Indirect estimates of body composition are useful for groups but unreliable in individuals

Validation of HF-Bioelectrical Impedance Analysis versus Body Mass Index in Classifying Overweight and Obese Pakistani Adults

Purpose

To determine the validity of hand-to-foot bioelectrical impedance analysis (HF-BIA) versus body mass index (BMI) to assess overweight and obesity status in adults against a reference method, dual-energy x-ray absorptiometry (DXA).

Patients and Methods

It is a validation study conducted on 206 Pakistani adults ≥20 years recruited through convenience sampling technique at PNS Shifa Hospital and Jinnah Post Medical Centre, Karachi, Pakistan.

Results

HF-BIA showed better sensitivity of 90.1% and 100% specificity with no false positive, but 9% false negative as compared to BMI which indicated 80.3% sensitivity and 100% specificity with a false-negative rate of 19.6%.HF-BIA also showed better sensitivity 80.9-97.1% with 100% specificity and PPV across all age groups. The correlation coefficient between BMI and DXA bf% (r=0.67) was moderate and less than the correlation coefficient between HF-BIA and DXA bf % (r=0.87). Kappa agreement showed weak to a fair agreement between BMI and DXA bf % (0.1 overall; 0.22 men; 0.14 women) compared to HF-BIA, which had a better agreement between BIA bf% and DXA bf% (0.43 overall; 0.46 men; 0.34 women). HF-BIA bf % demonstrated a better discriminatory power than BMI (AUC of ≥0.91) and was better predictor of body fat than BMI.

Conclusion

HF-BIA is a more accurate method than BMI and may be used consistently throughout the country in primary care and research to identify the fat-based overweight and obese in the Pakistani population.

The Association between Altitude and Waist-Height Ratio in Peruvian Adults: A Cross-Sectional Data Analysis of a Population-Based Survey

To evaluate the association between altitude and cardiometabolic risk calculated with the weight-height ratio (WHtR) in the Peruvian adult population via the cross-sectional data analysis of the Peruvian Demographic and Health Survey 2021. A total of 26,117 adults from 18 to 64 years of age were included in the analysis. The dependent variable was cardiometabolic risk, defined as "Yes" if the WHtR was ≥0.5 and "No" if the WHtR was <0.5. Exposure was altitude of residence categorized as: <1500 meters above sea level (masl); 1500 to 2499 masl; 2500 to 3499 masl; and ≥3500 masl. Crude and adjusted Poisson regression models were used to calculate prevalence ratios (PR) with 95% confidence intervals (CI). The mean WHtR in the population was 0.59 (standard deviation: 0.08), and 87.6% (95% CI: 86.9-88.2) were classified as at risk. After adjusting for sex, age, education level, well-being index, and area of residence, living at altitudes between 2500 and 3499 masl (aPR: 0.98; 95% CI: 0.96-1.00) and ≥3500 masl (aPR: 0.95; 95% CI: 0.93-0.97) were associated with lower cardiometabolic risk in comparison with living at <1500 masl. An inverse association was identified between living at a higher altitude and the proportion of cardiometabolic risk in the Peruvian adult population. However, at least 8 out of 10 people were identified as at risk in all categories of altitude.

Body fat assessment in youth with overweight or obesity by an automated bioelectrical impedance analysis device, in comparison with the dual-energy x-ray absorptiometry: a cross sectional study

BACKGROUND

Bioelectrical impedance analysis (BIA) is a widely used method to assess total body fat (TBF) depots characterising obesity. Automated BIA devices provide an inexpensive and easy assessment of TBF, making them widely available to the general public and healthcare providers without specific qualification to assess body composition. The equations included in the automated BIA devices have been developed in very few specific populations, which means that they are not suitable to assess TBF for everyone and need to be validated before use in other populations. The aim of the present work is to evaluate the accuracy of the automated BIA device Tanita® BC-532 in youth of White European ethnicity, compared with the dual-energy x-ray absorptiometry (DEXA), gold standard measurement of TBF.

METHODS

Total body fat percentage (TBF%) was measured with the BIA device Tanita® BC-532 and DEXA (Hologic® QDR4500W) in 197 youth of White European ethnicity (N = 104 girls), 7-17 years old, and visiting the Diabetes & Endocrinology Care Paediatrics Clinic, Centre Hospitalier de Luxembourg, for overweight or obesity management.

RESULTS

TBF% evaluated with BIA was significantly correlated with TBF% measured with DEXA in both boys (r _Pearson = 0.617) and girls (r _Pearson = 0.648) (p <  10^- 4). However, the residual mean between the assessment of TBF% by BIA and by DEXA [TBF _BIA (%)-TBF _DEXA (%)] is extremely high (mean ± standard deviation = 10.52% ± 5.22% in boys, respectively 9.96% ± 4.40% in girls). The maximal absolute residual value is also very high, about 24% in both genders.

CONCLUSIONS

The automated BIA device Tanita® BC-532 appears to be not accurate to assess total body fat in youth with overweight or obesity. There is a need to calibrate the BIA device before its use in the populations where it was not previously validated.

Prevalence of obesity and associated cardiovascular risk factors in the Spanish population: the ENPE study

INTRODUCTION AND OBJECTIVES

Obesity is a significant public health problem associated with an increased risk of cardiovascular risk factors (CVRF). The aim of this study was to determine the prevalence of overweight and abdominal obesity (AO) in the Spanish population aged ≥ 3 years and to analyze the influence of sociodemographic and lifestyle factors and their association with CVRF.

METHODS

The sample was drawn from the ENPE study (n=6800). The study protocol included individual anthropometric measurements, sociodemographic factors, food intake (food frequency questionnaire), physical activity, lifestyles, and health problems.

RESULTS

The estimated overall prevalence of obesity (22.0%; 95%CI, 21.0-23.0) and AO (64.7%; 95%CI, 63.5-65.8) was higher in men, in persons aged ≥ 65 years, and in those with a lower socioeconomic level or from southern regions. Lifestyle pattern was significantly associated with obesity and AO (P=.011), which were less likely in people with an active lifestyle pattern (P <.0001). Obesity (OR, 1.85; 95%CI, 1.24-2.78) and AO (OR, 2.16; 95%CI, 1.1-4.24) were positively associated with CVRF. Clustering of CVRF with obesity and/or AO was higher in women (12.6%; 95%CI, 11.4-13.9) and in persons aged ≥ 65 years (32.7%; 95%CI, 30.0-35.4).

CONCLUSIONS

The prevalence of obesity and AO in the Spanish population is high; it is higher in men, increases with age, and is inversely related to socioeconomic status. A lifestyle pattern combining a higher level of physical activity, moderate sedentariness and a Mediterranean dietary pattern is associated with a lower probability of obesity, AO, and CVRF.

Tailoring Body Mass Index for Prediction of Obesity in Young Adults: A Multi-Centric Study on MBBS Students of Southeast India

INTRODUCTION

Body mass index (BMI) has been used for a long period as a surrogative measure for obesity. But BMI does not differentiate between fat and nonfat tissue (blood, bone, and muscle) due to which it is not considered accurate anymore. But since BMI is easier to estimate and used widely for assessment of obesity, it is better if it is re-standardized according to the body fat percentage (BFP) of a specific population, community, and their ethnicity.

OBJECTIVE

To estimate and propose the BMI cut-off values in young Indian population especially MBBS students taking BFP as a standard.

DESIGN

This is a cross-sectional study. Anthropometric data (age, gender, height, weight, waist circumference, and hip circumference) were collected from the participants after taking consent. BMI was calculated using Quetelet's Rule. BFP was estimated using Omron Body fat Monitor (HBF 385). It measures the BFP by the bioelectrical impedance (BI) method. Data were analyzed with appropriate statistical tests and receiver operating curve (ROC) curves were drawn to find the cut-off values of BMI to determine obesity.

SETTING

The present study is a multi-centric study conducted in four medical colleges (two in each state; Odisha and Andhra Pradesh, India).

PARTICIPANTS

Apparently healthy MBBS students aged 18-24 years were included in this study. Students having any chronic or acute illnesses were excluded from the study. Out of 904 students contacted from four medical colleges, 863 (430 males and 433 females) consented and participated.

RESULTS

Some 863 MBBS students have participated in this study. After adjusting for age, BMI was found to be higher in males. BMI was found to be 29.33 for males and in females it was 29.06. BFP was higher in females (34.23) as compared to males (20.77). Waist hip ratio was found to be higher in females (0.92) than in males (0.84). Whereas, fat free mass (FFM) and fat free mass index (FFMI) are higher in males, i.e., 56.24 and 18.48 respectively. Most appropriate cut-off value for obesity on ROC curve was found to be 22.09 (sensitivity 84.5%, specificity 83.46%) in males and that of females was 23.73 (sensitivity 85.26, specificity 81.23). Whereas, the conventional cut-off of 25 for males had sensitivity of only 46% and that of females was 70.5%. For total population BMI cut-off value was found to be 22.2 with 81% sensitivity and 74% specificity.  Conclusion: We propose the cut-off value for overweight/obesity in males to be 22.09 kg/m² and for females to be 23.73 kg/m² in young adult Indian population. These values were found to have more sensitivity and specificity than current BMI cut-off value.

Diagnostic performance of body mass index in detection of obesity using different cutoff points for excess body fat

OBJECTIVES

The aim of this study was to assess the diagnostic sensitivity of body mass index (BMI) in detecting obesity according to different cutoff points in order to classify a high body fat percentage (%BF) in adolescents and young adults.

METHODS

This was a cross-sectional study conducted with 2447 adolescents 18 and 19 y of age residing in São Luís, Brazil and 951 young adults 21 to 23 y of age residing in Ribeirão Preto, Brazil. Three references were used to define a high %BF (i.e., those of Williams et al., Ramírez-Vélez et al., and Macias et al.). The area under the receiver operating characteristic area under the curve (AUC) was used to assess the performance of BMI.

RESULTS

Sensitivity ranged from 38.3% to 54.1% among boys and from 12.7% to 72.7% among girls. Among young adults, it ranged from 52.3% to 67.1% in men and from 33.7% to 86.6% in women. The AUC ranged from 0.69 to 0.76 among boys, from 0.56 from 0.85 among girls, from 0.75 to 0.80 among men, and from 0.67 to 0.88 among women. The best cutoff points for the BMI were 24.79 to 25.10 kg/m² for boys, 21.89 to 27.04 kg/m² for girls, 26.43 to 28.22 kg/m² for men, and 23.34 to 29.28 kg/m² for women.

CONCLUSION

The use of different references for the classification of a high %BF implied a difference in the diagnostic sensitivity of the BMI. Higher cutoff points resulted in greater sensitivity and ability to differentiate individuals with and without obesity.

Relationship of Body Composition and Urinary Incontinence in Women: A Cross-Sectional Case-Control Study

OBJECTIVE

To describe the profile of segmental body composition through the bioelectrical impedance analysis (BIA) method in continent and incontinent women and analyze the association between overweight/obesity and urinary incontinence (UI).

METHODS

This was a cross-sectional case-control study that included women aged between 20 and 65 years, who were not pregnant, were outside of their menstrual period, without neurological, psychiatric, orthopedic, or cardiac comorbidities. The presence of UI was verified using the International Consultation on Incontinence Questionnaire-Short Form. Segmental body composition was assessed with BIA. The independent Student t test was used to compare body composition means between groups, and multivariate logistic regression was used to test the association between body composition and UI.

RESULTS

The study included 62 women with a mean age of 34.4 ± 11.6 years, of whom 27 (43.5%) had UI. Of these, 15 (55.6%) were nulliparous and had a body mass index of 25.1 ± 4.2 kg/m, similar to that of continent women, who had a body mass index of 23.6 ± 3.9 kg/m (P=0.16). The sociodemographic and obstetric data were similar among continent and incontinent women. With respect to the parameters of segmental body fat, visceral fat, and waist circumference, incontinent women presented higher values than the continent group. In the final multivariate analysis model, women with high levels of visceral fat had a 1.13-times higher likelihood of presenting UI.

CONCLUSIONS

In adult women, there is an association between the level of visceral fat assessed by BIA and complaints of urinary loss, being more evident in overweight and obese women.

Racial differences in body composition and cardiometabolic risk during the menopause transition: a prospective, observational cohort study

BACKGROUND

Obesity disproportionately affects more women than men. The loss of ovarian function during the menopause transition coincides with weight gain, increases in abdominal adiposity, and impaired metabolic health. Racial differences in obesity prevalence that results from the menopause transition are not well understood.

OBJECTIVE

The purpose of the study was to assess longitudinal changes in body composition and cardiometabolic risk among black and white women during the menopausal transition.

STUDY DESIGN

In a secondary analysis of a prospective, observational cohort study (the Healthy Transitions study), 161 women ≥43 years old with a body mass index of 20-40 kg/m2 and who had not yet transitioned through menopause were enrolled at Pennington Biomedical Research Center. Women were seen annually for body composition by dual-energy X-ray absorptiometry, for abdominal adipose tissue distribution by computed tomography, for sex steroid hormones, and for cardiometabolic risk factors that include fasting glucose, insulin, and lipids. Surrogate measures of insulin sensitivity were also calculated.

RESULTS

Ninety-four women (25 black, 69 white) transitioned through menopause and were included within the analyses. At menopause onset, black women weighed more (77.8±3.0 vs 70.8±1.8 kg) and had a higher systolic (125±16 vs 118±14 mm Hg) and diastolic (80±8 vs 74±7 mm Hg) blood pressure compared with white women (all P≤.05). No other differences in body composition, sex steroid hormones, or cardiometabolic risk factors were observed at menopause onset. Before menopause, white women gained significant weight (3 kg), total body adiposity (6% percent body fat, 9% fat mass, 12% trunk fat mass) and abdominal adipose tissue (19% subcutaneous fat, 15% visceral fat, 19% total adipose tissue), which coincided with significant decreases in estradiol, sex hormone-binding globulin, and estrone sulfate and increases in follicle-stimulating hormone, total cholesterol, and low-density lipoprotein cholesterol. Conversely, black women had more abdominal adipose tissue before menopause, which was maintained across the menopause transition. Black women also had significant decreases in estrone sulfate and total testosterone and increases in follicle-stimulating hormone before menopause. In the postmenopausal years, abdominal subcutaneous adipose tissue, total adipose tissue, follicle-stimulating hormone, total cholesterol, and low-density and high-density lipoprotein cholesterol increased only in white women.

CONCLUSION

White women gained more abdominal adiposity during the menopause transition compared with black women, which, in part, may be due to differences in the pattern of sex steroid hormone changes between women of different racial backgrounds. The gains in abdominal adiposity in white women were observed in tandem with increased cardiometabolic risk factors. Future studies should consider comprehensive lifestyle approaches to target these increased gains in abdominal adiposity (ie, nutrition and physical activity coaching), while taking into account the potential interactions of race, body adiposity, sex steroid hormones, and their influence on cardiometabolic risk.

Usefulness of New Indicators of Obesity (BAI and VAI) in Estimation of Weight Reduction

Objective: Obesity is responsible for a large proportion of the total burden of diseases in Europe. The aim of this study was to compare classic anthropometric parameters with new obesity-related indices (the visceral adiposity index [VAI] and the body adiposity index [BAI]) and to examine their usefulness in the assessment of weight reduction and its effect on the leptin concentration.Methods: We tested 50 patients with obesity, undergoing the implementation of the BioEnterics^® Intragastric Balloon (BIB-system) for 6 months. The leptin concentrations and the calculated subcutaneous fat thickness as well as the anthropometric indices were determined prior to the implementation and after the balloon removal.Results: The therapy resulted in a drop in the BAI value without a significant effect on the VAI in subgroups of patients with class I, II, and III obesity. The therapy-induced changes in BAI both in the entire tested group and in patients with class I and II obesity correlated well with the percentage of drop in body weight, body mass index (BMI), subcutaneous fat thickness, waist-to-height ratio (WHtR), and leptin concentration. Changes in the VAI value correlated with changes in the body weight, BMI, WHtR values, subcutaneous fat thickness, and leptin concentration decrease only in patients with class III obesity.Conclusions: BAI seems to be a better indicator than VAI for reflecting the reduction in body weight in people with class I and II obesity treated with the BIB-System. VAI appears to be a better obesity indicator than BAI only in people with class III obesity.

Metabolic profiling of adherence to diet, physical activity and body size recommendations for cancer prevention

Maintaining a healthy body weight, eating well and being physically active lowers cancer risk by 30%. However, the biology underlying these relationships is not well understood. We examined cross-sectional associations between metabolites and cancer preventive behaviors as well as the relevance to cancer-related pathways among 120 participants (50% men, mean BMI 26.6 kg/m², mean age 54 years) with no history of smoking or cancer. Participants completed questionnaires, physical measurements and provided blood samples. Non-targeted nuclear magnetic resonance captured 223 metabolite measures. Factor analysis was performed separately for amino acid, fatty acid and lipoprotein groups. Multivariable-adjusted linear regression was used to evaluate associations between cancer preventive recommendations and metabolite-containing factors (p-value < 0.05, false discovery rate <0.20). An inflammation-related metabolite (glycoprotein acetylation) loaded strongly on a factor that was associated with excess adiposity (body fat ≥25% (men) or ≥30% (women) ß (SE) = 0.74 (0.18)) and not meeting physical activity recommendations (ß (SE) = 0.40 (0.20)). Insulin sensitivity-related metabolites including monounsaturated and polyunsaturated fats were lower among participants not meeting recommendations for adiposity, fruits and vegetables and physical activity while branched chain amino acids were higher. Cancer preventive behaviors were associated with complex metabolic signatures, including alterations in pathways known to be involved in cancer pathogenesis.

Use of various obesity measurement and classification methods in occupational safety and health research: a systematic review of the literature

BACKGROUND

This study systematically examined obesity research in occupational safety and health regarding the use of various obesity measurement and classification methods.

METHODS

A systematic search of the PubMed database on English language publications from 2000 to 2015 using related keywords and search of citations resulted in selection of 126 studies. They were categorized into two groups based on their main research question: 1) general physical or mental work-related functioning; and 2) task or body part specific functioning.

RESULTS

Regardless of the study group, body mass index (BMI) was the most frequently used measure. Over 63% of the studies relied solely on BMI to define obesity. In only 22% of the studies, body fat was directly measured by methods such as dual energy x-ray absorptiometry. Abdominal obesity was defined using waist circumference in recent years, and waist-hip ratio in earlier years. Inconsistent cut-offs have also been used across studies investigating similar topics.

CONCLUSIONS

Few authors acknowledged the limitations of using indirect obesity measures. This is in part due to the limited understanding of some occupational safety and health researchers regarding the complex issues surrounding obesity classification and also the mixed recommendations over the past 2-3 decades and across populations. Efforts need to be made to promote appropriate obesity measurement and reporting in this field.

Recent progress in genetics, epigenetics and metagenomics unveils the pathophysiology of human obesity

In high-, middle- and low-income countries, the rising prevalence of obesity is the underlying cause of numerous health complications and increased mortality. Being a complex and heritable disorder, obesity results from the interplay between genetic susceptibility, epigenetics, metagenomics and the environment. Attempts at understanding the genetic basis of obesity have identified numerous genes associated with syndromic monogenic, non-syndromic monogenic, oligogenic and polygenic obesity. The genetics of leanness are also considered relevant as it mirrors some of obesity's aetiologies. In this report, we summarize ten genetically elucidated obesity syndromes, some of which are involved in ciliary functioning. We comprehensively review 11 monogenic obesity genes identified to date and their role in energy maintenance as part of the leptin-melanocortin pathway. With the emergence of genome-wide association studies over the last decade, 227 genetic variants involved in different biological pathways (central nervous system, food sensing and digestion, adipocyte differentiation, insulin signalling, lipid metabolism, muscle and liver biology, gut microbiota) have been associated with polygenic obesity. Advances in obligatory and facilitated epigenetic variation, and gene-environment interaction studies have partly accounted for the missing heritability of obesity and provided additional insight into its aetiology. The role of gut microbiota in obesity pathophysiology, as well as the 12 genes associated with lipodystrophies is discussed. Furthermore, in an attempt to improve future studies and merge the gap between research and clinical practice, we provide suggestions on how high-throughput '-omic' data can be integrated in order to get closer to the new age of personalized medicine.

Nutritional management in the critically ill child with acute kidney injury: a review

Acute kidney injury (AKI) in critically ill children is frequently a component of the multiple organ failure syndrome. It occurs within the framework of the severe catabolic phase determined by critical illness and is intensified by metabolic derangements. Nutritional support is a must for these children to improve outcomes. Meeting the special nutritional needs of these children often requires nutritional supplementation by either the enteral or the parenteral route. Since critically ill children with AKI comprise a heterogeneous group of subjects with varying nutrient needs, nutritional requirements should be frequently reassessed, individualized and carefully integrated with renal replacement therapy. This article is a state-of-the-art review of nutrition in critically ill children with AKI.

Association of body mass index (BMI) and percent body fat among BMI-defined non-obese middle-aged individuals: Insights from a population-based Canadian sample

OBJECTIVES

To evaluate the association between percent body fat (%BF) and body mass index (BMI) among BMI-defined non-obese individuals between 40 and 69 years of age using a population-based Canadian sample.

DATA AND METHODS

Cross-sectional data from the Canadian Health Measures Survey (2007 and 2009) was used to select all middle-aged individuals with BMI &lt; 30 kg/m2 (n = 2,656). %BF was determined from anthropometric skinfolds and categorized according to sex-specific equations. Association of other anthropometry measures and metabolic markers were evaluated across different %BF categories. Significance of proportions was evaluated using chi-squared and Bonferroni-adjusted Wald test. Diagnostic performance measures of BMI-defined overweight categories compared to those defined by %BF were reported.

RESULTS

The majority (69%) of the sample was %BF-defined overweight/obese, while 55% were BMI-defined overweight. BMI category was not concordant with %BF classification for 30% of the population. The greatest discordance between %BF and BMI was observed among %BF-defined overweight/obese women (32%). Sensitivity and specificity of BMI-defined overweight compared to %BF-defined overweight/obese were (58%, 94%) among females and (82%, 59%) among males respectively. According to the estimated negative predictive value, if an individual is categorized as BMI-defined non-obese, he/she has a 52% chance of being in the %BF-defined overweight/obese category.

CONCLUSION

Middle-aged individuals classified as normal by BMI may be overweight/obese based on measures of %BF. These individuals may be at risk for chronic diseases, but would not be identified as such based on their BMI classification. Quantifying %BF in this group could inform targeted strategies for disease prevention.

Agreement between BMI and body fat obesity definitions in a physically active population

OBJECTIVES

Body mass index (BMI) is a widely used proxy of body composition (BC). Concerns exist regarding possible BMI misclassification among active populations. We compared the prevalence of obesity as categorized by BMI or by skinfold estimates of body fat percentage (BF%) in a physically active population.

SUBJECTS AND METHODS

3,822 military firefighters underwent a physical fitness evaluation including cardiorespiratory fitness (CRF) by the 12 min-Cooper test, abdominal strength by sit-up test (SUT) and body composition (BC) by BF% (as the reference), as well as BMI. Obesity was defined by BF% > 25% and BMI ≥ 30 kg/m2. Agreement was evaluated by sensitivity and specificity of BMI, positive and negative predictive values (PPV/NPV), positive and negative likelihood (LR+/LR-), receiver operating characteristic (ROC) curves and also across age, CRF and SUT subgroups.

RESULTS

The prevalence of obesity estimated by BMI (13.3%) was similar to BF% (15.9%). Overall agreement was high (85.8%) and varied in different subgroups (75.3-94.5%). BMI underestimated the prevalence of obesity in all categories with high specificity (≥ 81.2%) and low sensitivity (≤ 67.0). All indices were affected by CRF, age and SUT, with better sensitivity, NPV and LR- in the less fit and older groups; and higher specificity, PPV and LR+ among the fittest and youngest groups. ROC curves showed high area under the curve (≥ 0.77) except for subjects with CRF ≥ 14 METs (= 0.46).

CONCLUSION

Both measures yielded similar obesity prevalences, with high agreement. BMI did not overestimate obesity prevalence. BMI ≥ 30 was highly specific to exclude obesity. Because of systematic under estimation, a lower BMI cut-off point might be considered in this population.

Posttraumatic stress symptoms and body mass index among World Trade Center disaster-exposed smokers: A preliminary examination of the role of anxiety sensitivity

Among individuals exposed to the World Trade Center (WTC) disaster on September 11, 2001, posttraumatic stress disorder (PTSD) and symptoms are both common and associated with increased cigarette smoking and body mass. However, there is little information on the specific processes underlying the relationship of PTSD symptoms with body mass. The current study is an initial exploratory test of anxiety sensitivity, the fear of internal bodily sensations, as a possible mechanism linking PTSD symptom severity and body mass index (BMI). Participants were 147 adult daily smokers (34.0% female) exposed to the WTC disaster (via rescue/recovery work or direct witness). The direct and indirect associations between PTSD symptom severity and BMI via anxiety sensitivity (total score and subscales of physical, cognitive, and social concerns) were examined. PTSD symptom severity was related to BMI indirectly via anxiety sensitivity; this effect was specific to physical concerns about the meaning of bodily sensations. Interventions focusing on anxiety sensitivity reduction (specifically addressing physical concerns about bodily sensations) may be useful in addressing elevated BMI among trauma-exposed persons.

Body composition of women 20-49 years old as a predictor for noncommunicable diseases: a community-based study

BACKGROUND

Obesity increases a person's risk of developing a number of noncommunicable diseases (NCDs), including, type 2 diabetes, coronary heart disease, hypertension, and certain cancers. The bioelectrical impedance analysis (BIA) has been considered as a safe, noninvasive, simple, and least expensive portable method for the evaluation of body composition in clinical practice. However, there is not enough information about its use in community-based surveys to detect the optimal cutoff point for the body fat percent (BF%) that could predict NCDs.

OBJECTIVE

To identify the cutoff point for the BF%, at which NCD risk could be predicted compared with BMI and waist circumference (WC).

METHODS

A community-based study was conducted in a randomly selected cluster located within the catchment area of Cairo University Hospitals. All ever-married women 20-49 years old and not currently pregnant (n=373) in the selected cluster were included in the study. A questionnaire was used for recoding data during the household survey. Portable equipment that estimates body composition (water, fat, protein, and bone) through BIA was used.

RESULTS

Receiver operating characteristic curve analysis showed cutoff point for BF% of 37.5% (P=0.02) at the time of reporting hypertension, with 78% sensitivity and 40% specificity. For diagnosed diabetes, cutoff point for the BF% was 38.5% (P=0.005), with 71% sensitivity and 46% specificity. For diagnosed cardiovascular diseases, cutoff point for BF% was 38.5% (P=0.001) with 86% sensitivity and 47% specificity. For diagnosed joint diseases, cutoff point for BF% was 38.5% (P=0.005), with 67% sensitivity and 48% specificity.

CONCLUSION AND RECOMMENDATIONS

BIA was effective in predicting and suggesting the cutoff points for the BF% associated with four types of NCDs (hypertension, cardiovascular, diabetes, and joint diseases). The use of BIA for women before the age of 20 years could guide strategies for reducing body fat and its risk of NCDs.

The Validity of Body Adiposity Indices in Predicting Metabolic Syndrome and Its Components among Egyptian Women

AIM

To assess the associations between the body adiposity indices and risk of metabolic syndrome (MS) and its components in Egyptian women and to evaluate their predictive power.

MATERIALS AND METHODS

This was a cross-sectional analysis performed on 180 Egyptian women aged between 25-35 years. They were 90 women with MS diagnosed by International Diabetes Federation (IDF) and 90 healthy age matched controls. Body adiposity index (BAI), body mass index (BMI), waist to hip ratio (WHR) and waist to height ratio (WHtR) were calculated and serum samples were analyzed for metabolic parameters. Receiver operating characteristic curves (ROC) was used to determine the discriminatory capacity of BAI, WHR WHtR and BMI for MS.

RESULTS

Area under the curve (AUC) was highest for BIA, followed by WHR, WHtR and then BMI. All adiposity indices were significantly correlated with metabolic components and BAI had the highest correlation coefficients compared to other indices.

CONCLUSION

BAI is a practical predictor for MS and has satisfactory diagnostic accuracy for diagnosing MS among Egyptian women and can be used in addition to WHR, WHtR and BMI for identifying MS in the field studies.

Greater body mass index is a better predictor of subclinical cardiac damage at long-term follow-up in men than is insulin sensitivity: a prospective, population-based cohort study

BACKGROUND

To examine whether lower insulin sensitivity as determined by homeostatic model assessment (HOMA-%S) was associated with increased left ventricular mass (LVM) and presence of LV diastolic dysfunction at long-term follow-up, independently of body mass index (BMI), in middle-aged, otherwise healthy males.

METHODS

Prospective population-based cohort study with a median (IQR) follow-up time of 28 (27-28) years, in which traditional cardiovascular risk factors, including HOMA-%S and BMI, were assessed at baseline, and echocardiographic determination of LVM and LV diastolic function was performed at follow-up. Associations between risk factors and echocardiographic variables were tested using multivariable linear and binary logistic regression.

RESULTS

The study population comprised 247 men with a median (IQR) age of 47 (47-48) years. Mean (SD) BMI was 25.1 +/- 3.0 kg/m(2), and median (IQR) HOMA-%S was 113.0 (68.3-284.6). Subjects with low insulin sensitivity (lowest HOMA-%S quartile (Q1)) had significantly greater BMI, fasting plasma insulin, and higher fasting blood glucose (FBG) (p <0.02 for all). BMI and HOMA-%S were significantly correlated (r = -0.383, p <0.0001). At follow-up, mean (SD) LVM and LVMI were 202 +/- 61 g and 103 +/- 31 g/m(2), respectively, whereas median (IQR) E/é was 10 (8-12). Moreover, 36 % had grade 2 or 3 diastolic dysfunction. In multivariable analyses, greater BMI, but not low insulin sensitivity was independently associated with later detection of increased LVM and diastolic dysfunction.

CONCLUSION

Greater baseline BMI, but not lower insulin sensitivity was independently associated with greater LVM and diastolic dysfunction at long-term follow-up.

Body composition during fetal development and infancy through the age of 5 years

Fetal body composition is an important determinant of body composition at birth, and it is likely to be an important determinant at later stages in life. The purpose of this work is to provide a comprehensive overview by presenting data from previously published studies that report on body composition during fetal development in newborns and the infant/child through 5 years of age. Understanding the changes in body composition that occur both in utero and during infancy and childhood, and how they may be related, may help inform evidence-based practice during pregnancy and childhood. We describe body composition measurement techniques from the in utero period to 5 years of age, and identify gaps in knowledge to direct future research efforts. Available literature on chemical and cadaver analyses of fetal studies during gestation is presented to show the timing and accretion rates of adipose and lean tissues. Quantitative and qualitative aspects of fetal lean and fat mass accretion could be especially useful in the clinical setting for diagnostic purposes. The practicality of different pediatric body composition measurement methods in the clinical setting is discussed by presenting the assumptions and limitations associated with each method that may assist the clinician in characterizing the health and nutritional status of the fetus, infant and child. It is our hope that this review will help guide future research efforts directed at increasing the understanding of how body composition in early development may be associated with chronic diseases in later life.

Fluid retention, muscle damage, and altered body composition at the Ultraman triathlon

PURPOSE

The primary purpose of this investigation was to determine the effects of participation in a 3-day multistage ultraendurance triathlon (stage 1 = 10 km swim, 144.8 km bike; stage 2 = 275.4 km bike; stage 3 = 84.4 km run) on body mass and composition, hydration status, hormones, muscle damage, and blood glucose.

METHODS

Eighteen triathletes (mean ± SD; age 41 ± 7.5 years; height 175 ± 9 cm; weight 73.5 ± 9.8 kg; male n = 14, female n = 4) were assessed before and after each stage of the race. Body mass and composition were measured via bioelectrical impedance, hydration status via urine specific gravity, hormones and muscle damage via venous blood draw, and blood glucose via fingerstick.

RESULTS

Following the race, significant changes included reductions in body mass (qualified effect size: trivial), fat mass (moderate), and percent body fat (small); increases in percent total body water (moderate) and urine specific gravity (large); and unchanged absolute total body water and fat-free mass. There were also extremely large increases in creatine kinase, C-reactive protein, aldosterone and cortisol combined with reductions in testosterone (small) and the testosterone:cortisol ratio (moderate). There were associations between post-race aldosterone and total body water (r = -0.504) and changes in cortisol and fat-free mass (r = -0.536). Finally, blood glucose increased in a stepwise manner prior to each stage.

CONCLUSIONS

Participation in Ultraman Florida leads to fluid retention and dramatic alterations in body composition, muscle health, hormones, and metabolism.

Diagnostic performance of skinfold method to identify obesity as measured by air displacement plethysmography in cardiac rehabilitation

PURPOSE

To assess the diagnostic performance of the skinfold (SKF) method to detect obesity in patients enrolled in an outpatient cardiac rehabilitation (CR) program.

METHODS

This study involves outpatients attending a phase II CR program who underwent air displacement plethysmography (ADP) to assess body composition. We measured body fat percentage (BF%), using a 3-site SKF method calculated through the Jackson-Pollock equation utilizing a Harpenden caliper. Air displacement plethysmography calculated BF% using a bicompartmental model, deriving the body composition after the direct calculation of body density (BD), using the Siri equation [(BF% = 495/BD) - 450]. We calculated the diagnostic performance of SKF to detect obesity, utilizing a BF% cutoff of ≥35% for women and ≥25% for men determined by SKF and ADP to define obesity.

RESULTS

Our sample (n = 310) was 80% men, 60.2 ± 11 years of age, had a mean weight of 89.88 ± 17.96 kg, height 173.38 ± 8.68 cm, body mass index (BMI) 29.78 ± 5.01 kg/m, waist circumference 100.55 ± 14.38 cm, and waist-to-hip ratio of 0.96 ± 0.09. The evaluation of the diagnostic performance of SKF to detect obesity showed a sensitivity of 57%, specificity of 93%, a positive predictive value of 97%, and a negative predictive value of 33%. These values were not different from the diagnostic performance of BMI to detect obesity as defined by BF%. SKF and BMI misclassified 43% and 49% of obese patients as nonobese, respectively.

CONCLUSION

Our findings underscore the limitation of using SKF to assess body fatness in the CR setting.

Body mass index and waist circumference rather than body adiposity index are better surrogates for body adiposity in a Chinese population

BACKGROUND

Several studies have found that body adiposity index (BAI) is a better index of body adiposity than body mass index (BMI) in African and Mexican American adults. This study aims to evaluate the ability of BAI to predict body adiposity in Chinese children and adults.

MATERIALS AND METHODS

In total, 2425 children and 5726 adults were recruited from rural China. All participants completed whole-body dual-energy X-ray absorptiometry (DXA) and anthropometric measures. The correlation of BMI, BAI, and waist circumference (WC) to DXA adiposity indexes was performed across sex-specific adult and age- and sex-specific child cohorts, using Spearman correlation and linear regression models, respectively.

RESULTS

Both BMI and WC had a higher correlation with all adiposity indexes (whole body fat, percent body fat [Bfat%], trunk fat, and percent trunk fat [Tfat%]) measured by DXA than did BAI in both adults and children. Meanwhile, most of the linear regression model associations for BMI with Bfat% and Tfat% had a greater adjusted R(2) than those for BAI among both children and adults.

CONCLUSION

This study indicates that BMI and WC are better tools than BAI for estimating whole body fat and central body fat in a Chinese population.

Comparison of the body adiposity index to body mass index in Korean women

PURPOSE

Obesity is a major public health issue and is associated with many metabolic abnormalities. Consequently, the assessment of obesity is very important. A new measurement, the body adiposity index (BAI), has recently been proposed to provide valid estimates of body fat percentages. The objective of this study was to compare the BAI and body mass index (BMI) as measurements of body adiposity and metabolic risk.

MATERIALS AND METHODS

This was a cross-sectional analysis performed on Korean women. The weight, height, and hip circumferences of 2950 women (mean age 25±5 years old, 18-39 years) were measured, and their BMI and BAI [hip circumference (cm)/height (m)1.5-18] values were calculated. Bioelectric impedance analysis was used to evaluate body fat content. Glucose tolerance status was assessed with a 75-g oral glucose tolerance test, and insulin sensitivity was estimated with the insulin sensitivity index.

RESULTS

BMI was more significantly correlated with fat mass and fat percentage. Additionally, BMI was also more significantly associated with metabolic parameters, including fasting glucose, post-load 2-h glucose, fasting insulin, post-load 2-h insulin, triglycerides, and high density lipoprotein cholesterol than BAI. Receiver operating characteristic curve analysis revealed that BMI was a better tool for predicting body fat percentage than BAI. Insulin sensitivity and metabolic syndrome were more significantly associated with BMI than with BAI.

CONCLUSION

In Korean women, the current BMI-based classifications for obesity might be superior to BAI-based measurements for determining obesity and predicting metabolic risk.

Nutritional adequacy of meals offered and consumed by soldiers of the Brazilian Army

OBJECTIVE: The purpose of this research is to evaluate the nutritional adequacy of meals served and consumed by soldiers in a construction unit (army and civil employees) of the Brazilian Army Construction. METHODS: Body mass index, fat percentage (bioimpedance) and the physical activity level were evaluated. Furthermore, the nutritional evaluation of meals offered and consumed by soldiers was evaluated, in relation to the macronutrients, sodium, fibers and total energetic value. RESULTS: Through the results, we verified that 76% of the soldiers were eutrophic, and that the population's energetic requirement was approximately 3.600 kcal. We verified that the energetic consumption of this population was below the required value (3.200 kcal) and with inadequacy regarding the distribution of macronutrients: percentage of carbohydrates above the recommended one, percentage of lipid below the minimum value recommended and percentage of proteins within the recommendation. Moreover, the amount of fibers was in accordance to the standards; however, there was an excessive amount of sodium, which may put this population in danger. CONCLUSION: We concluded that it is necessary to improve the quality of the meals offered in relation to the nutritional aspect, by promoting the adequacy to the soldiers' needs. Other types of quality were not studied, but they are important when evaluating acceptability of meals.

An Average Body Circumference Can Be a Substitute for Body Mass Index in Women

Introduction. Significant correlations between BMI and some body circumferences have been previously reported. In this study we investigated if the average of the sum of eight body circumferences can be a substitute for BMI. Patients and Methods. BMI and eight body circumferences (neck, waist, hip, arm, forearm, wrist, thigh, and ankle) were measured in 193 apparently healthy women aged 20-83, and within a wide range of BMI. Women with BMI ≤ 24.9 were designated as normal, with BMI 25-29.9 as overweight and with BMI ≥ 30 as obese. The relationship of the average body circumference (ABC) of the sum of the eight circumferences, and of each individual circumference with BMI, was evaluated. Results. ABC had the strongest correlation with BMI (r = 0.95, P < 0.001) among all the circumferences tested. Hip circumference had the strongest correlation with BMI (r = 0.89, P < 0.001) among the circumferences of individual body sites. Receiver-Operator Characteristic analysis showed that women with ABC > 44.0 cm could be recognized as having BMI ≥ 25 with sensitivity 90.2% and specificity 88.5%, while women with ABC > 47.1 cm could be diagnosed as having BMI ≥ 30 with sensitivity 92.2% and specificity 91.5%. Conclusion. An average body circumference strongly correlated with BMI in women and can serve as a surrogate of BMI.

Use of anthropometry for the prediction of regional body tissue distribution in adults: benefits and limitations in clinical practice

Regional body composition changes with aging. Some of the changes in composition are considered major risk factors for developing obesity related chronic diseases which in turn may lead to increased mortality in adults. The role of anthropometry is well recognized in the screening, diagnosis and follow-up of adults for risk classification, regardless of age. Regional body composition is influenced by a number of intrinsic and extrinsic factors. Therapeutic measures recommended to lower cardiovascular disease risk include lifestyle changes. The aim of this review is to systematically summarize studies that assessed the relationships between anthropometry and regional body composition. The potential benefits and limitations of anthropometry for use in clinical practice are presented and suggestions for future research given.

A method comparison study to validate a novel parameter of obesity, the body adiposity index, in Chinese subjects

OBJECTIVE

A recently developed parameter, the body adiposity index (BAI)-a composite index based on hip circumference and height-estimates the percentage (%) body adiposity indirectly. The BAI was compared with dual energy X-ray absorptiometer (DEXA)-derived % adiposity to validate the BAI in the local Chinese population.

DESIGN AND METHODS

105 Chinese were recruited and % adiposity estimated by BAI was compared with that derived from DEXA using the Bland Altman plot. A correlation study comparing the BAI with body mass index (BMI) was also done.

RESULTS

BAI underestimated DEXA-derived % adiposity by a mean of 5.77% with 95% limits of agreement of ±8.4%. When stratified by gender, BMI correlated with DEXA-derived % adiposity better than BAI (r = 0.81 vs. 0.74 for males, P = 0.088, and r = 0.87 vs. 0.82 for females, P = 0.087). Hip circumference and waist circumference also correlated better with the BMI than BAI (r = 0.94 vs. 0.71 for hip circumference, P < 0.001, and r = 0.93 vs. 0.50 for waist circumference, P < 0.001, respectively).

CONCLUSIONS

The BAI underestimates DEXA-derived % adiposity in a Chinese population in Singapore and is unlikely to be a better overall index of adiposity than the established BMI.

Simplified method of clinical phenotyping for older men and women using established field-based measures

The purpose of this investigation was to determine body composition classification using field-based testing measurements in healthy elderly men and women. The use of isoperformance curves is presented as a method for this determination. Baseline values from 107 healthy Caucasian men and women, over the age of 65years old, who participated in a separate longitudinal study, were used for this investigation. Field-based measurements of age, height, weight, body mass index (BMI), and handgrip strength were recorded on an individual basis. Relative skeletal muscle index (RSMI) and body fat percentage (FAT%) were determined by dual-energy X-ray absorptiometry (DXA) for each participant. Sarcopenia cut-off values for RSMI of 7.26kg·m(-2) for men and 5.45kg·m(-2) for women and elderly obesity cut-off values for FAT% of 27% for men and 38% for women were used. Individuals above the RSMI cut-off and below the FAT% cut-off were classified in the normal phenotype category, while individuals below the RSMI cut-off and above the FAT% cut-off were classified in the sarcopenic-obese phenotype category. Prediction equations for RSMI and FAT% from sex, BMI, and handgrip strength values were developed using multiple regression analysis. The prediction equations were validated using double cross-validation. The final regression equation developed to predict FAT% from sex, BMI, and handgrip strength resulted in a strong relationship (adjusted R(2)=0.741) to DXA values with a low standard error of the estimate (SEE=3.994%). The final regression equation developed to predict RSMI from the field-based testing measures also resulted in a strong relationship (adjusted R(2)=0.841) to DXA values with a low standard error of the estimate (SEE=0.544kg·m(-2)). Isoperformance curves were developed from the relationship between BMI and handgrip strength for men and women with the aforementioned clinical phenotype classification criteria. These visual representations were used to aid in the classification and evaluation of sarcopenia, obesity, and sarcopenic-obesity in elderly individuals. Future research should replicate the current findings with an increased sample size and the development of tailored interventions for each body composition category.

Lower limb body composition is associated to knee passive extension torque-angle response

PURPOSE

People vary in flexibility regarding maximum joint angle, resistance to stretch and mechanical responses during stretching exercises. Body composition (BC) has been been mentioned as one of the factors for flexibility differences. The aim of this study was to determine how body composition and anthropometric measures of the lower limb is associated with passive knee extension (PKE) torque-angle (T-A) response.

METHODS

Twenty-five male subjects with poor flexibility performed a maximal PKE repetition (velocity of 2°/s; 90 seconds in the static phase). Knee passive T-A, vastus medialis and semitendinosous electromyographic activity were recorded during the protocol. Viscoelastic stress relaxation (VSR) amplitude, knee passive stiffness (KPS), lower limb body composition assessed by dual energy x-ray absorptiometry, and anthropometry measures were determined.

RESULTS

Thigh skeletal muscle and bone mass, as well as thigh perimeter, showed a moderated correlation with passive torque (r = 0.45; r = 0.6; r = 0.59, respectively), joint angle (r = 0.46; r = 0.5; r = 0.5), and VSR (r = 0.46; r = 0.49; r = 0.5). Thigh skeletal muscle was also correlated with KPS (r = 0.42). All these correlations were statistically significant (p < 0.05).

CONCLUSIONS

Passive knee extension T-A was found to be moderately correlated with lower limb BC. In particular, thigh perimeter and skeletal muscle mass were associated with knee passive stiffness and viscoelastic stress relaxation. More research is needed to understand what influences joint maximum angle, resistance to stretch and mechanical response to stretching.

What makes a BIA equation unique? Validity of eight-electrode multifrequency BIA to estimate body composition in a healthy adult population

BACKGROUND/OBJECTIVES

The validity of bioelectrical impedance analysis (BIA) for body composition analysis is limited by assumptions relating to body shape. Improvement in BIA technology could overcome these limitations and reduce the population specificity of the BIA algorithm.

SUBJECTS/METHODS

BIA equations for the prediction of fat-free mass (FFM), total body water (TBW) and extracellular water (ECW) were generated from data obtained on 124 Caucasians (body mass index 18.5-35 kg/m(2)) using a four-compartment model and dilution techniques as references. The algorithms were validated in an independent multiethnic population (n=130). The validity of BIA results was compared (i) between ethnic groups and (ii) with results from the four-compartment model and two-compartment methods (air-displacement plethysmography, dual-energy X-ray absorptiometry and deuterium dilution).

RESULTS

Indices were developed from segmental R and Xc values to represent the relative contribution of trunk and limbs to total body conductivity. The coefficient of determination for all prediction equations was high (R(2): 0.94 for ECW, 0.98 for FFM and 0.98 for TBW) and root mean square error was low (1.9 kg for FFM, 0.8 l for ECW and 1.3 kg for TBW). The bias between BIA results and different reference methods was not statistically different between Afro-American, Hispanic, Asian or Caucasian populations and showed a similar difference (-0.2-0.2 kg FFM) when compared with the bias between different two-compartment reference methods (-0.2-0.3 kg FFM).

CONCLUSIONS

An eight-electrode, segmental multifrequency BIA is a valid tool to estimate body composition in healthy euvolemic adults compared with the validity and precision of other two-compartment reference methods. Population specificity is of minor importance when compared with discrepancies between different reference methods.

An Overview of the Complexities in Obesity

A recent survey, even one limited to human studies, found considerable “publication scatter” in that more than 250 different professional journals publish articles on obesity. Over the years, and particularly since the 1970s and 1980s when the so-called obesity epidemic began, there has been an explosion of clinical interest in a field that encompasses general medicine, pediatrics, surgery, psychiatry, and almost every subspecialty. And rightly so, since even by 2008, there were an estimated 1.46 billion adults worldwide who were overweight, and of these, 502 million were in the obese category, all of which translate into major public health consequences. Despite many highly publicized studies, why do we not have a greater understanding about obesity than we do? It is certainly not from a lack of trying. This article presents an overview of the limitations and challenges, that is, complexities, due to discrepant frameworks and diverse conceptualizations of obesity; potential flaws inherent in its clinical studies; and particularly, impediments due to difficulties in the measurement of body composition (and particularly adipose accumulation), food intake, and physical activity, as well as to notoriously inaccurate self-reporting by subjects. As a result, clinicians remain limited in issuing recommendations to their patients.

Agreement between different versions of MNA

Malnutrition occurs frequently in the elderly with important clinical and functional consequences. Moreover, the treatment of malnutrition in the elderly may be effective if clinical and nutritional interventions are performed in the early stages. Therefore the early identification of the risk of malnutrition using validated and handy tools plays a pivotal role in terms of clinical outcome. Mini Nutritional Assessment (MNA) was validated for this purpose since many years but it is still ongoing the debate over whether the use of different items in certain clinical conditions can be effective without affecting the validity of the nutritional status evaluation. The aim of this study was to assess the agreement between different versions of MNA in the evaluation of nutritional risk in elderly subjects.

METHODS

522 subjects, 345 women and 177 men, were recruited from nursing homes or were free living in three different regions in Italy. All subjects underwent a multidimensional geriatric evaluation, addressed especially to nutritional status. We compared three different versions of MNA: the "original" version; a "proportional" MNA (MNA- P) in which the total MNA score was replaced by the ratio between the maximum score that each subject could obtain without including the body mass index (BMI) and the total original MNA score; and a third version in which calf circumference (CC) and mid- upper arm circumference (MAC) were used instead of BMI.

RESULTS

According to the original MNA, a high prevalence of malnutrition was found out in both genders (26% of women and 16.3% of men); both the versions of MNA, in which BMI was not considered, showed a good predictive value compared to original MNA. In particular, the MNA- P. showed an overall efficiency equal to 89,1% with specificity and positive predictive value respectively equal to 97.5% and 95.2%. MNA- CC- MAC showed even better results in terms of overall efficiency (91.4%), sensitivity (81.1%), specificity (97.1%), positive and negative predictive values (94.2% and 94.4%, respectively).

CONCLUSION

The different versions of MNA gave similar results in the classifications of subjects and in comparison with nutritional and biochemical parameters. Moreover MNA versions that did not considered BMI seem to be more effective in singling out subjects with risk factors related to malnutrition (disability, reduced strength and calf circumference, anaemia).

Overweight and obesity alters the cumulative transverse strain in the Achilles tendon immediately following exercise

This research evaluated the effect of obesity on the acute cumulative transverse strain of the Achilles tendon in response to exercise. Twenty healthy adult males were categorized into 'low normal-weight' (BMI <23 kg m(-2)) and 'overweight' (BMI >27.5 kg m(-2)) groups based on intermediate cut-off points recommended by the World Health Organization. Longitudinal sonograms of the right Achilles tendon were acquired immediately prior and following weight-bearing ankle exercises. Achilles tendon thickness was measured 20-mm proximal to the calcaneal insertion and transverse tendon strain was calculated as the natural log of the ratio of post- to pre-exercise tendon thickness. The Achilles tendon was thicker in the overweight group both prior to (t18 = -2.91, P = 0.009) and following (t18 = -4.87, P < 0.001) exercise. The acute transverse strain response of the Achilles tendon in the overweight group (-10.7 ± 2.5%), however, was almost half that of the 'low normal-weight' (-19.5 ± 7.4%) group (t18 = -3.56, P = 0.004). These findings suggest that obesity is associated with structural changes in tendon that impairs intra-tendinous fluid movement in response to load and provides new insights into the link between tendon pathology and overweight and obesity.

Improved Prediction of Body Fat by Measuring Skinfold Thickness, Circumferences, and Bone Breadths

OBJECTIVE

To develop improved predictive regression equations for body fat content derived from common anthropometric measurements.

RESEARCH METHODS AND PROCEDURES

117 healthy German subjects, 46 men and 71 women, 26 to 67 years of age, from two different studies were assigned to a validation and a cross-validation group. Common anthropometric measurements and body composition by DXA were obtained. Equations using anthropometric measurements predicting body fat mass (BFM) with DXA as a reference method were developed using regression models.

RESULTS

The final best predictive sex-specific equations combining skinfold thicknesses (SF), circumferences, and bone breadth measurements were as follows: BFM(New) (kg) for men = -40.750 + {(0.397 x waist circumference) + [6.568 x (log triceps SF + log subscapular SF + log abdominal SF)]} and BFM(New) (kg) for women = -75.231 + {(0.512 x hip circumference) + [8.889 x (log chin SF + log triceps SF + log subscapular SF)] + (1.905 x knee breadth)}. The estimates of BFM from both validation and cross-validation had an excellent correlation, showed excellent correspondence to the DXA estimates, and showed a negligible tendency to underestimate percent body fat in subjects with higher BFM compared with equations using a two-compartment (Durnin and Womersley) or a four-compartment (Peterson) model as the reference method.

DISCUSSION

Combining skinfold thicknesses with circumference and/or bone breadth measures provide a more precise prediction of percent body fat in comparison with established SF equations. Our equations are recommended for use in clinical or epidemiological settings in populations with similar ethnic background.

Footprint-based estimates of arch structure are confounded by body composition in adults

Previous research employing indirect measures of arch structure, such as those derived from footprints, have indicated that obesity results in a "flatter" foot type. In the absence of radiographic measures, however, definitive conclusions regarding the osseous alignment of the foot cannot be made. We determined the effect of body mass index (BMI) on radiographic and footprint-based measures of arch structure. The research was a cross-sectional study in which radiographic and footprint-based measures of foot structure were made in 30 subjects (10 males, 20 female) in addition to standard anthropometric measures of height, weight, and BMI. Multiple (univariate) regression analysis demonstrated that both BMI (β = 0.39, t(26) = 2.12, p = 0.04) and radiographic arch alignment (β = 0.51, t(26) = 3.32, p < 0.01) were significant predictors of footprint-based measures of arch height after controlling for all variables in the model (R(2) = 0.59, F(3,26) = 12.3, p < 0.01). In contrast, radiographic arch alignment was not significantly associated with BMI (β = -0.03, t(26) = -0.13, p = 0.89) when Arch Index and age were held constant (R(2) = 0.52, F(3,26) = 9.3, p < 0.01). Adult obesity does not influence osseous alignment of the medial longitudinal arch, but selectively distorts footprint-based measures of arch structure. Footprint-based measures of arch structure should be interpreted with caution when comparing groups of varying body composition.

Body composition after bone marrow transplantation in childhood

PURPOSE/OBJECTIVES

To describe the body composition and fat distribution of childhood bone marrow transplantation (BMT) survivors at least one year post-transplantation and examine the ability of the Centers for Disease Control and Prevention criteria to identify survivors with elevated body fat percentage.

DESIGN

Cross-sectional, descriptive.

SETTING

Pediatric oncology program at a National Cancer Institute-designated comprehensive cancer center.

SAMPLE

48 childhood BMT survivors (27 males and 21 females).

METHODS

Measurements included dual-energy x-ray absorptiometry scan, height, weight, and physical activity. Descriptive statistics were reported and mixed-model linear regression models were used to describe findings and associations.

MAIN RESEARCH VARIABLES

Total body fat percentage and central obesity (defined as a ratio of central to peripheral fat of 1 or greater).

FINDINGS

Fifty-four percent of survivors had body fat percentages that exceeded recommendations for healthy body composition and 31% qualified as having central obesity. Previous treatment with total body irradiation was associated with higher body fat percentage and central obesity, and graft-versus-host disease was associated with lower body fat percentage. The body mass index (BMI) criteria did not correctly identify the BMT survivors who had elevated body fat percentage.

CONCLUSIONS

Survivors of childhood BMT are at risk for obesity and central obesity that is not readily identified with standard BMI criteria.

IMPLICATIONS FOR NURSING

Nurses caring for BMT survivors should include evaluation of general and central obesity in their assessments. Patient education materials and resources for healthy weight and muscle building should be made available to survivors. Research is needed to develop appropriate interventions.

Reliability and intermethod agreement for body fat assessment among two field and two laboratory methods in adolescents

To increase knowledge about reliability and intermethods agreement for body fat (BF) is of interest for assessment, interpretation, and comparison purposes. It was aimed to examine intra- and inter-rater reliability, interday variability, and degree of agreement for BF using air-displacement plethysmography (Bod-Pod), dual-energy X-ray absorptiometry (DXA), bioelectrical impedance analysis (BIA), and skinfold measurements in European adolescents. Fifty-four adolescents (25 females) from Zaragoza and 30 (14 females) from Stockholm, aged 13-17 years participated in this study. Two trained raters in each center assessed BF with Bod-Pod, DXA, BIA, and anthropometry (DXA only in Zaragoza). Intermethod agreement and reliability were studied using a 4-way ANOVA for the same rater on the first day and two additional measurements on a second day, one each rater. Technical error of measurement (TEM) and percentage coefficient of reliability (%R) were also reported. No significant intrarater, inter-rater, or interday effect was observed for %BF for any method in either of the cities. In Zaragoza, %BF was significantly different when measured by Bod-Pod and BIA in comparison with anthropometry and DXA (all P < 0.001). The same result was observed in Stockholm (P < 0.001), except that DXA was not measured. Bod-Pod, DXA, BIA, and anthropometry are reliable for %BF repeated assessment within the same day by the same or different raters or in consecutive days by the same rater. Bod-Pod showed close agreement with BIA as did DXA with anthropometry; however, Bod-Pod and BIA presented higher values of %BF than anthropometry and DXA.

Analysis of body composition methods in a community sample of African American women

The purposes of the authors in this study were: (1) to determine whether published body mass index and bioelectrical impedance analysis equations agreed with dual energy x-ray absorptiometry body fat percentage measures and (2) to estimate new body mass index and bioelectrical impedance analysis equations in a sample of African American women. Linear regression was used to determine how well 10 body mass index and bioelectrical impedance analysis equations reflected dual energy x-ray absorptiometry body fat percentage measures in this sample of 74 African American women; new body mass index and bioelectrical impedance analysis equations were created using dual energy x-ray absorptiometry body fat percentage measures as the dependent variable. Participants (M = 47.6 years, SD = 7.7) were classified as overweight or obese (BMI Mean BF% = 35.4, SD = 8.2; BIA Mean BF% = 43.3, SD = 6.9; DXA Mean BF% = 41.5, SD = 6.1). R(2) and SEE values indicated that all body mass index and bioelectrical impedance analysis equations were a poorer fit with less precision, and the new bioelectrical impedance analysis equation discussed in this article was a better fit and was more precise. All 10 body mass index and bioelectrical analysis equations inaccurately estimated dual energy x-ray absorptiometry body fat percentage measures in our sample. The new body mass index equation discussed in this article had less estimation bias and more precision than the published body mass index equations and may be a more accurate equation in African American women.

Body Mass Index Misclassification of Obesity among Community Police Officers

Occupational health nurses are at the forefront of obesity assessment and intervention and must be aware of potential inaccuracies of obesity measurement. The purpose of this study was to identify the prevalence of obesity among a sample of 84 male police officers 22 to 63 years old and determine the accuracy of body mass index (BMI) in estimating obesity compared to body fat percent (BF %). BMI identified 39.3% of the participants as obese, compared to 70.2% by BF %. BMI misclassified normal-weight officers as obese or overweight and obese officers as normal 48.8% ( n = 41) of the time. The two misclassified groups had similar average BMIs but significantly different BF %. BMI was not an accurate measure of obesity among adult males. BMI underestimated the true prevalence of obesity and could represent a missed opportunity for early intervention and disease prevention.

Body mass index misclassification of obesity among community police officers

Occupational health nurses are at the forefront of obesity assessment and intervention and must be aware of potential inaccuracies of obesity measurement. The purpose of this study was to identify the prevalence of obesity among a sample of 84 male police officers 22 to 63 years old and determine the accuracy of body mass index (BMI) in estimating obesity compared to body fat percent (BF %). BMI identified 39.3% of the participants as obese, compared to 70.2% by BF %. BMI misclassified normal-weight officers as obese or overweight and obese officers as normal 48.8% (n = 41) of the time. The two misclassified groups had similar average BMIs but significantly different BF %. BMI was not an accurate measure of obesity among adult males. BMI underestimated the true prevalence of obesity and could represent a missed opportunity for early intervention and disease prevention.

Longitudinal associations of adiposity with adult lung function in the Childhood Determinants of Adult Health (CDAH) study

Childhood BMI has been reported to be positively associated with adult lung function. The aim of this study was to investigate the effect of childhood BMI on young adult lung function independently of the effects of lean body mass (LBM). Clinical and questionnaire data were collected from 654 young Australian adults (aged 27-36 years), first studied when age 9, 12, or 15 years. Adult lung function was measured by forced vital capacity (FVC), forced expiratory volume in 1 s (FEV(1)), FEV(1)/FVC ratio, and the forced expiratory flow in the middle 50% of FVC (FEF(25-75)). BMI and LBM were derived from anthropometric measures at baseline (1985) and at follow-up (2004-2006). Multivariable models were used to investigate the effect of age and sex standardized BMI in childhood on adult lung function, before and after adjustment for LBM. Adult adiposity had a strong deleterious effect on lung function, irrespective of childhood BMI, and adjustment for childhood LBM eliminated any apparent beneficial effect of childhood BMI on adult FEV(1) or FVC. This suggests that the beneficial effect of increased BMI in childhood on adult FEV(1) and FVC observed in previous longitudinal studies is likely to be attributable to greater childhood LBM not adiposity. Obese children who become obese adults can expect to have poorer lung function than those who maintain healthy weight but large deficits in lung function are also likely for healthy weight children who become obese adults. This highlights the importance of lifetime healthy weight maintenance.

Comparisons of body-composition prediction accuracy: a study of 2 bioelectric impedance consumer devices in healthy Chinese persons using DXA and MRI as criteria methods

We compared the accuracy of body-composition estimation for 2 commercial single-frequency bioelectric impedance analysis (BIA) devices in 200 healthy Chinese adults using magnetic resonance imaging (MRI) and dual-energy X-ray absorptiometry (DXA) as criterion methods. We evaluated the fat mass percentage (%FM), skeletal muscle mass percentage (%SM), or total-body bone-free lean mass percentage (%TBBLM), and level of visceral fat mass (VF(level)) using the Omron HBF-359 (SF-BIA8) and Tanita BC-532 (SF-BIA4) BIA devices, MRI, and DXA. Both devices showed a similarly high correlation with DXA for %FM prediction (r=0.89 for SF-BIA8 and 0.90 for SF-BIA4) and with MRI and DXA for %SM and %TBBLM prediction (r=0.85 for SF-BIA8 and 0.89 for SF-BIA4). There were small but significant biases in all body-composition parameter evaluations except for %SM assessed by the SF-BIA8. Both the SF-BIA8 and SF-BIA4 provided small, insignificant mean biases but wide limits of agreement with MRI for VF(level) assessments. Both BIA devices can relatively accurately predict %FM and %SM in healthy Chinese adults. The SF-BIA8 is suitable for individual prediction of %SM, whereas the SF-BIA8 is required to eliminate systematic errors in this population by improving population-specific prediction equations from height, weight, and age to increase estimation accuracy.