Is the current BMI obesity classification appropriate for black and white postmenopausal women?

Association between egg consumption and risk of obesity: A comprehensive review: EGG CONSUMPTION AND OBESITY

Eggs serve as a vital source of high-quality protein and lipids in the human diet, contributing significantly to nutritional intake; however, the relation between egg intake and health risks has been controversial. This study aimed to assess the relationship between egg intake and obesity and the effects of the various nutrients in eggs on obesity were separately investigated. This review involved searching Scopus, PubMed, Google Scholar for relevant articles from 2002 to 2022. Studies suggested that moderate egg consumption exerts little effect on blood lipid levels, that due to the body regulates endogenous cholesterol production in response to the external cholesterol intake. Furthermore, certain studies also verified that the presence of other nutrients in eggs, such as lecithin, unsaturated fatty acids, and apolipoproteins, not only does not contribute to elevated blood lipids but also plays a role in regulating lipid metabolism to prevent obesity. Additionally, the study reveals that different cooking methods significantly impact the nutritional composition of eggs, with soft-boiled eggs generally being the most advantageous for human health. This article reveals that dietary cholesterol or moderate egg intake was not significantly associated with a higher risk of obesity in healthy adults. Nevertheless, cholesterol-sensitive individuals should ensure moderate cholesterol intake.

Analysis of body composition, functionality and muscle-specific strength of older women with obesity, sarcopenia and sarcopenic obesity: a cross-sectional study

During aging, changes in body composition can result in sarcopenic obesity, which is a condition in which obesity occurs accompanied by the loss of muscle mass and strength caused by sarcopenia. Although the effects of obesity and sarcopenia on body composition are known, the muscle-specific strength in older women with sarcopenic obesity remains under-researched. The objective of this study was to evaluate community-dwelling older women for the absence or presence of obesity, sarcopenia and sarcopenic obesity and compare them in terms of body composition, functional physical performance and muscle-specific strength. One hundred and fifty-six older women (± 74 years) were evaluated for body composition using Dual X-ray Absorptiometry, handgrip strength with a Jamar dynamometer and functional performance using gait speed and timed up and go tests. The presence of obesity, sarcopenia and sarcopenic obesity was found in 32.7%, 15.4% and 25% of the sample, respectively. Comparing groups, community-dwelling older women with sarcopenic obesity exhibited poorer functional physical performance (TUG ± 14 s), and lower muscle-specific strength (± 1.18). Sarcopenic obesity was associated with muscle-specific strength (95% IC 0.016-0.241), and TUG (95% CI 1.001-1.137). These findings indicate that the combination of obesity and sarcopenia has a negative impact on skeletal muscle, reducing muscle-specific strength and physical performance in older women with more declines than either disease alone. Therefore, this comprehensive assessment gives useful information for incorporating muscle-specific strength into the diagnosis of sarcopenic obesity in the older people.

Age-appropriate BMI cut-offs for malnutrition among older adults in India

With the increasing prevalence of obesity in India, body mass index (BMI) has garnered importance as a disease predictor. The current World Health Organization (WHO) body mass index (BMI) cut-offs may not accurately portray these health risks in older adults aged 60 years and above. This study aims to define age-appropriate cut-offs for older adults (60-74 years and 75 years and above) and compare the performance of these cut-offs with the WHO BMI cut-offs using cardio-metabolic conditions as outcomes. Using baseline data from the Longitudinal Ageing Study in India (LASI), classification and regression tree (CART) cross-sectional analysis was conducted to obtain age-appropriate BMI cut-offs based on cardio-metabolic conditions as outcomes. Logistic regression models were estimated to compare the association of the two sets of cut-offs with cardio-metabolic outcomes. The area under the receiver operating characteristic curve (AUC), sensitivity and specificity were estimated. Agreement with waist circumference, an alternate measure of adiposity, was conducted. For older adults aged 60-74 years and 75 years and above, the cut-off for underweight reduced from < 18.5 to < 17.4 and < 13.3 respectively. The thresholds for overweight and obese increased for older adults aged 60-74 years old from >  = 25 to > 28.8 and >  = 30 to > 33.7 respectively. For older adults aged 75 years and above, the thresholds decreased for both categories. The largest improvement in AUC was observed in older adults aged 75 years and above. The newly derived cut-offs also demonstrated higher sensitivity and specificity among all age-sex stratifications. There is a need to adopt greater rigidity in defining overweight/obesity among older adults aged 75 years and above, as opposed to older adults aged 60-74 years old among whom the thresholds need to be less conservative. Further stratification in the low risk category could also improve BMI classification among older adults. These age-specific thresholds may act as improved alternatives of the current WHO BMI thresholds and improve classification among older adults in India.

Midlife body mass index, central adiposity and neuropsychological performance over 10 years in women living with and without HIV

Background and objective

Observations of overweight and obesity in association with neuropsychological performance (NP) vary over the adult life course depending on baseline levels, biological sex, age, race, temporality of measurements, and other factors. Therefore, similar published analyses across cohorts are inconsistent. In our sample of women living with HIV (WLWH) and women without HIV (WWOH), we conducted comparable analyses as those published in men with and without HIV. We examined cross-sectional and longitudinal associations between body mass index (BMI) and waist circumference (WC) and NP.

Methods

Four hundred thirty two 432 virologically-suppressed WLWH and 367 WWOH, ≥40 years in the Women's Interagency HIV Study (WIHS) with anthropometry and NP assessments every two years from 2009-2019 were included in the study. Demographically-adjusted T-scores were calculated for six NP domains: learning, memory, executive function, processing speed, attention and working memory, and motor function. Multivariable linear regression models stratified by HIV status were used to examine cross-sectional associations of BMI and WC by NP domain; repeated measures analyses assessed baseline BMI and WC in association with longitudinal change in NP. Covariates included sociodemographic, behavioral, and HIV-related characteristics.

Results

At baseline among all women, the median age was 45 years, 65% were Non-Latinx Black women, and 45% were obese women. Obese WLWH (BMI≥30.0 kg/m2) had poorer executive function (β=-2.27, 95%CI [-4.46, -0.07]) versus WLWH with healthy BMI (18.5-24.9 kg/m2). Longitudinally over ~8 years, obese versus overweight WWOH improved on memory (β=2.19, 95%CI [0.13, 4.26]), however overweight versus healthy WWOH experienced declining memory (β= -2.67, 95%CI [-5.40, -0.07]). Increasing WC was associated with declining executive, processing speed, and motor function (p's<0.05); an at-risk WC was associated with improved memory (β=1.81, 95%CI [0.19, 3.44]) among WWOH. Among WLWH, increasing BMI was associated with improved learning (β=0.07, 95%CI [0.00, 0.15].

Conclusion

Our cross-sectional and longitudinal analyses evaluating the associations of BMI and WC and NP were mixed compared to previous reports. This illustrates the importance of sociodemographic characteristics, baseline levels of exposures and outcomes, HIV status, temporality of measurements, and other factors when evaluating aging HIV epidemiology study results.

Characterising the prevalence of overweight and obese status among adults with sickle cell disease

Individuals with sickle cell disease (SCD) have historically been considered underweight. Despite increasing body mass index (BMI) in the general population, the prevalence of overweight and obese status remains unclear in the adult SCD population. Our primary aim was to determine the prevalence of overweight and obese status and to identify associations between BMI, demographic, and clinical characteristics. We conducted an analysis of abstracted electronic health record data and patient-reported outcomes from the Sickle Cell Disease Implementation Consortium registry; individuals aged 20-45 years were included. The median (interquartile range) BMI for the 1664 adults in this analysis was 23.9 (21.1-28) kg/m2 . In this cohort, 42.9% had a BMI of >25 kg/m2 (Centers for Disease Control and Prevention definition of overweight/obese). In multivariable analysis, higher odds of being overweight or obese were associated with female gender, older age, college education, private insurance, and hypertension diagnosis. Higher odds of a BMI of >25 kg/m2 were observed in individuals with HbSC or HbSβ+ thalassaemia regardless of hydroxycarbamide (hydroxyurea) exposure (odds ratio [OR] 3.4, p < 0.0001) and HbSS or HbSβ0 thalassaemia exposed to hydroxycarbamide (OR 1.6, p = 0.0003) compared to those with HbSS or HbSβ0 thalassaemia with no hydroxycarbamide exposure. These data highlight the importance of early identification, prevention, and intervention for increasing BMI to reduce obesity-related complications that may impact SCD-related complications.

New BMI Cut-Off Points for Obesity in Middle-Aged and Older Adults in Clinical Nutrition Settings in Italy: A Cross-Sectional Study

Obesity is a major health problem defined as an excess accumulation of body fat (BF). The World Health Organization (WHO) usually relies on a body mass index (BMI) ≥ 30 kg/m2 as an indicator of obesity. Due to changes in body composition that occur across the lifespan, with an increase in BF and a decrease in lean mass, we aimed to test the validity of this BMI cut-off point for adiposity in middle-aged and older adults. This cross-sectional study, composed of 4800 adults of mixed gender aged between 40 and 80 years, included (according to the WHO BMI classification) 1087 normal-weight, 1826 overweight, and 1887 obese individuals who were referred to the Department of Biomedicine and Prevention, University of Rome "Tor Vergata", Italy. The sample was then categorized by adiposity status based on the total BF% as measured by dual-energy X-ray absorptiometry (DXA), and the best sensitivity and specificity were attained for predicting obesity according to the receiver operating characteristic curve (ROC) analysis. In a real-world clinical setting, a new BMI cut-off point (BMI = 27.27 kg/m2) has been identified for predicting obesity in middle-aged and older adults. Obesity guidelines in Italy therefore need to be revised accordingly.

Influence of Rolfing Structural Integration on Active Range of Motion: A Retrospective Cohort Study

Background: Recent work has investigated significant force transmission between the components of myofascial chains. Misalignments in the body due to fascial thickening and shortening can therefore lead to complex compensatory patterns. For the treatment of such nonlinear cause−effect pathology, comprehensive neuromusculoskeletal therapy such as the Rolf Method of Structural Integration (SI) could be targeted. Methods: A total of 727 subjects were retrospectively screened from the medical records of an SI practice over a 23-year period. A total of 383 subjects who had completed 10 basic SI sessions met eligibility criteria and were assessed for active range of motion (AROM) of the shoulder and hip before and after SI treatment. Results: Shoulder flexion, external and internal rotation, and hip flexion improved significantly (all p < 0.0001) after 10 SI sessions. Left shoulder flexion and external rotation of both shoulders increased more in men than in women (p < 0.0001) but were not affected by age. Conclusions: An SI intervention could produce multiple changes in the components of myofascial chains that could help maintain upright posture in humans and reduce inadequate compensatory patterns. SI may also affect differently the outcome of some AROM parameters in women and men.

Obesity, Body Composition, and Sex Hormones: Implications for Cardiovascular Risk

Cardiovascular disease (CVD) continues to be the leading cause of death in adults, highlighting the need to develop novel strategies to mitigate cardiovascular risk. The advancing obesity epidemic is now threatening the gains in CVD risk reduction brought about by contemporary pharmaceutical and surgical interventions. There are sex differences in the development and outcomes of CVD; premenopausal women have significantly lower CVD risk than men of the same age, but women lose this advantage as they transition to menopause, an observation suggesting potential role of sex hormones in determining CVD risk. Clear differences in obesity and regional fat distribution among men and women also exist. While men have relatively high fat in the abdominal area, women tend to distribute a larger proportion of their fat in the lower body. Considering that regional body fat distribution is an important CVD risk factor, differences in how men and women store their body fat may partly contribute to sex-based alterations in CVD risk as well. This article presents findings related to the role of obesity and sex hormones in determining CVD risk. Evidence for the role of sex hormones in determining body composition in men and women is also presented. Lastly, the clinical potential for using sex hormones to alter body composition and reduce CVD risk is outlined. © 2022 American Physiological Society. Compr Physiol 12:1-45, 2022.

Associations between DNA methylation and BMI vary by metabolic health status: a potential link to disparate cardiovascular outcomes

Background

Body mass index (BMI), a well-known risk factor for poor cardiovascular outcomes, is associated with differential DNA methylation (DNAm). Similarly, metabolic health has also been associated with changes in DNAm. It is unclear how overall metabolic health outside of BMI may modify the relationship between BMI and methylation profiles, and what consequences this may have on downstream cardiovascular disease. The purpose of this study was to identify cytosine-phosphate-guanine (CpG) sites at which the association between BMI and DNAm could be modified by overall metabolic health.

Results

The discovery study population was derived from three Women’s Health Initiative (WHI) ancillary studies (n = 3977) and two Atherosclerosis Risk in Communities (ARIC) ancillary studies (n = 3520). Findings were validated in the Multi-Ethnic Study of Atherosclerosis (MESA) cohort (n = 1200). Generalized linear models regressed methylation β values on the interaction between BMI and metabolic health Z score (BMI × MHZ) adjusted for BMI, MHZ, cell composition, chip number and location, study characteristics, top three ancestry principal components, smoking, age, ethnicity (WHI), and sex (ARIC). Among the 429,566 sites examined, differential associations between BMI × MHZ and DNAm were identified at 22 CpG sites (FDR q < 0.05), with one site replicated in MESA (cg18989722, in the TRAPPC9 gene). Three of the 22 sites were associated with incident coronary heart disease (CHD) in WHI. For each 0.01 unit increase in DNAm β value, the risk of incident CHD increased by 9% in one site and decreased by 6–10% in two sites over 25 years.

Conclusions

Differential associations between DNAm and BMI by MHZ were identified at 22 sites, one of which was validated (cg18989722) and three of which were predictive of incident CHD. These sites are located in several genes related to NF-kappa-B signaling, suggesting a potential role for inflammation between DNA methylation and BMI-associated metabolic health.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13148-021-01194-3.

Body weight and self-perception are associated with depression: Results from the National Health and Nutrition Examination Survey (NHANES) 2005-2016

BACKGROUND

Despite evidence suggesting that perceptual body image measurements are strongly associated with depression, few studies examined the association between perceptual body image and depression in adults. This study aimed to investigate the association of different measures of perceptual body image measurements with depression.

METHODS

We analyzed data of 22,735 adults participating in the National Health and Nutrition Examination Survey between 2005 and 2016. Depression was ascertained using the validated Patient Health Questionnaire (PHQ-9) and depression was defined as PHQ score ≥10. The associations of measured body mass index (BMI) and body image (i.e., self-reported BMI, BMI discordance, perceived weight, and desired weight) with depression were assessed using logistic regression.

RESULTS

Women perceiving themselves as overweight or reporting their BMI as obese had significantly higher odds of depression (odds ratio [OR] 1.48, 95% confidence interval [CI] 1.17-1.72 and 1.29, 1.04-1.60, respectively) compared to women perceiving themselves as about the right weight or reporting their BMI as normal. The association between perceived overweight and depression was independent of measured BMI (OR 1.37, 95% CI 1.09-1.72). Men perceiving themselves as underweight had higher odds of depression (OR 1.50, 95% CI 1.06-2.11) than men perceiving themselves as about the right weight. In women, but not in men, measured obesity was associated with higher odds of depression.

LIMITATIONS

The study's cross-sectional design and missing information on comorbidities.

CONCLUSION

Weight perception (in women and men), measured BMI and BMI discordance in women are associated with depression..

The performance of anthropometric tools to determine obesity: a systematic review and meta-analysis

The aim of this systematic review was to assess the performance of anthropometric tools to determine obesity in the general population (CRD42018086888). Our review included 32 studies. To detect obesity with body mass index (BMI), the meta-analyses rendered a sensitivity of 51.4% (95% CI 38.5-64.2%) and a specificity of 95.4% (95% CI 90.7-97.8%) in women, and 49.6% (95% CI 34.8-64.5%) and 97.3% (95% CI 92.1-99.1%), respectively, in men. For waist circumference (WC), the summary estimates for the sensitivity were 62.4% (95% CI 49.2-73.9%) and 88.1% for the specificity (95% CI 77.0-94.2%) in men, and 57.0% (95% CI 32.2-79.0%) and 94.8% (95% CI 85.8-98.2%), respectively, in women. The data were insufficient to pool the results for waist-to-hip ratio (WHR) and waist-to-height ratio (WHtR) but were similar to BMI and WC. In conclusion, BMI and WC have serious limitations for use as obesity screening tools in clinical practice despite their widespread use. No evidence supports that WHR and WHtR are more suitable than BMI or WC to assess body fat. However, due to the lack of more accurate and feasible alternatives, BMI and WC might still have a role as initial tools for assessing individuals for excess adiposity until new evidence emerges.

Obesity and cardiovascular disease risk among Africans residing in Europe and Africa: the RODAM study

BACKGROUND

The association between anthropometric variables and cardiovascular disease (CVD) risk among Africans is unclear. We examined the discriminative ability of anthropometric variables and estimate cutoffs for predicting CVD risk among Africans.

METHODS

The Research on Obesity and Diabetes among African Migrants (RODAM) study was a multisite cross-sectional study of Africans in Ghana and Europe. We calculated AHA/ACC Pooled Cohort Equations (PCE) scores for 3661 participants to ascertain CVD risk, and compared a body shape index (ABSI), body mass index (BMI), waist circumference (WC), waist-to-hip ratio (WHR), Relative Fat Mass (RFM), and Waist to Height Ratio (WHtR). Logistic regression and receiver operating curve analyses were performed to derive cutoffs for identifying high predicted CVD risk (PCE score ≥7.5%).

RESULTS

Among men, WC (adjusted Odds Ratio (aOR): 2.25, 95% CI; 1:50-3:37) was strongly associated with CVD risk. Among women, WC (aOR: 1.69, 95% CI: 1:33-2:14) also displayed the strongest association with CVD risk in the BMI-adjusted model but WHR displayed the strongest fit. All variables were superior discriminators of high CVD risk in men (c-statistic range: 0.887-0.891) than women (c-statistic range: 0.677-0.707). The optimal WC cutoff for identifying participants at high CVD risk was 89 cm among men and identified the most cases (64%). Among women, the recommended WC cutoff of 94 cm or WHR cutoff of 0.90 identified the most cases (92%).

CONCLUSIONS

Anthropometric variables were stronger discriminators of high CVD risk in African men than women. Greater WC was associated with high CVD risk in men while WHR and WC were associated with high CVD risk in women.

Racial Disparity in the Sex Distribution, the Prevalence, and the Incidence of Dysplasia in Barrett's Esophagus

GOALS

Our aim was to study the prevalence of dysplasia and progression to high-grade dysplasia (HGD) and esophageal adenocarcinoma (EAC) in African Americans (AA) with Barrett's esophagus (BE) and compare it with that of non-Hispanic white (NHW) controls.

BACKGROUND

BE, a precursor of EAC, is a disease of predominantly white men and is uncommon in AA. The prevalence of dysplasia and progression to HGD and EAC in AA patients with BE is not clearly known.

STUDY

All AA or NHW patients with confirmed BE, that is specialized intestinal metaplasia, seen between 2002 and 2013 at our institution were included. Variables such as age, gender, medication use, the body mass index, the date of endoscopy, the hiatal hernia size, the BE length, and histologic findings were noted. Progression to HGD/EAC was evaluated.

RESULTS

Fifty-two AA and 2394 NHW patients with BE were identified. There was a higher percentage of women in the AA cohort (46.2%) than in the NHW cohort (24.9%, P<0.001). Nondysplastic BE was more prevalent in AA than in NHW (80.8% vs. 68.4%, P=0.058). In the surveillance cohort of 20 AA and 991 NHW, no racial differences in progression to HGD/EAC were observed during a median follow-up of 43 months.

CONCLUSIONS

This study includes the largest number of AA with histologically confirmed BE reported so far. About 46.2% of the AA cohort with BE in our study consisted of women. There was a trend toward a higher prevalence of nondysplastic BE in AA compared with NHW.

Body Mass Index Is a Better Indicator of Body Composition than Weight-for-Length at Age 1 Month

OBJECTIVE

To assess whether body mass index (BMI) provides a better assessment of measured adiposity at age 1 month compared with weight-for-length (WFL).

STUDY DESIGN

Participants were healthy term-born infants in the Infant Growth and Microbiome (n = 146) and the Baby Peas (n = 147) studies. Length, weight, and body composition by air displacement plethysmography were measured at 1 month. World Health Organization-based WFL and BMI z-scores were calculated. Within-cohort z-scores of percent fat-Z, fat mass-Z, fat mass/length2-Z, fat mass/length3-Z, fat-free mass-Z, and fat-free mass/length2-Z were calculated. Correlation and multiple linear regression (adjusted for birth weight) analyses tested the associations between body composition outcomes and BMI-Z vs WFL-Z. Quantile regression was used to test the stability of these associations across the distribution of body compositions.

RESULTS

The sample was 52% female and 56% African American. Accounting for birth weight, both BMI-Z and WFL-Z were strongly associated with fat mass-Z (coefficients 0.56 and 0.35, respectively), FM/L2-Z (0.73 and 0.51), and FM/L3-Z (0.79 and 0.58), with stronger associations for BMI-Z compared with WFL-Z (P < .05). Even after accounting statistically for birth weight, BMI-Z was persistently more strongly associated than WFL-Z with body composition outcomes across the distribution of body composition outcomes.

CONCLUSIONS

We demonstrate in 2 distinct cohorts that BMI is a better indicator of adiposity in early infancy compared with WFL. Our findings support the preferred use of BMI for growth and nutritional status assessment in infancy.

Stratified Probabilistic Bias Analysis for Body Mass Index-related Exposure Misclassification in Postmenopausal Women

BACKGROUND

There is widespread concern about the use of body mass index (BMI) to define obesity status in postmenopausal women because it may not accurately represent an individual's true obesity status. The objective of the present study is to examine and adjust for exposure misclassification bias from using an indirect measure of obesity (BMI) compared with a direct measure of obesity (percent body fat).

METHODS

We used data from postmenopausal non-Hispanic black and non-Hispanic white women in the Women's Health Initiative (n=126,459). Within the Women's Health Initiative, a sample of 11,018 women were invited to participate in a sub-study involving dual-energy x-ray absorptiometry scans. We examined indices of validity comparing BMI-defined obesity (≥30 kg/m), with obesity defined by percent body fat. We then used probabilistic bias analysis models stratified by age and race to explore the effect of exposure misclassification on the obesity-mortality relationship.

RESULTS

Validation analyses highlight that using a BMI cutpoint of 30 kg/m to define obesity in postmenopausal women is associated with poor validity. There were notable differences in sensitivity by age and race. Results from the stratified bias analysis demonstrated that failing to adjust for exposure misclassification bias results in attenuated estimates of the obesity-mortality relationship. For example, in non-Hispanic white women 50-59 years of age, the conventional risk difference was 0.017 (95% confidence interval = 0.01, 0.023) and the bias-adjusted risk difference was 0.035 (95% simulation interval = 0.028, 0.043).

CONCLUSIONS

These results demonstrate the importance of using quantitative bias analysis techniques to account for nondifferential exposure misclassification of BMI-defined obesity. See video abstract at, http://links.lww.com/EDE/B385.

Is BMI a valid measure of obesity in postmenopausal women?

OBJECTIVE

Body mass index (BMI) is a widely used indicator of obesity status in clinical settings and population health research. However, there are concerns about the validity of BMI as a measure of obesity in postmenopausal women. Unlike BMI, which is an indirect measure of obesity and does not distinguish lean from fat mass, dual-energy x-ray absorptiometry (DXA) provides a direct measure of body fat and is considered a gold standard of adiposity measurement. The goal of this study is to examine the validity of using BMI to identify obesity in postmenopausal women relative to total body fat percent measured by DXA scan.

METHODS

Data from 1,329 postmenopausal women participating in the Buffalo OsteoPerio Study were used in this analysis. At baseline, women ranged in age from 53 to 85 years. Obesity was defined as BMI ≥ 30 kg/m and body fat percent (BF%) greater than 35%, 38%, or 40%. We calculated sensitivity, specificity, positive predictive value, and negative predictive value to evaluate the validity of BMI-defined obesity relative BF%. We further explored the validity of BMI relative to BF% using graphical tools, such as scatterplots and receiver-operating characteristic curves. Youden's J index was used to determine the empirical optimal BMI cut-point for each level of BF% defined obesity.

RESULTS

The sensitivity of BMI-defined obesity was 32.4% for 35% body fat, 44.6% for 38% body fat, and 55.2% for 40% body fat. Corresponding specificity values were 99.3%, 97.1%, and 94.6%, respectively. The empirical optimal BMI cut-point to define obesity is 24.9 kg/m for 35% BF, 26.49 kg/m for 38% BF, and 27.05 kg/m for 40% BF according to the Youden's index.

CONCLUSIONS

Results demonstrate that a BMI cut-point of 30 kg/m does not appear to be an appropriate indicator of true obesity status in postmenopausal women. Empirical estimates of the validity of BMI from this study may be used by other investigators to account for BMI-related misclassification in older women.

The Prevalence of Overfat Adults and Children in the US

The overfat condition is defined as excess body fat sufficient to impair health. The problem exists in most overweight and obese individuals and can also occur in those who are normal-weight and non-obese, often due to excess abdominal fat. Despite previous indications that the prevalence overweight and obesity is leveling, these conditions are currently at their highest levels in US history. Our review estimated the number of overfat Americans at 91% for adults and 69% for children. The primary purpose of this review was to build upon previous estimations of overfat prevalence in developed countries by using new data from the Centers for Disease Control and Prevention to estimate the overfat prevalence in American adults (≥20 years) and children (2-19 years), and to expand the definition of overfat as excess body fat associated with at least one additional risk factor of impaired cardiometabolic or physical health. The secondary goals are to highlight the role of dietary sugar as a primary cause of the overfat pandemic and mention new data showing the increased prevalence of exercise that parallels the rising prevalence of overfat to further emphasize the secondary role exercise may play in fat loss. Current public health guidelines to address the overfat pandemic may require more emphasis on reducing the consumption of refined carbohydrates, including added sugars.

Race and Obesity in Adolescent Hypertension

BACKGROUND AND OBJECTIVES

The overall prevalence of essential hypertension in adolescents may be growing. Differences in blood pressure (BP) are well established in adults, but are less clear in adolescents. We hypothesize that the prevalence of hypertension differs by race/ethnicity among adolescents at school-based screenings.

METHODS

We performed school-based BP screening in over 20 000 adolescents from 2000 to 2015. Race/ethnicity was self-reported. Height and weight were measured to determine BMI, and BP status was confirmed on 3 occasions to diagnose sustained hypertension according to Fourth Working Group Report criteria.

RESULTS

We successfully screened 21 062 adolescents aged 10 to 19 years (mean, 13.8 years). The final prevalence of sustained hypertension in all subjects was 2.7%. Obesity rates were highest among African American (3.1%) and Hispanic (2.7%) adolescents. The highest rate of hypertension was seen in Hispanic (3.1%), followed by African American (2.7%), white (2.6%), and Asian (1.7%) adolescents (P = .019). However, obese white adolescents had the highest prevalence of sustained hypertension (7.4%) compared with obese African American adolescents (4.5%, P < .001). At lower BMI percentiles (<60th percentile), Hispanic adolescents actually had the lowest predicted prevalence of hypertension among the 4 groups.

CONCLUSIONS

The prevalence of hypertension varies among different race/ethnicities. Although obesity remains the strongest predictor of early hypertension, the strength of this relationship is intensified in Hispanic and white adolescents, whereas it is lessened in African American adolescents.

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

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

Limitations of body mass index for counseling individuals with unilateral lower extremity amputation

BACKGROUND

Body composition is important for health screening, but appropriate methods for unilateral lower extremity amputees have not been validated.

OBJECTIVES

To compare body mass index adjusted using Amputee Coalition equations (body mass index-Amputee Coalition) to dual-energy X-ray absorptiometry in unilateral lower limb amputees.

STUDY DESIGN

Cross-sectional, experimental.

METHODS

Thirty-eight men and women with lower limb amputations (transfemoral, transtibial, hip disarticulation, Symes) participated. Body mass index (mass/height²) was compared to body mass index corrected for limb loss (body mass index-Amputee Coalition). Accuracy of classification and extrapolation of percent body fat with body mass index was compared to dual-energy X-ray absorptiometry.

RESULTS

Body mass index-Amputee Coalition increased body mass index (by ~ 1.1 kg/m²) but underestimated and mis-classified 60% of obese and overestimated 100% of lean individuals according to dual-energy X-ray absorptiometry. Estimated mean percent body fat (95% confidence interval) from body mass index-Amputee Coalition (28.3% (24.9%, 31.7%)) was similar to dual-energy X-ray absorptiometry percent body fat (29.5% (25.2%, 33.7%)) but both were significantly higher ( p < 0.05) than percent body fat estimated from uncorrected body mass index (23.6% (20.4%, 26.8%)). However, total errors for body mass index and body mass index-Amputee Coalition converted to percent body fat were unacceptably large (standard error of the estimate = 6.8%, 6.2% body fat) and the discrepancy between both methods and dual-energy X-ray absorptiometry was inversely related ( r = -0.59 and r = -0.66, p < 0.05) to the individual's level of body fatness.

CONCLUSIONS

Body mass index (despite correction) underestimates health risk for obese patients and overestimates lean, muscular individuals with lower limb amputation. Clinical relevance Clinical recommendations for an ideal body mass based on body mass index-Amputee Coalition should not be relied upon in lower extremity amputees. This is of particular concern for obese lower extremity amputees whose health risk might be significantly underestimated based on body mass index despite a "correction" formula for limb loss.

Healthy obesity as an intermediate state of risk: a critical review

Obesity is a top public health priority but interventions to reverse the condition have had limited success. About one-in-three obese adults are free of metabolic risk factor clustering and are considered 'healthy', and much attention has focused on the implications of this state for obesity management. Areas covered: We searched for individual studies, systematic reviews, and meta-analyses which examined correlates and outcomes of metabolically healthy obesity. We discuss the key roles of fat distribution and physical activity in determining healthy vs. unhealthy obesity and report a greatly increased risk of incident type 2 diabetes associated with healthy obesity vs. healthy normal weight, among other outcomes. We argue that despite inconsistencies in the definition, patterns across studies clearly show that healthy obesity is a state of intermediate disease risk. Expert commentary: Given the current state of population-level evidence, we conclude that obesity and metabolic dysfunction are inseparable and that healthy obesity is best viewed only as a state of relative health but not of absolute health. We recommend that weight loss through energy restriction be a stand-alone target in addition to increased physical activity for minimising risk of future disease.

Health Behavior and Metabolic Risk Factors Associated with Normal Weight Obesity in Adolescents

OBJECTIVE

To explore health behaviors and metabolic risk factors in normal weight obese (NWO) adolescents compared with normal weight lean (NWL) peers.

DESIGN AND METHODS

A cross-sectional study of 18-year-old students (n = 182, 47% female) in the capital area of Iceland, with body mass index within normal range (BMI, 18.5-24.9 kg/m2). Body composition was estimated via dual energy X-ray absorptiometry, fitness was assessed with maximal oxygen uptake (VO2max) during treadmill test, dietary intake through 24-hour recall, questionnaires explained health behavior and fasting blood samples were taken. NWO was defined as normal BMI and body fat >17.6% in males and >31.6% in females.

RESULTS

Among normal weight adolescents, 42% (n = 76) were defined as NWO, thereof 61% (n = 46) male participants. Fewer participants with NWO were physically active, ate breakfast on a regular basis, and consumed vegetables frequently compared with NWL. No difference was detected between the two groups in energy- and nutrient intake. The mean difference in aerobic fitness was 5.1 ml/kg/min between the groups in favor of the NWL group (p<0.001). NWO was positively associated with having one or more risk factors for metabolic syndrome (Odds Ratio OR = 2.2; 95% confidence interval CI: 1.2, 3.9) when adjusted for sex. High waist circumference was more prevalent among NWO than NWL, but only among girls (13% vs 4%, p = 0.019).

CONCLUSIONS

High prevalence of NWO was observed in the study group. Promoting healthy lifestyle with regard to nutrition and physical activity in early life should be emphasized regardless of BMI.

Trend of Body Compositions with Aging among Chinese Adolescents, Adults and Elders

INTRODUCTION

Rare reports can be found about sex- and age-specific body composition survey among Chinese population. The aim of this study is to explore the change of sex-specific body compositions with aging among Chinese adolescents, adults and elders.

METHODS

In a large-scale population survey about physiological constants and health conditions, 75,714 subjects who aged from 8 to 80 completed body composition array. Body mass index (BMI), percentage body fat (PBF), water percentage of body weight (WPBW), water percentage of lean body mass (WPLBM), fat-free mass index (FFMI) and basic metabolic rate were examined with Biodynamics BI-310 body composition analyzer. General obesity is defined as BMI equal to or greater than 28 kg/m2.

RESULTS

The prevalence rates of general obesity were 9.4% for males and 7.7% for females respectively. With aging, PBF and FMI showed a U-shape curvilinear trend and WPBW showed a parabolic trend for males. At same age group: 18-19 age groups, PBF and FMI declined to the valley and WPBW rose to the peak. For females, PBF, WPBW and FMI changed in a linear trend. The values of WPLBM and FFMI showed same curvilinear trend for two genders. WPLBM changed in a U-shape trend and touched the valley in twenties for males and in 18-19 age groups for females. The value of FFMI was larger for older age groups in the younger generation but smaller in the older generation. A parabolic trend peaking was seen in the thirties for males and in the forties for females. Regression models with age as independent variable showed that the larger rate of increase of PBF and smaller rates of increase for WPBM and WPLBM with aging for males.

CONCLUSION

This study presents detailed data about sex-specific body composition conditions. Different change trend with aging was found about body composition conditions.

Using Blood Indexes to Predict Overweight Statuses: An Extreme Learning Machine-Based Approach

The number of the overweight people continues to rise across the world. Studies have shown that being overweight can increase health risks, such as high blood pressure, diabetes mellitus, coronary heart disease, and certain forms of cancer. Therefore, identifying the overweight status in people is critical to prevent and decrease health risks. This study explores a new technique that uses blood and biochemical measurements to recognize the overweight condition. A new machine learning technique, an extreme learning machine, was developed to accurately detect the overweight status from a pool of 225 overweight and 251 healthy subjects. The group included 179 males and 297 females. The detection method was rigorously evaluated against the real-life dataset for accuracy, sensitivity, specificity, and AUC (area under the receiver operating characteristic (ROC) curve) criterion. Additionally, the feature selection was investigated to identify correlating factors for the overweight status. The results demonstrate that there are significant differences in blood and biochemical indexes between healthy and overweight people (p-value < 0.01). According to the feature selection, the most important correlated indexes are creatinine, hemoglobin, hematokrit, uric Acid, red blood cells, high density lipoprotein, alanine transaminase, triglyceride, and γ-glutamyl transpeptidase. These are consistent with the results of Spearman test analysis. The proposed method holds promise as a new, accurate method for identifying the overweight status in subjects.

Obesity and Pulmonary Function in African Americans

Background

Obesity prevalence in United States (US) adults exceeds 30% with highest prevalence being among blacks. Obesity is known to have significant effects on respiratory function and obese patients commonly report respiratory complaints requiring pulmonary function tests (PFTs). However, there is no large study showing the relationship between body mass index (BMI) and PFTs in healthy African Americans (AA).

Objective

To determine the effect of BMI on PFTs in AA patients who did not have evidence of underlying diseases of the respiratory system.

Methods

We reviewed PFTs of 339 individuals sent for lung function testing who had normal spirometry and lung diffusion capacity for carbon monoxide (DLCO) with wide range of BMI.

Results

Functional residual capacity (FRC) and expiratory reserve volume (ERV) decreased exponentially with increasing BMI, such that morbid obesity resulted in patients breathing near their residual volume (RV). However, the effects on the extremes of lung volumes, at total lung capacity (TLC) and residual volume (RV) were modest. There was a significant linear inverse relationship between BMI and DLCO, but the group means values remained within the normal ranges even for morbidly obese patients.

Conclusions

We showed that BMI has significant effects on lung function in AA adults and the greatest effects were on FRC and ERV, which occurred at BMI values < 30 kg/m2. These physiological effects of weight gain should be considered when interpreting PFTs and their effects on respiratory symptoms even in the absence of disease and may also exaggerate existing lung diseases.

A Weighty Issue: Diminished Net Nutrition Among the U.S. Working Class in the Nineteenth Century

Much has been written about the modern obesity epidemic, and historical BMIs are low compared with their modern counterparts. However, interpreting BMI variation is difficult because BMIs increase when weight increases or when stature decreases, and the two have different implications for human health. An alternative measure for net current nutritional conditions is body weight. After controlling for height, I find that African American and white weights decreased throughout the late nineteenth and early twentieth centuries. Farmers had greater average weights than workers in other occupations. Individuals from the South had taller statures, greater BMIs, and heavier weights than workers in other U.S. regions, indicating that even though the South had higher disease rates in the nineteenth century, it had better net nutritional conditions.

Indices of adiposity and thyroid hormones in euthyroid postmenopausal women

OBJECTIVE

We aimed to evaluate the association between thyroid hormones and indices of obesity in a sample of euthyroid postmenopausal women.

DESIGN

Cross-sectional study.

METHODS

Serum levels of TSH, free triiodothyronine (FT3), and free thyroxine (FT4) as well as BMI and waist:hip ratio (WHR) were evaluated in 194 healthy euthyroid postmenopausal women. Ultrasonography was used to assess abdominal fat layers (subcutaneous fat (SF), preperitoneal fat (PF), and SF:PF ratio). Indices of adiposity were defined as high vs low depending on the median value of the assessed parameters.

RESULTS

After multivariate adjustment for traditional risk factors, lower FT4 levels and a higher FT3:FT4 ratio predicted higher SF mass (FT4, Exp(β)=0.035, P=0.020 and FT3:FT4, Exp(β)=2.374, P=0.018), whereas higher FT3 predicted higher PF mass (Exp(β)=2.815, P=0.032). Women with FT3:FT4 above the highest quartile had a significantly higher SF mass as compared to women in the lowest quartile (1.81 ± 0.62 cm vs 1.54 ± 0.46 cm, P=0.027). BMI had a positive independent association with TSH (Exp(β)=1.829, P=0.018). Finally, FT3 was significantly associated with SF mass among women with higher BMI (FT3, β=0.259, P=0.040) and women with higher WHR (β=0.309, P=0.020) but not among women with lower BMI or WHR values.

CONCLUSION

Thyroid hormone levels, and in particular FT3, were independently associated with SF and PF in euthyroid postmenopausal women, and this association was mainly evident in women with higher BMIs. On the other hand, among traditional indices of adiposity, only TSH was positively associated with BMI. Larger prospective studies are needed to evaluate the significance of the present findings.

Adiposity estimated using dual energy X-ray absorptiometry and body mass index and its association with cognition in elderly adults

OBJECTIVES

To determine whether obesity, estimated according to body mass index (BMI), waist circumference, and body fat and abdominal fat assessed using dual-energy X-ray absorptiometry (DEXA), was associated with cognitive performance.

DESIGN

Cross-sectional.

SETTING

Community based.

PARTICIPANTS

Individuals aged 74-94 (N = 406).

MEASUREMENTS

BMI, waist circumference, body fat, and abdominal fat were assessed using DEXA. Cognitive performance was assessed using a comprehensive neuropsychological battery.

RESULTS

When categorized using BMI, overweight individuals had higher global cognitive function and executive function scores than normal-weight individuals. This relationship did not differ according to sex. When categorized according to DEXA, there were no relationships between body fat and cognitive function in the whole group, but women in the middle and highest tertiles of DEXA body fat had better executive function than those in the lowest tertile. Men in the middle tertile of DEXA body fat had significantly better executive function and memory than those in the lowest tertile. BMI had greater power to predict executive function than DEXA body fat. No significant associations were found between cognition and estimates of abdominal adiposity.

CONCLUSION

This study found an association between being overweight and better executive function in elderly adults; this association was stronger for the simpler BMI than the more-elaborate DEXA measures.

The relationship between 19th century BMIs and family size: Economies of scale and positive externalities

The use of body mass index values (BMI) to measure living standards is now a well-accepted method in economics. Nevertheless, a neglected area in historical studies is the relationship between 19th century BMI and family size, and this relationship is documented here to be positive. Material inequality and BMI are the subject of considerable debate, and there was a positive relationship between BMI and wealth and an inverse relationship with inequality. After controlling for family size and wealth, BMI values were related with occupations, and farmers and laborers had greater BMI values than workers in other occupations.

Obesity index and the risk of diabetes among Chinese women with prior gestational diabetes

AIMS

There is some confusion regarding which anthropometric measurement of adiposity should be used to indicate diabetes, especially for Asians. The present study was to evaluate different indicators of adiposity (BMI, waist circumference and body fat) with Type 2 diabetes risk among women with prior gestational diabetes mellitus.

METHODS

We performed a cross-sectional survey in 1263 women with gestational diabetes at 1-5 years after delivery. Logistic regression models were used to estimate the association of BMI, waist circumference and body fat with Type 2 diabetes risk.

RESULTS

BMI, waist circumference and body fat were all associated with an increased risk of Type 2 diabetes among women with prior gestational diabetes (all P(trend) < 0.001). After adjustment for waist circumference and body fat, the positive association of BMI with Type 2 diabetes risk became non-significant and reversed. There was a significantly positive association of waist circumference with Type 2 diabetes risk after adjustment for BMI, and a significantly positive association of body fat with Type 2 diabetes risk after adjustment for both BMI and waist circumference. When the joint effects were examined, the significantly positive associations of waist circumference or body fat with Type 2 diabetes risk were consistent among women with different levels of BMI, and the positive association of BMI and Type 2 diabetes risk was significant among women with gestational diabetes with a waist circumference of ≥ 50% or body fat ≥ 50%.

CONCLUSIONS

BMI, waist circumference and body fat were all associated with an increased risk of Type 2 diabetes, and waist circumference and body fat were better indicators than BMI for Type 2 diabetes risk among Chinese women with prior gestational diabetes.

Overweight/obesity and weight-related treatment among patients in U.S. federally supported health centers

BACKGROUND

We obtained the prevalence of overweight/obesity, weight-loss attempts, and weight-related counseling and treatment among U.S. adults who sought care in federally funded community health centers. We investigated whether racial/ethnic and gender disparities existed for these measures.

METHODS

Data came from the 2009 Health Center Patient Survey. Measures included body mass index (BMI), self-perceived weight, weight-loss attempts, being told of a weight problem, receipt of weight-related counseling, nutritionist referrals, weight-loss prescriptions, and cholesterol checks. We conducted bivariate analyses to determine distributions by race/ethnicity and gender, then ran logistic regressions to examine the effects of several sociodemographic factors on weight-loss attempts and on being told of a weight problem.

RESULTS

Overall, 76% of adult patients seen in health centers were overweight or obese (BMI ≥ 25.0 kg/m(2)); 55% of overweight patients, and 87% of obese patients correctly perceived themselves as overweight. There were no racial/ethnic differences in BMI categories or self-perceptions of weight. Females were more likely than males to be obese and also more likely to perceive themselves as overweight. About 60% of overweight/obese patients reported trying to lose weight in the past year. There were no racial/ethnic disparities favoring non-Hispanic White patients in weight-related treatment. Women were more likely than men to receive referrals to a nutritionist or weight-loss prescriptions. Overweight/obese patients had higher adjusted odds of a past-year weight-loss attempt if they perceived themselves as overweight (OR = 3.30, p < 0.0001), were female (OR = 1.95, p < 0.05), African American (OR = 3.34, p < 0.05), or Hispanic/Latino (OR = 2.14, p < 0.05). Overweight/obese patients had higher odds of being told they had a weight problem if they were Hispanic/Latino (OR = 2.56, p < 0.05) or if they had two or more chronic conditions (OR = 2.77, p < 0.01).

CONCLUSIONS

Patients seen in community health centers have high rates of overweight and obesity, even higher than the general U.S. population. Efforts to address weight problems during primary care visits are needed to reduce the burden of obesity and its sequellae among health center patients.

Body image satisfaction and depression in midlife women: the Study of Women's Health Across the Nation (SWAN)

With aging, women's bodies undergo changes that can affect body image perception, yet little is known about body image in midlife. The purpose of this study was to examine associations between body image and depressive symptoms in Caucasian and African-American midlife women from the Study of Women's Health Across the Nation (SWAN) Chicago site. Body image was measured using the Stunkard Adult Female Figure Rating Scale, and a clinically significant level of depressive symptoms was defined as Center for Epidemiologic Studies Depression Scale (CES-D) score of ≥16 (N=405; N=63 (15.6%) with clinically significant levels of depressive symptoms). Differences between perceived actual, perceived ideal, and actual body size and responses to questions concerning weight satisfaction and attractiveness were examined using logistic regression for associations with a CES-D score of ≥16. Women with body image dissatisfaction (odds ratio (OR)=1.91; p=0.04) or who perceived themselves as "unattractive" (OR=7.74; p<0.01) had higher odds of CES-D of ≥16. We found no significant difference by race. Our results were not confounded by BMI. These results suggest that midlife women with poor body image may be more likely to have clinically significant levels of depressive symptoms. Larger prospective studies are needed to better understand this association.

Greater Effect of Adiposity Than Physical Activity or Lean Mass on Physical Function in Community-Dwelling Older Adults

Adiposity, lean mass, and physical activity (PA) are known to influence physical function in older adults, although the independent influences are not completely characterized. Older adults (N= 156,Mage = 68.9 ± 6.7 yr, 85 men) were assessed for body composition via dual-energy X-ray absorptiometry, PA by accelerometer, and physical function via timed up-and-go (UP&GO), 30-s chair stand, 6-min walk (6-min WALK), and Star-Excursion Balance Test. In the absence of percentage-body-fat by PA interactions (p> .05), main effects existed such that a higher percentage body fat was associated with poorer performance in UP&GO, 30-s chair stand, and 6-min WALK (p< .05). No significant main effects were found for PA and functional performance. Adiposity explains 4.6–11.4% in physical functional variance (p< .05). Preventing increases in adiposity with age may help older adults maintain functional independence.

Black and white body mass index values in developing nineteenth century Nebraska

Little is known about late 19th and early 20th century BMIs on the US Central Plains. Using data from the Nebraska state prison, this study demonstrates that the BMIs of dark complexioned blacks were greater than for fairer complexioned mulattos and whites. Although modern BMIs have increased, late 19th and early 20th century BMIs in Nebraska were in normal ranges; neither underweight nor obese individuals were common. Farmer BMIs were consistently greater than those of non-farmers, and farm labourer BMIs were greater than those of common labourers. The BMIs of individuals born in Plains states were greater than for other nativities, indicating that rural lifestyles were associated with better net current biological living conditions.

Association of lean body mass with cardiometabolic risk factors in healthy postmenopausal women

OBJECTIVE

Aim of this study was to investigate the association of total and regional lean body mass (LBM) with cardiometabolic risk factors in healthy obese and nonobese postmenopausal women.

METHODS

A total of 150 postmenopausal women (age 54 ± 7 years, BMI 29.6 ± 5.8 kg/m2) underwent a comprehensive assessment of cardiometabolic risk, including metabolic syndrome (MS). Body composition analysis was performed with Dual-energy X-ray Absorptiometry, and multiple height-adjusted indices of total and regional LBM were evaluated.

RESULTS

After controlling for age, diet, physical activity, and total fat mass, most indices of total, central, and peripheral LBM displayed significant positive correlations with cardiometabolic risk factors. Most associations were no longer significant after controlling for waist circumference, with the only exception of lean mass in the arms, which remained significantly associated with the presence and severity of MS (number of MS abnormalities), independently of central adiposity. A significant additive interaction was found between lean mass in the arms and waist circumference in increasing the prevalence of MS.

CONCLUSIONS

LBM is unfavorably associated with cardiometabolic risk factors in healthy postmenopausal women. Whether LBM, especially in arms, is associated with cardiometabolic health independently of central fat distribution in postmenopausal women, merits further investigation.

Regional fat distribution and cardiometabolic risk in healthy postmenopausal women

BACKGROUND

Regional fat distribution is an important determinant of cardiometabolic risk after menopause. The aim of the present study was to investigate the association between indices of fat distribution obtained by Dual-energy X-ray Absorptiometry (DXA) and representative cardiometabolic risk factors in a cohort of healthy postmenopausal women.

METHODS

In this cross-sectional study, cardiometabolic risk factors were correlated with a variety of central and peripheral fat depots obtained by DXA, in a total of 150 postmenopausal women, free of diabetes and cardiovascular disease (age 54 ± 7 years, BMI 29.6 ± 5.8 kg/m(2), mean ± 1 SD).

RESULTS

After adjusting for age and total adiposity, DXA-derived indices of central and peripheral fat distribution displayed opposite associations (positive versus negative) with the examined cardiometabolic risk factors. In multivariate regression analysis, thoracic fat mass % was an independent predictor of blood pressure, HOMA index and triglycerides, abdominal fat mass % was an independent predictor of high sensitivity C-reactive protein, and abdominal-to-gluteofemoral fat ratio was an independent predictor of high density lipoprotein cholesterol. An index of peripheral fat distribution, gluteofemoral fat mass %, proved to be the most important determinant of metabolic syndrome (Odds Ratio 0.76, 95% confidence intervals 0.67-0.87, p<0.001), independent of total and central adiposity.

CONCLUSION

DXA-derived indices of regional fat distribution such as thoracic, abdominal and gluteofemoral fat, correlate significantly with cardiometabolic risk factors in healthy postmenopausal women, and may serve as clinically useful tools for evaluating cardiometabolic risk after menopause.

Body fat and breast cancer risk in postmenopausal women: a longitudinal study

Associations between anthropometric indices of obesity and breast cancer risk may fail to capture the true relationship between excess body fat and risk. We used dual-energy-X-ray-absorptiometry- (DXA-) derived measures of body fat obtained in the Women's Health Initiative to examine the association between body fat and breast cancer risk; we compared these risk estimates with those for conventional anthropometric measurements. The study included 10,960 postmenopausal women aged 50–79 years at recruitment, with baseline DXA measurements and no history of breast cancer. During followup (median: 12.9 years), 503 incident breast cancer cases were diagnosed. Hazard ratios (HR) and 95% confidence intervals (CI) were estimated using Cox proportional hazards models. All baseline DXA-derived body fat measures showed strong positive associations with breast cancer risk. The multivariable-adjusted HR for the uppermost quintile level (versus lowest) ranged from 1.53 (95% CI 1.14–2.07) for fat mass of the right leg to 2.05 (1.50–2.79) for fat mass of the trunk. Anthropometric indices (categorized by quintiles) of obesity (BMI (1.97, 1.45–2.68), waist circumference (1.97, 1.46–2.65), and waist : hip ratio (1.91, 1.41–2.58)) were all strongly, positively associated with risk and did not differ from DXA-derived measures in prediction of risk.

Sex differences in assessment of obesity in rheumatoid arthritis

OBJECTIVE

To determine the prevalence of obesity and how accurately standard anthropometric measures identify obesity among men and women with rheumatoid arthritis (RA).

METHODS

Dual x-ray absorptiometry (DXA) was performed for 141 persons with RA (56 men and 85 women). Two anthropometric proxies of obesity (body mass index [BMI] and waist circumference [WC]) were compared to a DXA-based obesity criterion. Receiver operating characteristic curves determined optimal cut points for each anthropometric measure, relative to DXA. The association of body fat and anthropometric obesity measures with disease status and cardiovascular risk was assessed in multiple regression analyses, controlling for age and glucocorticoid use. All analyses were performed separately for men and women.

RESULTS

A total of 20%, 32%, and 44% of women and 41%, 36%, and 80% of men were classified as obese by BMI, WC, and DXA, respectively. Cut points were identified for anthropometric measures to better approximate DXA estimates of percent body fat (BMI ≥26.1 kg/m(2) for women and ≥24.7 kg/m(2) for men; WC ≥83 cm for women and ≥96 cm for men). For women and men, higher percent fat was associated with poorer RA status. Anthropometric measures were more closely linked to RA status for women, but identified cardiovascular risk for both women and men.

CONCLUSION

A large percentage of this RA sample was overfat; DXA-defined obesity was twice as common in men as in women. Utility of revised BMI and WC cut points compared to traditional cut points remains to be examined in prospective studies, but results suggest that lower, sex-specific cut points may be warranted to better identify individuals at risk for poor RA and/or cardiovascular outcomes.

Body fat and body-mass index among a multiethnic sample of college-age men and women

Obesity prevalence and average body composition vary by US race and gender. Asian Americans have the lowest prevalence of obesity. Relying on body-mass index (BMI) to estimate obesity prevalence may misclassify subgroups that appear normally weighted but have excess body fat. We evaluated percentage body fat (PBF) and BMI to determine whether BMI reflects PBF consistently across different races. 940 college students were recruited from a local public university over four consecutive years. We measured PBF by bioelectrical impedance analysis (BIA), weight by physicians' scales, and height with stadiometers. Our sample comprised Asians (49%), Caucasians (23%), Hispanics (7%), and Other (21%). Participants averaged 21.4 years old; BMI was 22.9 kg/m(2); PBF was 24.8%. BMI and PBF varied significantly by race and gender (P value = 0.002 and 0.005 for men; 0.0009 and 0.0008 for women). Asian-American women had the lowest BMI (21.5 kg/m(2)) but the second highest PBF (27.8%). Linear association between BMI and PBF was the weakest (r (2) = 0.09) among Asian-American women and BMI had the poorest sensitivity (37%) to detect PBF. The high PBF with low BMI pattern exhibited by Asian-American women suggests that they could escape detection for obesity-related disease if BMI is the sole measure that estimates body composition.

How well does the body adiposity index capture adiposity change in midlife women?: The SWAN fat patterning study

OBJECTIVES

The body adiposity index (BAI) is a proposed alternative to the body mass index (BMI) that has shown good cross-sectional agreement with percent body fat (%BF) in validation studies. The objective of this study was to examine the ability of BAI to track adiposity change over time in a biracial sample of midlife women.

METHODS

African-American (n = 159) and Caucasian (n = 206) women, aged 42-60 years, at the Chicago site of the Study of Women's Health Across the Nation were followed from 2002 to 2008. BAI and BMI were calculated from measurements taken at annual assessments. %BF was quantified using whole-body dual-energy X-ray absorptiometry. Difference scores (BAI(Δ) , BMI(Δ) , and %BF(Δ) ) quantified adiposity change over a mean of 1.6 (SD = 0.7) years. Lin's concordance correlation (ρ(c) ) and Bland-Altman limits-of-agreement assessed agreement between BAI and %BF.

RESULTS

In examining adiposity change, BAI(Δ) showed poor agreement with %BF(Δ) in the overall sample (ρ(c) = 0.41), African-American women (ρ(c) = 0.36), and Caucasian women (ρ(c) = 0.43). BAI(Δ) estimated %BF(Δ) with minimal bias (+0.4%) but low precision (±6.3%BF limits-of-agreement). %BF(Δ) had weaker correlations with BAI(Δ) (rs = 0.38-0.48) than with BMI(Δ) (rs = 0.48-0.59). BAI and BMI showed similar cross-sectional associations with %BF in the overall sample and within each race (rs > 0.74).

CONCLUSIONS

We conclude that BAI is less accurate than BMI in tracking adiposity change in midlife women, and would not be a suitable replacement for BMI in most research applications involving adiposity change.

BLACK AND WHITE BODY MASS INDEX VALUES IN NINETEENTH CENTURY DEVELOPING PHILADELPHIA COUNTY

This paper demonstrates that although modern BMIs in the US have increased, 19th century BMIs in Philadelphia were lower than elsewhere within Pennsylvania, indicating that urbanization and agricultural commercialization were associated with lower BMIs. After controlling for stature, blacks consistently had greater BMI values than mulattos and whites; therefore, there is no evidence of a 19th century mulatto BMI advantage in the industrializing North. Farmers' BMIs were consistently heavier than those of non-farmers.

Relationship of adipokines with insulin sensitivity in African Americans

INTRODUCTION

Cytokines produced by adipose tissue, including adiponectin, have been associated with metabolic abnormalities. The purpose of this study was to examine the relationship of insulin sensitivity measured by euglycemic hyperinsulinemic insulin clamp with plasma adiponectin and other adipokines in young adult African Americans.

METHODS

Participants were healthy African Americans. Anthropometric measures, blood pressure, an oral glucose tolerance test and an euglycemic hyperinsulinemic insulin clamp were performed. Insulin sensitivity measurements were adjusted for percentage of fat mass. Plasma concentrations of adiponectin, plasminogen activator inhibitor-1 (PAI-1) and interleukin-6 (IL-6) were assayed on plasma from fasting blood samples. Pearson correlation coefficients and multiple regression models were fitted to assess the association between glucose sensitivity and cytokines.

RESULTS

In univariate analysis, there were statistically significant correlations of plasma adiponectin level (r = 0.19, P = 0.004), PAI-1 (r = -0.19, P = 0.020) and IL-6 (r = -0.24, P < 0.001) with measures of insulin sensitivity after adjustment for both fat mass and insulin clamp concentration. In multivariate analysis, adiponectin [geometric mean ratios (GMR) 1.15, P = 0.007], PAI-1 (GMR 0.998, P = 0.021) and body mass index (GMR 0.95, P < 0.001) were each independently associated with insulin sensitivity. For IL-6, there was no significant association with insulin sensitivity independent of obesity.

CONCLUSION

These data show a significant and independent positive correlation of adiponectin with insulin sensitivity. The relationship of IL-6 with insulin sensitivity seems to be dependent on adiposity.

Association of body mass index with self-report and performance-based measures of balance and mobility

BACKGROUND

The incidence of obesity is increasing in older adults, with associated worsening in the burden of disability. Little is known about the impact of body mass index (BMI) on self-report and performance-based balance and mobility measures in older adults.

OBJECTIVE

The purposes of this study were (1) to examine the association of BMI with measures of balance and mobility and (2) to explore potential explanatory factors.

DESIGN

This was a cross-sectional, observational study.

METHODS

Older adults (mean age=77.6 years) who participated in an ongoing observational study (N=120) were classified as normal weight (BMI=18.5-24.9 kg/m(2)), overweight (BMI=25.0-29.9 kg/m(2)), moderately obese (BMI=30.0-34.9 kg/m(2)), or severely obese (BMI ≥ 35 kg/m(2)). Body mass index data were missing for one individual; thus, data for 119 participants were included in the analysis. Mobility and balance were assessed using self-report and performance-based measures and were compared among weight groups using analysis of variance and chi-square analysis for categorical data. Multiple linear regression analysis was used to examine the association among BMI, mobility, and balance after controlling for potential confounding variables.

RESULTS

Compared with participants who were of normal weight or overweight, those with moderate or severe obesity were less likely to report their mobility as very good or excellent (52%, 55%, 39%, and 6%, respectively); however, there was no difference in self-report of balance among weight groups. Participants with severe obesity (n=17) had the lowest levels of mobility on the performance-based measures, followed by those who were moderately obese (n=31), overweight (n=42), and of normal weight (n=29). There were no differences on performance-based balance measures among weight groups. After controlling for age, sex, minority status, physical activity level, education level, and comorbid conditions, BMI still significantly contributed to mobility (β=-.02, adjusted R(2)=.41).

CONCLUSIONS

Although older adults with severe obesity were most impaired, those with less severe obesity also demonstrated significant decrements in mobility.

Overweight and obesity in women with physical disabilities: associations with demographic and disability characteristics and secondary conditions

BACKGROUND

This cross-sectional study was designed to examine weight in association with demographic and disability characteristics and secondary conditions in a sample of community living women with physical disabilities.

METHODS

443 predominantly ethnic minority women with physical disabilities were recruited through public and private health clinics and community organizations. They completed questionnaires including measures of body mass index and a health conditions checklist.

RESULTS

Data showed that nearly three-quarters of the sample were overweight (26.6%) or obese (47.6%) with 14% extremely obese. Obesity was highest among middle aged women (aged 45-54, 52.7%; aged 55-64, 52.5%; compared to aged 18-44, 37.8%; or aged ≥65, 39.1%). Black (84.0%) and Hispanic women (83.8%) were more likely to be overweight or obese compared to non-Hispanic white women (56.7%). Women with joint and connective tissue diseases and women with more extensive functional limitations were more likely to have excess weight. Disability factors were more strongly associated with excess weight than demographic factors other than age. Weight classification was significantly related to whether or not the women had ever had diabetes or blood pressure problems. Diabetes was reported 4 times as often as among women in general (36.3% versus 8.9%), and hypertension nearly twice as often (56.2% versus 30.9%).

CONCLUSIONS

These findings indicate extremely high rates of overweight and obesity in women with physical disabilities, a growing population greatly in need of effective weight management interventions. Overweight and obesity in combination with disability in women was associated with disproportionately high rates of diabetes and hypertension.