The validity of predicted body fat percentage from body mass index and from impedance in samples of five European populations

Cardiometabolic risk stratification using a novel obesity phenotyping system based on body adiposity and waist circumference

BACKGROUND

The estimation of obesity-associated cardiometabolic risk does not usually take into account body composition or the distribution of adiposity. The aim of the present study was to assess the clinical usefulness of a novel obesity phenotyping system based on the combination of actual body fat percentage (BF%) and waist circumference (WC) according to the cardiometabolic risk estimation.

METHODS

A classification matrix combining BF% and WC as measures of both amount and distribution of adiposity establishing nine body phenotypes (3 BF% x 3 WC) was developed. Individuals were grouped in five different cardiometabolic risk phenotypes. We conducted a validation study in a large cohort of White subjects from both genders representing a wide range of ages and adiposity (n = 12,754; 65 % females, aged 18-88 years).

RESULTS

The five risk groups using the matrix combination of BF% and WC exhibited a robust linear distribution regarding cardiometabolic risk, estimated by the Metabolic Syndrome Severity Score, showing a continuous increase between groups with significant differences (P < 0.001) among them, as well as in other cardiometabolic risk factors. An additional 24 % of patients at very high risk was detected with the new classification system proposed (P < 0.001) as compared to an equivalent matrix using BMI and WC instead of BF% and WC.

CONCLUSIONS

A more detailed phenotyping should be a priority in the diagnosis and management of patients with obesity. Our classification system allows to gradually estimate the cardiometabolic risk according to BF% and WC, thus representing a novel and useful tool for both research and clinical practice.

Impact of body fat location and volume on incisional hernia development and its outcomes following repair

BACKGROUND

Obesity is known to increase the likelihood of developing abdominal wall hernias, body mass index (BMI) alone does not provide detailed information about the amount and location of body fat. The aim of this study was to investigate the link between various adipose tissue parameters and the incidence of incisional hernias (IHs), as well as the outcomes of hernia repair.

METHODS

We conducted a comprehensive review of the existing literature to examine the relationship between various body fat parameters and the occurrence of IHs after abdominal surgeries, as well as the outcomes of hernia repair.

RESULTS

Thirteen studies were included for analysis. Eight trials evaluated the IH development after abdominal surgeries via specific fat parameters, and five studies evaluated the postoperative outcomes after IH repair. The findings of this study suggest that an increase in visceral fat volume (VFA or VFV) and subcutaneous fat (SFA or SFV) are linked to a higher incidence of IHs after abdominal surgeries. Higher levels of VFV or VFA were associated with more challenging fascia closure and greater postoperative recurrence rates following repair. Whereas BMI did not demonstrate a significant association.

CONCLUSION

Measuring visceral and subcutaneous fat composition preoperatively can be a useful tool for assessing the risk of IH, and is more reliable than BMI. Elevated levels of these fat parameters have been linked to increased recurrence of IH following hernia repair, as well as the use of complex surgical techniques during repair.

Patient-Level and Center-Level Factors Associated with Required Predonation Weight Loss among Obese Living Kidney Donors

Key Points

Among obese living kidney donors, year of donation, preoperative body mass index, hypertension, and center percent of living kidney donor transplants were associated with required predonation weight loss. There were no significant differences in the likelihood of predonation weight loss requirement by race, sex, or age or by markers of preoperative metabolic dysfunction.

Background

The proportion of overweight/mildly obese living kidney donors (OLKDs) has increased in the past few decades, with significant center variation in the body mass index (BMI) of LKDs. The purpose of this study was to examine factors associated with required predonation weight loss among OLKDs (BMI, ≥30 kg/m2).

Methods

This retrospective cohort study surveyed 1097 OLKDs (1979–2020) (mean BMI, 33 kg/m2) about their donation experience. Bivariate analyses compared donor demographic and center characteristics by whether the donor reported predonation weight loss requirement. Generalized estimating equations with logit link were used to estimate marginal effects of patient-level and center-level factors. Multiple imputation using chained equations was implemented to account for missing values.

Results

Of 1097 OLKDs surveyed, 340 (31.0%) reported predonation weight loss requirement. Donors with a predonation weight loss requirement had slightly higher predonation BMIs and donated in more recent years at centers performing a lower percentage of living donor nephrectomies and with a lower median BMI. In multivariable logistic regression analysis, we observed transplant year (odds ratio [OR], 1.04 per year donation; 95% confidence interval [CI], 1.01 to 1.07; P = 0.005), preoperative BMI (OR, 1.16; 95% CI, 1.05 to 1.28; P < 0.01), preoperative hypertension (OR, 1.61; 95% CI, 1.08 to 2.40; P = 0.02), and center percentage of living donor kidney transplants (OR, 0.99; 95% CI, 0.98 to 1.00; P = 0.02) as significantly associated with a predonation weight loss requirement. The study found no differences in the likelihood of predonation weight loss requirement by race, sex, age, preoperative creatinine, preoperative metabolic dysfunction, or center-level median BMI of living donors.

Conclusions

These results suggest that both center-level and patient-level factors influence whether OLKDs are required to lose weight before donation. Future study is needed to determine whether predonation weight loss is associated with improved long-term postdonation outcomes.

Obesity, Physical Performance, Balance Confidence, and Falls in Community-Dwelling Older Adults: Results from the Korean Frailty and Aging Cohort Study

Obesity affects physical functions in numerous ways. We aimed to evaluate the association between obesity and falls, physical performance, and balance confidence in community-dwelling older adults. Using first-year baseline data from the Korean Frailty and Aging Cohort Study, 979 older adults were included. General obesity was defined based on the body mass index and body fat percentage, whereas central obesity was classified based on the waist circumference and waist-to-height ratio. Data regarding fall history and balance confidence were acquired using self-questionnaires, and a timed up-and-go test was performed to measure balance-related physical performance. Overall, 17.3% of participants experienced falls in the previous year. Central obesity, as determined by waist circumference (odds ratio, 1.461; 95% confidence interval, 1.024-2.086; p-value, 0.037) and by waist-to-height ratio (odds ratio, 1.808; 95% confidence interval, 1.015-3.221; p-value, 0.044) was significantly associated with falls. Interestingly, general obesity, measured by body fat percentage, was protective against fall-related fractures (odds ratio, 0.211; 95% confidence interval, 0.072-0.615; p-value, 0.004). Participants with central obesity had poorer physical performances in the timed up-and-go test (odds ratio, 2.162; 95% confidence interval, 1.203-3.889; p-value, 0.010) and lower balance confidence according to the Activities-specific Balance Confidence scale (odds ratio, 1.681; 95% confidence interval, 1.153-2.341; p-value 0.007). In conclusion, assessment of central obesity, particularly waist circumference, should be considered as a screening strategy for falls, and older adults with a high waist circumference should receive advice on fall prevention.

Update of the risk assessment of polybrominated diphenyl ethers (PBDEs) in food

The European Commission asked EFSA to update its 2011 risk assessment on polybrominated diphenyl ethers (PBDEs) in food, focusing on 10 congeners: BDE-28, -47, -49, -99, -100, -138, -153, -154, -183 and ‑209. The CONTAM Panel concluded that the neurodevelopmental effects on behaviour and reproductive/developmental effects are the critical effects in rodent studies. For four congeners (BDE-47, -99, -153, -209) the Panel derived Reference Points, i.e. benchmark doses and corresponding lower 95% confidence limits (BMDLs), for endpoint-specific benchmark responses. Since repeated exposure to PBDEs results in accumulation of these chemicals in the body, the Panel estimated the body burden at the BMDL in rodents, and the chronic intake that would lead to the same body burden in humans. For the remaining six congeners no studies were available to identify Reference Points. The Panel concluded that there is scientific basis for inclusion of all 10 congeners in a common assessment group and performed a combined risk assessment. The Panel concluded that the combined margin of exposure (MOET) approach was the most appropriate risk metric and applied a tiered approach to the risk characterisation. Over 84,000 analytical results for the 10 congeners in food were used to estimate the exposure across dietary surveys and age groups of the European population. The most important contributors to the chronic dietary Lower Bound exposure to PBDEs were meat and meat products and fish and seafood. Taking into account the uncertainties affecting the assessment, the Panel concluded that it is likely that current dietary exposure to PBDEs in the European population raises a health concern.

Relationships between body composition, anthropometrics, and standard lipid panels in a normative population

Introduction

More than one third of adults in the United States (US) meet the clinical criteria for a diagnosis of metabolic syndrome, but often diagnosis is challenging due to healthcare access, costs and discomfort with the process and invasiveness associated with a standard medical examination. Less invasive and more accessible approaches to collecting biometric data may have utility in identifying individuals at risk of diagnoses, such as metabolic syndrome or dyslipidemia diagnoses. Body composition is one such source of biometric data that can be non-invasively acquired in a home or community setting that may provide insight into an individual's propensity for a metabolic syndrome diagnosis. Here we investigate possible associations between body composition, anthropometrics and lipid panels in a normative population.

Methods

Healthy participants visited the Lab100 clinic location at a hospital setting in New York City and engaged in a wellness visit led by a nurse practitioner. Blood was analyzed at point-of-care using the Abbott Piccolo Xpress portable diagnostic analyzer (Abbott Laboratories, IL, USA) and produced direct measures of total cholesterol (TC), high density lipoprotein (HDL-C), low density lipoprotein (LDL-C), very-low density lipoprotein (VLDL-C), and triglycerides (TG). Body composition and anthropometric data were collected using two separate pieces of equipment during the same visit (Fit3D and InBody570). Regression analysis was performed to evaluate associations between all variables, after adjusting for age, sex, race, AUDIT-C total score (alcohol use), and current smoking status.

Results

Data from 199 participants were included in the analysis. After adjusting for variables, percentage body fat (%BF) and visceral fat levels were significantly associated with every laboratory lipid value, while waist-to-hip ratio also showed some significant associations. The strongest associations were detected between %BF and VLDL-C cholesterol levels (t = 4.53, p = 0.0001) and Triglyceride levels (t = 4.51, p = 0.0001).

Discussion

This initial, exploratory analysis shows early feasibility in using body composition and anthropometric data, that can easily be acquired in community settings, to identify people with dyslipidemia in a normative population.

Relevance of body composition in phenotyping the obesities

Obesity is the most extended metabolic alteration worldwide increasing the risk for the development of cardiometabolic alterations such as type 2 diabetes, hypertension, and dyslipidemia. Body mass index (BMI) remains the most frequently used tool for classifying patients with obesity, but it does not accurately reflect body adiposity. In this document we review classical and new classification systems for phenotyping the obesities. Greater accuracy of and accessibility to body composition techniques at the same time as increased knowledge and use of cardiometabolic risk factors is leading to a more refined phenotyping of patients with obesity. It is time to incorporate these advances into routine clinical practice to better diagnose overweight and obesity, and to optimize the treatment of patients living with obesity.

Prediction of body fat percentage: Development and validation of new anthropometric equations

INTRODUCTION

The aim of this study was to test the validity of existing equations, retrieved from the literature, in the Algerian adult population. To develop, and validate, new predictive equations for body fat percentage (%BF) using simple and easy-to-measure anthropometric parameters.

METHODS

This is a cross-sectional study including 877 Algerian adults who underwent a body composition assessment by the direct segmental multi-frequency bioelectrical impedance technique (Inbody-770). Participants were randomly divided into two groups: the development group (n = 577) and the validation group (n = 300). To develop the equations, multiple linear regression models were analyzed. The predictive performance of the developed equations was compared with the direct technique. The following validation tests were used: Student's t-test for paired samples, correlation, and Bland-Altman diagram. Diagnostic accuracy has also been assessed.

RESULTS

Four existing equations were tested, and all showed statically significant bias. Four new equations were developed; all had satisfactory predictive performance, with a correlation coefficient ranging from 0.72 to 0.94 in men and 0.87 to 0.93 in women. The best-fitting equation was based on body mass index, waist-to-hip ratio, and chest circumference. The diagnostic accuracy of this equation was 96.7% in men and 95.3% in women.

CONCLUSION

The newly developed equations based on anthropometric parameters can serve as a simple tool for the accurate prediction of BF% in adult subjects, at both individual and epidemiological levels.

Metabolic Syndrome and Chronic Disease Risk in South Asian Immigrants: A Review of Prevalence, Factors, and Interventions

South Asians (SAs) are among the fastest-growing ethnic groups in the U.S. Metabolic syndrome (MetS) is a condition that is characterized by multiple health factors that increase the risk for chronic diseases, such as cardiovascular disease (CVD) and diabetes. MetS prevalence among SA immigrants ranges from 27-47% in multiple cross-sectional studies using different diagnostic criteria, which is generally higher compared to other populations in the receiving country. Both genetic and environmental factors are attributed to this increased prevalence. Limited intervention studies have shown effective management of MetS conditions within the SA population. This review reports MetS prevalence in SAs residing in non-native countries, identifies contributing factors, and discusses ways to develop effective community-based strategies for health promotion targeting MetS among SA immigrants. There is a need for more consistently evaluated longitudinal studies to facilitate the development of directed public health policy and education to address chronic diseases in the SA immigrant community.

Snacking Behavior and Association with Metabolic Risk Factors in Adults from North and South India

BACKGROUND

Snacks are increasingly contributing to daily diets around the world. Studies from high-income countries have demonstrated the link between snack consumption and metabolic risk factors, but there are very few studies from low- and middle-income countries.

OBJECTIVES

The objective of this study was to assess snack behavior and its associations with metabolic risk factors in Indian adults.

METHODS

Adults from the UDAY study (October 2018-February 2019, n = 8762) from rural and urban Sonipat (North) and Vizag (South) India were studied for snack consumption (food frequency questionnaire), demographic factors, including age, sex, etc. and metabolic risk factors, including BMI, waist circumference, fat percentage, plasma glucose, and blood pressure. We compared snack consumption by categories of sociodemographic factors (Mann-Whitney U test, Kruskal-Wallis test) and studied the likelihood for metabolic risk (logistic regression analysis).

RESULTS

Half of the study participants were women and resided in rural locations. Savory snacks were the most preferred; 50% of the participants consumed them 3-5 times/wk. Participants preferred to purchase out-of-home prepared snacks and eat them at home (86.6%) while watching television (69.4%) or with family/friends (49.3%). The reasons for snacking were hunger, craving, liking, and availability. Snack consumption was higher in Vizag (56.6%) than in Sonipat (43.4%), among women (55.5%) than men (44.5%), and the wealthiest; it was similar in rural-urban locations. Frequent consumers of snacks had 2 times higher likelihood for having obesity (OR: 2.22; 95% CI: 1.51, 3.27) central obesity (OR: 2.35; 95% CI: 1.60, 3.45), and higher fat percentage (OR: 1.92; 95% CI: 1.31, 2.82) and higher fasting glucose levels (r=0.12 (0.07-0.18) than consumers who consumed snacks rarely (all P ≤ 0.05).

CONCLUSIONS

Snack (savory and sweet) consumption was high among adults from sexes in both urban and rural locations of north and south India. This was associated with higher risk of obesity. There is a need to improve the food environment by promoting policies for ensuring healthier food options to reduce snacking and associated metabolic risk.

Correlation of Percentage Body Fat, Waist Circumference and Waist-to-Hip Ratio with Abdominal Muscle Strength

Sedentary lifestyle and consumption of high-fat foods have become widespread, especially in the urban population. This leads to a reduction in lean body mass and increased body fat. The correlation between body fat indices and low back pain has been less explored and documented. The aim of this study was to identify the correlation between the percentage of body fat, waist circumference and waist-to-hip ratio and abdominal muscle strength. Percentage of body fat was estimated by using the body composition analyzer method using Tanita BC-545 Innerscan Segmental Body Composition. Waist-to-hip ratio was calculated by dividing the waist circumference by hip circumference. Abdominal muscle (rectus abdominis and external oblique) strength was measured by maximum voluntary isometric contraction as measured by surface electromyography. A positive correlation was observed between waist circumference and the percentage of body fat, while a negative correlation was observed between the average maximum voluntary isometric contraction of rectus abdominis and external oblique muscles and the percentage of body fat. Individuals with a high percentage of body fat tend to have higher fat distribution over the abdominal region and decreased abdominal muscle strength. Therapists should emphasize the use of abdominal muscles in individuals with high body fat in order to reduce the associated risk of the development of poor posture and low back pain.

Population pharmacokinetic modeling of daridorexant, a novel dual orexin receptor antagonist

The analysis aimed at identifying subject-specific characteristics (covariates) influencing exposure to daridorexant and quantification of covariate effects to determine clinical relevance. Data from 13 phase I, two phase II, and two phase III studies were pooled to develop a population pharmacokinetic model describing daridorexant concentration over time. Covariate effects were quantified based on model predictions. A two-compartment model with dose-dependent bioavailability, absorption lag time, linear absorption, and nonlinear elimination described the data best. Statistically significant covariates were food status on absorption (lag time and rate constant), time of drug administration (morning, bedtime) on absorption rate constant, lean body weight on central volume of distribution and elimination, fat mass on peripheral volume of distribution and intercompartmental drug transfer, and age and alkaline phosphatase on elimination. Age, lean body weight, fat mass, and alkaline phosphatase influence exposure (area under the curve, time of maximum concentration after dose administration, maximum plasma concentration, and next-morning concentration) to a limited extent, that is, less than 20% difference from a typical subject. Morning administration is not relevant for daridorexant use by insomnia patients. The food effect with simultaneous intake of a high-fat, high-calorie food is an extreme-case scenario unlikely to occur in clinical practice. Body composition, alkaline phosphatase, and age showed clinically negligible effects on exposure to daridorexant. Lean body weight and fat mass described the pharmacokinetics of daridorexant better than other body size descriptors (body weight, height, body mass index), suggesting a convenient physiological alternative to reduce the number of covariates in population pharmacokinetic models. The results indicate that differences between subjects do not require dose adjustments.

Associations between exercise capacity, p16INK4a expression and inflammation among adult survivors of childhood cancer

BACKGROUND

Over 50% of childhood cancer survivors are exercise intolerant, with maximal aerobic capacities comparable to individuals decades older, suggesting early physiologic ageing. In addition, 36% of survivors are obese. Optimal exercise capacity provides a foundation to support daily function and healthy body habitus and is associated with benefits to cognition, cardiovascular health, and longevity. Cellular senescence and inflammation are key mechanisms that drive age-related disease, quantifiable as biomarkers in peripheral blood.

AIMS

This study aimed to evaluate associations between p16INKa, a biomarker of cellular senescence, and inflammation and exercise capacity among adult survivors of childhood cancer.

MATERIALS AND METHODS

Eligible survivors were recruited from the St. Jude Lifetime (SJLIFE) Cohort Study. Exercise capacity was assessed by maximal oxygen uptake (VO2, ml/kg/min) obtained via cardiopulmonary exercise testing using a modified Bruce protocol. Body fat (%) was determined from dual energy x-ray absorptiometry (DEXA). Peripheral blood samples were used to evaluate log2 p16INK4a mRNA expression, a biomarker of cellular senescence, and inflammation with high sensitivity C-reactive protein (hs-CRP) levels. Multivariable regression evaluated associations between p16INK4a, hs-CRP, body fat, and exercise capacity.

RESULTS

Participants included 185 five-year childhood cancer survivors (mean age 36.6 [range 20.1 - 55.7] years, 44% male, 77% non-Hispanic white, 53% leukemia/lymphoma). Compared to males, females had lower peak VO2 (mean ± SD, 22.5 ± 8.2 vs. 28.8 ± 7.7 ml/kg/min, p<0.01), higher p16INK4a expression (9.6 ± 1.2 vs. 9.2 ± 1.2 fold, p=0.02), and hs-CRP concentration (5.9 ± 8.4 vs. 3.3 ± 3.9 mg/L, p=0.01). Among females (n=103), hs-CRP concentration (β -0.2, 95% CI -0.34 to -0.05, p=0.01) and p16INK4a expression (β-5.32, 95% CI 10.42 to -0.22, p=0.04) were inversely associated and statistically significant with peak exercise capacity, with a significant interaction between p16INK4a expression and body fat (β 0.15, 95% CI 0.02 to 0.28, p=0.03). Among males (n=82), p16INK4a expression (β -1.01, 95% CI -2.14 to 0.12, p=0.08), and body fat (β -0.54, 95% CI -0.70 to -0.38, p<0.01) were inversely associated with peak exercise capacity.

CONCLUSION

Inflammation and p16INK4a expression, a biomarker of cellular senescence, are associated with lower exercise capacity in childhood cancer survivors, suggesting potential targets or outcome measures for interventions designed to prevent or remediate accelerated physiologic ageing in this population.

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.

Body Mass Index (BMI): A Screening Tool Analysis

Body mass index (BMI), a measurement based on a person’s height and weight, allows the classification of individuals into categories such as obese or overweight. With these classifications, we can assess risk for hypertension, diabetes, cancer, hypercholesterolemia, and other chronic diseases. Furthermore, childhood BMI serves as a prediction method for health and disease later in life. Along with BMI, researchers also study waist circumference and waist-to-hip ratio in correlation with the above-mentioned chronic illnesses. This brief review explores the associations between body mass index, waist circumference, and the waist-hip ratio as measurements and their capability as predictors for persistent conditions like diabetes and hypertension.

Egg Consumption in the Context of Plant-Based Diets and Cardiometabolic Risk Factors in Adults at Risk of Type 2 Diabetes

BACKGROUND

Plant-based diets (PBDs) are typically recommended to those at risk of type 2 diabetes mellitus (T2DM).

OBJECTIVES

We examined how including eggs, compared with excluding them from PBDs, affected cardiometabolic risk factors in adults at risk of T2DM.

METHODS

This was a randomized, controlled, single-blind, crossover trial of 35 adults (mean age: 60.7 y; 25 women, 10 men) at risk of T2DM assigned to 1 of 2 sequence permutations of 2 dietary treatments (plant-based plus eggs, and exclusively plant-based), with a 4-wk washout period. A dietitian counseled participants to exclude or include 2 eggs daily in the context of PBDs for a 6-wk interval. Our primary outcome measure was endothelial function (EF) measured as flow-mediated dilatation. Secondary outcome measures included lipid profile, blood pressure, insulin sensitivity, anthropometry, and dietary intake. Data were analyzed using generalized linear models.

RESULTS

Compared with egg exclusion, egg inclusion in the context of PBDs did not adversely affect EF (-1.7% ± 6.5% compared with -1.8% ± 7.5%; P = 0.9805). Likewise, egg inclusion, compared with egg exclusion, did not adversely affect (P = 0.1096-0.9781) lipid profile, blood pressure, insulin sensitivity, or anthropometry. Egg inclusion, compared with egg exclusion, improved reported intakes of selenium (23.1 ± 30.3 μg/d compared with 2.3 ± 34.9 μg/d; P = 0.0124) and choline (172.0 ± 96.0 mg/d compared with -3.4 ± 68.1 mg/d; P < 0.0001).

CONCLUSIONS

Consuming 2 eggs daily in the context of PBDs does not adversely affect cardiometabolic risk factors among adults at risk of T2DM. Eggs could be used as an adjuvant to enhance PBDs that are typically recommended for those at risk of T2DM.This trial was registered at clinicaltrials.gov as NCT04316429.

A targeted multi-omics approach reveals paraoxonase-1 as a determinant of obesity-associated fatty liver disease

Background

The multifactorial nature of non-alcoholic fatty liver disease cannot be explained solely by genetic factors. Recent evidence revealed that DNA methylation changes take place at proximal promoters within susceptibility genes. This emphasizes the need for integrating multiple data types to provide a better understanding of the disease’s pathogenesis. One such candidate gene is paraoxonase-1 (PON1). Substantial interindividual differences in PON1 are apparent and could influence disease risk later in life. The aim of this study was therefore to determine the different regulatory aspects of PON1 variability and to examine them in relation to the predisposition to obesity-associated fatty liver disease.

Results

A targeted multi-omics approach was applied to investigate the interplay between PON1 genetic variants, promoter methylation, expression profile and enzymatic activity in an adult patient cohort with extensive metabolic and hepatic characterisation including liver biopsy. Alterations in PON1 status were shown to correlate with waist-to-hip ratio and relevant features of liver pathology. Particularly, the regulatory polymorphism rs705379:C > T was strongly associated with more severe liver disease. Multivariable data analysis furthermore indicated a significant association of combined genetic and epigenetic PON1 regulation. This identified relationship postulates a role for DNA methylation as a mediator between PON1 genetics and expression, which is believed to further influence liver disease progression via modifications in PON1 catalytic efficiency.

Conclusions

Our findings demonstrate that vertical data-integration of genetic and epigenetic regulatory mechanisms generated a more in-depth understanding of the molecular basis underlying the development of obesity-associated fatty liver disease. We gained novel insights into how NAFLD classification and outcome are orchestrated, which could not have been obtained by exclusively considering genetic variation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13148-021-01142-1.

Using anthropometric measures to screen for obstructive sleep apnea in the Sleep Heart Health Study cohort

STUDY OBJECTIVES

To evaluate predictions of moderate-to-severe-obstructive sleep apnea (MS-OSA) by the neck circumference height ratio (NHR) and waist circumference height ratio (WHR) and compare to the derived STOP-Bang Questionnaire (dSBQ) prediction.

METHODS

Included were 6,167 participants from the Sleep Heart Health Study (SHHS) baseline evaluation who completed polysomnograms, had anthropometric measurements, and data to compute proxy dSBQ item answers. The sample was divided randomly into derivation (n = 2,035) and validation (n = 4,132) subsets. The derivation sample was used to estimate the NHR and WHR cut points to detect MS-OSA; the validation sample was used to evaluate sensitivity (SN) and specificity (SP).

RESULTS

Mean age was 63.1 years, and 47.2% were male for the overall sample. In the derivation sample, a cut point ≥ 0.21 for NHR yielded a SN of 92.0% and SP of 25.0%; a cut point ≥ 0.52 for WHR yielded a SN of 91.2% and SP of 25.0% for MS-OSA. Using the validation sample, the NHR, WHR, and dSBQ areas under the receiver operator curves (AUCs) were 69.8%, 65.2%, and 70.5% respectively for MS-OSA. There was no statistical difference with listwise comparison of the NHR and dSBQ AUCs (p = 0.997); however, there was a significant difference between the WHR and dSBQ AUCs (p = 0.015) for MS-OSA.

CONCLUSIONS

The NHR is a viable OSA screening tool comparable to the dSBQ, independent of witnessed apneas and BMI, that can be used for different body types.

Update of the risk assessment of hexabromocyclododecanes (HBCDDs) in food

The European Commission asked EFSA to update its 2011 risk assessment on hexabromocyclododecanes (HBCDDs) in food. HBCDDs, predominantly mixtures of the stereoisomers α-, β- and γ-HBCDD, were widely used additive flame retardants. Concern has been raised because of the occurrence of HBCDDs in the environment, food and in humans. Main targets for toxicity are neurodevelopment, the liver, thyroid hormone homeostasis and the reproductive and immune systems. The CONTAM Panel concluded that the neurodevelopmental effects on behaviour in mice can be considered the critical effects. Based on effects on spontaneous behaviour in mice, the Panel identified a lowest observed adverse effect level (LOAEL) of 0.9 mg/kg body weight (bw) as the Reference Point, corresponding to a body burden of 0.75 mg/kg bw. The chronic intake that would lead to the same body burden in humans was calculated to be 2.35 μg/kg bw per day. The derivation of a health-based guidance value (HBGV) was not considered appropriate. Instead, the margin of exposure (MOE) approach was applied to assess possible health concerns. Over 6,000 analytical results for HBCDDs in food were used to estimate the exposure across dietary surveys and age groups of the European population. The most important contributors to the chronic dietary LB exposure to HBCDDs were fish meat, eggs, livestock meat and poultry. The CONTAM Panel concluded that the resulting MOE values support the conclusion that current dietary exposure to HBCDDs across European countries does not raise a health concern. An exception is breastfed infants with high milk consumption, for which the lowest MOE values may raise a health concern.

Seasonal variability of the vitamin D effect on physical fitness in adolescents

Studies investigating the relationship between vitamin D and physical fitness in youth have provided inconsistent findings. Recent evidence indicates that the expression of receptors and vitamin D-modulated genes in young subjects has a seasonal profile. Therefore, we investigated the role of vitamin D on physical fitness across seasons in a total of 977 male adolescents. Anthropometrics, lifestyle, dietary habits, biochemical profiles and physical fitness were studied. Multiple linear regression models, including pairwise interaction terms involving total 25-OH-vitamin D, were fitted. The interacting effect of season and total 25-OH-vitamin D had a significant influence on physical fitness performance (spring and total 25-OH-vitamin D: ß 0.19, SE 0.07, p = 0.007; summer and total 25-OH-vitamin D: ß 0.10, SE 0.06, p = 0.11; autumn and total 25-OH-vitamin D: ß 0.18, SE 0.07, p = 0.01), whereas the main effect of total 25-OH-vitamin D alone was not significant (p = 0.30). Body fat percentage, recreational physical activity level, time spent per day gaming/TV-watching, smoking, and hemoglobin levels were also related to the physical fitness performance score. Future studies should further explore the role of seasonal-dependent effects of vitamin D on health.

Development and Validation of a Multidimensional Instrument: Assessing Barriers to Dietary Practices

BACKGROUND AND PURPOSE

Poor dietary practices are linked to many chronic diseases. The purpose of this validation study was to develop a psychometrically sound instrument that can be administered by health practitioners to measure dietary barriers.

METHODS

The Dietary Health Status (DHS) instrument, designed to measure dietary barriers is comprised of items in the National Health and Nutrition Examination Survey-What We Eat in America datasets. Content validity was established for DHS using an expert review process. Principal component analysis (PCA) was then used to assess validity and reliability as determined by Cronbach's alpha values.

RESULTS

The PCA supported a 10-component solution, explaining 61% of the total variance. Cronbach's alpha was .67 for the entire instrument, ranging from .55 to .87 for the 10 subscales.

CONCLUSION

Results suggest the instrument had sufficient construct and internal validity. This exploratory study is an important first step in validating the DHS instrument.

Is BMI a Valid Indicator of Overweight and Obesity for Adolescents?

Background: Overweight and obesity are mostly monitored via the Body Mass Index (BMI), based on self-reported or measured height and weight. Previous studies have shown that BMI as a measure of obesity can introduce important misclassification problems. The aim of this study was to assess the validity of overweight and obesity classification based on self-reported and on measured height and weight versus the proportion of body fat as the criterion. Methods: We used data on 782 adolescents (mean age = 13.5, 55.8% boys) from the Health Behaviour in School-Aged Children (HBSC) study conducted in 2018 in Slovakia. We obtained self-reported (height and weight) and objective measures (height, weight) and the proportion of fat (as the criterion measure) measured via bioimpedance body composition analysis (BIA) with an InBody 230 from the adolescents. Results: Both measured and self-reported BMI indicated overweight and obesity with relatively low sensitivity (66-82%), but high specificity (90-92%). The superior accuracy of measured BMI in comparison to self-reported BMI was confirmed by the area under the curve (AUC) based on the receiver operating characteristics (ROC) curves (AUC measured/self-reported: 0.94/0.89; p < 0.001). The misclassification of overweight and obesity was significantly higher when using self-reported BMI than when using measured BMI. Conclusion: Both self-reported and measured BMI as indicators of overweight and obesity underestimate the prevalence of adolescents with overweight and obesity.

Body adiposity measured by bioelectrical impedance is an alternative to dual-energy x-ray absorptiometry in black Africans: The Africans in America Study

OBJECTIVES

The prevalence of cardiometabolic disease has risen in Africa and parallels the obesity epidemic. To assess cardiometabolic risk, body composition measurements by dual-energy X-ray absorptiometry (DXA) are ideal. In communities with limited resources, alternative measures may be useful but have not been compared extensively in black Africans. Therefore, the aim of this study was to identify alternative methods of body composition assessment, such as body adiposity index (BAI) and bioelectrical impedance analysis (BIA), for use in African-born blacks.

METHODS

This was a cross-sectional study with African-born blacks. BAI and five BIA predictive equations (using variations of height, weight, age, sex, and impedance) were compared with DXA to estimate percent fat. Participants were 266 African-born blacks (39 ± 10 y, body mass index 28 ± 4 kg/m², and 68% men) living in metropolitan Washington DC. Equivalence (90% confidence interval, -3 to 3), concordance, and Bland-Altman analyses (bias <2%, R² closest to zero) compared BAI or BIA predictive equations to DXA as the criterion method.

RESULTS

DXA percent fat was 27.2% ± 5.5% and 40.3% ± 6.9% in men and women, respectively. BAI underestimated percent fat in men (bias: 1.88 ± 4.71, R² = 0.25, P < 0.001) and women (bias: 6.47 ± 4.94, R² = 0.08, P = 0.01). Of the five BIA predictive equations, the equation reported by Sun et al. had the best agreement with DXA percent fat for men (bias: -0.91 ± 3.67, R² = 0.02, P = 0.05) and women (bias: -0.92 ± 4.02, R² = 0.003, P = 0.58). Percent fat from the Sun et al. equation best agreed with DXA percent fat.

CONCLUSION

BIA with the Sun et al. predictive equation was the best alternative to DXA for body fat assessment in African-born blacks.

Development of a dual-energy X-ray absorptiometry-derived body volume equation in Hispanic adults for administering a four-compartment model

The purpose of the present study was: (1) to develop a new dual-energy X-ray absorptiometry (DXA)-derived body volume (BV) equation with the GE-Lunar prodigy while utilising underwater weighing (UWW) as a criterion and (2) to cross-validate the novel DXA-derived BV equation (4C-DXANickerson), Wilson DXA-derived BV equation (4C-DXAWilson) and air displacement plethysmography (ADP)-derived BV (4C-ADP) in Hispanic adults. A total of 191 Hispanic adults (18–45 years) participated in the present study. The development sample consisted of 120 females and males (50 % females), whereas the cross-validation sample comprised of forty-one females and thirty males (n 71). Criterion body fat percentage (BF %) and fat-free mass (FFM) were determined using a four-compartment (4C) model with UWW as a criterion for BV (4C-UWW). 4C-DXANickerson, 4C-DXAWilson and 4C-ADP were compared against 4C-UWW in the cross-validation sample. 4C-DXANickerson, 4C-DXAWilson and 4C-ADP all produced similar validity statistics when compared with 4C-UWW in Hispanic males (all P > 0·05). 4C-DXANickerson also yielded similar BF % and FFM values as 4C-UWW when evaluating the mean differences (constant error (CE)) in Hispanic females (CE = –0·79 % and 0·38 kg; P = 0·060 and 0·174, respectively). However, 4C-DXAWilson produced significantly different BF % and FFM values (CE = 3·22 % and –2·20 kg, respectively; both P < 0·001). Additionally, 4C-DXAWilson yielded significant proportional bias when estimating BF % (P < 0·001), whereas 4C-ADP produced significant proportional bias for BF % and FFM (both P < 0·05) when evaluated in Hispanic females. The present study findings demonstrate that 4C-DXANickerson is a valid measure of BV in Hispanics and is recommended for use in clinics, where DXA is the main body composition assessment technique.

High body fat percentage and low consumption of dairy products were associated with vitamin D inadequacy among older women in Malaysia

BACKGROUND

Serum vitamin D insufficiency is a public health issue, especially among older women. Sun exposure is fundamental in the production of vitamin D, but older women have less optimal sun exposure. Therefore, factors such as body composition and diet become more essential in sustaining sufficient serum levels of vitamin D. The objective of the current study is to determine factors contributing towards serum vitamin D insufficiency among 214 older women.

METHODS

The respondents had their body weight, height, waist circumference and body fat percentage measured, as well as interviewed for their socio-demographic characteristics, sun exposure and dietary intake. Fasting blood samples were obtained from the respondents to measure their serum 25-hydroxyvitamin D [25(OH)D] concentration.

RESULTS

There were 82.7% (95% CI: 77.6%, 87.8%) of the respondents that had serum vitamin D insufficiency (< 50 nmol/L) with an average of 37.4 ± 14.3nmol/L. In stepwise multiple linear regression, high percentage of body fat (ß = -0.211, p <0.01) and low consumption of milk and dairy products (ß = 0.135, p <0.05) were the main contributors towards insufficient serum vitamin D levels, but not socio-demographic characteristics, other anthropometric indices, sun exposure and diet quality.

CONCLUSION

Older women with high body fat percentage and low dairy product consumption were more likely to have serum vitamin D insufficiency. Older women should ensure their body fat percentage is within a healthy range and consume more milk and dairy products in preventing serum vitamin D insufficiency.

Are Obesity Indices Useful for Detecting Subclinical Atheromatosis in a Middle-Aged Population?

OBJECTIVE

There is a close relationship between excess adiposity and cardiovascular disease. Although body mass index (BMI) is the most used approach to estimate excess weight, other anthropometric indices have been developed to measure total body and abdominal adiposity. Here, our objective was to assess the usefulness of these anthropometric indices to detect subclinical atheromatous disease.

METHODS

A cross-sectional study with 6,809 middle-aged subjects (mean age, 57 [53-63] years) with low to moderate cardiovascular risk from the ILERVAS project. Measures of total body fat (BMI, Clínica Universidad de Navarra - Body Adiposity Estimator [CUN-BAE], and Deurenberg's formula) and central adiposity (waist and neck circumferences, conicity index, waist-to-height ratio, Bonora's equation, the A body adiposity index, and body roundness index) were performed in all participants. Bilateral carotid and femoral ultrasound vascular studies allowed the identification of subjects with plaque. -Results: All measured indices were significantly higher in males with subclinical carotid or femoral plaques (p ≤ 0.021 for all). Also, a positive and significant correlation between all indices and the number of affected territories was found (p ≤ 0.013 for all). From the ROC analysis, all measurements identified patients with asymptomatic atheromatosis but none of them helped make clinical decisions. Regarding females, the results were less conclusive.

CONCLUSION

Obesity indices are related to subclinical atheromatosis, especially in men, in a large cohort of middle-aged subjects. However, the indices could not detect the presence of arterial plaque, so, when used in isolation, are unlikely to be decisive.

Nutrient patterns and the skeletal muscle mass index among Polish women: a cross-sectional study

Ageing involves significant changes in skeletal muscle mass and its functioning. This study aimed to identify the major nutrient patterns (NPs) present in a sample of adult Polish women and evaluate their associations with the skeletal muscle mass index (SMI). A cross-sectional study initially recruited 527 women, and a final analysis was carried out on 275 women aged 32–60 years. Nutrient intake was assessed using fourteen repetitions of 24-hour dietary recall. NPs were derived using principal component analysis. Associations between adherence to NPs and the SMI were evaluated using linear regression models. Three NPs were identified: ‘Animal Protein-Vitamins’, ‘Fibre-Plant Protein-Minerals’ and ‘Fats’. In the adjusted model, the upper tertile compared to the bottom tertile of the ‘Animal Protein-Vitamins’ NP was related to a higher SMI (β = 0.123 95% CI: 0.019; 0.227; P for 1-SD increase of NP score = 0.009). No associations between the SMI and the ‘Fibre-Plant Protein-Minerals’ and ‘Fats’ NPs were observed. Our results indicate that high adherence to animal product-rich patterns might be related to higher muscle mass in adult women. Research on the influence of dietary and nutrient patterns on the quality of muscle tissue may contribute to the setting of guidelines for nutritional protection of skeletal muscle with ageing and, consequently, dietary recommendations that would improve the quality of women’s lives at the later stage of life.

COMPARISON BETWEEN DIFFERENT METHODS FOR MEASURING BODY FAT AFTER A WEIGHT LOSS PROGRAM

ABSTRACT Introduction Accurate and sensitive measurement of body composition is an important tool in the diagnosis and control of obesity. Objective To compare body fat changes measured by dual-energy X-ray absorptiometry (DXA), bioelectrical impedance analysis (BIA), and skinfolds (SK) in healthy overweight adults in order to evaluate whether all three methods can be used during a weight loss program (WLP). Methods Eighty-four men (n=36) and women (n=48), body mass index 25–29.9 kg/m2, aged between 18-50 years, non-smokers and sedentary, were randomly assigned to strength, endurance, combined strength plus endurance, or physical activity recommendations groups. All subjects followed a hypocaloric diet (25-30% decrease in energy intake in terms of the total daily energy expenditure). The intervention lasted 22 weeks. Results The highest correlation was obtained between DXA and SK when men and women were studied together (r=0.864, p<0.01). In women, significant differences were found between DXA and BIA in fat percentage (underestimation of BIA 2.4%, p<0.05). The underestimation was more determinant for both fat percentage and fat mass in men, 13.2% versus 10.2%, and 6.8 kg versus 4.2 kg between BIA and SK respectively (p<0.05). All the procedures obtained similar results (p>0.05) when changes in body fat caused by intervention were analyzed. However, considering results of the minimal difference compared to DXA, BIA showed the greatest sensitivity to detect changes in fat percentage and fat mass, while SK underestimated the changes, with a significantly lower percentage considered real (p=0.01). Conclusion The SK method seems to underestimate real changes, therefore DXA and BIA can serve as more effective tools to measure the change in fat percentage and fat mass during WLP. Level of evidence II, Diagnosis.

Vitamin D Status Among Male Late Adolescents Living in Southern Switzerland: Role of Body Composition and Lifestyle

Background: Poor vitamin D status is a worldwide health problem. Yet, knowledge about vitamin D status among adolescents in Southern Europe is limited. This study investigated concentrations and modulating factors of vitamin D in a healthy population of male late adolescents living in Southern Switzerland. Methods: All apparently healthy subjects attending for the medical evaluation before the compulsory military service in Southern Switzerland during 2014-2016 were eligible. Dark-skin subjects, subjects on vitamin D supplementation or managed with diseases or drugs involved in vitamin D metabolism were excluded. Anthropometric measurements (body height, weight, fat percentage, mid-upper arm and waist circumference) and blood sampling for total 25-hydroxy-vitamin D, total cholesterol and ferritin concentrations testing, were collected. Participants filled in a structured questionnaire addressing their lifestyle. Characteristics of the subjects with adequate (≥50 nmol/L–≤250 nmol/L) and insufficient (<50 nmol/L) vitamin D values were compared by Kruskal-Wallis test or χ² test. Odds ratios for 25-hydroxy-vitamin D insufficiency were calculated by univariate and AIC-selected multiple logistic regression models. Results: A total of 1045 subjects volunteered to participate in the study. Insufficient concentrations of vitamin D were detected in 184 (17%). The season of measurement was the most significant factor associated with vitamin D levels and approximately 40% of subjects presented insufficient vitamin D concentrations in winter. After model selection, body fat percentage, frequency and site of recreational physical activity, and the seasonality were significantly associated with the risk of vitamin D insufficiency. Conclusions: Among healthy male late adolescents in Southern Switzerland, about one every fourth subject presents a poor vitamin D status in non-summer seasons. Body fat percentage, frequent and outdoor recreational physical activity are modulating factors of vitamin D status in this population.

Consumption of dietary supplements to support weight reduction in adults according to sociodemographic background, body mass index, waist-hip ratio, body fat and physical activity

BACKGROUND

The aim of this study was to analyse the use of dietary supplements to support weight reduction (DSSWR) in adults according to sociodemographic background, body mass index (BMI), waist-hip ratio (WHR), body fat percentage (%BF) and level of physical activity (PA).

METHOD

Participants (n = 1130) were recruited from a region of Poland with a high rate of adult overweight and obesity. Based on anthropometric data, BMI and WHR were calculated. %BF was assessed using a bioimpedance method. To examine the association between DSSWR use and sociodemographic factors, BMI, WHR, %BF and PA multiple logistic regression were conducted.

RESULTS

The rate of DSSWR use in the group studied was high (69.5%). A higher proportion of women, individuals aged 18-35 years, those who had completed higher education, those who did not report financial status as "poor", with a BMI < 18.5, normal %BF and individuals with a high level of PA used DSSWR. In complete case analysis (n = 1108), primarily financial status reported as "good" (OR = 2.18, 95% CI: 1.69, 2.81) or "hard to say" (OR = 2.41, 95% CI: 1.86, 3.12) (vs. "poor") and female sex (OR = 2.59, 95% CI: 2.17, 3.08) were associated with DSSWR intake.

CONCLUSION

It seems that primarily financial status and sex, but also age, education, and level of PA, have significance in DSSWR use in adults and may be considered when developing appropriate strategies for body weight management and health promotion.

Blood pressure and body fat percent in women with NMOSD

BACKGROUND

Hypertension is a prevalent and impactful comorbid condition among patients with multiple sclerosis (MS). High level of body mass index (BMI) is associated with the risk and poor outcomes of neuromyelitis optica spectrum disorder (NMOSD) in women. However, the clinical implication of blood pressure (BP) and body fat percent (BF%) based on the Clínica Universidad de Navarra-Body Adiposity Estimator (CUN-BAE) in NMOSD has not been investigated thus far.

METHODS

Case data were collected from 47 NMOSD and 28 MS patients at acute phase, 21 NMOSD and 25 MS patients at stable phase, and 68 age- and sex-matched HCs. Four BP measures including systolic BP (SBP), diastolic BP (DBP), pulse pressure (PP), and mean arterial pressure (MAP); BMI; and BF% between NMOSD, MS, and healthy controls were determined.

RESULTS

Comparing NMOSD patients with MS patients, the former have significantly higher SBP (p < 0.001), DBP (p < 0.001), PP (p < 0.001), MAP (p < 0.001), BF% (p = 0.001), and BMI (p < 0.001) levels at acute phase after adjusting for age. Acute myelitis (OR 3.719, 95% CI 1.110-12.453) is more likely to occur in NMOSD patients with high BF% (≥30%) at acute phase. BF% was negatively correlated with 1/AQP4 titer in NMOSD at acute phase (r = -0.522, p = 0.004).

CONCLUSIONS

Women with NMOSD are probably more prone to have an increased BP and fat mass compared to MS.

School bullying, body size, and gender: an intersectionality approach to understanding US children's bullying victimization

We examine separate and combined effects of children's body size and gender on school bullying victimization in the US. Second-grade data from the 2012-2013 school year from the US Early Childhood Longitudinal Study, Kindergarten Class of 2011 were analyzed, hierarchical generalized logistic modeling was used, and three forms of school bullying were studied. Girls were less likely than boys to be verbally or physically bullied and obese children were more likely to be verbally and relationally bullied than non-obese children. The protective effect of gender extends to obese girls when obesity is not a risk factor (physical bullying). When obesity is a risk factor, gender is not protective (verbal bullying) or is a risk factor (relational bullying) for girls. These findings suggest an intersectional body size-gender lens is crucial to understanding how inequality is produced through school bullying. Future interventions should incorporate an intersectional understanding of school bullying.

Cardiometabolic Health in Relation to Lifestyle and Body Weight Changes 3⁻8 Years Earlier

The degree to which individuals change their lifestyle in response to interventions differs and this variation could affect cardiometabolic health. We examined if changes in dietary intake, physical activity and weight of obese infertile women during the first six months of the LIFEstyle trial were associated with cardiometabolic health 3⁻8 years later (N = 50⁻78). Lifestyle was assessed using questionnaires and weight was measured at baseline, 3 and 6 months after randomization. BMI, blood pressure, body composition, pulse wave velocity, glycemic parameters and lipid profile were assessed 3⁻8 years after randomization. Decreases in savory and sweet snack intake were associated with lower HOMA-IR 3⁻8 years later, but these associations disappeared after adjustment for current lifestyle. No other associations between changes in lifestyle or body weight during the first six months after randomization with cardiovascular health 3⁻8 years later were observed. In conclusion, reductions in snack intake were associated with reduced insulin resistance 3⁻8 years later, but adjustment for current lifestyle reduced these associations. This indicates that changing lifestyle is an important first step, but maintaining this change is needed for improving cardiometabolic health in the long-term.

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.

The reproducibility and validity verification for body composition measuring devices using bioelectrical impedance analysis in Korean adults

The purpose of this study is to examine the validity and reproducibility of impedance body fat measurement devices measuring the body composition of Korean male and female adults using three bioelectrical impedance analyzers. We compared two methods for evaluating body composition: dual energy X-ray absorptiometry (DEXA), and bioelectrical impedance analysis (BIA). Subjects were 200 healthy adult Korean males and females whose mean±standard deviation (range) age, standing height, body weight, and body mass index (BMI) were 44.1±14.5 years, 172.8±7.4 cm, 76.0±12.8 kg, and 25.4±3.3 kg/m2, and 44.5±14.7 years, 158.7±5.8 cm, 58.3±8.3 kg, and 23.2±3.0 kg/m2, respectively. As a result, first of all, the reproducibility of the bioelectrical impedance analyzer had very high coefficients at r=0.998, r=0.997 between men and women, respectively. The correlation coefficients among three comparisons for lean body mass (LBM) were provided the following coefficients: r=0.951 for DEXA vs. ACCUNIQ BC720, r=0.950 for DEXA vs. ACCUNIQ BC360, and r=0.946 for DEXA vs. ACCUNIQ BC380 in men. In the results for women, they also had the very high following coefficients: r=0.956 for DEXA vs. ACCUNIQ BC720, r=0.946 for DEXA vs. ACCUNIQ BC360, and r=0.957 for DEXA vs. ACCUNIQ BC380 in LBM. In conclusion, this research showed a higher correlation in terms of accuracy compared to existing BIA-based body composition measurement techniques, and the accuracy of LBM was improved with high correlation coefficients through the algorithm that was improved using the multifrequency BIA method in the ACCUNIQ BC products.

Racial/Ethnic Differences in the Associations of Overall and Central Body Fatness with Circulating Hormones and Metabolic Factors in US Men

BACKGROUND

Racial/ethnic disparities in the associations of body fatness with hormones and metabolic factors remain poorly understood. Therefore, we evaluated whether the associations of overall and central body fatness with circulating sex steroid hormones and metabolic factors differ by race/ethnicity.

METHODS

Data from 1,243 non-Hispanic white (NHW), non-Hispanic black (NHB) and Mexican-American (MA) adult men in the third national health and nutrition examination survey (NHANES III) were analyzed. Waist circumference (central body fatness) was measured during the physical examination. Percent body fat (overall body fatness) was calculated from bioelectrical impedance. Associations were estimated by using weighted linear regression models to adjust the two measures of body fatness for each other.

RESULTS

Waist circumference, but not percent body fat was inversely associated with total testosterone and SHBG in all three racial/ethnic groups after their mutual adjustment (all P < 0.0001). Percent body fat (P = 0.02), but not waist circumference was positively associated with total estradiol in NHB men; no association was present in NHW and MA men (P-interaction = 0.04). Waist circumference, but not body fat was strongly positively associated with fasting insulin (all P < 0.0001) and inversely associated with HDL cholesterol (all P ≤ 0.003) in all three racial/ethnic groups. Both percent body fat and waist circumference were positively associated with leptin (all P < 0.0001) in all three racial/ethnic groups.

CONCLUSIONS

There was no strong evidence in the associations of sex hormones and metabolic factors with body fatness in different racial/ethnic groups. These findings should be further explored in prospective studies to determine their relevance in racial/ethnic disparities of chronic diseases.

Body composition-derived BMI cut-offs for overweight and obesity in Indians and Creoles of Mauritius: comparison with Caucasians

BACKGROUND AND AIMS

Global estimates of overweight and obesity prevalence are based on the World Health Organisation (WHO) body mass index (BMI) cut-off values of 25 and 30 kg m-2, respectively. To validate these BMI cut-offs for adiposity in the island population of Mauritius, we assessed the relationship between BMI and measured body fat mass in this population according to gender and ethnicity.

METHODS

In 175 young adult Mauritians (age 20-42 years) belonging to the two main ethnic groups-Indians (South Asian descent) and Creoles (African/Malagasy descent), body weight, height and waist circumference (WC) were measured, total body fat assessed by deuterium oxide (D2O) dilution and trunk (abdominal) fat by segmental bioimpedance analysis.

RESULTS

Compared to body fat% predicted from BMI using Caucasian-based equations, body fat% assessed by D2O dilution in Mauritians was higher by 3-5 units in Indian men and women as well as in Creole women, but not in Creole men. This gender-specific ethnic difference in body composition between Indians and Creoles is reflected in their BMI-Fat% relationships, as well as in their WC-Trunk Fat% relationships. Overall, WHO BMI cut-offs of 25 and 30 kg m-2 for overweight and obesity, respectively, seem valid only for Creole men (~24 and 29.5, respectively), but not for Creole women whose BMI cut-offs are 2-4 units lower (21-22 for overweight; 27-28 for obese) nor for Indian men and women whose BMI cut-offs are 3-4 units lower (21-22 for overweight; 26-27 for obese).

CONCLUSIONS

The use of BMI cut-off points for classifying overweight and obesity need to take into account both ethnicity and gender to avoid gross adiposity status misclassification in this population known to be at high risk for type-2 diabetes and cardiovascular diseases. This is particularly of importance in obesity prevention strategies both in clinical medicine and public health.

Biliary tract visualization using near-infrared imaging with indocyanine green during laparoscopic cholecystectomy: results of a systematic review

Background

Near-infrared imaging with indocyanine green (ICG) has been extensively investigated during laparoscopic cholecystectomy (LC). However, methods vary between studies, especially regarding patient selection, dosage and timing. The aim of this systematic review was to evaluate the potential of the near-infrared imaging technique with ICG to identify biliary structures during LC.

Methods

A comprehensive systematic literature search was performed. Prospective trials examining the use of ICG during LC were included. Primary outcome was biliary tract visualization. Risk of bias was assessed using ROBINS-I. Secondly, a meta-analysis was performed comparing ICG to intraoperative cholangiography (IOC) for identification of biliary structures. GRADE was used to assess the quality of the evidence.

Results

Nineteen studies were included. Based upon the pooled data from 13 studies, cystic duct (Lusch et al. in J Endourol 28:261–266, 2014) visualization was 86.5% (95% CI 71.2–96.6%) prior to dissection of Calot’s triangle with a 2.5-mg dosage of ICG and 96.5% (95% CI 93.9–98.4%) after dissection. The results were not appreciably different when the dosage was based upon bodyweight. There is moderate quality evidence that the CD is more frequently visualized using ICG than IOC (RR 1.16; 95% CI 1.00–1.35); however, this difference was not statistically significant.

Conclusion

This systematic review provides equal results for biliary tract visualization with near-infrared imaging with ICG during LC compared to IOC. Near-infrared imaging with ICG has the potential to replace IOC for biliary mapping. However, methods of near-infrared imaging with ICG vary. Future research is necessary for optimization and standardization of the near-infrared ICG technique.

Electronic supplementary material

The online version of this article (doi:10.1007/s00464-016-5318-7) contains supplementary material, which is available to authorized users.