Comparisons of obesity assessments in over-weight elementary students using anthropometry, BIA, CT and DEXA

Obesity and cardiovascular disease: Risk assessment, physical activity, and management of complications

The patient with obesity is at risk of developing cardiovascular disease and risk factors. Obesity negatively impacts prognosis and increases cardiovascular morbidity and mortality. Therefore, a comprehensive risk assessment is needed to define the cardiovascular risk of the patient and, thus, a tailored management and treatment. Chronic and successful management of these patients involves the evaluation of the various therapeutic strategies available (comprehensive lifestyle intervention, weight-loss medications, and bariatric surgery) and the diagnosis and treatment of cardiovascular complications (coronary artery disease, heart failure, and atrial fibrillation). Cardiac rehabilitation in patients with obesity is showing beneficial effect and a positive impact on weight loss, cardiovascular risk factors, mental health, functional capacity, and adherence to lifestyle interventions and pharmacological treatment. Long-term weight loss and maintenance represent a key objective during the management of the patient with obesity to reduce the risk of future adverse events. Multidisciplinary management and interventions are necessary to prevent and reduce overall cardiovascular risk and mortality. The aim of our review is to propose a comprehensive, critical and updated overview regarding risk assessment, physical activity, and the management of cardiovascular complications in patient with obesity.

Waist-height ratio and body mass index as indicators of obesity and cardiometabolic risk in Korean children and adolescents

PURPOSE

We assessed the clinical relevance of waist-height ratio (WHtR) as an indicator of cardiometabolic risk and body fat mass measured by dual-energy x-ray absorptiometry (DXA) among Korean children and adolescents.

METHODS

Data from 1,661 children and adolescents aged 10-18 years who participated in the Korea National Health and Nutrition Examination Survey were analyzed. Unadjusted Pearson correlation, age- and sex-adjusted Pearson correlation, and multiple linear regression analyses were performed to investigate the relationships between WHtR standard deviation score (SDS) and cardiometabolic risk factors, as well as DXA-assessed parameters.

RESULTS

WHtR SDS was correlated with cardiometabolic risk factors, including systolic blood pressure, glucose, total cholesterol, high-density lipoprotein cholesterol, triglyceride, and low-density lipoprotein cholesterol, as well as DXA-assessed parameters such as lean mass SDS, fat mass SDS, and fat mass percentage SDS in both whole body and trunk using an adjusted Pearson correlation analyses among all participants (p<0.001). WHtR SDS was strongly correlated with whole-body fat mass and trunk fat mass (r=0.792, p<0.001 and r=0.801, p<0.001, respectively) whereas WHtR SDS had a low correlation coefficient with whole-body lean mass and trunk lean mass SDS (r=0.512, p<0.001 and r=0.487, p<0.001, respectively). In multiple linear regression analyses, WHtR SDS was significantly associated with whole-body and trunk fat mass after adjustment for confounders.

CONCLUSION

Cardiometabolic risk factors and body fat mass assessed by DXA in Korean children and adolescents were highly correlated with WHtR. Additionally, WHtR has an advantage in distinguishing fat-free mass. WHtR can be a useful and convenient clinical indicator of cardiometabolic risk factors.

Association of lower limb ischemia with loss of skeletal muscle mass in patients with peripheral artery disease

PURPOSE

The influence of lower limb ischemia on the loss of skeletal muscle mass, which is a prerequisite for sarcopenia, remains poorly studied in patients with peripheral artery disease (PAD). We determined whether or not lower limb ischemia correlates with a loss of skeletal muscle mass in patients with PAD.

METHODS

The data of 101 patients (202 legs) with PAD were retrospectively analyzed. Body composition was measured using a bioelectrical impedance analysis. Based on the Asian Working Group for Sarcopenia, low muscle mass (LMM) was defined as skeletal muscle mass index (SMI) < 7.00 kg/m² (male) and < 5.70 kg/m² (female). Both univariable and multivariable analyses of the risk factors for LMM were performed.

RESULTS

There were significant differences in age, ankle-brachial pressure index (ABI) per patient, and the geriatric nutritional risk index (GNRI), between patients with and without LMM. Multivariable logistic regression analysis showed age (odds ratio [OR], 1.09; p = 0.009), GNRI (OR, 0.93; p = 0.003), and ABI per patient (OR, 0.02; p = 0.027) as independent risk factors for LMM.

CONCLUSION

These data show a detrimental effect of lower limb ischemia on skeletal muscle mass loss, suggesting that PAD may affect the development of secondary sarcopenia.

From culture to chromosomes: A mother-child dyadic study of acculturation, telomere lengths and body fat

Studies suggest that telomere lengths, a biomarker of aging, could also capture the physiological weathering attributable to poor health behaviors and adverse experiences, particularly those experienced in early life. For these reasons, we propose that telomere lengths may be a pivotal biomarker for measuring the heightened susceptibility to illness resulting from the cumulative exposure to acculturation to the US culture. This binational study used an Actor–Partner Interdependence Model to test if maternal acculturation to the US moderates the cross-sectional associations of telomere lengths with percentage of body fat (PBF) among Mexican women, among their children, and the intergenerational associations of mother and children telomere lengths with each other’s PBF. Low income Mexican child–mother dyads (n ​= ​108 dyads) were recruited to participate in this cross-sectional study in Mexico and the US. The pooled dataset included measurements of maternal acculturation to the US, mother and children’s salivary telomere lengths, PBF measured through bioelectrical impedance, and demographic characteristics. Results showed that the influences of maternal acculturation in the associations of telomere lengths with PBF were different for mothers and their children: Among mothers with higher maternal acculturation to the US, longer salivary telomere lengths were associated with lower PBF. In contrast, among mothers with lower maternal acculturation to the US, salivary telomere lengths were not associated with PBF. There were no significant associations between children’s salivary telomere lengths and PBF, and the null associations did not vary across different levels of maternal acculturation to the US. Future longitudinal studies are needed to determine whether acculturation to the US (experienced through immigration or remotely) influences the association of telomere length attrition with obesity risks among immigrant and non-immigrant Mexican children and adults.

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Women’s acculturation to the US modified the association of their TL with body fat.

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In mothers with high acculturation to the US, longer TL associated with higher body fat.

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In mothers with low acculturation to the US, TL were not associated with body fat.

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We found no evidence of intergenerational associations between TL and body fat.

Comparison of Multi-Frequency Bioelectrical Impedance and Dual-Energy X-Ray Absorptiometry to Assess Body Composition in College-Aged Adults

The purpose of this study was to evaluate the validity of whole body percent fat (%BF) and segmental fat-free mass (FFM) using multi-frequency bioelectrical impedance analysis (MF-BIA) and dual-energy x-ray absorptiometry (DEXA) in college-aged adults. Sixty-two participants male (n = 32) and female (n = 30) completed MF-BIA and DEXA measurements following established pre-test guidelines. %BF and segmental FFM (right arm, left arm, trunk, right leg, and left leg) were collected and analyzed. The MF-BIA significantly (p < 0.05) underestimated %BF for all participants, females, and males compared to DEXA. In addition, MF-BIA significantly (p < 0.05) underestimated FFM in the arms and legs in all participants and males with the exception of the left arm in all subjects while significantly overestimating FFM in the trunk. In females, the MF-BIA overestimated FFM in the arms and trunk while significantly (p < 0.05) underestimating FFM in the legs. Difference plots also indicated that the underestimation of FFM from MF-BIA in the arms and legs increased as the amount of FFM increased. Thus, our findings suggested that the MF-BIA may not be accurate for measuring whole %BF and segmental FFM in the college-aged population.

A multidisciplinary weight loss intervention in obese adolescents with and without sleep-disordered breathing improves cardiometabolic health, whether SDB was normalized or not

OBJECTIVES

Pediatric obesity and sleep-disordered breathing (SDB) are strongly associated, and both promote metabolic impairments. However, the effects of a lifestyle intervention on the overall metabolic syndrome (MetS) are unknown. The objectives were i) to evaluate the effects of a lifestyle intervention on cardiometabolic risk (CMR), assessed with a dichotomous (MetS) and a continuous (MetScore_FM) instrument, in obese adolescents with and without SDB and ii) to compare the post-intervention cardiometabolic responses between adolescents with persistent (apnea-hypopnea index; AHI≥2) or normalized-SDB (AHI<2).

METHODS

Seventy-six adolescents with obesity recruited from two specialized institutions underwent a 9-12month diet and exercise intervention. Sleep and SDB (AHI≥2) were studied by polysomnography. Anthropometric parameters, fat mass (FM), glucose, insulin, lipid and leptin profiles, blood pressure (BP), MetScore_FM and MetS were assessed pre- and post-intervention. We performed comparisons between Non-SDB and SDB groups and between Normalized-SDB and Persistent-SDB subgroups.

RESULTS

Fifty participants completed the study. Pre-intervention, twenty youth had SDB (40%) with higher insulin concentrations and systolic BP than Non-SDB participants (p < 0.01), for a similar degree of obesity. Post-intervention, MetScore_FM (p < 0.001) and MetS prevalence (p < 0.05) were decreased in both groups. Eleven participants (55%) normalized SDB along with a decrease in insulin concentrations and BP (p < 0.05). Triglycerides, total cholesterol and LDL-cholesterol concentrations (p < 0.01) improved equally in the Normalized and Persistent-SDB subgroups.

CONCLUSION

SDB was associated with lower insulin sensitivity and higher BP but did not affect the lipid profile. A diet and exercise lifestyle intervention is effective in decreasing the CMR whether or not SDB was normalized in obese adolescents.

Sleep-disordered breathing in adolescents with obesity: When does it start to affect cardiometabolic health?

BACKGROUND AND AIMS

Pediatric obesity and sleep-disordered breathing (SDB) are associated with cardiometabolic risk (CMR), but the degree of severity at which SDB affects cardiometabolic health is unknown. We assessed the relationship between the CMR and the apnea-hypopnea index (AHI), to identify a threshold of AHI from which an increase in the CMR is observed, in adolescents with obesity. We also compared the clinical, cardiometabolic and sleep characteristics between adolescents presenting a high (CMR+) and low CMR (CMR-), according to the threshold of AHI.

METHODS AND RESULTS

114 adolescents with obesity were recruited from three institutions specialized in obesity management. Sleep and SDB as assessed by polysomnography, anthropometric parameters, fat mass (FM), glucose and lipid profiles, and blood pressure (BP) were measured at admission. Continuous (MetScore_FM) and dichotomous (metabolic syndrome, MetS) CMR were determined. Associations between MetScore_FM and AHI adjusted for BMI, sex and age were assessed by multivariable analyses. Data of 82 adolescents were analyzed. Multivariable analyses enabled us to identify a threshold of AHI = 2 above which we observed a strong and significant association between CMR and AHI (Cohen's d effect-size = 0.57 [0.11; 1.02] p = 0.02). Adolescents with CMR+ exhibited higher MetScore_FM (p < 0.05), insulin resistance (p < 0.05), systolic BP (p < 0.001), sleep fragmentation (p < 0.01) and intermittent hypoxia than CMR- group (p < 0.0001). MetS was found in 90.9% of adolescents with CMR+, versus 69.4% in the CMR- group (p < 0.05).

CONCLUSIONS

The identification of a threshold of AHI ≥ 2 corresponding to the cardiometabolic alterations highlights the need for the early management of SDB and obesity in adolescents, to prevent cardiometabolic diseases.

CLINICAL TRIALS

NCT03466359, NCT02588469 and NCT01358773.

Application of body composition zones in boys with nonalcoholic fatty liver disease

PURPOSE

Screening nonalcoholic fatty liver disease (NAFLD) by body mass index (BMI) as a single surrogate measure for obesity has limitations. We suggest considering body composition zones by drawing a body composition chart composed of body composition indices, including BMI and percent body fat (PBF), to visualize the risk of NAFLD in obese children and adolescents.

METHODS

Thirty-eight boys diagnosed with NAFLD were selected retrospectively from patients who visited Konkuk University Medical Center from 2006 to 2015. They had gone through body composition analysis by bioelectrical impedance analysis (BIA), and biochemical analyses, including a liver function test (LFT) and lipid panel, were performed. Fat-free mass index (FFMI) and fat mass index (FMI) were calculated from body composition analysis and height. We plotted FFMI and FMI of patients on a body composition chart and classified the patients into zones A to D. In addition, we analyzed the correlations between LFT, lipid panel, and body composition indices.

RESULTS

Thirty-three of 38 boys (86.8%) were located in zone C, corresponding to high BMI and PBF. Four boys (10.5%) were located in zone D, which correlates with sarcopenic obesity. One boy located in zone B was a muscular adolescent. Alanine aminotransferase level was positively correlated with PBF, FMI, and BMI z-score.

CONCLUSION

Body composition zones on a body composition chart might be useful in risk assessment in obesity-related diseases such as NAFLD. Zones on a body composition chart could have practical applications, especially in sarcopenic obese children and adolescents.

Changes in Physical Activities and Body Composition after Roux-Y Gastric Bypass Surgery

PURPOSE

Given the importance of physical activities for health outcomes, it is still unclear whether bariatric surgery per se and the standard care after surgery would result in an increase of physical activity level. This study aimed to determine physical activities preoperatively and at 6 and 12 months postoperatively among female patients who underwent bariatric surgery, and to investigate its relationship with body composition changes.

MATERIAL AND METHODS

Thirty-four women who had Roux-Y gastric bypass (RYGB) surgery completed the study. Physical activity was measured objectively for 7 consecutive days by using an ActiGraph GT3X+ accelerometer. Body composition was estimated by using multifrequency bioimpedance analysis.

RESULTS

The percentage of time spent in moderate-to-vigorous physical activity (MVPA) changed significantly from preoperatively to 6 months postoperatively; however, no difference was observed at 12 months. No significant changes were detected for other physical activity variables. Multivariable regression analysis suggested that the percentage of time spent in sedentary activity was associated with fat-free mass loss at 6 months (β = - 0.323; 95% CI = - 0.649 to 0.003) and 12 months (β = - 0.510; 95% CI = - 0.867 to - 0.154) postoperatively.

CONCLUSION

The overall MVPA increased at 6 months post-RYGB surgery; however, this change was not maintained at 12 months. Despite the considerable body mass loss postoperatively, most of the subjects were classified as being physically inactive and did not change their sedentary behavior. These findings indicate that female patients undergoing bariatric surgery should be encouraged to increase their physical activity level.

Clinically relevant body composition methods for obese pediatric patients

BACKGROUND

There is no gold standard in body composition measurement in pediatric patients with obesity. Therefore, the aim of this study was to investigate if there are any differences between two bioelectrical impedance analysis techniques performed in children and adolescents with obesity.

METHODS

Data were collected at the Department of Pediatrics and Adolescent Medicine in Vienna from September 2015 to May 2017. Body composition measurement was performed with TANITA scale and BIA-BIACORPUS.

RESULTS

In total, 38 children and adolescents (age: 10-18 years, BMI: 25-54 kg/m2) were included. Boys had significantly increased fat free mass (TANITA p = 0.019, BIA p = 0.003), total body water (TANITA p = 0.020, BIA p = 0.005), and basal metabolic rate (TANITA p = 0.002, BIA p = 0.029). Girls had significantly increased body fat percentage with BIA (BIA p = 0.001). No significant gender differences of core abdominal area have been determined. TANITA overestimated body fat percentage (p < 0.001), fat mass (p = 0.002), and basal metabolic rate (p < 0.001) compared to BIA. TANITA underestimated fat free mass (p = 0.002) in comparison to BIA. The Bland Altman plot demonstrated a low agreement between the body composition methods.

CONCLUSIONS

Low agreement between TANITA scale and BIA-BIACORPUS has been observed. Body composition measurement should always be performed by the same devices to obtain comparable results. At clinical routine due to its feasibility, safety, and efficiency, bioelectrical impedance analysis is appropriate for obese pediatric patients.

TRIAL REGISTRATION

ClinicalTrials NCT02545764 . Registered 10 September 2015.

Assessment of resting energy expenditure and body composition in Japanese pregnant women with diabetes

AIMS/INTRODUCTION

To measure longitudinal changes in resting energy expenditure and body composition of Japanese pregnant women with or without diabetes.

MATERIALS AND METHODS

The study population consisted of women who had delivered a live singleton neonate after 22 weeks' gestation at Okayama University Hospital from July 2013 to June 2017. Resting energy expenditure and body composition were measured in the first trimester, second trimester, third trimester and postpartum.

RESULTS

A total of 144 women participated in this study: 103 with normal glucose tolerance and 41 with diabetes. The resting energy expenditure (kcal/day) of pregnant women with normal glucose tolerance was significantly higher in the third trimester (1,644 ± 234) than in the first (1,461 ± 215) and second trimesters (1,491 ± 219), and postpartum (1,419 ± 254), whereas that of pregnant women with diabetes did not significantly change during all periods (1,568 ± 404, 1,710 ± 332, 1,716 ± 251, 1,567 ± 249). The resting energy expenditure of women with good glycemic control was lower than that of women with poor control. Fat-free mass was closely correlated with resting energy expenditure.

CONCLUSIONS

The resting energy expenditure of Japanese pregnant women with normal glucose tolerance was significantly increased in the third trimester. The resting energy expenditure of women with good glycemic control was lower than that of women with poor control. Resting energy expenditure and fat-free mass are potential indexes for medical nutrition therapy in pregnant women with diabetes.

Performance of Two Bioelectrical Impedance Analyses in the Diagnosis of Overweight and Obesity in Children and Adolescents: The FUPRECOL Study

This study aimed to determine thresholds for percentage of body fat (BF%) corresponding to the cut-off values for overweight/obesity as recommended by the International Obesity Task Force (IOTF), using two bioelectrical impedance analyzers (BIA), and described the likelihood of increased cardiometabolic risk in our cohort defined by the IOTF and BF% status. Participants included 1165 children and adolescents (54.9% girls) from Bogotá (Colombia). Body mass index (BMI) was calculated from height and weight. BF% of each youth was assessed first using the Tanita BC-418^® followed by a Tanita BF-689^®. The sensitivity and specificity of both devices and their ability to correctly classify children as overweight/obesity (≥2 standard deviation), as defined by IOTF, was investigated using receiver operating characteristic (ROC) by sex and age groups (9–11, 12–14, and 13–17 years old); Area under curve (AUC) values were also reported. For girls, the optimal BF% threshold for classifying into overweight/obesity was found to be between 25.2 and 28.5 (AUC = 0.91–0.97) and 23.9 to 26.6 (AUC = 0.90–0.99) for Tanita BC-418^® and Tanita BF-689^®, respectively. For boys, the optimal threshold was between 16.5 and 21.1 (AUC = 0.93–0.96) and 15.8 to 20.6 (AUC = 0.92–0.94) by Tanita BC-418^® and Tanita BF-689^®, respectively. All AUC values for ROC curves were statistically significant and there were no differences between AUC values measured by both BIA devices. The BF% values associated with the IOTF-recommended BMI cut-off for overweight/obesity may require age- and sex-specific threshold values in Colombian children and adolescents aged 9–17 years and could be used as a surrogate method to identify individuals at risk of excess adiposity.

Changes in body composition and growth pattern after adenotonsillectomy in prepubertal children

OBJECTIVE

Adenotonsillar hypertrophy and chronic tonsillitis are associated with growth interruption during childhood, while adenotonsillectomy has been associated with growth improvement and increased body mass index (BMI). However, no reported study has investigated the effect of adenotonsillectomy on the proportion of body muscle and fat mass. The aim of this prospective study was to evaluate the effect of adenoidectomy and adenotonsillectomy on body muscle and fat composition in prepubertal children.

METHODS

Thirty prepubertal children (22 boys, 8 girls; 3-9 years of age) were followed up for 6 months after adenoidectomy or adenotonsillectomy. Twenty-eight age-matched healthy children (12 boys, 16 girls) were followed for the same period, as controls. Data on dietary habits and physical activity were obtained from parent-completed questionnaires at baseline and 6 months. Height and weight z-scores, the amount and percentage of body fat and muscle mass, BMI z-scores, relative BMI and basal metabolic rate were evaluated before and 6 months after surgery with bioelectrical impedance analysis.

RESULTS

After 6 months, body muscle mass and basal metabolic rate scores were significantly higher than at baseline in both groups (P<0.05). The rate of increase was not different between the groups. In the study group, the relative BMI scores improved significantly (P<0.05). Increases in body fat mass, body fat percentage, height z-scores, weight z-scores and BMI z-scores were not significantly different between the groups at 6 months (P>0.05). The number of overweight and obese children did not change significantly in either group (P<0.05).

CONCLUSIONS

Adenotonsillectomy led to improvement in relative BMI and promoted healthy weight gain without increased body fat percentage in prepubertal children.

The relationships between body composition characteristics and cognitive functioning in a population-based sample of older British men

Background

Current research has established obesity as one of the main modifiable risk factors for cognitive impairment. However, evidence on the relationships of total and regional body composition measures as well as sarcopenia with cognitive functioning in the older population remains inconsistent.

Methods

Data are based on 1,570 participants from the British Regional Heart Study (BRHS), a cohort of older British men from 24 British towns initiated in 1978–80, who were re-examined in 2010–12, aged 71–92 years. Cognitive functioning was assessed with the Test-Your-Memory cognitive screening tool. Body composition characteristics assessed using bioelectrical impedance analysis included total fat mass (FM), central FM, peripheral FM, and visceral fat level. Sarcopenia was defined using the European Working Group on Sarcopenia in Older People (EWGSOP) definition of severe sarcopenia and the Foundation for the National Institutes of Health (FNIH) sarcopenia project criteria.

Results

Among 1,570 men, 636 (41 %) were classified in the mild cognitive impairment (MCI) and 133 (8 %) in the severe cognitive impairment (SCI) groups. Age-adjusted multinomial logistic regressions showed that compared with participants in the normal cognitive ageing group, those with SCI were more likely to have waist circumference >102 cm, BMI >30 kg/m², to be in the upper quintile of total FM, central FM, peripheral FM and visceral fat level and to be sarcopenic. The relationships remained significant for total FM (RR = 2.16, 95 % CI 1.29–3.63), central FM (RR = 1.85, 95 % CI 1.09–3.14), peripheral FM (RR = 2.67, 95 % CI 1.59–4.48), visceral fat level (RR = 2.28, 95 % CI 1.32–3.94), BMI (RR = 2.25, 95 % CI 1.36–3.72) and waist circumference (RR = 1.63, 95 % CI 1.05–2.55) after adjustments for alcohol, smoking, social class, physical activity and history of cardiovascular diseases or diabetes. After further adjustments for interleukin-6 and insulin resistance, central FM, waist circumference and sarcopenia were no longer significantly associated with SCI.

Conclusions

Increased levels of peripheral FM, visceral fat level, and BMI are associated with SCI among older people. Distinct pathophysiological mechanisms link regional adipose tissue deposition and cognitive functioning.

Validity of Four Commercial Bioelectrical Impedance Scales in Measuring Body Fat among Chinese Children and Adolescents

The aim of the study is to examine the validity in predicting body fat percentage (%BF) of different bioelectrical impedance (BIA) devices among Chinese children and adolescents. A total of 255 Chinese children and adolescents aged 9-19 years old participated in the study. %BF was assessed by BIA scales, namely, Biodynamics-310 (Model A), Tanita TBF-543 (Model B), Tanita BC-545 (Model C), and InBody 520 (Model D). Dual-energy X-ray absorptiometry (DXA) was used as the criterion measurement. Lin's concordance correlation coefficients of estimated %BF between Model A, Model B, Model C, and DXA showed poor agreements for both genders. Moderate agreements for %BF were found between DXA and Model D measurements. In boys, differences in %BF were found between DXA and Model B and Model C. No significant %BF differences were found between Model A, Model D, and DXA. However, the two BIA analyzers showed a significant positive correlation between the bias and average %BF between BIA and DXA. In girls, differences in %BF were observed between Model B, Model C, Model D, and DXA. Model A and DXA showed no significant differences of %BF; however, the bias and the average %BF between the BIA and DXA had a significant positive correlation. Using embedded equations in BIA devices should be validated in assessing the %BF of Chinese children and adolescents.

Should visceral fat, strictly linked to hepatic steatosis, be depleted to improve survival?

Numerous epidemiologic studies have implicated abdominal obesity as a major risk factor for insulin resistance, type 2 diabetes mellitus, cardiovascular disease, stroke, metabolic syndrome and its further expression, i.e., nonalcoholic fatty liver disease and death. Using novel models of visceral obesity, several studies have demonstrated that the relationship between visceral fat and longevity is causal, while the accrual of subcutaneous fat does not appear to play an important role in the etiology of disease risk. The need of reducing the visceral fat to improve survival, mainly taking into account the strict link between nonalcoholic fatty liver disease and the coronary artery disease is discussed.

How to estimate fat mass in overweight and obese subjects

Background. The prevalence of overweight and obesity is increasing and represents a primary health concern. Body composition evaluation is rarely performed in overweight/obese subjects, and the diagnosis is almost always achieved just considering body mass index (BMI). In fact, whereas BMI can be considered an important tool in epidemiological surveys, different papers stated the limitations of the use of BMI in single individuals. Aim. To assess the determinants of body composition in overweight and obese subjects. Methods. In 103 overweight or obese subjects (74 women, aged 41.5 ± 10 years, and 29 men, aged 43.8 ± 8 years), a multidimensional evaluation was performed including the assessment of body composition using Dual Energy X-Ray Absorptiometry (DXA), anthropometry, bioimpedance analysis (BIA), and biochemical parameters (total cholesterol, triacylglycerol, HDL- and LDL-cholesterol, free fatty acids and glycerol, glucose, insulin, C-reactive protein, plasma acylated and unacylated ghrelin, adiponectin, and leptin serum levels). Results. BMI does not represent the main predictor of FM estimated by DXA; FM from BIA and hip circumference showed a better association with FM from DXA. Moreover, models omitting BMI explained a greater part of variance. These data are confirmed by the predictive value analysis where BMI showed a performance similar to a "coin flip."

Obesity and its diagnostic methods in Turkish children

OBJECTIVE

The application of body mass index (BMI) for obesity classification in all population studies has been questioned by the scientific community. It has been found that the bioelectrical impedance analysis (BIA) is an accurate method for screening obesity. This study was conducted to evaluate the accuracies of BMI, skinfold thickness (SFT), leptin and BIA measurements in obesity classification and to find correlations between BIA and the other indicators for obesity.

MATERIALS AND METHODS

This case-control study included 178 children of whom 90 were in the obese group and 88 in the control group. The study measured BMI, SFT, leptin level and BIA-mediated body fat percentage (BIA BFP) in each child.

RESULTS

The BMIs, leptin levels, SFTs and BIA BFPs of children in the obese group were found to be higher than those in the control group (p<0.001). The measurement of BIA BFP strongly correlated with BMI, SFT and waist circumference, whereas BIA BFP measurement showed weak-moderate correlation with leptin level.

CONCLUSION

Bioelectrical impedance analysis was found to be an accurate measure of BFP in obesity. In addition, BIA may prevent the incorrect diagnosis of obesity as determined by BMI alone, especially in boys during the pubertal period.

Does body mass index accurately reflect body fat? A comparison of anthropometric measures in the longitudinal assessment of fat mass

OBJECTIVE

To determine which anthropometric measure best correlates with change in fat mass (FM) over time.

METHODS

The authors performed a retrospective cohort study of 76 obese patients (mean body mass index [BMI] 38 kg/m(2) and mean age 13 years) presenting to an obesity clinic between 2005 and 2010. For each patient, during 2 visits, FM was measured by bioelectrical impedance analysis and the following measures obtained: BMI, waist circumference, hip circumference, and neck circumference. Correlation coefficients and linear regression analyses were calculated to examine the relationship between each measure and FM.

RESULTS

Change in BMI correlated better with change in FM than any other measure and had the strongest effect on change in FM (P < .01, R (2) = .887). The best regression model included BMI only (R (2) = .891); without BMI, the model was significantly worse (R (2) = .521).

DISCUSSION

In the clinical management of obese children, BMI is an adequate measure of change in FM.