Obesity in the Elderly and Its Relationship with Cardiovascular Risk Factors in Taiwan**

Objectives: The obese elderly are at increased risk of mortality, morbidity, and functional disability. In this study, we examined the prevalence of obesity and relationship between various anthropometric indices (AI) and cardiovascular disease (CVD) risk factors in the elderly. Research Methods and Procedures: A stratified multistage clustered sampling scheme was used in the Elderly Nutrition and Health Survey in Taiwan during 1999 to 2000. 2432 non‐institutionalized subjects (age, 72.8 ± 9.4 years; BMI, 23.6 ± 6.4 kg/m²) were recruited. The receiver operating characteristic analysis was used to compare predictive validity of CVD risk factors among various AI, including BMI, waist circumference (WC), and waist‐to‐hip ratio (WHR). Results: The prevalence of obesity was 29.0% in men and 36.8% in women by obesity criteria for Asians (BMI ≥ 25 kg/m²) and 13.3% in men and 21.0% in women by the Taiwanese definition (BMI ≥ 27 kg/m²). Odds ratios of acquiring various CVD risk factors increased significantly with increment of WC, WHR, and BMI. The areas under the curve predicting metabolic syndrome were all <0.8. The cut‐off values of WC corresponding to the highest sensitivity and the highest specificity in predicting various CVD risk factors were 86.2–88.0 cm in men and 82.0–84.0 cm in women, respectively. Discussion: Obesity was prevalent in the Taiwanese elderly. WC was related to CVD risk factors to a greater extent than BMI and WHR. However, none of them alone was a good screening tool for CVD risk factors. Therefore, how to apply AI prudently to screen elderly for CVD risk factors needs further research.     

Waist circumference and BMI cut-off based on 10-year cardiovascular risk: evidence for "central pre-obesity"

Objective: The objective was to assess the waist circumference (WC) cut‐off point that best identifies a level of 10‐year cardiovascular disease (CVD) risk with optimal balance of sensitivity and specificity in Chinese subjects according to their predicted 10‐year CVD risk. Research Methods and Procedures: A community‐based cross‐sectional observational study involving 14,919 Hong Kong Chinese subjects. The 10‐year CVD risk based on various prediction models was calculated. The projected WC cut‐off points were then determined. Results: There were 4837 (32.4%) men and 10,082 (67.6%) women (mean age ± standard deviation, 47.3 ± 13.5 years; age range, 18 to 93 years; median age, 45.0 years). The mean optimal WC or BMI predicting a 15% to 30% 10‐year CVD risk were 83 to 88 cm and 25 kg/m² for men, and 76 cm and 23 kg/m² for women, respectively. With WC ≥90 cm in men and ≥80 cm in women, the likelihood ratio at various WC cut‐off points to develop a ≥20% 10‐year CVD risk is 1.5 to 2.0 in men and 3.0 in women. The likelihood ratio was 1.5 in men with WC at 84 cm and in women at 70 cm. Discussion: Our results agree with the present guidelines on the definition of general and central obesity in Asia‐Pacific regions. We propose the creation of an intermediate state of high WC, the “central pre‐obesity” for Chinese men with WC ≥84 to 90 cm (≥33 to 36 inches) and women with WC ≥74 to 80 cm (≥29 to 32 inches). People with central pre‐obesity, similar to those with overweight (BMI ≥23 to 25 kg/m²), already have an increased risk of co‐morbidities.     

BMI and waist circumference in predicting cardiovascular risk factor clustering in Chinese adolescents

Objective: To derive the optimal BMI and waist circumference (WC) cut‐off values to predict clustering of cardiovascular risk factors in Hong Kong Chinese adolescents. Research Methods and Procedures: A total of 2102 Hong Kong Chinese 12 to 19 years of age were recruited. Participants were considered to have clustering of risk factors if at least three of the following risk factors were present: 1) high‐density lipoprotein cholesterol (HDL‐C) ≤1.03 mM, 2) low‐density lipoprotein cholesterol (LDL‐C) ≥2.6 mM, 3) triglyceride (TG) ≥1.24 mM, 4) fasting plasma glucose (FPG) ≥6.1 mM, and 5) age‐, sex‐, and height‐adjusted systolic or diastolic blood pressure (BP) ≥ 90th percentile. Receiver operating characteristics (ROC) curves were generated to identify the optimal age‐adjusted BMI and WC cut‐off values to predict clustering of risk factors in boys and girls separately. These age‐adjusted BMI and WC cut‐offs were transformed to percentile values. Cole's lambda‐mu‐sigma (LMS) method was used to obtain smoothed age‐specific BMI and WC at these percentile values. Results: The areas under ROC curves for BMI in girls and boys were 0.85 [95% confidence interval (CI), 0.77 to 0.92] and 0.76 (95% CI, 0.66 to 0.85), respectively. The respective areas under ROC curves for WC in girls and boys were 0.82 (95% CI, 0.74 to 0.91) and 0.78 (95% CI, 0.68 to 0.87). The optimal BMI thresholds were at the 78th percentile for girls and the 72nd percentile for boys. The respective values for WC were at the 77th percentile for girls and the 76th percentile for boys. The sensitivities and specificities of these cut‐off values ranged from 72% to 80%. Discussion: Age‐ and sex‐specific BMI and WC cut‐off values can be used to identify adolescents with clustering of cardiovascular risk factors.     

Comparison of measures of adiposity in identifying cardiovascular disease risk among Ethiopian adults

We sought to determine which measures of adiposity can predict cardiovascular disease (CVD) risk and to evaluate the extent to which overall and abdominal adiposity are associated with cardiometabolic risk factors among working adults in Ethiopia. This was a cross-sectional study of 1,853 individuals (1,125 men, 728 women) in Addis Ababa, Ethiopia. The World Health Organization STEPwise approach was used to collect sociodemographic data, anthropometric measurements, and blood samples among study subjects. Fasting blood glucose (FBG) and lipid concentrations were measured using standard approaches. Spearman's rank correlation, receiver operating characteristic (ROC) curves, and logistic regression were employed to determine the association and predictive ability (with respect to CVD risk factors) of four measures of adiposity: BMI, waist circumference (WC), waist-to-hip ratio (WHR), and waist-to-height ratio (WHtR). Overall, FBG is best associated with WHtR in men and WC in women. Systolic blood pressure (SBP) is most strongly associated with BMI in men, but with WC in women. Compared to those with low BMI and low WC, the risk of having CVD is the highest for those with high BMI and high WC and those with high WC and low BMI. Review of ROC curves indicated that WC is the best predictor of CVD risk among study subjects. Findings from our study underscore the feasibility and face validity of using simple measures of central and overall adiposity in identifying CVD risk in resource-poor settings.     

Comparison of Body Mass Index (BMI), Body Adiposity Index (BAI), Waist Circumference (WC), Waist-To-Hip Ratio (WHR) and Waist-To-Height Ratio (WHtR) as Predictors of Cardiovascular Disease Risk Factors in an Adult Population in Singapore

Background

Excess adiposity is associated with cardiovascular disease (CVD) risk factors such as hypertension, diabetes mellitus and dyslipidemia. Amongst the various measures of adiposity, the best one to help predict these risk factors remains contentious. A novel index of adiposity, the Body Adiposity Index (BAI) was proposed in 2011, and has not been extensively studied in all populations. Therefore, the purpose of this study is to compare the relationship between Body Mass Index (BMI), Waist Circumference (WC), Waist-to-Hip Ratio (WHR), Waist-to-Height Ratio (WHtR), Body Adiposity Index (BAI) and CVD risk factors in the local adult population.

Methods and Findings

This is a cross sectional study involving 1,891 subjects (Chinese 59.1% Malay 22.2%, Indian 18.7%), aged 21–74 years, based on an employee health screening (2012) undertaken at a hospital in Singapore. Anthropometric indices and CVD risk factor variables were measured, and Spearman correlation, Receiver Operating Characteristic (ROC) curves and multiple logistic regressions were used. BAI consistently had the lower correlation, area under ROC and odd ratio values when compared with BMI, WC and WHtR, although differences were often small with overlapping 95% confidence intervals. After adjusting for BMI, BAI did not further increase the odds of CVD risk factors, unlike WC and WHtR (for all except hypertension and low high density lipoprotein cholesterol). When subjects with the various CVD risk factors were grouped according to established cut-offs, a BMI of ≥23.0 kg/m² and/or WHtR ≥0.5 identified the highest proportion for all the CVD risk factors in both genders, even higher than a combination of BMI and WC.

Conclusions

BAI may function as a measure of overall adiposity but it is unlikely to be better than BMI. A combination of BMI and WHtR could have the best clinical utility in identifying patients with CVD risk factors in an adult population in Singapore.     

BMI vs. waist circumference for identifying vascular risk

Objective: Current guidelines recommend measurement of both BMI and waist circumference (WC) in individuals with BMI between 25.0 and 34.9 kg/m². We investigated the relative contributions of BMI and WC toward identifying risk of adverse vascular events in a community‐based sample. Methods and Procedures: We evaluated Framingham Study participants (n = 4,195 person‐examinations, 53% women) using pooled logistic regression to assess the incremental prognostic utility of WC in predicting risk of a first cardiovascular disease (CVD) event in the three BMI categories (normal, <25 kg/m²; overweight, 25 to <30 kg/m²; obese, ≥ 30 kg/m²) and to assess the incremental prognostic utility of BMI and WC separately for predicting risk of a first cardiovascular event. Results: On follow‐up (16 years), 430 participants (158 women) had experienced a first CVD event. In overweight women, but not in overweight men, larger WC was found to be an independent predictor of CVD incidence, longitudinally (in women, multivariable‐adjusted odds ratio (OR) per s.d. increment in WC 1.86, 95% confidence interval (CI) = 1.03–3.36, P = 0.04; in men adjusted OR per s.d. increment in WC 0.91, 95% CI 0.60–1.38, P = 0.66). In obese individuals and in those with normal BMI, WC was not associated independently with incident CVD. When BMI and WC were analyzed separately for predicting risk of a first cardiovascular event, the c statistics associated with the multivariable CVD models incorporating BMI vs. WC were nearly identical in men and women. Discussion: Knowledge of WC aids identification of vascular risk among overweight women. Among normal weight or obese women and men (regardless of BMI category) WC did not appear to substantially add to prediction of risk of vascular events.     

Impact of Waist Circumference and Body Mass Index on Risk of Cardiometabolic Disorder and Cardiovascular Disease in Chinese Adults: A National Diabetes and Metabolic Disorders Survey

Background

We updated the prevalence of obesity and evaluated the clinical utility of separate and combined waist circumference (WC) or body mass index (BMI) category increments in identifying cardiometabolic disorder (CMD) and cardiovascular disease (CVD) risk in Chinese adults.

Methods and Findings

46,024 participants aged ≥20 years, a nationally representative sample surveyed in 2007–2008, were included in this analysis. Taking the cutoffs recommended by the Chinese Joint Committee for Developing Chinese Guidelines (JCDCG) and the Working Group on Obesity in China (WGOC) into account, the participants were divided into four WC and four BMI groups in 0.5-SD increments around the mean, and 16 cross-tabulated combination groups of WC and BMI. 27.1%, 31.4%, and 12.2% of Chinese adults are centrally obese, overweight, or obese according to JCDCG and WGOC criteria. After adjustment for confounders, after a 1-SD increment, WC is associated with a 1.7-fold or 2.2-fold greater risk of having DM or DM plus dyslipidemia than BMI, while BMI was associated with a 2.3-fold or 1.7-fold higher hypertension or hypertension plus dyslipidemia risk than WC. The combination of WC and BMI categories had stronger association with CMD risk, i.e., the adjusted ORs (95% CI) of having DM, hypertension, and dyslipidemia for the combined and separate highest WC and BMI categories were 2.19 (1.96–2.44) vs 1.88 (1.67–2.12) and 1.12 (0.99–1.26); 5.70 (5.24–6.19) vs 1.51 (1.39–1.65) and 1.69 (1.57–1.82); and 3.73 (3.42–4.07) vs 2.16 (1.98–2.35) and 1.33 (1.25–1.40), respectively. The combination of WC and BMI categories was more likely to identify individuals with lower WC and lower BMI at CVD risk, even after the effects of CMD were controlled (all P<0.05).

Conclusion

Central obesity, overweight, and obesity are epidemic in Chinese adults. The combination of WC and BMI measures is superior to the separate indices in identifying CMD and CVD risk.     

Entering a New Era of Body Indices: The Feasibility of a Body Shape Index and Body Roundness Index to Identify Cardiovascular Health Status

Background

The Body Mass Index (BMI) and Waist Circumference (WC) are well-used anthropometric predictors for cardiovascular diseases (CVD), but their validity is regularly questioned. Recently, A Body Shape Index (ABSI) and Body Roundness Index (BRI) were introduced as alternative anthropometric indices that may better reflect health status.

Objective

This study assessed the capacity of ABSI and BRI in identifying cardiovascular diseases and cardiovascular disease risk factors and determined whether they are superior to BMI and WC.

Design and Methods

4627 Participants (54±12 years) of the Nijmegen Exercise Study completed an online questionnaire concerning CVD health status (defined as history of CVD or CVD risk factors) and anthropometric characteristics. Quintiles of ABSI, BRI, BMI, and WC were used regarding CVD prevalence. Odds ratios (OR), adjusted for age, sex, and smoking, were calculated per anthropometric index.

Results

1332 participants (27.7%) reported presence of CVD or CVD risk factors. The prevalence of CVD increased across quintiles for BMI, ABSI, BRI, and WC. Comparing the lowest with the highest quintile, adjusted OR (95% CI) for CVD were significantly different for BRI 3.2 (1.4–7.2), BMI 2.4 (1.9–3.1), and WC 3.0 (1.6–5.6). The adjusted OR (95% CI) for CVD risk factors was for BRI 2.5 (2.0–3.3), BMI 3.3 (1.6–6.8), and WC 2.0 (1.6–2.5). No association was observed for ABSI in both groups.

Conclusions

BRI, BMI, and WC are able to determine CVD presence, while ABSI is not capable. Nevertheless, the capacity of BRI as a novel body index to identify CVD was not superior compared to established anthropometric indices like BMI and WC.     

Ethnic differences in body composition and other markers of cardiovascular disease risk: study in matched Haitian and White subjects from Quebec

Objectives: People of African descent may be at greater risk of metabolic syndrome (MS) compared with whites. We examined the associations among MS markers, body composition, and resting metabolic rate (RMR) in black Haitians and in white subjects living in Quebec, Canada. Research Methods and Procedures: Forty randomly selected Haitians were matched with 40 white subjects for age, sex, and BMI. Glycemic status and insulin resistance were assessed based on a 3‐hour glucose tolerance test. Blood lipids, blood pressure, abdominal fat (computed tomography), and waist circumference (WC) were measured. RMR was estimated by indirect calorimetry. Results: Triglycerides were significantly correlated with blood pressure only in Haitians and with the area under the curve for insulin only in whites. Haitians had significantly (p < 0.05) lower triglycerides and higher high‐density lipoprotein‐cholesterol concentrations but higher blood pressure than whites at any given WC value. General linear models showed that Haitians had less visceral adipose tissue than whites for the same WC. RMR was lower among Haitians for any given value of BMI or WC than in whites. Also, WC was more strongly associated with glucose area under the curve and to log‐homeostasis model assessment in white than in Haitian subjects. Discussion: The MS may be ethnospecific in its features and etiology. The standard anthropometric indices of obesity may not be as effective in populations of African descent compared with whites, unless appropriate cut‐off values are defined.     

Categorization of low cardiorespiratory fitness using obesity indices in non-smoking Singaporean women

Objective: To revisit cut‐off values of BMI, waist circumference (WC), and waist‐to‐stature ratio (WSR) based on their association with cardiorespiratory fitness (CRF). The derived cut‐off points were compared with current values (BMI, 25.0 kg/m²; WC, 80 cm) as recommended by the World Health Organization. Research Methods and Procedures: Anthropometric indices were measured in a cross sectional study of 358 Singaporean female employees of a large tertiary hospital (63% Singaporean Chinese, 28% Malays, and 9% Indians). CRF was determined by the 1‐mile walk test. Receiver operating characteristic curves were constructed to determine cut‐off points. Results: The cut‐off points for BMI, WC, and WSR were 23.6 kg/m², 75.3 cm, and 0.48, respectively. The areas under the curve of BMI, WC, and WSR were 0.68, 0.74, and 0.74, respectively. For a given BMI, women with low CRF had higher WSR compared with women with high CRF. Discussion: These findings provide convergent evidence that the cut‐off points for Singaporean women were lower than the World Health Organization's criteria but were in good agreement with those reported for Asians.     

Impact of Obesity and Body Fat Distribution on Cardiovascular Risk Factors in Hong Kong Chinese

Objective: Body fat distribution has been reported to differentially contribute to the development of cardiovascular risk. We report the relative associations between general and central obesity and risk factors in 2893 Chinese subjects recruited from the Hong Kong population. Research Methods and Procedures: Anthropometric parameters [waist circumference (WC) and BMI], surrogate measures of insulin resistance (fasting plasma glucose and insulin, oral glucose tolerance test, 2 hours glucose and insulin), fasting lipids (total, low‐density lipoprotein‐cholesterol, high‐density lipoprotein‐cholesterol, and triglycerides) and systolic and diastolic blood pressure were measured. General obesity was classified as BMI ≥25.0 kg/m² and central obesity as a WC ≥80 or ≥90 cm in women and men, respectively. Results: A total of 39.2% of the population was found to be obese. Obesity per se increased the levels of the risk factors, but central adiposity contributed to a greater extent to adverse high‐density lipoprotein‐cholesterol, triglyceride, and insulin resistance levels. There was a continuous relationship between increasing obesity, both general and central, and cardiovascular risk, with lowest risk associated with the lowest indices of obesity. In the 1759 nonobese subjects divided into quartiles of BMI or WC, the levels of the cardiovascular risk factors still significantly increased with increasing quartiles of adiposity. Discussion: Central adiposity appears to contribute to a greater extent than general adiposity to the development of cardiovascular risk in this population. The relationship between obesity parameters and risk is a continuum, with risk factors significantly increasing even at levels usually considered nonobese. These observations support the proposed redefinition of overweight and obesity in Asian populations using lower cut‐off points.     

Eligibility for Obesity Treatment and Risk of Mortality in Men

Objective: To evaluate the risk of all‐cause and cardiovascular disease (CVD) mortality associated with each outcome of the NIH obesity treatment algorithm and to examine the effects of cardiorespiratory fitness on the risk of mortality associated with these outcomes. Research Methods and Procedures: The NIH obesity treatment algorithm was applied to 18, 666 men (20 to 64 years of age) from the Aerobics Center Longitudinal Study in Dallas, TX, examined between 1979 and 1995. Risk of all‐cause and CVD mortality was assessed using Cox proportional hazards regression. Results: A total of 7029 men (37.7%) met the criteria for needing weight loss treatment [overweight (BMI = 25 to 29.9 kg/m² or WC > 102 cm) with ≥2 CVD risk factors or obese (BMI ≥ 30 kg/m²)]. Mortality surveillance through 1996 identified 435 deaths (151 from CVD) during 191, 364 man‐years of follow‐up. Compared with the normal weight reference group, the hazard ratios (95% confidence interval) for death from all causes were 0.63 (0.45 to 0.88), 1.23 (0.98 to 1.54), 1.05 (0.60 to 1.85), and 1.71 (1.64 to 2.31) for men who were overweight with <2 CVD risk factors, overweight with ≥2 CVD risk factors, obese with <2 CVD risk factors, and obese with ≥2 CVD risk factors, respectively. Corresponding hazard ratios for CVD mortality were 0.72 (0.38 to 1.37), 1.67 (1.12 to 2.50), 1.69 (0.67 to 4.30), and 3.31 (2.07 to 5.30). Including physical fitness as a covariate significantly attenuated all risk estimates. Discussion: The NIH obesity treatment algorithm is useful in identifying men at increased risk of premature mortality; however, including an assessment of fitness would help improve risk stratification among all groups of patients.     

BMI, waist circumference, and selected cardiovascular disease risk factors among preschool-age children

In adults, overweight is often associated with other cardiovascular disease (CVD) risk factors. We determined whether these associations were also present in young children. This study examined the relationships between elevated BMI (≥85th and ≥95th percentiles for age and sex) and the highest quintile of waist circumference (WC) with CVD risk factors, including fasting triglyceride (TGL), high- and low-density lipoprotein (HDL and LDL), total cholesterol (TC), non-HDL cholesterol, and C-reactive protein (CRP) in 3,644 3- to 6-year-old children included in the 1999-2008 National Health and Nutrition Examination Surveys (NHANES). Results showed that 20% (highest quintile) of the sample had a TC >170 mg/dl, LDL >109 mg/dl, TGL >103 mg/dl, non-HDL >128 mg/dl, CRP >0.13 mg/dl, WC >57.2 cm, and HDL <42 mg/dl. Increased BMI and WC were associated with increased CRP levels in non-Hispanic black boys and girls, Hispanic boys, and non-Hispanic white girls, whereas elevated TGL and non-HDL cholesterol and low HDL cholesterol were generally associated with elevated BMI and WC in Hispanic children. TC and LDL cholesterol were not significantly associated with elevated weight in 3- to 6-year-olds. BMI and WC were similar in predicting the same risk factors. In summary, this analysis shows that in preschool-age children, greater BMI and WC are associated with biomarkers that are related to CVD risk, but these associations vary by ethnicity. Child health providers should consider using both BMI and WC to identify young children who may be at risk for elevated CVD biomarkers.     

Visceral and Subcutaneous Adiposity and Brachial Artery Vasodilator Function

Endothelial dysfunction may link obesity to cardiovascular disease (CVD). We tested the hypothesis that visceral abdominal tissue (VAT) as compared with subcutaneous adipose tissue (SAT) is more related to endothelium‐dependent vasodilation. Among Framingham Offspring and Third Generation cohorts (n = 3,020, mean age 50 years, 47% women), we used multivariable linear regression adjusted for CVD and its risk factors to relate computed tomography (CT)‐assessed VAT and SAT, BMI, and waist circumference (WC), with brachial artery measures. In multivariable‐adjusted models, BMI, WC, VAT, and SAT were positively related to baseline artery diameter and baseline mean flow velocity (all P < 0.001), but not hyperemic mean flow velocity. In multivariable‐adjusted models, BMI (P = 0.002), WC (P = 0.001), and VAT (P = 0.01), but not SAT (P = 0.24) were inversely associated with percentage of flow‐mediated dilation (FMD%). However, there was little incremental increase in the proportion of variability explained by VAT (R² = 0.266) as compared to SAT (R² = 0.265), above and beyond traditional risk factors. VAT, but not SAT was associated with FMD% after adjusting for clinical covariates. Nevertheless, the differential association with VAT as compared to SAT was minimal.     

Waist circumference correlates with metabolic syndrome indicators better than percentage fat

Objective : Percent fat is often considered the reference for establishing the magnitude of adipose tissue accumulation and the risk of excess adiposity. However, the increasing recognition of a strong link between central adiposity and metabolic disturbances led us to test whether waist circumference (WC) is more highly correlated with metabolic syndrome components than percent fat and other related anthropometric measures such as BMI. Research Methods and Procedures : BMI, WC, and percent fat, measured by DXA, were evaluated in 1010 healthy white and African‐American men and women [age, 48.3 ± 17.2 (standard deviation) years; BMI, 27.0 ± 5.3 kg/m²]. The associations of BMI, WC, and percent fat with age and laboratory‐adjusted health risk indicators (i.e., serum glucose, insulin, triglycerides, high‐density lipoprotein cholesterol, blood pressure) in each sex and ethnicity group were examined. Results : For 18 of 24 comparisons, the age‐ and laboratory‐adjusted correlations were lowest for percent fat and in 16 of 24 comparisons were highest for WC. Fifteen of the between‐method differences reached statistical significance. With health risk indicator as the dependent variable and anthropometric measures as the independent variable, the contribution of percent fat to the WC regression model was not statistically significant; in contrast, adding WC to the percent fat regression model did make a significant independent contribution for most health risk indicators. Discussion : WC had the strongest associations with health risk indicators, followed by BMI. Although percent fat is a useful measure of overall adiposity, health risks are best represented by the simply measured WC.     

Waist Circumference,BMI, and Visceral Adipose Tissue in White Women and Women of African Descent

Although waist circumference (WC) is a marker of visceral adipose tissue (VAT), WC cut‐points are based on BMI category. We compared WC‐BMI and WC‐VAT relationships in blacks and whites. Combining data from five studies, BMI and WC were measured in 1,409 premenopausal women (148 white South Africans, 607 African‐Americans, 186 black South Africans, 445 West Africans, 23 black Africans living in United States). In three of five studies, participants had VAT measured by computerized tomography (n = 456). Compared to whites, blacks had higher BMI (29.6 ± 7.6 (mean ± s.d.) vs. 27.6 ± 6.6 kg/m², P = 0.001), similar WC (92 ± 16 vs. 90 ± 15 cm, P = 0.27) and lower VAT (64 ± 42 vs. 101 ± 59 cm², P < 0.001). The WC‐BMI relationship did not differ by race (blacks: β (s.e.) WC = 0.42 (.01), whites: β (s.e.) WC = 0.40 (0.01), P = 0.73). The WC‐VAT relationship was different in blacks and whites (blacks: β (s.e.) WC = 1.38 (0.11), whites: β (s.e.) WC = 3.18 (0.21), P < 0.001). Whites had a greater increase in VAT per unit increase in WC. WC‐BMI and WC‐VAT relationships did not differ among black populations. As WC‐BMI relationship did not differ by race, the same BMI‐based WC guidelines may be appropriate for black and white women. However, if WC is defined by VAT, race‐specific WC thresholds are required.     

Longitudinal associations between BMI,waist circumference,and cardiometabolic risk in US youth: Monitoring implications

Objective:

This study examined whether change in body mass index (BMI) or waist circumference (WC) is associated with change in cardiometabolic risk factors and differences between cardiovascular disease specific and diabetes specific risk factors among adolescents. We also sought to examine any differences by gender or baseline body mass status.

Design:

The article is a longitudinal analysis of pre‐ and post‐data collected in the HEALTHY trial. Participants were 4,603 ethnically diverse adolescents who provided complete data at 6th and 8th grade assessments.

Methods:

The main outcome measures were percent change in the following cardiometabolic risk factors: fasting triglycerides, systolic and diastolic blood pressure, high density lipoprotein cholesterol, and glucose as well as a clustered metabolic risk score. Main exposures were change in BMI or WC z‐score. Models were run stratified by gender; secondary models were additionally stratified by baseline BMI group (normal, overweight, or obese).

Results:

Analysis showed that when cardiometabolic risk factors were treated as continuous variables, there was strong evidence (P < 0.001) that change in BMI z‐score was associated with change in the majority of the cardiovascular risk factors, except fasting glucose and the combined risk factor score for both boys and girls. There was some evidence that change in WC z‐score was associated with some cardiovascular risk factors, but change in WC z‐score was consistently associated with changes in fasting glucose.

Conclusions:

In conclusion, routine monitoring of BMI should be continued by health professionals, but additional information on disease risk may be provided by assessing WC.     

Minimal versus umbilical waist circumference measures as indicators of cardiovascular disease risk

Objective: Measures of central obesity are strongly correlated with cardiovascular disease (CVD) risk. Although waist circumference (WC) is a commonly used measure of central obesity, there is no standard measurement location. We examined two WC locations to determine which was more highly correlated with CVD risk factors and metabolic syndrome (MS). Research Methods and Procedures: WC measures were taken on 266 sedentary, overweight men and women 45 to 60 years old. Intravenous glucose tolerance tests, fasting plasma lipid analysis, and computed tomography scans were conducted. Correlational analyses followed by the Test for Equal Correlations determined whether one WC measure better correlated with the cardiovascular risk factors. Results: In women, minimal waist had higher correlation coefficients than umbilical waist for all eight variables presented. High‐density lipoprotein‐cholesterol, low‐density lipoprotein particle size, and MS score were significantly correlated with minimal waist, but not umbilical waist. For high‐density lipoprotein size and insulin sensitivity, minimal waist was a better correlate, although the difference between waist measures only approached statistical significance (p < 0.06). In men, minimal waist had a higher correlation coefficient than umbilical waist for insulin sensitivity, fasting insulin, and visceral adipose tissue. Additionally, minimal waist was significantly correlated with MS in men and umbilical waist was not. For both genders, minimal waist was more highly correlated with visceral adipose tissue than umbilical waist. Discussion: For every metabolic variable presented, minimal WC was more highly correlated with CVD risk than was umbilical WC in women. The data for women indicate that WC location is important when determining CVD risk. In men, minimal waist was better, although the data were less compelling.     

Are Current UK National Institute for Health and Clinical Excellence (NICE) Obesity Risk Guidelines Useful? Cross-Sectional Associations with Cardiovascular Disease Risk Factors in a Large,Representative English Population

The National Institute for Health and Clinical Excellence (NICE) has recently released obesity guidelines for health risk. For the first time in the UK, we estimate the utility of these guidelines by relating them to the established cardiovascular disease (CVD) risk factors. Health Survey for England (HSE) 2006, a population-based cross-sectional study in England was used with a sample size of 7225 men and women aged ≥35 years (age range: 35–97 years). The following CVD risk factor outcomes were used: hypertension, diabetes, total and high density lipoprotein cholesterol, glycated haemoglobin, fibrinogen, C-reactive protein and Framingham risk score. Four NICE categories of obesity were created based on body mass index (BMI) and waist circumference (WC): no risk (up to normal BMI and low/high WC); increased risk (normal BMI & very high WC, or obese & low WC); high risk (overweight & very high WC, or obese & high WC); and very high risk (obese I & very high WC or obese II/III with any levels of WC. Men and women in the very high risk category had the highest odds ratios (OR) of having unfavourable CVD risk factors compared to those in the no risk category. For example, the OR of having hypertension for those in the very high risk category of the NICE obesity groupings was 2.57 (95% confidence interval 2.06 to 3.21) in men, and 2.15 (1.75 to 2.64) in women. Moreover, a dose-response association between the adiposity groups and most of the CVD risk factors was observed except total cholesterol in men and low HDL in women. Similar results were apparent when the Framingham risk score was the outcome of interest. In conclusion, the current NICE definitions of obesity show utility for a range of CVD risk factors and CVD risk in both men and women.     

Paradoxical protective effect of central obesity in patients with suspected stable coronary artery disease

Objective:

Increased body mass index (BMI) has been paradoxically inversely associated with the presence of angiographic coronary artery disease (CAD). Central obesity measures, considered to be more appropriate for assessing obesity‐related cardiovascular risk, have been little studied in relation to the presence of CAD. The aim was to investigate the association of central obesity with the presence of angiographic CAD as well as the prognostic significance of obesity measures in CAD prediction when added to other cardiovascular risk factors.

Design and Methods:

Patients with suspected stable CAD (n = 403, age 61 ± 10 years, 302 males) referred for diagnostic coronary angiography with documented anthropometric data were enrolled.

Results:

Significant angiographic CAD was found in 51% of patients. Both BMI (OR = 0.64 per 1 SD increase, P = 0.001) and waist circumference (WC) (OR = 0.54 per 1 SD increase, P < 0.001) were inversely associated with the presence of CAD even after adjustment for cardiovascular risk factors. In subgroup analysis, BMI and WC were significantly inversely associated with the presence of CAD in males, non diabetics, patients >60 years old and patients with Framingham risk score (FRS) >20% (P < 0.01 for all). The addition of BMI or WC in FRS‐based regression models improved prediction of CAD (P = 0.03 and P < 0.001 for BMI and WC respectively) without a significant difference between the two models (P = 0.08).

Conclusions:

Central and overall obesity were independently associated with a reduced prevalence of angiographic CAD, lending further credence to the existence of the ‘obesity paradox’. Obesity measures may further improve risk discrimination for the presence of CAD when added in an established risk score such as FRS.