Combination of BMI and Waist Circumference for Identifying Cardiovascular Risk Factors in Whites

Comparison of four quick and reliable methods of assessing body fat appropriate for clinical settings among young, middle-age, and older healthy male and female adults

[Purpose] Compare four quick (approximately 60 s), reliable methods of assessing %body-fat (%BF) among young (Y, 18-34 years), middle-age (M, 35-59 years), and older (O, 60-88 years) healthy-adults. [Participants and Methods] One-hundred-eighty healthy males-and-females were equally (n=30) divided into Y, M, and O age groups to assess %BF. The %BF methods were: 1) Bioelectrical-impedance-Inbody770 (IB)-criterion reference; 2) Body-mass-index (BMI); 3) Abdominal-and-hip circumferences (CIR); and 4) Skinfold (SF). [Results] %BF were significantly different among the four body-fat methods and among the three age-groups for both males-and-females. %BF among IB,BMI,CIR, and SF were, respectively, 15.7 ± 4.7%, 19.6 ± 3.2%, 17.3 ± 3.5%, and 12.1 ± 4.1% for Y-males; 18.3 ± 5.7%, 22.8 ± 3.6%, 19.6 ± 3.6%, and 15.6 ± 4.5% for M-males; 24.4 ± 6.5%, 25.8 ± 3.3%, 24.0 ± 4.5%, and 20.0 ± 4.1% for O-males; 24.9 ± 6.9%, 28.9 ± 4.1%, 29.4 ± 4.6%, and 22.4 ± 6.3% for Y-females; 25.1 ± 7.0%, 31.4 ± 4.7%, 33.0 ± 4.5%, and 25.0 ± 4.5% for M-females; 35.1 ± 6.3%, 35.5 ± 4.3%, 38.4 ± 4.8%, and 26.4 ± 3.7% for O-females. [Conclusion]The most accurate %BF-methods to use in clinical settings are CIR for Y-and-M-males, CIR and BMI for O-males, SF for Y-and M-females, and BMI for O-females. The least accurate %BF methods are BMI and SF for Y-males, BMI for M-males, SF for O-males, BMI and CIR for Y-and M-females, and SF for O-females. While all 4-methods of assessing %BF can easily and quickly be employed in clinical settings, some methods significantly underestimate or overestimate %BF and yield different results among varying age groups and sex. These findings help identify people at early health risk of cardiometabolic disease, with O-males and O-females at higher risk.

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.

[Overweight and obesity in adults: general principles of treatment and conservative management]

The prevalence of overweight and obesity is steadily increasing in Austria as well as internationally. Obesity in particular is associated with multiple health risks, comorbidities, functional disability, and social stigma. Obesity is an independent, complex, chronic disease and should be treated as such by a multidisciplinary team of appropriately qualified personnel. In addition to recent international guidelines, this consensus paper outlines the overall principles of the management of overweight and obesity and provides guidance for the diagnosis and conservative treatment, focusing on lifestyle modifications and pharmacotherapy. Using the "5A" framework of behavioral health intervention, guidelines for a structured, pragmatic, and patient-centered medical care of adults with overweight or obesity are presented.

Prevalence and Predictors of Combined Body Mass Index and Waist Circumference Among Indian Adults

Objective: To determine the prevalence and predictors of combined BMI-WC disease risk categories among Indian adults.

Methods: The study utilizes data from Longitudinal Ageing Study in India (LASI Wave 1) with an eligible sample of 66, 859 individuals. Bivariate analysis was done to get the proportion of individuals in different BMI-WC risk categories. Multinomial logistic regression was used to identify the predictors of BMI-WC risk categories.

Results: Poor self-rated health, female sex, urban place of residence, higher educational status, increasing MPCE quintile, and cardio-vascular disease increased with increasing BMI-WC disease risk level while increasing age, tobacco consumption, and engagement in physical activities was negatively associated with BMI-WC disease risk.

Conclusion: Elderly persons in India have a considerable higher prevalence of BMI-WC disease risk categories which make them vulnerable to developing several disease. Findings emphasize the need of using combined BMI categories and waist circumference to assess the prevalence of obesity and associated disease risk. Finally, we recommend that intervention programs with an emphasis on urbanites wealthy women and those with a higher BMI-WC risk categories be implemented.

The value of combining the simple anthropometric obesity parameters, Body Mass Index (BMI) and a Body Shape Index (ABSI), to assess the risk of non-alcoholic fatty liver disease

Background

Body mass index (BMI) and A Body Shape Index (ABSI) are current independent risk factors for non-alcoholic fatty liver disease (NAFLD). The aim of this study was to explore the value of combining these two most common obesity indexes in identifying NAFLD.

Methods

The subjects in this study were 14,251 individuals from the NAfld in the Gifu Area, Longitudinal Analysis (NAGALA) cohort who underwent routine health examination. We integrated BMI with WC and with ABSI to construct 6 combined obesity indicators—obesity phenotypes, the combined anthropometric risk index (ARI) for BMI and ABSI, optimal proportional combination O_BMI+WC and O_BMI+ABSI, and multiplicative combination BMI*WC and BMI*ABSI. Several multivariable logistic regression models were established to evaluate the relationship between BMI, WC, ABSI, and the above six combined indicators and NAFLD; receiver operating characteristic (ROC) curves were drawn to compare the ability of each obesity indicator to identify NAFLD.

Results

A total of 2,507 (17.59%) subjects were diagnosed with NAFLD. BMI, WC, ABSI, and all other combined obesity indicators were significantly and positively associated with NAFLD in the current study, with BMI*WC having the strongest correlation with NAFLD in female subjects (OR per SD increase: 3.13) and BMI*ABSI having the strongest correlation in male subjects (OR per SD increase: 2.97). ROC analysis showed that ARI and O_BMI+ABSI had the best diagnostic performance in both sexes, followed by BMI*WC (area under the curve: female 0.8912; male 0.8270). After further age stratification, it was found that ARI and multiplicative indicators (BMI*WC, BMI*ABSI) and optimal proportional combination indicators (O_BMI+WC, O_BMI+ABSI) significantly improved the NAFLD risk identification ability of the basic anthropometric parameters in middle-aged females and young and middle-aged males.

Conclusion

In the general population, BMI combined with ABSI best identified obesity-related NAFLD risk and was significantly better than BMI or WC, or ABSI. We find that ARI and the multiplicative combined indicators BMI*WC and BMI*ABSI further improved risk prediction and may be proposed for possible use in clinical practice.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12944-022-01717-8.

Insulin-resistance in paediatric age: Its magnitude and implications

Insulin resistance (IR) is insulin failure in normal plasma levels to adequately stimulate glucose uptake by the peripheral tissues. IR is becoming more common in children and adolescents than before. There is a strong association between obesity in children and adolescents, IR, and the metabolic syndrome components. IR shows marked variation among different races, crucial to understanding the possible cardiovascular risk, specifically in high-risk races or ethnic groups. Genetic causes of IR include insulin receptor mutations, mutations that stimulate autoantibody production against insulin receptors, or mutations that induce the formation of abnormal glucose transporter 4 molecules or plasma cell membrane glycoprotein-1 molecules; all induce abnormal energy pathways and end with the development of IR. The parallel increase of IR syndrome with the dramatic increase in the rate of obesity among children in the last few decades indicates the importance of environmental factors in increasing the rate of IR. Most patients with IR do not develop diabetes mellitus (DM) type-II. However, IR is a crucial risk factor to develop DM type-II in children. Diagnostic standards for IR in children are not yet established due to various causes. Direct measures of insulin sensitivity include the hyperinsulinemia euglycemic glucose clamp and the insulin-suppression test. Minimal model analysis of frequently sampled intravenous glucose tolerance test and oral glucose tolerance test provide an indirect estimate of metabolic insulin sensitivity/resistance. The main aim of the treatment of IR in children is to prevent the progression of compensated IR to decompensated IR, enhance insulin sensitivity, and treat possible complications. There are three main lines for treatment: Lifestyle and behavior modification, pharmacotherapy, and surgery. This review will discuss the magnitude, implications, diagnosis, and treatment of IR in children.

Metabolic function in patients with bipolar depression receiving anti-inflammatory agents: Findings from the MINDCARE study, a multicentre, randomised controlled trial

BACKGROUND

Metabolic dysfunction is prevalent in bipolar disorder (BD) and associated with illness severity and treatment outcomes. There is little research exploring this relationship in low and middle-income countries (LMICs) and little is known about the moderating effect of metabolic health on treatment response to anti-inflammatory drugs in BD.

METHODS

MINDCARE, a randomized-controlled-trial conducted in Pakistan, investigated the efficacy of minocycline and celecoxib in 266 adults with bipolar depression. This secondary analysis evaluated the association between depression severity at baseline and treatment outcome with metabolic parameters including body mass index (BMI), waist circumference (WC), heart rate (HR), systolic blood pressure (s-BP), and diastolic blood pressure (d-BP). Depression severity was measured using the Hamilton Depression Rating Scale-17. The exploratory aim was to assess whether treatment impacted change in metabolic variables. Associations were evaluated using linear regression.

RESULTS

Higher BMI (B=-0.38, 95%CI: -0.55 to -0.21) and WC (B=-0.68, 95%CI: -0.97 to -0.39) were associated with lower baseline depression severity in both the unadjusted and the adjusted models. Baseline metabolic parameters were not associated with treatment response to minocycline or celecoxib nor did treatment significantly impact metabolic variables.

LIMITATIONS

Our sample represents patients in an RCT and may not be fully representative of the overall BD population in Pakistan.

CONCLUSIONS

Our findings indicate a potential association of poor metabolic health and lower severity of bipolar depression but not treatment outcomes. Future work should evaluate potential relationships of metabolic parameters and BD in diverse populations to increase the transferability of this line of work.

Changes in general and central fatness are associated with hepatocellular carcinoma: A Korean nationwide longitudinal study

We investigated the impact of short-term changes in general and central fatness on the risk of hepatocellular carcinoma (HCC) in a large, population-based cohort. We screened 7,221,479 subjects who underwent health examinations provided by the National Health Insurance Service of South Korea in 2009 and 2011. In total, 6,789,472 subjects were included in the final analysis. General fatness was defined as a body mass index (BMI) ≥25 kg/m² , and central fatness was defined as a waist circumference (WC) ≥90 cm in men and ≥85 cm in women. Subjects were classified according to the change in body fatness between 2009 and 2011, as follows: 1) persistent no fatness as no fatness in both 2009 and 2011, 2) reversed fatness as fatness in 2009, but no fatness in 2011, 3) incident fatness as no fatness in 2009, but fatness in 2011, or 4) persistent fatness as fatness in both 2009 and 2011. During a median 6.4-year follow-up, we documented 9,952 HCC cases. Compared to subjects with a persistent no general fatness, the risk of HCC significantly increased in those with incident (adjusted hazard ratio [aHR]=1.10, 95% confidence interval [CI]=1.01-1.20) and persistent (aHR=1.28, 95% CI=1.23-1.34) general fatness. Compared to subjects with persistent no central fatness, those with incident and persistent central fatness showed a significantly increased risk of HCC (aHR=1.19, 95% CI=1.11-1.27, and aHR=1.33, 95% CI=1.26-1.40, respectively). Taken together, these findings indicate the importance of strategies for preventing and reversing body fatness to reduce the incidence of HCC. This article is protected by copyright. All rights reserved.

Obesity and long-term outcomes after incident stroke: a prospective population-based cohort study

BACKGROUND

The association between obesity, major adverse cardiovascular events (MACE), and mortality in patients with incident stroke is not well established. We assessed the relationship between body mass index (BMI) and MACE in patients with incident stroke.

METHODS

The population-based cohort study identified 30 702 individuals from the Clinical Practice Research Datalink (CPRD GOLD) and Hospital Episode Statistics (HES) databases from the United Kingdom. Individuals were aged ≥18 years with incident stroke between 1-1-1998 and 31-12-2017, a BMI recorded within 24 months before incident stroke, and no prior history of MACE. BMI was categorized as underweight (<18.5 kg/m² ), normal (18.5-24.9 kg/m² ), overweight (25.0-29.9 kg/m² ), obesity class I (30.0-34.9 kg/m² ), class II (35.0-39.9 kg/m² ) and class III (≥40 kg/m2). MACE was defined as a composite of incident coronary heart disease, recurrent stroke, peripheral vascular disease (PVD), heart failure, and cardiovascular-related mortality. Multivariable Cox regression was used to assess differences in MACE risk between BMI categories.

RESULTS

At baseline, 1217 (4.0%) were underweight, 10 783 (35.1%) had a normal BMI, 10 979 (35.8%) had overweight, 5206 (17.0%) had obesity Class I, 1749 (5.7%) Class II, and 768 (2.5%) Class III. In multivariable analysis, higher BMI were associated with lower risk of subsequent MACE [overweight: HR 0.96, 95% CI 0.93-0.99)]; PVD [overweight: 0.65 (0.49-0.85); obesity Class III: 0.19 (0.50-0.77)]; cardiovascular-related death [overweight: 0.80 (0.74-0.86); obesity Class I: 0.79 (0.71-0.88); Class II: 0.80 (0.67-0.96)]; and all-cause mortality [overweight: 0.75 (0.71-0.79); obesity Class I: 0.75 (0.70-0.81); Class II: 0.77 (0.68-0.86)] when compared to those with normal BMI. The results were similar irrespective of sex, diabetes mellitus, smoking or cancer at time of incident stroke.

CONCLUSIONS

In patients with incident stroke, overweight or obesity were associated with a more favourable prognosis for subsequent MACE, PVD, and mortality, irrespective of sex, diabetes mellitus, smoking, or cancer at baseline. As with other cohort studies, our study demonstrates an association. Randomized control trials should be considered to robustly evaluate the impact of weight management recommendations on subsequent cardiovascular outcomes in stroke survivors.

Metabolic variables associated with response to cognitive behavioural therapy for depression in females: A Canadian biomarker integration network for depression (CAN-BIND) study

INTRODUCTION

Cognitive behavioural therapy (CBT) is an established first-line treatment for depression; however, it remains unclear which factors predict a positive outcome with this approach. Prior work suggests that co-morbid obesity predicts a poorer response to antidepressant medication. The current study examined whether there is an association between weight parameters and improvement of depressive symptoms with CBT.

METHODS

This was a secondary analysis of data from the "Clinical and Biological Markers of Response to Cognitive Behavioural Therapy for Depression - 6" (CANBIND-6; https://clinicaltrials.gov/ct2/show/NCT02883257) study. Adult participants (n = 41) with a diagnosis of Major Depressive Disorder (MDD) or Persistent Depressive Disorder (PDD) were recruited from an outpatient tertiary psychiatric centre in Canada. Participants completed 20 individual sessions of CBT over 16 weeks. The primary measure for treatment outcome was the Montgomery-Åsberg Depression Rating Scale (MADRS) total score at week 16.

RESULTS

Thirty-seven participants completed assessments pre and post CBT. Baseline weight parameters were not correlated with treatment response to CBT in the entire group. There was a significant sex*waist circumference (WC) (B:-1.34; p = 0.004) and sex*body mass index (BMI) interaction (B:-2.03; p:0.009). In female participants, baseline waist circumference, but not BMI, significantly predicted week 16 MADRS after controlling for age and baseline MADRS (B:0.422 p:0.049).

LIMITATIONS

The major limitation of our preliminary finding is the small sample size.

CONCLUSION

Our preliminary findings suggest that higher waist circumference may be associated with a better treatment response to CBT for depression in females. This result could be of clinical relevance and warrants further investigation in larger and independent samples.

Individual and Combined Performance of Indicators of Overall and Central Obesity to Estimate Coronary Risk in ELSA-Brasil Participants

BACKGROUND

Anthropometric indicators have been used in clinical practice and epidemiological studies for screening of health risk factors.

OBJECTIVES

To evaluate the individual discriminatory power of body adiposity index (BAI), body mass index (BMI), waist circumference (WC) and waist-hip-ratio (WHR) to identify individuals at risk for coronary heart disease and to evaluate whether combinations of anthropometric indicators of overall obesity with indicators of central obesity improve predictive ability in adults.

METHODS

A total of 15,092 participants (54.4% women) aged 35-74years were assessed at baseline of the ELSA-Brasil study. Individuals at risk for coronary heart disease were identified using the Framingham risk score and divided into very-high risk (VHR 20%) and high risk (HR10%). Measures of diagnostic accuracy and area under the ROC curves (AUC) were analyzed. Associations were tested using Poisson regression analysis with robust variance, according to age and sex. Statistical significance was set at 5%.

RESULTS

WHR showed the highest discriminatory power for VHR20% in all groups, with higher predictive ability in women (AUC: 0.802; 95%CI: 0.748-0.856 vs 0.657; 95%CI: 0.630-0.683 in the age range of 35-59 years, and AUC: 0.668; 95%CI: 0.621-0.715 vs 0.611; 95%CI: 0.587-0.635 in the age range of 60-74 years). BAI + WHR and BMI + WHR had the highest predictive power in men and women, respectively. Combinations of indicators of overall obesity with indicators of central obesity were more strongly associated with VHR20% and HR10% in all subgroups.

CONCLUSION

Combined indicators had greater predictive ability than indicators taken individually. BAI+ WHR and BMI + WHR were the best estimators of coronary risk in men and women, respectively, and WHR had the best individual performance.

Assessment of the Nutritional Status of Four Selected Rural Communities in KwaZulu-Natal, South Africa

Under- and over-nutrition co-exist as the double burden of malnutrition that poses a public health concern in countries of the developing regions, including South Africa (SA). Vulnerable groups such as pregnant women and children under five years are the most affected by malnutrition, especially in rural areas. Major contributing factors of malnutrition include food and nutrition insecurity, poverty, and unhealthy lifestyles. The current study aimed to assess the nutritional status, using selected anthropometric indices and dietary intake methods (repeated 24 h recall and food frequency), of four rural communities in KwaZulu-Natal (SA). Purposive sampling generated a sample of 50 households each in three rural areas: Swayimane, Tugela Ferry, and Umbumbulu and 21 households at Fountain Hill Estate. The Estimated Average Requirement cut-point method was used to assess the prevalence of inadequate nutrient intake. Stunting (30.8%; n = 12) and overweight (15.4%; n = 6) were prevalent in children under five years, whilst obesity was highly prevalent among adult females (39.1%; n = 81), especially those aged 16-35 years. There was a high intake of carbohydrates and a low intake of fibre and micronutrients, including vitamin A, thus, confirming the need for a food-based approach to address malnutrition and micronutrient deficiencies, particularly vitamin A deficiency.

Assessment of aerobic fitness in individuals with and without nonspecific chronic low back pain: a pilot study

Aerobic fitness assessment in patients with low back pain (LBP) may help clinicians to plan how to progress the aerobic training. This was a pilot study designed to evaluate the performance of people with LBP on two different aerobic fitness tests performed on a treadmill and to compare the measure of aerobic fitness between people with LBP and healthy individuals. Ten people with LBP and 10 healthy individuals underwent two aerobic fitness protocols, the modified Bruce and maximum incremental test protocols, performed on a treadmill. Data collected during the protocols were: oxygen consumption, heart rate (HR), blood lactate concentration, respiratory quotient, rating of perceived exertion response, and pain intensity. Independent t-test and two-way analysis of variance were used respectively to assess difference between groups characteristics and physiological responses to the protocols. Our results showed that both groups were similar with regards to age (P = 0.839) or HRrest (P = 0.730) but the LBP group showed higher BMI compared to the healthy group (P = 0.031). Regarding the performance of both groups on the aerobic fitness tests, the only significant difference was reported for respiratory quotient which showed a main effect of test (P = 0.015) with higher values favoring the modified Bruce over the incremental test. Our study showed that most people with LBP are able to perform and tolerate both aerobic fitness tests but no significant differences between people with LBP and healthy individuals on both protocols were reported.

Assessing the utility of cardiorespiratory fitness, visceral fat, and liver fat in predicting changes in insulin sensitivity beyond simple changes in body weight after exercise training in adolescents

To examine the utility of changes in cardiorespiratory fitness (CRF) and body composition in response to exercise training in adolescents with obesity beyond simple measures of body weight change. This is a secondary analysis of our previously published randomized trials of aerobic, resistance, and combined training. We included 104 adolescents (body mass index (BMI) ≥85th percentile) who had complete baseline and post-intervention data for CRF, regional body fat, insulin sensitivity, and oral glucose tolerance. Associations between changes in body composition and CRF with cardiometabolic variables were examined adjusted for age, sex, Tanner stage, race, exercise group, and weight loss. At baseline, CRF, visceral fat and liver fat were correlated with insulin sensitivity with and without adjustment for BMI percentile. Training-associated changes in CRF, visceral fat, and liver fat were also correlated with insulin sensitivity changes, but not independent of body weight change. After accounting for body weight change, none of the body composition or CRF were associated with changes in insulin sensitivity, glucose tolerance, systolic blood pressure, or high-density lipoprotein cholesterol. Although CRF and body composition were strong independent correlates of insulin sensitivity at baseline, changes in CRF and visceral fat were not associated with changes in insulin sensitivity after accounting for body weight change. Clinicaltrials.gov registration nos.: NCT00739180, NCT01323088, NCT01938950. Novelty With exercise training, changes in body weight, CRF, visceral fat, and liver fat were correlated with changes in insulin sensitivity. Changes in body composition or CRF generally did not remain significant correlates of changes in insulin sensitivity after adjusting for body weight changes.

Prediction for cardiovascular diseases based on laboratory data: An analysis of random forest model

Background

To establish a prediction model for cardiovascular diseases (CVD) in the general population based on random forests.

Methods

A retrospective study involving 498 subjects was conducted in Xi'an Medical University between 2011 and 2018. The random forest algorithm was used to screen out the variables that greatly affected the CVD prediction and to establish a prediction model. The important variables were included in the multifactorial logistic regression analysis. The area under the curve (AUC) was compared between logistic regression model and random forest model.

Results

The random forest model revealed the variables, including the age, body mass index (BMI), fasting blood glucose (FBG), diastolic blood pressure (DBP), triglyceride (TG), systolic blood pressure (SBP), total cholesterol (TC), waist circumference, and high‐density lipoprotein‐cholesterol (HDL‐C), were more significant for CVD prediction; the AUC was 0.802 in CVD prediction. Multifactorial logistic regression analysis indicated that the risk factors for CVD included the age [odds ratio (OR): 1.14, 95% confidence intervals (CI): 1.10‐1.17, P < .001], BMI (OR: 1.13, 95% CI: 1.06‐1.20, P < .001), TG (OR: 1.11, 95% CI: 1.02‐1.22, P = .023), and DBP (OR: 1.04, 95% CI: 1.02‐1.06, P = .001); the AUC was 0.843 in CVD prediction. The established logistic regression prediction model was Logit P = Log[P/(1 − P)] = −11.47 + 0.13 × age + 0.12 × BMI + 0.11 × TG + 0.04 × DBP; P = 1/[1 + exp(−Logit P)]. People were prone to develop CVD at the time of P > .51.

Conclusions

A prediction model for CVD is developed in the general population based on random forests, which provides a simple tool for the early prediction of CVD.

Optimal cut-off values for anthropometric measures of obesity in screening for cardiometabolic disorders in adults

Excessive accumulation of body fat (BF) promotes obesity, whilst posing a significant health hazard. There being no agreed, optimal quantifying methods, application of BF variable in clinical practice is not deemed an effective assessment option. The study, involving 4,735 patients (33.6% men), aged 45-64, aimed to identify optimal cut-off values for anthropometric indicators of obesity to evaluate cardiometabolic risk. A minimum P-value approach was applied to calculate the cut-offs for BF%. Threshold values for body mass index (BMI), waist circumference (WC), waist-to-hip ratio (WHR), and waist-to-height (WHTR) ratio, facilitating optimal differentiation of cardiometabolic risk, were based on BF%, expressed as a binary classifier. The newly estimated cut-off values for predicting cardiometabolic risk, based on BMI, were lower than the referential obesity thresholds, whereas the threshold values of WC, WHR, and WHTR were higher. Apart from dyslipidemia, the odds of cardiometabolic disorders were higher, when the anthropometric indicators under study exceeded the cut-off points in both sexes. The proposed cut-offs proved instrumental in predicting cardiometabolic risk, whilst highlighting diagnostic and clinical potential of BF%, whereas BMI boasted the highest predictive potential. Cardiometabolic risk also proved significantly higher even in the overweight patients.

Optimal Body Fat Percentage Cut-Off Values in Predicting the Obesity-Related Cardiovascular Risk Factors: A Cross-Sectional Cohort Study

BACKGROUND

Reliable obesity assessment is essential in evaluating the risk of cardiovascular risk factors (CRFs). Non-availability of clearly defined cut-offs for body fat percentage (BF%), as well as a widespread application of surrogate measures for obesity assessment, may result in incorrect prediction of cardio-metabolic risk.

PURPOSE

The study aimed to determine optimal cut-off points for BF%, with a view of predicting the CRFs related to obesity.

PATIENTS AND METHODS

The study involved 4735 (33.6% of men) individuals, the Polish-Norwegian Study (PONS) participants, aged 45-64. BF% was measured with the aid of bioelectrical impedance analysis (BIA) method. The gender-specific cut-offs of BF% were found with respect to at least one CRF. A P-value approach, and receiver operating characteristic curve analyses were pursued for BF% cut-offs, which optimally differentiated normal from the risk groups. The associations between BF% and CRFs were determined by logistic regression models.

RESULTS

The cut-offs for BF% were established as 25.8% for men and 37.1% for women. With the exception of dyslipidemia, in men and women whose BF% was above the cut-offs, the odds for developing CRFs ranged 2-4 times higher than those whose BF% was below the cut-offs.

CONCLUSION

Controlling BF% below the thresholds indicating an increased health hazard may be instrumental in appreciably reducing overall exposure to developing cardio-metabolic risk.

Dietary fat and obesity as modulators of breast cancer risk: Focus on DNA methylation

Breast cancer (BC) is the most common cancer and second leading cause of cancer mortality in women worldwide. Validated biomarkers enhance efforts for early detection and treatment, which reduce the risk of mortality. Epigenetic signatures have been suggested as good biomarkers for early detection, prognosis and targeted therapy of BC. Here, we highlight studies documenting the modifying effects of dietary fatty acids and obesity on BC biomarkers associated with DNA methylation. We focus our analysis on changes elicited in writers of DNA methylation (i.e., DNA methyltransferases), global DNA methylation and gene-specific DNA methylation. To provide context, we precede this discussion with a review of the available evidence for an association between BC incidence and both dietary fat consumption and obesity. We also include a review of well-vetted BC biomarkers related to cytosine-guanine dinucleotides methylation and how they influence BC risk, prognosis, tumour characteristics and response to treatment. LINKED ARTICLES: This article is part of a themed section on The Pharmacology of Nutraceuticals. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v177.6/issuetoc.

Optimum waist circumference-height indices for evaluating adult adiposity: An analytic review

Phenotyping adults for excess adiposity and related health risks usually include three body size measurements: height, weight and waist circumference (WC). Height and weight are now widely used as components of the body shape measure, body mass index (BMI, weight/height² ), with the height power referred to as the scaling factor, α. At present, WC is usually not adjusted for height or is expressed as WC/height in which α = 1. Although other α values have been proposed, a critical review of these shape measures is lacking. Here, we examine classical pathways by which the scaling exponent for height used in BMI was developed and then apply this strategy to identify the optimum WC index characteristic of adult shape. Our analyses explored anthropometric, body composition and clinically-relevant data from US and Korean National Health and Nutrition Surveys. Our findings provide further support for the WC index of WC/height^0.5 as having the strongest associations with adiposity while having the weakest correlations with height across non-Hispanic white and black, Mexican American and Korean men and women. The WC index, defined as WC/height^0.5 , when combined with BMI, can play an important role when phenotyping adults for excess adiposity and associated health risks in research and clinical settings.

Effect of Obesity and Other Risk Factors on Hypertension among Women of Reproductive Age in Ghana: An Instrumental Variable Probit Model

Background: The growing incidence of mortality as a result cardiovascular diseases (CVDs) is a major public health concern in several developing countries. In Ghana, unhealthy food consumption pattern and sedentary lifestyle are promoting overweight and obesity, with significant consequences on the incidence of CVDs. Specifically, hypertension morbidity is now a public health concern among Ghanaian health policy makers. This paper analysed the effect of body mass index (BMI)/arm circumference and other associated factors on hypertension risk among women of reproductive ages in Ghana. Methods: The data were collected as Demographic and Health Survey (DHS) in 2014. This paper analysed the subset of the data that were collected from eligible women 15-49 years of age. The total sample was 9396, while 9367 gave consents to have their blood pressure measured. Data were analysed with instrumental probit regression model with consideration of potential endogeneity of BMI and arm circumference. Results: The results showed that 25% of the women were either overweight or obese, while 13.28% were hypertensive. Women from the Greater Accra (18.15%), Ashanti (15.53%) and Volta (15.02%) regions had the highest incidences of hypertension. BMI and arm circumferences were truly endogenous and positively associated with the probability of being hypertensive. Other factors that influenced hypertension were age of women, region of residence, urban/rural residence, being pregnant, access to medical insurance, currently working, consumption of broth cubes, processed can meats, salted meat and fruits. Conclusion: It was concluded that hypertension risk was positively associated with being overweight, obesity, age and consumption of salted meat.It was inter aliaemphasized that engagement in healthy eating with less consumption of salted meats, and more consumption of fruits would assist in controlling hypertension among Ghanaian women.

Changes in waist circumference and risk of all-cause and CVD mortality: results from the European Prospective Investigation into Cancer in Norfolk (EPIC-Norfolk) cohort study

BACKGROUND

Measures of abdominal adiposity are strongly associated with all-cause mortality and cardiovascular disease (CVD). However, data are limited and conflicting regarding the consequences of changes in body fat distribution. The main aims of this paper are to investigate the association between changes in waist circumference (WC) and all-cause and CVD mortality and to examine these changes in relation to concurrent changes in weight.

METHODS

The European Prospective Investigation into Cancer and Nutrition (EPIC-Norfolk) study recruited 25,639 participants between 1993 and 1997, aged 39-79, a number of whom also attended a second examination (1998-2000), and were followed up to 2016 for mortality. Participants were eligible for inclusion if they had WC, weight and height measurements at both time-points; those with a self-reported history of CVD or cancer, body mass index < 18.5 kg/m2 or missing data on covariates were excluded, leaving 12,337 participants for analyses. The median (IQR) follow-up time was 16.4 (15.7, 17.2) years. Hazard Ratios (HRs) for all-cause (2866 deaths) and CVD mortality (822 deaths), by categories of WC change, were determined using Cox proportional hazards analyses.

RESULTS

After multivariable adjustment, the HRs (95% CIs) for all-cause mortality for men and women with a WC gain (WCG) >  5 cm were 1.51 (1.29-1.75) and 1.25 (1.06-1.46) respectively. For CVD mortality in men and women with a WCG >  5 cm, the HRs were 1.84 (1.39-2.43) and 1.15 (0.85-1.55) respectively. In analyses of concurrent changes in WC and weight, the greatest risk (HRs) (95% CIs) in men occurred with weight loss and WCG: 1.80 (1.13-2.86) for all-cause and 2.22 (1.03-4.82) for CVD mortality. In women, the greatest risk for both all-cause (HR 1.50 (1.16-1.95)) and CVD mortality (HR 1.81 (1.15-2.85)) was observed in those with weight loss and maintenance of WC (WCM).

CONCLUSIONS

Objectively measured WCG > 5 cm, was associated with subsequent higher total mortality risk and higher CVD mortality risk in men. Interventions focusing on preventing increase in central adiposity rather than lowering weight per se in later life may potentially have greater health benefits.

The ability of waist-to-height ratio to identify health risk

OBJECTIVE

To evaluate the performance of the ratio between the waist circumference and the height in the identification of health risk compared with the correlation matrix between the anthropometric parameters body mass index and waist circumference.

METHODS

A population-based study presenting a transversal cut in a representative sample of the Brazilian adult and older population. The combination of the body mass index with the waist circumference resulted in health risk categories, and the cutoff points of the ratio between the waist circumference and the height as anthropometric indicator were used for classification of low and increased risk. Poisson regression was used to verify the association of systemic arterial hypertension with the health risk categories.

RESULTS

The results showed 26% of adult men, 10.4% of adult women and more than 30% of the older adults of both genders classified as without risk by the combination matrix between body mass index and waist circumference presented a ratio between the waist circumference and height that showed increased risk. All risk categories continued to be associated with hypertension after control for confounding factors, being almost two times higher for adults with moderate and high risk according to both methods. When the waist-to-height ratio was used as a risk indicator, the prevalence of hypertension ratios for the older adults was 1.37 (95%CI 1.16–1.63) and 1.35 (95%CI 1.12–1.62) for men and women, respectively, being these values close to the combination matrix body mass index and waist circumference.

CONCLUSIONS

The waist-to-height ratio identified more individuals at early health risk than the combination matrix between the body mass index and the waist circumference and showed comparable ability to identify health risk, regardless of gender and age, regarding the prevalence ratios for systemic arterial hypertension.

Predictive values of obesity categories for cardiovascular disease risk factors in Chinese adult population

OBJECTIVE

Whether obesity categories can be used to predict cardiovascular disease (CVD) in Chinese adults remains unclear. This aim of this study was to examine the predictive values of obesity categories for CVD risk factors in Chinese adults.

METHODS

This study comprised a sample size of 3480 men and 6364 women aged ≥25 years (age range 25-89 years), from the medical health check-up center of Lianyungang First People's Hospital. The following CVD risk factor outcomes were used: hypertension, diabetes, dyslipidemia, insulin resistance, and metabolic syndrome (Mets). Framingham risk scores were used to evaluate the CVD. Four categories of obesity were used, based on body mass index (BMI) and waist circumference: no risk, increased risk, high risk, and very high risk. Predictive abilities were determined by calculating the odds ratios (OR) of CVD risk.

RESULTS

A graded linear relationship between obesity categories and CVD risk was observed across the categories, except for dyslipidemia. The people in the very high-risk category had the highest OR of having more unfavorable CVD risk factors compared with those in the lower risk category. For example, the OR of diabetes increased with the increase in risk category (OR, 1.13, 1.36, and 1.83, respectively, for increased, high, and very high risk categories in men and OR, 1.52, 1.80, and 2.78, respectively, for increased, high, and very high risk category in women).

CONCLUSIONS

These findings suggest that obesity categories provide clinical insights into identifying multiple CVD risk factors in Chinese adults.

Lifestyle behaviours or socioeconomic characteristics? Gender differences in covariates of BMI in Hungary

Objective

Lifestyle behaviours are everyday activities that result from individual's values, knowledge, and norms shaped by broader cultural and socioeconomic context. These behaviours affect body weight as well as overall health and are influenced by a number of social characteristics. The aim of this paper was to examine the net effects of lifestyle behaviours and socioeconomic factors on body mass index (BMI), and how these differed by gender.

Methods

This study used the 2009/2010 Hungarian Time Use Survey combining behavioural records, background information, and measures of self‐reported health and weight. The sample (n = 7765) was representative for the Hungarian population. Multivariate linear OLS regression models were employed to analyse the net effects of lifestyle and sociodemographic variables.

Results

Daily behaviours were associated with BMI for women, but not for men, except for smoking. Meals frequency and duration of sleep had negative effects on female BMI, whereas duration of TV viewing had a positive effect. Occupational class was associated with male BMI, but not with female. The strong negative effect of smoking was significant for both genders.

Conclusions

Lifestyle behaviours were linked with female BMI, with socioeconomic characteristics impacting on male BMI. These results suggest that a gender‐specific approach may be appropriate to address obesity issues in the Hungarian population.

The Independent Associations between Walk Score® and Neighborhood Socioeconomic Status, Waist Circumference, Waist-To-Hip Ratio and Body Mass Index Among Urban Adults

Background: Environmental and policy factors can influence weight status via facilitating or discouraging physical activity and healthy diet. Despite mixed evidence, some findings suggest that the neighborhood built environment, including &ldquo;walkability&rdquo;, is associated with overweight and obesity. Most of these findings have measured body mass index (BMI), yet other weight status measures including waist circumference (WC) and waist-to-hip (W-H) ratio are also predictive of health outcomes, independent of BMI. Our study aim was to estimate the associations between walkability, measured using Walk Score^&reg;, and each of WC, W-H ratio, and BMI among urban Canadian adults. Methods: In 2014, n = 851 adults recruited from 12 structurally and socioeconomic diverse neighborhoods (Calgary, Alberta, Canada) provided complete data on a physical activity, health and demographic questionnaire and self-reported anthropometric measures (i.e., height and weight, WC and hip circumference). Anthropometric data were used to estimate WC, W-H ratio, and BMI which were categorized into low and high risk in relation to their potential adverse effect on health. WC and BMI were also combined to provide a proxy measure of both overall and abdominal adiposity. Multivariable logistic regression models estimated odds ratios (OR) and 95% confidence intervals (CI) for associations between each weight status outcome and Walk Score^&reg;. Results: A one-unit increase in Walk Score^&reg; was associated with lower odds of being high-risk based on WC (OR = 0.99; 95%CI 0.97⁻0.99). Notably, those residing in socioeconomically disadvantage neighborhoods had significantly higher odds of being high risk based on WC, BMI, and WC-BMI combined compared with advantaged neighborhoods. Conclusions: Interventions that promote healthy weight through the design of neighborhoods that support and enhance the effect of physical activity and diet-related interventions could have a significant population health impact.

The relationship of waist circumference and body mass index to grey matter volume in community dwelling adults with mild obesity

Objective

Previous work has shown that high body mass index (BMI) is associated with low grey matter volume. However, evidence on the relationship between waist circumference (WC) and brain volume is relatively scarce. Moreover, the influence of mild obesity (as indexed by WC and BMI) on brain volume remains unclear. This study explored the relationships between WC and BMI and grey matter volume in a large sample of Japanese adults.

Methods

The participants were 792 community-dwelling adults (523 men and 269 women). Brain magnetic resonance images were collected, and the correlation between WC or BMI and global grey matter volume were analysed. The relationships between WC or BMI and regional grey matter volume were also investigated using voxel-based morphometry.

Results

Global grey matter volume was not correlated with WC or BMI. Voxel-based morphometry analysis revealed significant negative correlations between both WC and BMI and regional grey matter volume. The areas correlated with each index were more widespread in men than in women. In women, the total area of the regions significantly correlated with WC was slightly greater than that of the regions significantly correlated with BMI.

Conclusions

Results show that both WC and BMI were inversely related to regional grey matter volume, even in Japanese adults with somewhat mild obesity. Especially in populations with less obesity, such as the female participants in current study, WC may be more sensitive than BMI as a marker of grey matter volume differences associated with obesity.

Changes in Adult BMI and Waist Circumference Are Associated with Increased Risk of Advanced Colorectal Neoplasia

BACKGROUND

Waist circumference (WC) is a stronger predictor of colon cancer (CRC) risk than body mass index (BMI). However, how well change in either WC or BMI predicts risk of advanced colorectal neoplasia (AN) is unclear.

AIMS

To determine the relationship between change in BMI and WC from early adulthood to later age and the risk of AN and which change measure is a stronger predictor.

METHODS

In 4500 adults, ages 50-80, with no previous neoplasia and undergoing screening colonoscopy, BMI and WC at age 21 and at time of screening were reported. Changes in BMI and WC were defined using universal risk cutoffs. Known CRC risk factors were controlled in the logistic models.

RESULTS

Overall, model statistics showed WC change (omnibus test χ ² = 10.15, 2 DF, p value = 0.006) was a statistically stronger predictor of AN than BMI change (omnibus test χ ² = 5.66, 5 DF, p value = 0.34). Independent of BMI change, participants who increased WC (OR 1.44; 95% CI 1.05-1.96) or maintained a high-risk WC (OR 2.50; 95% CI 1.38-4.53) at age 21 and at screening had an increased risk of AN compared to those with a low-risk WC. Study participants who were obese at age 21 and at screening had an increased risk of AN (OR 1.87; 95% CI 1.08-3.23) compared to those who maintained a healthy BMI. Maintaining an overweight BMI or increasing BMI was not associated with AN.

CONCLUSIONS

Maintaining an unhealthy BMI and WC throughout adult life may increase risk of AN. WC change may be a better predictor of AN than BMI change.

Secular and race/ethnic trends in glycemic outcomes by BMI in US adults: The role of waist circumference

BACKGROUND

For the same body mass index (BMI) level, waist circumference (WC) is higher in more recent years. How this impacts diabetes and prediabetes prevalence in the United States and for different race/ethnic groups is unknown. We examined prevalence differences in diabetes and prediabetes by BMI over time, investigated whether estimates were attenuated after adjusting for waist circumference, and evaluated implications of these patterns on race/ethnic disparities in glycemic outcomes.

METHODS

Data came from 12 614 participants aged 20 to 74 years from the National Health and Nutrition Examination Surveys (1988-1994 and 2007-2012). We estimated prevalence differences in diabetes and prediabetes by BMI over time in multivariable models. Relevant interactions evaluated race/ethnic differences.

RESULTS

Among normal, overweight, and class I obese individuals, there were no significant differences in diabetes prevalence over time. However, among individuals with class II/III obesity, diabetes prevalence rose 7.6 percentage points in 2007-2012 vs 1988-1994. This estimate was partly attenuated after adjustment for mean waist circumference but not mean BMI. For prediabetes, prevalence was 10 to 13 percentage points higher over time at lower BMI values, with minimal attenuation after adjustment for WC. All patterns held within race/ethnic groups. Diabetes disparities among blacks and Mexican Americans relative to whites remained in both periods, regardless of BMI, and persisted after adjustment for WC.

CONCLUSIONS

Diabetes prevalence rose over time among individuals with class II/III obesity and may be partly due to increasing waist circumference. Anthropometric measures did not appear to account for temporal increases in prediabetes, nor did they attenuate race/ethnic disparities in diabetes. Reasons underlying these trends require further investigation.

Waist circumference, body mass index and waist-height ratio: Are two indices better than one for identifying hypertension risk in older adults?

OBJECTIVE

To investigate if the combination of Waist Circumference (WC) and Body Mass Index (BMI) or Waist to Height Ratio (WHtR) and BMI measures is superior to the separate indicators in identifying hypertension risk in older adults from southern Brazil.

METHOD

This cross-sectional study analyzed data from the second wave (2013/14) of a population- and household-based survey carried out with 1197 older adults (778 women). Hypertension (i.e., outcome) was identified by self-report. The independent variables were body mass index (BMI≥27kg/m²), waist circumference (WC≥88cm for women and WC≥102cm for men), waist/height ratio (WHtR≥0.5), and the combined indexes BMI+WC (BMI≥27kg/m²+WC≥88cm for women and WC≥102cm for men) and BMI+WHtR (BMI≥27kg/m²+WHtR≥0.5). The associations were explored using binary logistic regression.

RESULTS

The results showed sex differences in all study characteristics. In women, all indicators were associated with the outcome, after adjustments (age, race/color, marital status, schooling, smoking, alcohol consumption, physical activity, and diabetes). WHtR was the indicator most strongly associated with hypertension (OR=2.97; 95% CI 1.58 to 5.59). For men, only BMI and the combined indicators were associated with hypertension. Combined measures of BMI+WHtR showed a stronger association with the outcome (OR=2.68; IC95% 1.62 to 4.44).

CONCLUSION

The associated indicators differed between the sexes. The combination of BMI+WC and BMI+WHtR using current cut-off points may provide an improved measure of hypertension risk.

Comparison of the Combined Obesity Indices to Predict Cardiovascular Diseases Risk Factors and Metabolic Syndrome in Northeast China

Background: Obesity is associated with cardiovascular disease (CVD) risk factors (hypertension, dyslipidemia and diabetes) and metabolic syndrome (MetS), and it may be flawed that most studies only use one obesity index to predict these risk factors. Therefore, our study aims to compare the various combined obesity indices systematically, and to find the optimal combined obesity indices to predict CVD risk factors and MetS. Methods: A total of 16,766 participants aged 18–79 years old were recruited in Jilin Province in 2012. Receiver operating characteristic curve (ROC) curves and multiple logistic regressions were used to evaluate the predictive capacity of the combined obesity indices for CVD risk factors and MetS. Results: The adjusted area under receiver operating characteristic (AUROC) with two combined obesity indices had been improved up to 19.45%, compared with one single obesity index. In addition, body mass index (BMI) and waist circumference (WC) were the optimal combinations, where the AUROC (95% confidence interval (CI)) for hypertension, dyslipidemia, diabetes and MetS in males were 0.730 (0.718, 0.740), 0.694 (0.682, 0.706), 0.725 (0.709, 0.742) and 0.820 (0.810, 0.830), and in females were 0.790 (0.780, 0.799), 0.727 (0.717, 0.738), 0.746 (0.731, 0.761) and 0.828 (0.820, 0.837), respectively. Conclusions: The more abnormal obesity indices that one has the higher the risk for CVD risk factors and MetS, especially in males. In addition, the combined obesity indices have better predictions than one obesity index, where BMI and WC are the optimal combinations.

Single and combined effects of body composition phenotypes on carotid intima-media thickness

BACKGROUND

Central fatness might be a more sensitive predictor of atherosclerotic changes in children than are total body fat measures. However, it is unclear whether a total body fat measure coupled with an estimate of a more central pattern of fat accumulation predicts increased carotid intima-media-thickness (cIMT) better than either measure alone.

OBJECTIVE

The objective of the study is to identify the ability of a combination of simple anthropometric screening tools or a combination of objective measures of body composition to predict cIMT.

METHODS

cIMT was assessed on the common carotid artery in 349 children aged 11-12 years old (183 girls). Body mass index (BMI), waist circumference (WC) and waist-to-height ratio (WHtR) were dichotomized according to established criteria and indices of total body (TBFI) and abdominal (ABFMI) fat were assessed by dual-energy X-ray absorptiometry and categorized (increased risk ≥85%). Single and combined associations among anthropometric and laboratorial measures with the risk of having increased cIMT (≥85%) and discriminatory performance were tested with logistic regression analysis and Receiver Operator Curve analysis.

RESULTS

Children with higher total fatness (BMI and TBFI) or higher central pattern of fat accumulation (WC, WHtR and BFMI) were in higher risk for increased cIMT [odds ratio (OR): 2.08-3.24). The risk for increased cIMT was not higher among children who coupled high total and high central fatness (OR: 2.27-3.10).

CONCLUSIONS

Combination of total and central measures of fat does not improve the prediction of increased cIMT in children. Simple surrogate measures of fatness can be used to predict increased cIMT urging special attention to those children who exhibit increased abdominal fat.

Impact of body fat changes in mediating the effects of antiretroviral therapy on blood pressure in HIV-infected persons in a sub-Saharan African setting

Background

Previous studies of HIV-infected patients have shown significant associations between highly active antiretroviral therapy (HAART) and increased blood pressure; however, the mechanisms involved are less clear. Therefore, we sought to investigate the potential impact of body fat changes in mediating the effects of HAART on blood pressure changes among people living with HIV.

Methods

Four hundred six consenting patients (≥18 years of age) attending a tertiary HIV clinic in semi-urban Nigeria were recruited between August and November 2014 as part of a cross-sectional study. We performed bias-corrected bootstrap tests of mediation using 95 % confidence intervals (CI) to determine the mediating effects of body mass index and waist circumference (mediators) on the total effects of HAART exposure (primary predictor) on blood pressure (outcome), while controlling for age, sex and other potential confounders.

Results

Waist circumference remained a significant partial mediator of the total effects of HAART exposure on increasing systolic blood pressure (coefficient: 1.01, 95 % CI: 0.33 to 2.52, 11 % mediated) and diastolic blood pressure (coefficient: 0.68, 95 % CI: 0.26 to 1.89, 9 % mediated) after adjusting for age, sex, smoking status, CD4 count and duration of HIV infection. No significant mediating effect was observed with body mass index alone or in combination with waist circumference after adjusting for all potential confounders.

Conclusion

Waist circumference significantly mediates the effects of HAART on blood pressure in persons living with HIV, independent of the role of traditional risk factors. The use of waist circumference as a complementary body fat measure to body mass index may improve the clinical prediction of hypertension in HIV-infected patients on antiretroviral therapy.

Electronic supplementary material

The online version of this article (doi:10.1186/s40249-016-0152-7) contains supplementary material, which is available to authorized users.

Examining the mediating roles of binge eating and emotional eating in the relationships between stress and metabolic abnormalities

To test whether binge eating and emotional eating mediate the relationships between self-reported stress, morning cortisol and the homeostatic model of insulin resistance and waist circumference. We also explored the moderators of gender and age. Data were from 249 adults (mean BMI = 26.9 ± 5.1 kg/m(2); mean age = 28.3 ± 8.3 years; 54.2% male; 69.5% white) recruited from the community who were enrolled in a cross-sectional study. Participants completed a comprehensive assessment panel of psychological and physiological assessments including a morning blood draw for plasma cortisol. We found negative relationships between stress and morning cortisol (r = -0.15 to -0.21; p < 0.05), and cortisol and the homeostatic model of insulin resistance and waist circumference (r = -0.16, -0.25, respectively; p < 0.05). There was not statistical support for binge eating or emotional eating as mediators and no support for moderated mediation for either gender or age; however, gender moderated several paths in the model. These include the paths between perceived stress and emotional eating (B = 0.009, p < 0.001), perceived stress and binge eating (B = 0.01, p = 0.003), and binge eating and increased HOMA-IR (B = 0.149, p = 0.018), which were higher among females. Among women, perceived stress may be an important target to decrease binge and emotional eating. It remains to be determined what physiological and psychological mechanisms underlie the relationships between stress and metabolic abnormalities.

Metabolic stress-induced joint inflammation and osteoarthritis

Osteoarthritis (OA) is a heterogeneous disorder with several risk factors. Among them, obesity has a major impact on both loading and non-loading joints. Mechanical overload and activity of systemic inflammatory mediators derived from adipose tissue (adipokines, free fatty acids (FFA), reactive oxygen species (ROS)) provide clues to the increased incidence and prevalence of OA in obesity. Recently, research found greater OA prevalence and incidence in obese patients with cardiometabolic disturbances than "healthy" obese patients, which led to the description of a new OA phenotype - metabolic syndrome (MetS)-associated OA. Indeed, individual metabolic factors (diabetes, dyslipidemia, and hypertension) may increase the risk of obesity-induced OA. This review discusses hypotheses based on pathways specific to a metabolic factor in MetS-associated OA, such as the role of advanced glycation end products (AGEs) and glucose toxicity. A better understanding of these phenotypes based on risk factors will be critical for designing trials of this specific subset of OA.

Associations Between Hypertension and Body Mass Index and Waist Circumference in U.S. Adults: A Comparative Analysis by Gender

INTRODUCTION

The body mass index (BMI) and waist circumference (WC) are a risk of hypertension, but their potentially multiplicative effect on hypertension is underexplored.

AIM

To examine modifying effects of BMI and WC on hypertension using a nationally representative U.S. adult sample stratified by gender.

METHODS

Data were derived from the 2009-2010 NHANES. Overweight and obesity were based on BMI of 25.0-29.9 and ≥30 kg/m(2), respectively. High-risk WC was based on ≥102.0 and ≥88.0 cm for males and females, respectively. Hypertension was determined by systolic/diastolic blood pressure of ≥140/≥90 mmHg, or taking prescribed medications. Logistic regression was used to examine the association between hypertension and BMI and WC by gender. Interaction terms were added to examine if BMI modified the effect of WC on hypertension.

RESULTS

Both BMI and WC were significant predictors of hypertension in overall population. Gender-specific models indicated that BMI played an important role in hypertension risk among males, but WC in females. The interaction effects were present among males implying that the association of WC with hypertension was stronger if subjects were overweight or obese. This effect, however, was not present in females.

CONCLUSION

BMI and WC may influence hypertension differently among males and females.

Smoking is associated with more abdominal fat in morbidly obese patients

INTRODUCTION

While the association between cigarette smoking and abdominal fat has been well studied in normal and overweight patients, data regarding the influence of tobacco use in patients with morbid obesity remain scarce. The aim of this study is to evaluate body fat distribution in morbidly obese smokers.

METHODS

We employed a cross-sectional study and grouped severely obese patients (body mass index [BMI] >40 kg/m2 or >35 kg/m2 with comorbidities) according to their smoking habits (smokers or non-smokers). We next compared the anthropometrical measurements and body composition data (measured by electric bioimpedance) of both groups. We analyzed the effect of smoking on body composition variables using univariate and multiple linear regression (MLR); differences are presented as regression coefficients (b) and their respective 95% confidence intervals.

RESULTS

We included 536 morbidly obese individuals, 453 (84.5%) non-smokers and 83 (15.5%) smokers. Male smokers had a higher BMI (b=3.28 kg/m2, p=0.036), larger waist circumference (b=6.07 cm, p=0.041) and higher percentage of body fat (b=2.33%, p=0.050) than non-smokers. These differences remained significant even after controlling for confounding factors. For females, the only significant finding in MLR was a greater muscle mass among smokers (b=1.34kg, p=0.028). No associations were found between tobacco load measured in pack-years and anthropometric measures or body composition.

DISCUSSION

Positive associations between smoking and BMI, and waist circumference and percentage of body fat, were found among male morbidly obese patients, but not among females. To the best of our knowledge, this study is the first investigation of these aspects in morbidly obese subjects. We speculate that our findings may indicate that the coexistence of morbid obesity and smoking helps to explain the more serious medical conditions, particularly cardiovascular diseases and neoplasms, seen in these patients.

In cross-sectional observations, dietary quality is not associated with CVD risk in women; in men the positive association is accounted for by BMI

The role that BMI plays in the association between dietary quality and CVD risk is not known. We aimed to better understand this relationship using statistical methods which correct for sex-specific underreporting of dietary intake. Overall, dietary quality was assessed using the Healthy Eating Index (HEI) on data from 9797 non-pregnant adults (aged >20 years) who participated in the National Health and Nutrition Examination Survey from 2005 to 2010. CVD risk factors included blood pressure, fasting glucose and insulin, homeostatic models of insulin resistance (HOMA-IR), HDL- and LDL-cholesterol (HDL-C and LDL-C), TAG and C-reactive protein (CRP). We controlled for demographic and lifestyle covariates, and we used the population ratio approach (which adjusts for the underreporting of intake) to compare mean HEI scores between the top and bottom quartiles of covariate-adjusted CVD risk factors. In women, the total HEI score was not associated with any CVD risk factors (all Q>0·11). In men, the total HEI score was associated with covariate-adjusted residuals for fasting insulin (Q<0.001), HOMA-IR (Q<0.001), HDL-C (Q=0.01) and CRP (Q<0.001). When we additionally adjusted for BMI, the association with total HEI score was not significant (all P>0.10). In the present analyses, dietary quality was associated with five CVD risk factors in a sex-specific manner. Moreover, the association of BMI with CVD risk attenuated the relationship between CVD risk and diet, which suggests that BMI is an important factor in heart disease prevention.

Indicadores nutricionais combinados e fatores associados em população Quilombola no Sudoeste da Bahia, Brasil

Este estudo estimou a prevalência de duas combinações de indicadores nutricionais: Índice de Massa Corporal (IMC) + Circunferência da Cintura (CC) e IMC + Razão Cintura Estatura (RCE), e investigou os fatores associados em adultos Quilombolas. Amostra aleatória em dois estágios de 739 adultos ≥ 20 anos, residentes em Comunidades Quilombolas em Vitória da Conquista (BA), em 2011. Risco combinado IMC + RCE incluiu os indivíduos que simultaneamente apresentaram IMC ≥ 25,0Kg/m2 ou ≥ 27,0Kg/m2, se idade ≥ 60 anos e RCE ≥ 0,5. O risco IMC + RCE incluiu indivíduos com IMC elevado que também apresentavam CC ≥ 80cm, se mulher, ou ≥ 94cm, se homem. As prevalências dos indicadores nutricionais combinados foram de 35,3% (IMC + RCE) e 26,8% (IMC + CC). Sexo feminino e hipertensão aumentaram a chance para os dois indicadores enquanto que o estado civil não casado diminuiu esta chance. O indicador IMC + RCE foi maior na faixa etária de 40 a 59 anos e o indicador IMC + CC foi mais frequente na faixa de 40 a 49 anos. A baixa escolaridade elevou o indicador IMC + RCE, enquanto assistir televisão por mais de duas horas por dia, o indicador IMC + CC. A elevada prevalência de risco nutricional para DCNT, especialmente de obesidade central, confirmou a necessidade de ações de promoção de dieta saudável e saúde.

Optimal cut-off values of BMI, waist circumference and waist:height ratio for defining obesity in Chinese adults

It has not been established which specific measures of obesity might be most appropriate for predicting CVD risk in Asians. The objectives of the present study were to determine the associations of BMI, waist circumference (WC) and waist:height ratio (WHtR) with CVD risk factors and to evaluate the optimal cut-off values to define overweight or obesity in Chinese adults. Data collected from seven nationwide health examination centres during 2008 and 2009 were analysed. The BMI, WC and WHtR of 244 266 Chinese adults aged ≥ 20 years included in the study were measured. Logistic regression models were fit to evaluate the OR of each CVD risk factor according to various anthropometric indices. Receiver operating characteristic (ROC) analyses were conducted to assess the optimal cut-off values to predict the risk of diabetes, hypertension, dyslipidaemia and the metabolic syndrome. WHtR had the largest areas under the ROC curve for all CVD risk factors in both sexes, followed by WC and BMI. The optimal cut-off values were approximately 24·0 and 23·0 kg/m2 for BMI, 85·0 and 75·0 cm for WC, and 0·50 and 0·48 for WHtR for men and women, respectively. According to well-established cut-off values, BMI was found to be a more sensitive indicator of hypertension in both men and women, while WC and WHtR were found to be better indicators of diabetes and dyslipidaemia. A combination of BMI and central obesity measures was found to be associated with greater OR of CVD risk factors than either of them alone in both sexes. The present study demonstrated that WHtR and WC may be better indicators of CVD risk factors for Chinese people than BMI.

Impact of different obesity assessment methods after acute coronary syndromes

BACKGROUND

Abdominal obesity is an important cardiovascular risk factor. Therefore, identifying the best method for measuring waist circumference (WC) is a priority.

OBJECTIVE

To evaluate the eight methods of measuring WC in patients with acute coronary syndrome (ACS) as a predictor of cardiovascular complications during hospitalization.

METHODS

Prospective study of patients with ACS. The measurement of WC was performed by eight known methods: midpoint between the last rib and the iliac crest (1), point of minimum circumference (2); immediately above the iliac crest (3), umbilicus (4), one inch above the umbilicus (5), one centimeter above the umbilicus (6), smallest rib and (7) the point of greatest circumference around the waist (8). Complications included: angina, arrhythmia, heart failure, cardiogenic shock, hypotension, pericarditis and death. Logistic regression tests were used for predictive factors.

RESULTS

A total of 55 patients were evaluated. During the hospitalization period, which corresponded on average to seven days, 37 (67%) patients had complications, with the exception of death, which was not observed in any of the cases. Of these complications, the only one that was associated with WC was angina, and with every cm of WC increase, the risk for angina increased from 7.5 to 9.9%, depending on the measurement site. It is noteworthy the fact that there was no difference between the different methods of measuring WC as a predictor of angina.

CONCLUSION

The eight methods of measuring WC are also predictors of recurrent angina after acute coronary syndromes.

[Association between waist circumference and body mass index of Brazilian women: NDHS 2006]

The scope of this study was to evaluate the association between waist circumference (WC) and body mass index (BMI) of Brazilian women of childbearing age studied in the most recent National Demographic and Health Survey (NDHS), in 2006. This study is an excerpt of the NDHS, which is a home-based cross-sectional study. The nutritional status of women was assessed by WC and BMI, considering excess weight to be BMI = 25 Kg/m2 and WC risk to be = 80 cm. To evaluate the statistical significance, Poisson Regression was applied to identify factors associated with WC risk in women with or without excess weight, presenting the p-value corresponding to the Wald test for heterogeneity or linear trend. Of the 14,101 women studied, 45.8% were overweight and 55.5% at WC risk. Regarding the association between BMI and WC, it was found that 23.5% of women who were not overweight showed WC risk. After a stratified analysis by BMI, the prevalence of WC risk among women without excess weight was greatest in the Northeast, 26.0%, and the Southeast, 24.5%, while the South region presented the lowest prevalence at 18.5%. It follows that the anthropometric WC and BMI measures should be used concomitantly since the use of only one of these measures may overlook individuals at risk for various diseases.

The influences of obesity and age on functional performance during intermittent upper extremity tasks

In this study, the main and interactive effects of obesity and age on functional performance were assessed during intermittent exertions involving the upper extremity. The prevalence of obesity has doubled over the past 30 years and this increase is associated with higher health care costs, rates of workplace injury, and lost workdays. Obesity and aging can modify job demands and affect worker capacity in terms of muscular and psychomotor function. However, there is a lack of empirical studies quantifying the work-relevant (or ergonomic) impacts related to task demands, capacities, and their potential imbalance. Eight obese and eight non-obese participants from each of two age groups (18-25 and 50-65 years) completed three endurance tasks involving fixed levels of task demands: hand grip, shoulder flexion, and a simulated assembly task using the upper extremity. Measures of functional performance including endurance, discomfort, motor control, and task performance were recorded for each of the task conditions. Endurance times were ∼60% longer for the non-obese group, and older participants had longer endurance times; however there was no evidence of interactive effects of obesity and age. Obesity also impaired functional performance, as indicated by higher rates of strength loss, increases in discomfort, and declines in task performance. These observed impairments may reflect underlying physiological differences among individuals who are obese, but that are independent of age. Obesity-related impairments may have implications for the design of work duration and demand level to prevent fatigue development for workers who are obese.

Cutoff point of waist circumference for the diagnosis of metabolic syndrome in an Iranian population

SUMMARY

BACKGROUND

Proposed cutoffs for waist circumference (WC) in western populations may be not appropriate for Asian populations. The published data among Iranians are insufficient to address this issue. This study was designed to identify cutoffs for WC that confer increased risk of metabolic syndrome in Iranian adults living in Zanjan, a province located in the west of Tehran.

MATERIALS AND METHODS

Data of a cross-sectional sample of 3277 Iranian adults aged more than 20 years were analyzed. In the original study individual body weight, height, WC, and blood pressure were assessed and fasting plasma glucose, triglycerides, total cholesterol, low- and high-density lipoprotein cholesterol were measured. After excluding WC, existence of two or more of the remaining four risk factors of the modified NCEP III criteria for metabolic syndrome were defined as multiple risk factors. Receiver operating characteristic (ROC) analysis was used to find out the optimal cutoff values of WC to predict metabolic syndrome.

RESULTS

The cutoff level yielding the maximal sensitivity and specificity for predicting the presence of metabolic syndrome (multiple risk factors) was 87 cm in men and 82 cm in women. Cutoffs corresponding to body mass index (BMI) 25 and 30 kg/m(2) to predict metabolic syndrome were 84 and 97 cm in men and 78 and 91 cm in women, respectively.

CONCLUSIONS

Lower cutoffs for WC should be considered in the identification of Iranian population at high risk of metabolic syndrome.

Obesity is associated with lower coronary microvascular density

Background

Obesity is associated with diastolic dysfunction, lower maximal myocardial blood flow, impaired myocardial metabolism and increased risk of heart failure. We examined the association between obesity, left ventricular filling pressure and myocardial structure.

Methods

We performed histological analysis of non-ischemic myocardium from 57 patients (46 men and 11 women) undergoing coronary artery bypass graft surgery who did not have previous cardiac surgery, myocardial infarction, heart failure, atrial fibrillation or loop diuretic therapy.

Results

Non-obese (body mass index, BMI, ≤30 kg/m², n=33) and obese patients (BMI >30 kg/m², n=24) did not differ with respect to myocardial total, interstitial or perivascular fibrosis, arteriolar dimensions, or cardiomyocyte width. Obese patients had lower capillary length density (1145±239, mean±SD, vs. 1371±333 mm/mm³, P=0.007) and higher diffusion radius (16.9±1.5 vs. 15.6±2.0 μm, P=0.012), in comparison with non-obese patients. However, the diffusion radius/cardiomyocyte width ratio of obese patients (0.73±0.11 μm/μm) was not significantly different from that of non-obese patients (0.71±0.11 μm/μm), suggesting that differences in cardiomyocyte width explained in part the differences in capillary length density and diffusion radius between non-obese and obese patients. Increased BMI was associated with increased pulmonary capillary wedge pressure (PCWP, P<0.0001), and lower capillary length density was associated with both increased BMI (P=0.043) and increased PCWP (P=0.016).

Conclusions

Obesity and its accompanying increase in left ventricular filling pressure were associated with lower coronary microvascular density, which may contribute to the lower maximal myocardial blood flow, impaired myocardial metabolism, diastolic dysfunction and higher risk of heart failure in obese individuals.

Associations between Tai Chi Chung Program, Anxiety, and Cardiovascular Risk Factors

Purpose.

To examine the effects of a Tai Chi Chung (TCC) program, an efficiency approach, on anxiety and cardiovascular risk factors.

Design.

A quasi-experimental study.

Setting.

A community in Taipei City, Taiwan.

Subjects.

One hundred thirty-three adults aged 55 years and older.

Intervention.

Sixty-four participants (experimental group) attended a 60-minute Tai Chi exercise three times per week for 12 weeks, whereas 69 participants (control group) maintained their usual daily activities.

Measures.

Anxiety states, systolic blood pressure (SBP), diastolic blood pressure (DBP), body mass index (BMI), and waist circumference (WC) were assessed at baseline, 6 weeks into the experiment, and 12 weeks into the experiment.

Analysis.

Generalized estimating equations were used to evaluate the changes.

Results.

Participants showed a greater drop in anxiety levels (β = −2.57, p = .001) and DBP (β = −7.02, p < .001) at the 12-week follow-up than did the controls. SBP significantly decreased in the 6-week follow-up and 12-week follow-up tests. The participants in the intervention achieved a greater drop in BMI at the 6-week and 12-week follow-up visits than the controls. The interventions demonstrated decreased average WC at the 6-week and 12-week follow-up visits as compared to the controls.

Conclusion.

The results highlight the long-term benefits of a TCC program in facilitating health promotion by reducing anxiety and risk factors for cardiovascular diseases.