusiones: Se evidenció gran deterioro ge­neral del paciente añoso en diálisis, alertando sobre la nece­sidad de realizar tratamientos individualizados enfocados en su recuperación, incluida la propia diálisis.

Liraglutide for the Treatment of Obesity: Analyzing Published Reviews

Background:

Several drugs have been currently approved for the treatment of obesity. The pharmacokinetic of liraglutide, as well as the treatment of type 2 diabetes mellitus, have been widely described.

Objective:

To analyze the published systematic reviews on the use of liraglutide for the treatment of obesity.

Methods:

Systematic reviews were found out through MEDLINE searches, through EBSCO host and the Cochrane Library based on the following terms: "liraglutide" as major term and using the following Medical Subject Headings (MesH) terms: "obesity", "overweight", "weight loss". A total of 3 systematic reviews were finally included to be analyzed.

Results:

From the three systematic reviews selected, only two included the randomized clinical trials, while the third study reviewed both randomized and non-randomized clinical trials. Only one review performed statistical tests of heterogeneity and a meta-analysis, combining the results of individual studies. Another review showed the results of individual studies with odds ratio and confidence interval, but a second one just showed the means and confidence intervals. In all studies, weight loss was registered in persons treated with liraglutide in a dose dependent form, reaching a plateau at 3.0 mg dose, which was reached just in men. Most usual adverse events were gastrointestinal.

Conclusion:

More powerful and prospective studies are needed to assess all aspects related to liraglutide in the overweight and obesity treatment.

Gender Stratified Analyses of the Association of Skinfold Thickness with Hypertension: A Cross-Sectional Study in General Northeastern Chinese Residents

The association of hypertension with skinfold thickness (ST) in adults is not clear. Our study was aimed at finding out the association of hypertension with ST in different gender and obesity categories. This is a cross-sectional study based on 2336 Chinese residents (767 men). Both subscapular skinfold thickness (SST) and tricep skinfold thickness (TST) were examined. We estimated the association of hypertension with per SD increase of SST and TST using multivariable logistic regression analyses in men and women. Six subgroups were stratified using cutoff points of body mass index (BMI) and ST: larger and smaller ST in normal weight (BMI < 24 kg/m²), overweight (24 kg/m² ≤ BMI < 28 kg/m²) and obesity (BMI ≥ 28 kg/m²), respectively. The association of hypertension with ST was only shown in women after adjustment for other risk factors. Among women of the normal weight subgroup, higher prevalence of hypertension was shown in those with larger ST. No difference of the prevalence of hypertension was found between women with larger ST in the normal weight subgroup and those with smaller ST in overweight or obesity subgroups. Our study suggested that even for people with normal weight, it was necessary to monitor the subcutaneous fat using ST for preventing hypertension at least in general Chinese women.

Clusters of anthropometric indicators of body fat associated with maximum oxygen uptake in adolescents

Introduction

The aim of this study was to evaluate different clusters of anthropometric indicators (body mass index | BMI |, waist circumference | WC |, waist-to-height ratio | WHtR |, triceps skinfold |TR SF|, subscapular skinfold |SE SF|, sum of the triceps and subscapular skinfolds | ΣTR + SE |, and sum of the triceps, subscapular and suprailiac folds | ΣTR + SE + SI|) associated with the VO₂max levels in adolescents.

Methods

The study included 1,132 adolescents (aged 14–19 years) enrolled in public schools of São José, Santa Catarina, Brazil, in the 2014 academic year. The dependent variable was the cluster of anthropometric indicators (BMI, WC, WHtR, TR SF, SE SF, SI SF, ΣTR + SE and ΣTR + SE + SI) of excess body fat. The independent variable was maximum oxygen uptake (VO₂max), estimated by the modified Canadian aerobic fitness test—mCAFT. Control variables were: age, skin color, economic level, maternal education, physical activity and sexual maturation. Multinomial logistic regression was used for associations between the dependent and independent variables. Binary logistic regression was performed to identify the association between adolescents with all anthropometric indicators in excess and independent variables.

Results

One in ten adolescents presented all anthropometric indicators of excess body fat. Multinomial regression showed that with each increase of one VO₂max unit, the odds of adolescents having three, four, five or more anthropometric indicators of excess body fat decreased by 0.92, 0.85 and 0.73 times, respectively. In the binary regression, this fact was reconfirmed, demonstrating that with each increase of one VO₂max unit, the odds of adolescents having simultaneously the eight anthropometric indicators of excess body fat decreased by 0.55.

Conclusion

It was concluded that with each increase of one VO₂max unit, adolescents decreased the odds of simultaneously presenting three or more anthropometric indicators of excess body fat, regardless of biological, economic and lifestyle factors. In addition, the present study identified that one in ten adolescents had all anthropometric indicators of excess body fat.

Obesity does not influence prostate intrafractional motion

Introduction

Motion of the prostate is problematic in the accurate delivery of external beam radiation therapy (EBRT) for prostate cancer. This study investigated the relationship between body mass index (BMI), an easily measured indicator of obesity, and prostate motion.

Methods

Prostate motion during EBRT was assessed by measuring the displacement of fiducial markers implanted within the prostate in 130 prostate cancer patients. Interfractional motion was corrected on daily imaging through pre‐treatment cone‐beam‐computed tomography (CBCT) and intrafractional motion measured using movie sequences captured using an electronic portal imaging device (EPID) during treatment delivery.

Results

There was no statistically significant relationship between the mean intrafractional motion and BMI, except in the left‐right (LR) translation (P = 0.049) over the study population. For each BMI category, there was no statistical significance (P > 0.05) between any of the translations/rotations except LR (P = 0.003).

Conclusion

While intrafractional motion is an important consideration, prostate motion cannot be reliably predicted through measurement of patient's BMI.

Body composition in a population of school adolescents: a comparison of simple anthropometric methods and bioelectrical impedance

OBJECTIVES

To report the anthropometric characteristics and body composition and to analyze the potential sex-based differences in Spanish schoolchildren and adolescents living in Granada and Ceuta. To estimate body fat percentage using regression equations and bioelectrical impedance to check for sex differences. An additional objective was to see whether the body fat percentages obtained by these two methods were similar.

METHODS

A cross-sectional study including 1,518 children and adolescents (aged 9-16) from 12 primary and secondary schools in Ceuta and Granada. The nutritional status of the subjects was assessed and their body fat percentage was calculated.

RESULTS

There was a strong sexual dimorphism, with higher prevalence rates of overweight in boys and obesity in girls. Girls had higher mean body fat levels regardless of the measuring method used (p<.001). Correlation between bioelectrical impedance analysis and regression equations was high (r=0.830), as was the internal correlation coefficient (ICC>0.75). A Bland-Altman comparison showed a high agreement between bioelectrical impedance and Behnke and Lohman equations.

CONCLUSIONS

Specific equations considering subject sex and age should be used to estimate body density. Regardless of the method used, girls had higher body fat percentages. The Behnke and Lohman equations, combined with BIA, were found to be the most accurate methods for measuring body density in the study population.

Early and Late Postnatal Accelerated Growth Have Distinct Effects on Metabolic Health in Normal Birth Weight Infants

Accelerated growth in postnatal life in low birth weight infants has been associated with insulin resistance and metabolic syndrome-related disorders in later life. Postnatal accelerated growth in also common in normal birth weight infants, but little is known about the impact on metabolic health. In a prospective cohort study of 203 term normal birth weight infants, we evaluated the impacts of accelerated (Δweight Z score > 0.5) or decelerated (Δweight ΔZ < -0.5) growth during early (0-3 months) and late (3-12 months) postnatal life on metabolic health indicators at age 1-year. The primary outcomes were homeostasis model assessment of insulin resistance (HOMA-IR), β-cell function [homeostasis model assessment of β-cell function (HOMA-β)], and fasting plasma lipids. Adjusting for maternal, paternal, and infant characteristics, accelerated growth during the first 3 months of life was associated with a 41.6% (95% confidence interval 8.9-84.2%) increase in HOMA-β, and a 8.3% (0.7-15.4%) decrease in fasting plasma total cholesterols, and was not associated with HOMA-IR in infants at age 1-year. Accelerated growth during 3-12 months was associated with a 30.9% (3.3-66.0%) increase in HOMA-IR and was not associated with HOMA-β. Neither accelerated nor decelerated growth was associated with fasting plasma triglycerides, high-density lipoprotein or low-density lipoprotein cholesterol concentrations in infants at age 1-year. Accelerated growth during early postnatal life may be beneficial for β-cell function, but during late postnatal life harmful for insulin sensitivity in normal birth weight infants.

Triceps and Subscapular Skinfold Thickness Percentiles and Cut-Offs for Overweight and Obesity in a Population-Based Sample of Schoolchildren and Adolescents in Bogota, Colombia

The assessment of skinfold thickness is an objective measure of adiposity. The aims of this study were to establish Colombian smoothed centile charts and LMS L (Box-Cox transformation), M (median), and S (coefficient of variation) tables for triceps, subscapular, and triceps + subscapular skinfolds; appropriate cut-offs were selected using receiver operating characteristic (ROC) analysis based on a population-based sample of children and adolescents in Bogotá, Colombia. A cross-sectional study was conducted in 9618 children and adolescents (55.7% girls; age range of 9-17.9 years). Triceps and subscapular skinfold measurements were obtained using standardized methods. We calculated the triceps + subscapular skinfold (T + SS) sum. Smoothed percentile curves for triceps and subscapular skinfold thickness were derived using the LMS method. ROC curve analyses were used to evaluate the optimal cut-off point of skinfold thickness for overweight and obesity, based on the International Obesity Task Force definitions. Subscapular and triceps skinfolds and T + SS were significantly higher in girls than in boys (p < 0.001). The ROC analysis showed that subscapular and triceps skinfolds and T + SS have a high discriminatory power in the identification of overweight and obesity in the sample population in this study. Our results provide sex- and age-specific normative reference standards for skinfold thickness values from a population from Bogotá, Colombia.

[Body composition by dual-energy x-ray absorptiometry in women with fibromyalgia]

OBJECTIVES

To assess body composition in women with fibromyalgia (FM) comparing to the reference value for healthy women.

PATIENTS AND METHODS

Cross-sectional observational analytical study, with 52 women selected with Fibromyalgia, according American College of Rheumatology (ACR, 1990) criteria. The patients were selected in Hospital de Clínicas da Universidade Federal do Paraná (HC-UFPR) and divided into two groups, 28 patients with a BMI (Body Mass Index) equal or higher (≥) than 25kg/m2 and 24 patients with BMI less or equal (≤) 24.99 kg/m2, subjected to physical examination for the count of tender points (TP) and completing the fibromyalgia impact questionnaire (FIQ). The assessment of body composition was performed by the Dual-Energy X-Ray Absorptiometry (DXA). The values of the fat mass percentage (MG %) found in the two groups were compared to the average percentage of MG by age and sex, described by Heward (2004).

RESULTS

The mean age of the study groups was 47.8 ± 8.6 years, the FIQ score was 70.5 ± 18.6 and TP 16.2 ± 2.0. The mean BMI was 26.4 ± 4.1 kg/m2, and the amount of MG was 25.2 ± 7.8 kg and 39.5 ± 6.8%, and lean mass (LM) was 37 2 ± 3.7 kg and 60.4 ± 7.3%. In the group with BMI ≤ 25 kg/m2, the MG % was 33.8% (21.5 -42.4) and in the group with BMI ≥ 25 kg/m2 of the MG was 44.4% (37.6 -56.2).

CONCLUSION

Both groups women with FM eutrophic as the overweight and obese group, presented higher reference MG% levels comparing with the standard levels for healthy women.

Efectividad de una intervención educativa sobre nutrición y actividad física en una población de adolescentes. Prevención de factores de riesgo endocrino-metabólicos y cardiovasculares

Objetivo: verificar una mejora del estado nutricional y la adopción de hábitos alimentarios y de actividad física saludables en una población de estudiantes tras una intervención educativa en salud. Materiales y métodos: población compuesta por 90 adolescentes entre 15 y 17 años de edad, 46 hombres (51,1 %) y 44 mujeres (48,9 %), pertenecientes a un centro educativo público de la ciudad de Almería (España). El estudio se realizó en tres fases. La primera fase contempló valoración del estado nutricional; la segunda, intervención educativa sobre alimentación saludable y actividad física; la tercera, evaluación de la eficacia de dicha intervención. Resultados: estadísticamente hubo mejoría (p < 0,000) en el estado nutricional de los alumnos valorados con independencia de su sexo. Respecto de la adopción de hábitos saludables, se observaron diferencias significativas en las puntuaciones del test Kreceplus (p < 0,000), aunque no para la actividad física tras la intervención (p = 0,568). Conclusiones: los resultados muestran la efectividad de los procedimientos aplicados en esta intervención para modificar hábitos alimentarios. Con todo ello, la práctica de ejercicio físico continúa siendo una asignatura pendiente entre los adolescentes.

Liver in the analysis of body composition by dual-energy X-ray absorptiometry

OBJECTIVE

To investigate the predictive value for hepatic steatosis of a new software for the quantification of visceral fat by dual-energy X-ray absorptiometry (DXA) and to design new regions of interest (ROIs).

METHODS

Adult volunteers were prospectively screened for hepatic steatosis by ultrasonography to obtain a well-balanced population according to the presence/absence of the disease. 90 adult patients without steatosis and 90 with steatosis (mild, 53.3%; moderate, 37.7%; and severe, 10.0%) were recruited. On the same day, all subjects were submitted to blood testing and to anthropometric and whole-body DXA for body composition evaluation. A new software for android visceral fat assessment was employed, and six new "liver-suited" ROIs as well as two modified android ROIs were designed. Their association with steatosis grade was tested by correlation analysis.

RESULTS

Fat mass (FM) of the new ROIs showed the highest correlation coefficients with steatosis grade (ρ = 0.610-0.619; p < 0.001), which was also confirmed by multivariate analysis. On the whole population, the new ROIs maintained the highest predictive role for liver steatosis, with areas under the receiver operating characteristic curve up to 0.820 ± 0.032. Inter- and intra-operator agreement for the new ROIs was excellent (k = 0.915-1.000 and k = 0.927-1.000).

CONCLUSION

New ROIs could be designed, standardized and implemented in DXA whole-body scan to provide more specific and predictive values of hepatic lipid content.

ADVANCES IN KNOWLEDGE

This is the first study to investigate the predictive value for hepatic steatosis of visceral and regional FM assessed on the hepatic site by DXA in comparison with ultrasonography, anthropometry and surrogate markers derived by previously validated algorithms (fatty liver index).

The Quételet index revisited in children and adults

BACKGROUND

The body mass index (BMI) is based on the original concept that body weight increases as a function of height squared. As an indicator of obesity the modern BMI assumption postulates that adiposity also increases as a function of height in states of positive energy balance.

OBJECTIVE

To evaluate the BMI concept across different adiposity magnitudes, in both children and adults.

METHODS

We studied 975 individuals who underwent anthropometric evaluation: 474 children and 501 adults. Tetrapolar bioimpedance analysis was used to assess body fat and lean mass.

RESULTS

BMI significantly correlated with percentage of body fat (%BF; children: r=0.893; adults: r=0.878) and with total fat mass (children: r=0.967; adults: r=0.953). In children, body weight, fat mass, %BF and waist circumference progressively increased as a function of height squared. In adults body weight increased as a function of height squared, but %BF actually decreased with increasing height both in men (r=-0.406; p<0.001) and women (r=-0.413; p<0.001). Most of the BMI variance in adults was explained by a positive correlation of total lean mass with height squared (r(2)=0.709), and by a negative correlation of BMI with total fat mass (r=-0.193).

CONCLUSIONS

Body weight increases as a function of height squared. However, adiposity progressively increases as a function of height only in children. BMI is not an ideal indicator of obesity in adults since it is significantly influenced by the lean mass, even in obese individuals.