Similarity in percent body fat between white and Vietnamese women: implication for a universal definition of obesity

Relationship between BMI with percentage body fat and obesity in Singaporean adults - The Yishun Study

BACKGROUND

The main aim of this study was to the determine relationship between Body Mass Index (BMI) and percentage body fat (BF%) in Singaporean adults, derive a prediction model to estimate BF%, and to report population BF%. The secondary aim was to determine the prevalence of overweight and obesity based on BF% threshold and the new risk categories for obesity in Singaporean population.

METHODS

This was a population-based study of 542 community-dwelling Singaporeans (21-90 years old, 43.1% men). Anthropometry and body composition were assessed. Relationship between BMI and BF% were analysed using multiple regression models. Prevalence of overweight and obesity were estimated using WHO and Singapore Ministry of Health (MOH) Clinical Practice Guidelines for BMI classification, and BF% cut-off points of 25 and 35% for men and women respectively.

RESULTS

We derived a prediction model to estimate BF% based on BMI, age and sex. The current cohort of Singaporeans when compared to Caucasians in the US and Europe as well as a Singapore cohort from 20 years age have higher BF% when matched for BMI, age, and sex. The overall population-adjusted prevalence of obesity according to WHO International classification (BMI ≥30 kg/m2) was 12.9% (14.9% men; 11.0% women); and 26.6% (30.7% men; 22.8% women) according to the MOH classification (BMI ≥27.5 kg/m2). However, using the BF% cut-off (> 25% for men and > 35% for women) resulted in very high prevalence of obesity of 82.0% (80.2% men; 83.8% women).

CONCLUSION

There is a large discrepancy between BF% and BMI measured obesity in Singaporean adults. The results confirmed that Singaporean adults have higher BF% at lower BMI compared to US and Europe white counterparts; and that BF% in our population has increased over two decades.

Reference values of body composition parameters for Vietnamese men and women

BACKGROUND

Body composition parameters are linked to cardio-metabolic risk. However, high-quality reference values of body composition are scarce, particularly in Asian population. The aim of study was to construct sex- and age-specific normative reference values of body composition for the Vietnamese population.

METHODS

This study was designed as a cross-sectional investigation that involved 2700 women and 1459 men aged between 20 and 90 (average 48, SD 15) who were participants in the population-based Vietnam Osteoporosis Study. Whole-body composition parameters (e.g., fat mass and lean mass) and site-specific (head, arms, trunk, and legs) parameters were measured by dual-energy X-ray absorptiometry (Hologic Horizon). Reference curves for each parameter and anatomical site were constructed using the Generalized Additive Model for Location Scale and Shape modeling technique.

RESULTS

Overall, 8% of women and 11% of men were classified as obese (body mass index ≥ 27.5 kg/m²). Most fat mass was deposited at the trunk (~50%), followed by the leg (~33%). Women had ~10% more body fat (relative to body weight) than men. However, whole-body lean mass was higher in men than women, with the average difference being ~13 kg. Moreover, men had more bone mineral content than women (2110 vs. 1600 g). We also provided a comparison of age-related changes in body composition parameters between Vietnamese and US Whites.

CONCLUSION

These data provide gender- and age-specific reference values of body composition parameters for Vietnamese population. These normative values provide health professionals and the public with a resource for interpretation of body composition data.

Global burden of noncommunicable disease attributable to high body mass index in 195 countries and territories, 1990-2017

PURPOSE

The increasing burden of noncommunicable diseases (NCDs) attributable to high body mass index (BMI) represents both a threat and an opportunity for intervention. Estimates of the global latest trend of high BMI-related NCDs and its association with socioeconomic status can facilitate strategic intervention and inform further research.

METHODS

This global burden of disease study extracted global, regional, and national data on death and disability-adjusted life years (DALYs) attributable to high BMI-related NCDs from the GBD Study 2017. Secondary analyses were performed by year, age, sex, and specific causes of death and DALYs. The 2017 Socio-demographic Index (SDI) was used as an indicator of national socioeconomic status. The association between age-standardized death or DALYs rate and socioeconomic status were analyzed.

RESULTS

Worldwide, 4.7 million deaths and 147.7 million DALYs of NCDs were related to high BMI in 2017, with a projection to 5.5 million deaths and 176.9 million DALYs in 2025. Globally, high BMI-related burden showed an increasing trend with males being more heavily impacted overall. The trend and magnitude of high BMI-related disease burden varied substantially in different geographical and socioeconomic regions. Specifically, the low-middle, middle, and high-middle SDI countries were associated with a higher burden. The leading three causes of DALYs attributable to high BMI in 2017 were ischemic heart diseases, stroke, and diabetes mellitus.

CONCLUSIONS

High BMI-related burden of NCDs is worsening, particularly in developing countries. Our findings may enhance public awareness of interventions to reduce the diseases burden caused by high BMI.

Koreans Do Not Have Higher Percent Body Fat than Australians: Implication for the Diagnosis of Obesity in Asians

OBJECTIVE

It has been assumed that, for a given BMI, Asians have higher percent body fat (PBF) than Caucasians. As a result, it has been suggested that the BMI threshold for diagnosing obesity in Asians be lowered to less than  30 kg/m² . This study sought to compare PBF between Koreans and Australians.

METHODS

Whole-body fat mass and PBF were measured in 1,211 Koreans and 1,006 Australians using dual-energy x-ray absorptiometry (Lunar Prodigy; GE Healthcare, Madison, Wisconsin). The two groups were then matched for age and BMI by the propensity score method.

RESULTS

For a given age and BMI, Koreans had lower PBF than Australians, and the difference was statistically significant in women (mean difference: -2.13%; 95% CI: -2.61% to -1.65%) but not in men (difference: -0.54%; 95% CI: -1.22% to 0.14%). Matched-pair analysis (423 pairs of women and 208 pairs of men) also showed that Korean women had statistically lower PBF than their Australian counterparts (P < 0.001).

CONCLUSIONS

In individuals aged 60 years and older, Koreans do not have higher PBF than Australians after adjusting for BMI. These results suggest that there is no evidence for lowering the BMI threshold for the diagnosis of obesity in elderly Koreans.

Variations in fat mass contribution to bone mineral density by gender, age, and body mass index: the Korea National Health and Nutrition Examination Survey (KNHANES) 2008-2011

The relationship of body composition and bone mineral density is complex and controversial. When classifying Korean population based on gender, age, and body mass index, fat mass had varying contributions to bone mineral density.

INTRODUCTION

The relationship between body composition and bone mineral density (BMD) is complex, and it is uncertain how components of body mass variably affect BMD.

METHODS

This cross-sectional observational study was performed in subjects ≥20 years based on the Korea National Health and Nutrition Examination Survey (KNHANES) 2008 to 2011. Among 17,583 subjects, the mean ages were 49.1 ± 16.0 years (M, n = 7495) and 49.3 ± 16.3 years (F, n = 10,088). Subjects were divided into age groups, either <50 or ≥50 years for males, or menopausal state, either premenopausal or postmenopausal, for females. A further classification used BMI, either <25 or ≥25 kg/m(2). Anthropometric and body composition parameters were compared and evaluated to look for correlations with BMD. Further, appendicular lean mass (ALM), fat mass (FM), fat percentage (FP), and waist circumference (WC) were included for multivariate analysis with BMD, controlling for covariates in each age group and BMI subgroup.

RESULTS

Anthropometric and body composition parameters significantly correlated with BMD in all age groups for both genders. After adjusting for covariates, ALM strongly affected BMD in all age groups for both genders. FM, FP, and WC significantly affected BMD in both age groups of women and in older men, but they did not affect BMD in younger men. Fat indices positively affected BMD of all sites in all non-obese women and in non-obese older men. However, little contribution was found in obese subgroups of both genders and in non-obese younger men.

CONCLUSION

Considering different weights of covariates, ALM strongly contributed to BMD in all gender, age, and BMI groups. On the other hand, fat indices positively affected BMD of both age groups in women and older men with normal BMI, but they showed little contribution to BMD within the same age groups with high BMI or any BMI subgroups of younger men.

Food cravings, food addiction, and a dopamine-resistant (DRD2 A1) receptor polymorphism in Asian American college students

BACKGROUND AND OBJECTIVES

In an era where obesity remains an important public health concern, food addiction has emerged as a possible contributor to obesity. The DRD2 gene is the most studied polymorphism. The aim of this study was to investigate a relationship between food addiction questionnaires, body composition measurements, and a dopamine- resistant receptor polymorphism (DRD2 A1) among Asian Americans.

METHODS AND STUDY DESIGN

A total of 84 Asian American college students were recruited. Participants underwent body composition measurement via bioelectrical impedance, answered questionnaires (Food Craving Inventory and Power of Food Scale), and had blood drawn for genotyping (PCR).

RESULTS

There was no difference in body composition (BMI, percent body fat) between the A1 (A1A1 or A1A2) and A2 (A2A2) groups. There were statistically significant differences in food cravings of carbohydrates and fast food on the Food Craving Inventory between the A1 and A2 groups (p=0.03), but not for sugar or fat. Among Asian college females, there was also a difference on the Power of Food questionnaire (p=0.04), which was not seen among men. 13 out of 55 women also had >30% body fat at a BMI of 21.4 to 28.5 kg/m2.

CONCLUSION

Greater carbohydrate and fast food craving was associated with the DRD2 A1 versus A2 allele among Asian Americans. Further studies examining the ability of dopamine agonists to affect food craving and to reduce body fat in Asian American are warranted. More studies in food addiction among obese Asian Americans are needed with careful definition of obesity, specifically for Asian women.

Relationship between Body Mass Index and Percent Body Fat in Vietnamese: Implications for the Diagnosis of Obesity

Background

The burden of obesity in Vietnam has not been well defined because there is a lack of reference data for percent body fat (PBF) in Asians. This study sought to define the relationship between PBF and body mass index (BMI) in the Vietnamese population.

Methods

The study was designed as a comparative cross-sectional investigation that involved 1217 individuals of Vietnamese background (862 women) aged 20 years and older (average age 47 yr) who were randomly selected from the general population in Ho Chi Minh City. Lean mass (LM) and fat mass (FM) were measured by DXA (Hologic QDR 4500). PBF was derived as FM over body weight.

Results

Based on BMI ≥30, the prevalence of obesity was 1.1% and 1.3% for men and women, respectively. The prevalence of overweight and obesity combined (BMI ≥25) was ~24% and ~19% in men and women, respectively. Based on the quadratic relationship between BMI and PBF, the approximate PBF corresponding to the BMI threshold of 30 (obese) was 30.5 in men and 41 in women. Using the criteria of PBF >30 in men and PBF >40 in women, approximately 15% of men and women were considered obese.

Conclusion

These data suggest that body mass index underestimates the prevalence of obesity. We suggest that a PBF >30 in men or PBF >40 in women is used as criteria for the diagnosis of obesity in Vietnamese adults. Using these criteria, 15% of Vietnamese adults in Ho Chi Minh City was considered obese.

Environmental fate and dietary exposures of humans to TCDD as a result of the spraying of Agent Orange in upland forests of Vietnam

The fate and transport of 2,3,7,8-tetrachloro-p-dibenzodioxin (TCDD) released into the environment of South Vietnam (SVN) as a consequence of the aerial application of the herbicidal defoliant Agent Orange (AO) were simulated for a generic upland forest scenario and followed over a 50-year period (1965, 1968 and 1970 onwards). Modeled concentrations of TCDD in the environment were then used as inputs to a human exposure model, which focused on long-term exposures via the food chain. Intake rates and body burdens of TCDD were estimated for adult males over the course of the simulation period and compared to available biomonitoring data. One of the most important factors determining the magnitude of the simulated human exposure to TCDD was the fraction of the chemical deposited directly to soil (where it was assumed to have a degradation half-life of 10 or 15years) relative to the fraction assumed to remain on/in the forest canopy following the spray application (where it was assumed to have a degradation half-life of ≤48h). The simulated body burdens under the various scenarios considered were broadly consistent with the biomonitoring data from SVN collected in the mid-1980s to late 1990s. Taken together, the modeling results and empirical data suggest that highly elevated exposures to TCDD (i.e., body burdens in the several 100s of pg/g lipid range and greater) were not common among people inhabiting upland forest locations in SVN sprayed with AO and that peak and average body burdens were broadly similar to those of the general population of the U.S. in the 1970s and early 1980s. The model-based assessment is consistent with the 'hot spot' hypothesis i.e., potential exposures to TCDD linked to activities conducted on or near former bases where AO was stored are greater than potential exposures in areas subjected to aerial spraying.

Population differences in the relationship between height, weight, and adiposity: an application of Burton's model

The study of human variation in adiposity and lean mass is important for understanding core processes in human evolution, and is increasingly a public health concern as the "obesity epidemic" expands globally. The dominant measure of population differences in adiposity is Body Mass Index (BMI), which suffers from systematic biases across populations due to variation in the relationship between true body fat, height and weight. Here we develop simplified corrections for such anthropometric-based measures of adiposity that can take into account this population variation. These corrections derive from a recent model proposed by Burton that assumes humans accrue mass in two ways-growth in height that adds bone and muscle, and growth in body fat and the ancillary fat-free mass (FFM) needed to support this additional body fat. We analyze two ethnically diverse datasets with dual X-ray absorptiometry-measured (DXA) fat mass, assessing the fit of Burton's model and deriving novel corrections based on estimated musculoskeletal slenderness. The resulting model provides excellent fit to fat mass within populations (average R2 = 0.92 for women and R2 = 0.83 for men). World populations differ dramatically in musculoskeletal slenderness (up to a difference of 4.4 kg/m2), as do men and women (differences of 3.3-4.5 kg/m2), leading to clear population corrections. These findings point to a conceptually straightforward tool for estimating true differences in adiposity across populations, and suggest an alternative to BMI that provides a more accurate and theoretically based estimate of body fat than that traditionally derived from height and weight measures.

Vitamin D deficiency is correlated with poor outcomes in patients with luminal-type breast cancer

Purpose

Vitamin D deficiency may be an indicator of poor prognosis in patients with breast cancer before surgery. We investigated the association between serum vitamin D concentration and breast cancer prognosis according to intrinsic cancer subtypes.

Methods

From June to December 2006, serum 25-OHD was measured in 310 Korean women with breast cancer who were treated at the Asan Medical Center, Korea. Clinicopathologic data were examined to determine the prognostic effects of serum 25-OHD. Expression of estrogen receptor (ER), progesterone receptor (PR), and epidermal growth factor receptor 2 (Her2) were measured using tissue microarrays. Patients were classified with luminal A, luminal B, Her2-enriched, or basal-like subtypes of breast cancer.

Results

Mean patient age was 48.7 years, and mean serum 25-OHD concentration was 31.4 ± 16.1 ng/ml. The 25-OHD levels were deficient (< 20 ng/ml) in 75 patients (24.2%), insufficient (20–29 ng/ml) in 95 (30.6%), and sufficient (30–150 ng/ml) in 140 (45.2%). Women with deficient 25-OHD levels were at increased risk of recurrence compared with those with sufficient vitamin D levels (P = 0.002). The 25-OHD concentration was inversely associated with prognosis of patients with cancer of the luminal A (P = 0.012) and luminal B subtypes (P = 0.023), but not with the prognosis of patients with Her2/neu-enriched (P = 0.245) or triple-negative (P = 0.879) cancer subtypes. This association remained valid after adjustment for age, tumor size, nodal status, and estrogen receptor status (hazards ratio = 3.97; 95% confidence interval = 1.77–9.61).

Conclusions

Vitamin D deficiency may be associated with poor outcomes in patients with luminal-type breast cancer.