Waist Circumference Cut-points Research Articles

BMI-specific waist circumference is better than skinfolds for health-risk determination in the general population.

Distribution of fat is important when considering health risk; however, the value added from skinfold measurements (SKF) when using body mass index (BMI) refined by waist circumference (WC) is not well understood. The purpose of this study was to assess the utility of SKF compared with WC in determination of health risk in the general population. Data from the Canadian Health Measures Survey (cycles 1 and 2; N = 5217) were used. Health outcomes included directly measured blood pressure, cholesterol, glycated haemoglobin, lung function, self-reported health, and chronic conditions. Technical errors of measurements (TEM), sensitivity, and specificity analysis and linear regressions were conducted. Data indicated that TEM for SKF was above the acceptable 5% in most age and sex categories. Sensitivity and specificity of chronic conditions was not improved with the inclusion of SKF in models containing WC (in those aged 45-69 years) and SKF did not explain any additional variance in regression models containing WC. Health outcomes for those in the normal weight and overweight BMI category were significantly worse in those classified as high risk based on WC, whereas SKF did not consistently discriminate risk. In conclusion, evidence-based WC cut-points were shown to identify health risk, particularly in normal weight and overweight individuals. Thus, BMI refined by WC appears to be more appropriate than SKF for assessment of body composition when determining health risk in the general population.

Ethnicity-specific obesity cut-points in the development of Type 2 diabetes - a prospective study including three ethnic groups in the United Kingdom.

AimsConventional definitions of obesity, e.g. body mass index (BMI) ≥ 30 kg/m2 or waist circumference cut-points of 102 cm (men) and 88 cm (women), may underestimate metabolic risk in non-Europeans. We prospectively identified equivalent ethnicity-specific obesity cut-points for the estimation of diabetes risk in British South Asians, African-Caribbeans and Europeans.MethodsWe studied a population-based cohort from London, UK (1356 Europeans, 842 South Asians, 335 African-Caribbeans) who were aged 40–69 years at baseline (1988–1991), when they underwent anthropometry, fasting and post-load (75 g oral glucose tolerance test) blood tests. Incident Type 2 diabetes was identified from primary care records, participant recall and/or follow-up biochemistry. Ethnicity-specific obesity cut-points in association with diabetes incidence were estimated using negative binomial regression.ResultsDiabetes incidence rates (per 1000 person years) at a median follow-up of 19 years were 20.8 (95% CI: 18.4, 23.6) and 12.0 (8.3, 17.2) in South Asian men and women, 16.5 (12.7, 21.4) and 17.5 (13.0, 23.7) in African-Caribbean men and women, and 7.4 (6.3, 8.7), and 7.2 (5.3, 9.8) in European men and women. For incidence rates equivalent to those at a BMI of 30 kg/m2 in European men and women, age- and sex-adjusted cut-points were: South Asians, 25.2 (23.4, 26.6) kg/m2; and African-Caribbeans, 27.2 (25.2, 28.6) kg/m2. For South Asian and African-Caribbean men, respectively, waist circumference cut-points of 90.4 (85.0, 94.5) and 90.6 (85.0, 94.5) cm were equivalent to a value of 102 cm in European men. Waist circumference cut-points of 84.0 (74.0, 90.0) cm in South Asian women and 81.2 (71.4, 87.4) cm in African-Caribbean women were equivalent to a value of 88 cm in European women.ConclusionsIn prospective analyses, British South Asians and African-Caribbeans had equivalent diabetes incidence rates at substantially lower obesity levels than the conventional European cut-points.

Evidence of inappropriate cardiovascular risk assessment in middle-age women based on recommended cut-points for waist circumference

Background and aimsDiverse waist circumference thresholds for assessment of metabolic and cardiovascular risk in Caucasians are recommended by different health professional organizations. We aimed to determine optimal sex-specific thresholds for anthropometric measures showing the strongest association with cardiovascular risk factors in a cohort of middle-aged Germans. Methods and resultsStatistical analyses are based on data from 426 mothers and 267 fathers of participants of the Ulm Birth Cohort Study undergoing a clinical follow-up examination in 2008 (median age 41 years) using logistic regression analyses. The prevalence of many cardiometabolic risk factors was significantly higher in men than in women; hypertension: 45%/17% (p < 0.0001), apolipoprotein ratio B/A1 > 0.72: 35%/9% (<0.0001), hyperglycemia: 11%/14% (p = 0.3), which is in contrast to the predicted cardiovascular risk of 52%/70% and 24%/36% based on thresholds for waist circumference proposed by International Diabetes Federation and American Heart Association, respectively. We determined optimal thresholds for waist circumference between 90 and 95 cm for men and women. Using a threshold of 92 cm the prevalence of abdominal obesity was 59% in men and 24% in women, which was in agreement with the higher prevalence of overweight and obesity in men than in women (Body Mass Index (BMI) > 25: 64%/35%). The prediction of cardiometabolic risk factors by waist circumference and waist-to-height ratio did not outperform the prediction by BMI. In contrast to BMI, waist circumference was correlated with body height independent of sex. ConclusionCurrently proposed thresholds for waist circumference spuriously overestimate the cardiovascular risk in women, but not in men in a German population.

Body Mass Index and Waist Circumference Cut-Points in Multi-Ethnic Populations from the UK and India: The ADDITION-Leicester, Jaipur Heart Watch and New Delhi Cross-Sectional Studies

AimsTo derive cut-points for body mass index (BMI) and waist circumference (WC) for minority ethnic groups that are risk equivalent based on endogenous glucose levels to cut-points for white Europeans (BMI 30 kg/m2; WC men 102 cm; WC women 88 cm).Materials and MethodsCross-sectional data from participants aged 40–75 years: 4,672 white and 1,348 migrant South Asian participants from ADDITION-Leicester (UK) and 985 indigenous South Asians from Jaipur Heart Watch/New Delhi studies (India). Cut-points were derived using fractional polynomial models with fasting and 2-hour glucose as outcomes, and ethnicity, objectively-measured BMI/WC, their interaction and age as covariates.ResultsBased on fasting glucose, obesity cut-points were 25 kg/m2 (95% Confidence Interval: 24, 26) for migrant South Asian, and 18 kg/m2 (16, 20) for indigenous South Asian populations. For men, WC cut-points were 90 cm (85, 95) for migrant South Asian, and 87 cm (82, 91) for indigenous South Asian populations. For women, WC cut-points were 77 cm (71, 82) for migrant South Asian, and 54 cm (20, 63) for indigenous South Asian populations. Cut-points based on 2-hour glucose were lower than these.ConclusionsThese findings strengthen evidence that health interventions are required at a lower BMI and WC for South Asian individuals. Based on our data and the existing literature, we suggest an obesity threshold of 25 kg/m2 for South Asian individuals, and a very high WC threshold of 90 cm for South Asian men and 77 cm for South Asian women. Further work is required to determine whether lower cut-points are required for indigenous, than migrant, South Asians.

New ACC/AHA Prevention Guidelines: Building a Bridge to Even Stronger Guideline Collaborations

John Gordon Harold, MD, FAHA, MACC President, American College of Cardiology Mariell Jessup, MD, FACC, FAHA President, American Heart Association This past month, the American College of Cardiology (ACC) and the American Heart Association (AHA), in collaboration with the National Heart, Lung, and Blood Institute (NHLBI) and other specialty societies, released 4 long-awaited guidelines focused on the assessment of cardiovascular risk, lifestyle modifications to reduce cardiovascular risk, and management of elevated blood cholesterol and body weight in adults. A fifth guideline, which addresses hypertension, will be initiated by the AHA and ACC in the near future. These guidelines are based on rigorous, comprehensive, systematic evidence reviews sponsored by the NHLBI. The ACC and AHA collaborated with professional organizations to finalize these ACC/AHA cardiovascular prevention guidelines and stakeholder organizations were invited to review and endorse the final documents. Each guideline provides important updated guidance for primary care providers, nurses, pharmacists, and specialty medicine providers on how best to manage the care of patients at risk for cardiovascular-related diseases on the basis of the latest scientific evidence. For example, the Guideline for the Management of Overweight and Obese Adults addresses the appropriateness of the current body mass index and waist circumference cut points used …

Reprint: 2013 AHA/ACC/TOS Guideline for the Management of Overweight and Obesity in Adults.

Reprint: 2013 AHA/ACC/TOS Guideline for the Management of Overweight and Obesity in Adults.

Structural Vascular Disease in Africans: Performance of Ethnic-specific Waist Circumference Cut Points using Logistic Regression and Neural Network Analyses: The SABPA Study

A recently proposed model for waist circumference cut points (RPWC), driven by increased blood pressure, was demonstrated in an African population. We therefore aimed to validate the RPWC by comparing the RPWC and the Joint Statement Consensus (JSC) models via Logistic Regression (LR) and Neural Networks (NN) analyses. Urban African gender groups (N=171) were stratified according to the JSC and RPWC cut point models. Ultrasound carotid intima media thickness (CIMT), blood pressure (BP) and fasting bloods (glucose, high density lipoprotein (HDL) and triglycerides) were obtained in a well-controlled setting. The RPWC male model (LR ROC AUC: 0.71, NN ROC AUC: 0.71) was practically equal to the JSC model (LR ROC AUC: 0.71, NN ROC AUC: 0.69) to predict structural vascular -disease. Similarly, the female RPWC model (LR ROC AUC: 0.84, NN ROC AUC: 0.82) and JSC model (LR ROC AUC: 0.82, NN ROC AUC: 0.81) equally predicted CIMT as surrogate marker for structural vascular disease. Odds ratios supported validity where prediction of CIMT revealed -clinical -significance, well over 1, for both the JSC and RPWC models in African males and females (OR 3.75-13.98). In conclusion, the proposed RPWC model was substantially validated utilizing linear and non-linear analyses. We therefore propose ethnic-specific WC cut points (African males, ≥90 cm; -females, ≥98 cm) to predict a surrogate marker for structural vascular disease.

The Predictive Ability of Triglycerides and Waist (Hypertriglyceridemic Waist) in Assessing Metabolic Triad Change in Obese Children and Adolescents

The metabolic triad [fasting insulin, apolipoprotein B, and low-density lipoporotein (LDL) peak particle density] is characteristic of increased intra-abdominal adipose tissue and insulin resistance and can be predicted by the simple and adoptable screening tool, the hypertriglyceridemic waist. The associations between hypertriglyceridemic waist components [fasting triglycerides (TG) and waist circumference cut-points derived from a child-specific metabolic syndrome definition] with the metabolic triad were examined in obese youth before and after weight loss. A continuous metabolic triad score (MTS) was calculated as a cumulative and standardized residual score of fasting insulin, apolipoprotein B, and LDL peak particle density (z-scores of the metabolic triad variables regressed onto age and sex). The predictive ability of TG and waist in assessing metabolic triad change was undertaken in 75 clinically obese boys and girls, aged 8-18, body mass index (BMI) 34.2±6.4 kg/m(2) before and after weight loss. Fasting TG concentrations (r(2)=0.216, P<0.0001) and waist circumference (r(2)=0.049, P=0.019) were both significant independent predictors of the cumulative MTS, together accounting for 26.5% of its total variance. All cardiometabolic risk factors [except a reduction in high-density lipoprotein cholesterol (HDL-C)] were favorably modified following weight loss. Fasting TG change was the only significant predictor of the MTS change (r(2)=0.177, P<0.0001). Waist circumference was not a significant predictor of MTS change. The reduction in fasting TG concentration (but not waist circumference) was the only significant predictor of MTS change. Fasting TG may be the most important metabolic syndrome component to best characterize the metabolic heterogeneity in obese cohorts and the changes in metabolic risk in clinically obese youth.

Gender‐assortative waist circumference in mother–daughter and father–son pairs, and its implications. An 11‐year longitudinal study in children (EarlyBird 59)

Body mass index (BMI) is reportedly gender assortative (mother-daughter, father-son) in contemporary children. We investigated the corresponding transmission of waist circumference (WC) and its implications. We measured parental WC at baseline and WC, height, weight and para-umbilical skin-fold (USF) annually in their offspring from 5 to 15 years (n = 223 trios). Parents were deemed normal metabolic risk (NR) or high risk (HR) according to World Health Organization (WHO) cut-points for WC (mothers 80 cm, fathers 94 cm). The residual from WC adjusted for BMI (WC|BMI ) was used as a surrogate for excess intra-abdominal fat, and its association with insulin resistance (HOMA2-IR) was sought. WC and USF were both gender assortative, while WC|BMI was not. WC was greater by 1.62 cm (P < 0.05, confidence interval [CI]: 0.09-3.16) and USF by 0.37 cm (P < 0.01, CI: 0.19-0.56) among the daughters (but not the sons) of HR compared with those of NR mothers, and by 1.32 cm (P < 0.05, CI: 0.09-2.55) and 0.18 cm (P < 0.05, CI: 0.04-0.32), respectively in the corresponding father-son (but not father-daughter) pairings. No such differences could be demonstrated for WC|BMI . A standard deviation score 1(SDS) change in WC|BMI , independent of BMI, was associated with a 7.14% change in IR in girls (P < 0.01, CI: 1.76-12.80) and 8.02% in boys (P < 0.001, CI: 2.93-13.36), but there was no relationship between IR and USF. The relationship of offspring WC to metabolic health and to parental size is complex. Subcutaneous abdominal fat is gender assortative but harmless, while intra-abdominal fat (its surrogate in this analysis) is unrelated to parental waist circumference, but metabolically harmful.

Predictors of Metabolic Syndrome in the Iranian Population: Waist Circumference, Body Mass Index, or Waist to Hip Ratio?

This study aimed to investigate whether body mass index (BMI), waist circumference (WC), or waist to hip ratio (WHR) could be a better predictor of metabolic syndrome and, if so, what would be the cutoff points for these surrogates to appropriately differentiate metabolic syndrome in different age and sex subgroups. Methods. The present cross-sectional study was conducted on a sample of Isfahan Cohort Study (ICS). In total, 468 individuals (194 with and 274 subjects without metabolic syndrome) according to the National Cholesterol Education Program's Adult Treatment Panel III (ATP-III) criteria were selected. Anthropometric indices were measured and plotted using receiver-operating characteristic (ROC) curves. Results. According to ROC curve analysis, WC and WHR parameters were better indicators of metabolic syndrome compared to BMI in women, whereas in men WHR had a lower discriminating value compared to the other two parameters. Among these three anthropometric parameters, BMI had a lower sensitivity and WC and WHR both had a higher sensitivity for predicting metabolic syndrome in women compared with in men. The cut points for WC were nearly equal in men and women, 90.3 versus 90.0, respectively. Women had higher cut points for BMI (28.5 kg/m2) compared to men (26.0 kg/m2). Our results showed the highest sensitivity and specificity for WC cut points specially in women. To predict metabolic syndrome, we looked into optimal age-specific cut points for BMI, WC, and WHR. The results indicated that WC had the highest discriminating value compared to other indicators in the different age subgroups. The optimal cut points for all three parameters gradually increased with age. Conclusion. Our results demonstrated that regardless of gender and age variables, WC could be a preferred parameter for predicting metabolic syndrome compared to BMI and WHR in Iranian population.

The current waist circumference cut point used for the diagnosis of metabolic syndrome in sub-Saharan African women is not appropriate.

The waist circumference cut point for diagnosing the metabolic syndrome in sub-Saharan African subjects is based on that obtained from studies in European populations. The aim of this study was to measure the prevalence of obesity and related metabolic disorders in an urban population of African females, a group at high risk for such diseases, and to determine the appropriate waist cut point for diagnosing the metabolic syndrome. Anthropometry and fasting lipid, glucose and insulin levels were measured in a cohort of 1251 African females participating in the Birth to Twenty cohort study in Soweto, Johannesburg. The waist circumference cut points for diagnosing metabolic syndrome (as defined using the new harmonised guidelines), insulin resistance, dysglycaemia, hypertension and dyslipidaemia were obtained using receiver operator characteristic curve analysis. The prevalence of obesity, type 2 diabetes and metabolic syndrome were 50.1%, 14.3% and 42.1%, respectively. The appropriate waist cut point for diagnosing metabolic syndrome was found to be 91.5 cm and was similar to the cuts points obtained for detecting increased risk of insulin resistance (89.0 cm), dysglycaemia (88.4 cm), hypertension (90.1 cm), hypo-high density lipoproteinaemia (87.6 cm) and hyper-low density lipoproteinaemia (90.5 cm). The present data demonstrates that urban, African females have a high prevalence of obesity and related disorders and the waist cut point currently recommended for the diagnosis of the metabolic syndrome (80.0 cm) in this population should be increased to 91.5 cm. This latter finding demonstrates a clear ethnic difference in the relationship between abdominal adiposity and metabolic disease risk. The similar waist cut points identified for the detection of the individual components of the metabolic syndrome and related cardiovascular risk factors demonstrates that the risk for different metabolic diseases increases at the same level of abdominal adiposity suggesting a common aetiological pathway.

682 PREVALENCE OF METABOLIC SYNDROME AMONG MALAYSIAN ADULTS AGED ≥ 30 YEARS ACCORDING TO THE NCEP-ATP III, IDF AND JIS DEFINITIONS

Objective: The objective of this study is to compare the prevalence of Metabolic Syndrome (MetS) as defined by the National Cholesterol Education Program Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults (NCEP-ATP III)1, International Diabetes Federation (IDF) world-wide definition2 and the ‘harmonised’ definition by the Joint Interim Statement (JIS)3. Methods: A community based cross-sectional study involving 11,288 adults aged ≥ 30 years was conducted in urban and rural areas of Malaysia between 2007 and 2010. Demographic data, waist circumference (WC), blood pressure readings; and fasting venous blood for lipid and glucose assays were obtained. Data was analysed using STATA version 11. Results: Out of the11,288 subjects, 8836 had complete data on all the MetS components and were therefore included in the analysis. Mean age was 53.2 years (SD ± 10.6). The table shows the overall and age-adjusted prevalence of MetS according to the NCEP-ATP III, IDF and JIS definitions by location, gender, ethnicity and education attainment.Conclusions: The JIS definition gave the highest overall prevalence of MetS among Malaysian adults, as well as the age-adjusted prevalence by location, gender, ethnicity and education attainment. The NCEP-ATP III gave the lowest prevalence due to the higher WC cut points. Prevalence was significantly lower in Chinese and Indigenous groups regardless of the criteria used. There was no significant difference in the prevalence between urban and rural population using IDF and JIS definitions. References National Cholesterol Education Program (NCEP)Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults (Adult Treatment Panel III). Third Report of the National Cholesterol Education Program (NCEP) Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults (Adult Treatment Panel III) final report. Circulation 2002; 106: 3143–421. Alberti KG, Zimmet P, Shaw J, International Diabetes Federation (IDF) Epidemiology Task Force Consensus Group. The metabolic syndrome: a new world- wide definition. Lancet 2005; 366: 1059–62. Alberti KGMM, Eckel RH, Grundy SM, Zimmet PZ, Cleeman JI, Donato KA, et al. Harmonizing the metabolic syndrome. A Joint Interim Statement (JIS) of the International Diabetes Federation Task Force on Epidemiology and Prevention; National Heart, Lung, and Blood Institute; American Heart Association; World Heart Federation; International Atherosclerosis Society; and International Association for the Study of Obesity. Circulation 2009; 120: 1640–5.

Association of waist circumference with perception of own health in urban African males and females: the Sympathetic Activity and Ambulatory Blood Pressure in Africans (SABPA) study

Background: Current waist circumference (WC) cut-points of the Joint Statement Consensus (JSC) (male ≥ 94 cm, female ≥ 80 cm) were compared with a recently proposed WC cut-point (RPWC) (male ≥ 90 cm, female ≥ 98 cm). In this study, we aimed to compare the two cut-points to assess the association between central obesity and perception of own health. Method: We determined blood pressure and fasting bloods [glucose, high-density lipoprotein (HDL) and triglycerides] as metabolic syndrome markers for 171 urban teachers. Perception of own health was determined via the General Health Questionnaire-28 (GHQ-28) to indicate probable psychological distress or a psychiatric disorder or caseness (≥ 4). Results: The RPWC was an improved discrimination between the WC groups on perception of own health as reflected in the GHQ-28 subscales. In the male group, higher scores were found in the RPWC high WC group (≥ 90 cm) with regard to somatic symptoms, social dysfunction and GHQ-28 caseness, compared to those of the low WC groups (< 90 cm). Compared to the RPWC high WC females (≥ 98 cm), the low WC (< 98 cm) reflected significantly higher anxiety and sleeplessness subscale scores. Conclusion: Our results suggest that the RPWC (men 90 cm, women 98 cm), (determined in this African cohort when adding GHQ-28 caseness as a discriminatory variable between WC cut-point), distinguished better between WC groups based on their perception of own health than the JSC cut-point.

The association between waist circumference and risk of mortality considering body mass index in 65- to 74-year-olds: a meta-analysis of 29 cohorts involving more than 58 000 elderly persons

For the elderly, the association between waist circumference (WC) and mortality considering body mass index (BMI) remains unclear, and thereby also the evidence base for using these anthropometric measures in clinical practice. This meta-analysis examined the association between WC categories and (cause-specific) mortality within BMI categories. Furthermore, the association of continuous WC with lowest and increased mortality risks was examined. Age- and smoking-adjusted relative risks (RRs) of mortality associated with WC-BMI categories and continuous WC (including WC and WC(2)) were calculated by the investigators and pooled by means of random-effects models. During a 5-year-follow-up of 32 678 men and 25 931 women, we ascertained 3318 and 1480 deaths, respectively. A large WC (men: ≥102 cm, women: ≥88 cm) was associated with increased all-cause mortality RRs for those in the 'healthy' weight {1.7 [95% confidence interval (CI): 1.2-2.2], 1.7 (95% CI: 1.3-2.3)}, overweight [1.1(95% CI: 1.0-1.3), 1.4 (95%: 1.1-1.7)] and obese [1.1 (95% CI: 1.0-1.3), 1.6 (95% CI: 1.3-1.9)] BMI category compared with the 'healthy' weight (20-24.9 kg/m(2)) and a small WC (<94 cm, men; <80 cm, women) category. Underweight was associated with highest all-cause mortality RRs in men [2.2 (95% CI: 1.8-2.8)] and women [2.3 (95% CI: 1.8-3.1]. We found a J-shaped association for continuous WC with all-cause, cardiovascular (CVD) and cancer, and a U-shaped association with respiratory disease mortality (P < 0.05). An all-cause (CVD) mortality RR of 2.0 was associated with a WC of 132 cm (123 cm) in men and 116 cm (105 cm) in women. Our results showed increased mortality risks for elderly people with an increased WC-even across BMI categories- and for those who were classified as 'underweight' using BMI. The results provide a solid basis for re-evaluation of WC cut-points in ageing populations.

Development and Comparison of Two Field-Based Body Fat Prediction Equations: NHANES 1999-2004

Clinical guidelines define obesity in terms of excess body weight adjusted for height (i.e., bodymass index [BMI] categories) and/or gender-specific waist circumference (WC) cut-point values. Since body composition, particularly fat mass, is the most variable among individuals due to differences by gender, age, and race, and total percent body fat (%BF) can be estimated accurately using dual-energy X-ray absorptiometry (DXA), the purpose of this study was to develop and compare two field-based body fat prediction equations suitable for a nationally representative sample of the US adult population. Data were analyzed from subjects 20+ years of age (n = 11,907) with BMI and WC values, and that participated in DXA scans as part of the 1999-2004 National Health and Nutrition Examination Survey (NHANES). Multiple linear regression was used to develop and compare DXA-estimated %BF as the dependent variable versus BMI or WC, gender, age, and race as predictor variables. Mean values for age, BMI, WC, and %BF among the sample were 46.84 ± 0.30 years, 28.17 ± 0.11 kg/m2, 96.69 ± 0.27 cm, and 34.19 ± 0.14 %, respectively. Both equations were similar in terms of explained variance, with R2 values of 0.82 for the BMI and WC equations, respectively. Both equations are easy to use, and could easily be developed as an application on a smartphone or other handheld device, or simply integrated into a spreadsheet for use as an additional tool for health professionals to assess the current health status of individuals based on predicted body fat from BMI, WC, and demographics.

Optimal cut points of waist circumference (WC) and visceral fat area (VFA) predicting for metabolic syndrome (MetS) in elderly population in the Korean Longitudinal Study on Health and Aging (KLoSHA)

Optimal cut points of central obesity identifying subjects at risk for MetS were proposed ethnic-specifically, but have not been established yet. Of particular interest are the values for elderly persons, which have not been identified previously. We investigated the appropriate cut points of WC and VFA for elderly in a community-based cohort in Korea. We recruited 294 men and 313 women aged 65 or over who participated in the KLoSHA. A receiver operating characteristic (ROC) curve analysis was used to estimate the optimal cut points of WC and VFA indicative of MetS. The optimal cut points for predicting MetS were 87cm for WC, 140cm2 for VFA in men, and 85cm for WC, 100cm2 for VFA in women with the Youden index. Similar cut points were obtained with the closest-to-(0, 1) criterion except for VFA in men, which was 122cm2. When adjusted for age, exercise, smoking, and alcohol consumption, men with ≥122cm2 and women with ≥100cm2 of VFA had a higher risk of MetS than subjects with lower values. The cut points of VFA and WC at risk for MetS were higher in men than women. In this community-based elderly cohort, the optimal cut points of WC at risk for MetS were lower than the Western criteria. Compared with the cut points in middle-aged Koreans, the cut points for elderly were lower in men and similar in women.

The Trends of Metabolic Syndrome in Normal-Weight Tehranian Adults

Background: In recent decades, more attention has been directed to the clustering of cardiometabolic risk factors in normal-weight adults. This study investigates trends of the prevalence of metabolic syndrome (MetS) in a normal-weight Tehranian adult population during 6.6 years of follow-up. Methods: In this population-based cohort study of 5,269 participants aged ≧20 years during the 3 phases (1999–2001, 2002–2005 and 2005–2008) of the Tehran Lipid and Glucose Study, we selected 390 males and 358 females with a normal body mass index (18.5–24.9) during all 3 periods of follow-up. MetS was defined according to the International Diabetes Federation criteria, and waist circumference (WC) cut points were ≧89 cm for males and ≧91 cm for females. Results: The overall prevalence of MetS increased from 2.3 and 4.0% in phases I and II to 9.6% in phase III. This trend was significant in males (p < 0.001) but not in females (p = 0.6). No significant changes in components of MetS were seen, except in WC among males. In the 3 study phases, prevalence of abdominal obesity was 3.1, 18.5 and 36.2% in males, respectively. Conclusions: There was a dramatic 4-fold increase in the prevalence of MetS in the Tehranian normal-weight adult population, highlighting the importance of MetS components, especially of WC, in normal-weight adult males.

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.

Appropriate waist circumference cut points for identifying insulin resistance in black youth: a cross sectional analysis of the 1986 Jamaica birth cohort

BackgroundWhile the International Diabetes Federation (IDF) has ethnic specific waist circumference (WC) cut-points for the metabolic syndrome for Asian populations it is not known whether the cut-points for black populations should differ from those for European populations. We examined the validity of IDF WC cut points for identifying insulin resistance (IR), the underlying cause of the metabolic syndrome, in predominantly black, young Jamaican adults.MethodsParticipants from a 1986 birth cohort were evaluated between 2005 and 2007 when they were 18-20 years old. Trained observers took anthropometric measurements and collected a fasting blood sample. IR was assessed using the homeostasis model assessment computer programme (HOMA-IR). Sex specific quartiles for IR were generated using HOMA-IR values and participants in the highest quartile were classified as "insulin resistant". Receiver operator characteristic (ROC) curves were used to estimate the best WC to identify insulin resistance. The sensitivity and specificity of these values were compared with the IDF recommended WC cut-points.ResultsData from 707 participants (315 males; 392females) were analysed. In both sexes those with IR were more obese, had higher mean systolic blood pressure, glucose and triglycerides and lower mean HDL cholesterol. The WC was a good predictor of IR with an ROC area under the curve (95% CI) of 0.71(0.64,0.79) for men and 0.72(0.65,0.79) for women. Using the Youden Index (J) the best WC cut point for identifying IR in male participants was 82 cm (sensitivity 45%, specificity 93%, J 0.38) while the standard cut point of 94 cm had a sensitivity of 14% and specificity of 98% (J 0.12). In the female participants 82 cm was also a good cut point for identifying IR (sensitivity 52%, specificity 87%, J 0.39) and was similar to the standard IDF 80 cm cut point (sensitivity 53%, specificity 82%, J 0.35).ConclusionsThe WC that identified IR in young black men is lower than the IDF recommended WC cut point. Sex differences in WC cut points for identifying IR were less marked in this population than in other ethnic groups.

Cut‐points for Waist Circumference in Europids and South Asians

There is little strong evidence that currently recommended higher waist circumference cut-points for Europids compared with South Asians are associated with similar risk for type 2 diabetes. This study was designed to provide such evidence. Longitudinal studies over 5 years were conducted among 5,515 Europid and 2,214 ethnically South Asian participants. Age-standardized diabetes incidence at different levels of waist circumference and incidence difference relative to a reference value were calculated. The Youden Index was used to determine waist circumference cut-points. At currently recommended cut-points, estimated annual diabetes incidence for a 50-year-old Europid was <0.6% for both sexes, and for a 50-year-old South Asian, 5.8% for men and 2.1% for women. Annual diabetes incidence of 1% was observed for a 50 year old at a waist circumference 35-40cm greater in Europid compared to South Asian men and women. Incidence difference between recommended cut-points and a reference value (80cm in men, 70cm in women) was 0.3 and 4.4% per year for Europid and South Asian men, and 0.2 and 0.8% per year for Europid and South Asian women, respectively. Waist circumference cut-points chosen using the Youden Index were shown to be dependent on obesity levels in the population. The much higher observed risk of diabetes in South Asians compared to Europids at the respective recommended waist circumference cut-points suggests that differences between them should be greater. Approaches that use the Youden Index to select waist circumference cut-points are inappropriate and should not be used for this purpose.