Race-ethnicity-specific waist circumference cutoffs for identifying cardiovascular disease risk factors

BACKGROUND: Waist circumferences (WCs) in white men and women that represent a risk of cardiovascular disease (CVD) equivalent to that of body mass indexes (BMIs; in kg/m2) of 25 and 30 have been identified. However, WC cutoffs for other race-ethnicity groups remain unknown. OBJECTIVE: The objective was to determine WC cutoffs for CVD risk in non-Hispanic blacks (blacks), Mexican Americans (MA), and non-Hispanic whites (whites). DESIGN: Data from 10,969 participants in the third National Health and Nutrition Examination Survey (1988-1994) were analyzed. The presence of CVD risk factors was the main outcome. Sex- and race-ethnicity-specific WC cutoffs were determined with logistic regression models by linking WC cutoffs with equivalent CVD risk based on BMI cutoffs for overweight and obesity. WC cutoffs for metabolic syndrome risk factors were similarly calculated. RESULTS: Correlations between WC and lipid profiles, blood pressure, and glucose were significantly higher than those between BMI and these same variables in all groups. The WC cutoffs were approximately 5-6 cm greater for white than for black men at BMIs between 25 and 40, and those for MA were intermediate. In women, few differences in WC cutoffs were observed between the groups. Simplified WC cutoffs corresponding to BMIs of 25 and 30, largely independent of age, for the 3 race-ethnicity groups were 89 and 101 cm for men and 83 and 94 cm for women. Minimal distances in receiver operating characteristic curves tended to be shorter when WC cutoffs rather than BMI cutoffs were used. CONCLUSIONS: WC is a better indicator of CVD risk than is BMI in the 3 race-ethnicity groups studied. The proposed WC cutoffs are more sensitive than are BMI cutoffs in predicting CVD risk.     

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>or=25 kg/m2) and 13.3% in men and 21.0% in women by the Taiwanese definition (BMI>or=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 obesity-associated risk factors among whites in the third National Health and Nutrition Examination Survey: clinical action thresholds

BACKGROUND: Waist circumference (WC) is strongly linked to obesity-associated risks. However, currently proposed WC risk thresholds are not based on associations with obesity-related risk factors but rather with body mass index (BMI; in kg/m(2)). OBJECTIVE: The objective was to determine the relations of WC to obesity-associated risk factors in a representative sample of US whites and to derive comparable risk thresholds for WC and BMI. DESIGN: Data on 9019 white participants of the third National Health and Nutrition Examination Survey were divided into 2 groups according to the presence of >or= 1 of 4 obesity-associated risk factors: low HDL cholesterol, high LDL cholesterol, high blood pressure, and high glucose. Odds ratio (OR) equations were derived from logistic regression models for WC and BMI with the use of the 25th percentile in the study population as the reference. Receiver operating characteristic curves for identifying risk factors were computed for WC and BMI. RESULTS: At BMIs of 25 and 30, ORs were 1.19 (95% CI: 1.06, 1.35) and 2.37 (95% CI: 1.33, 4.22) for men and 1.56 (95% CI: 1.29, 1.91) and 3.16 (95% CI: 1.94, 5.28) for women, respectively. The corresponding ORs for WC were at 90 and 100 cm for men and at 83 and 93 cm for women. Minima on the receiver operating characteristic curves for men were at 96 cm for WC and at 26 for BMI and for women were at 86 cm for WC and 25 for BMI. CONCLUSION: WC is more closely linked to cardiovascular disease risk factors than is BMI.     

Body mass index (BMI) and waist circumference (WC) as screening tools for cardiovascular risk factors in Guadeloupean women

Hypertension, dyslipidemia and type 2 diabetes, important cardiovascular risk factors, are strongly linked to obesity. Body mass index (BMI) and waist circumference (WC) are measures of obesity that can be useful in identifying individuals with these risk factors. We assessed which of the two measures is more informative at the population level. The study population included 5,149 consecutive women aged 18 to 74 recruited in an Health Center of Guadeloupe (FWI) in 1999. The areas under the ROC curves of BMI and WC and their 95% CI were computed and compared. Logistic regression analysis of BMI and WC and the areas under the ROC curves in two separate age groups (18-39 years and 40-74 years) showed that age modifies the discriminant ability of these parameters in identifying the CVD risk factors. Sensitivity equalled specificity at levels between 52-70% for BMI and 55-80% for WC. ROC areas for identifying each risk factors by BMI varied from 0.52 to 0.84 and by WC from 0.55 to 0.88. For the identifying of women with at least one CVD risk factor, in the whole population, the areas under the curves for BMI and WC (respectively, 0.71; 95% CI: 0.69-0.73 and 0.76; 95% CI: 0.74-0.78) were both significantly greater than 0.5. The difference between these correlated areas was 0.04, 95% CI [-0.05, -0.03]. The lowest values of the areas were noted in detecting women with dyslipidemia and the highest in detecting those with type 2 diabetes. Waist circumference, a practical tool that had a higher discriminant ability than BMI in identifying presence or absence of all these risk factors, appears as the best screening tool in this population.     

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

BackgroundThe association between anthropometric variables and cardiovascular disease (CVD) risk among Africans is unclear. We examined the discriminative ability of anthropometric variables and estimate cutoffs for predicting CVD risk among Africans.MethodsThe Research on Obesity and Diabetes among African Migrants (RODAM) study was a multisite cross-sectional study of Africans in Ghana and Europe. We calculated AHA/ACC Pooled Cohort Equations (PCE) scores for 3661 participants to ascertain CVD risk, and compared a body shape index (ABSI), body mass index (BMI), waist circumference (WC), waist-to-hip ratio (WHR), Relative Fat Mass (RFM), and Waist to Height Ratio (WHtR). Logistic regression and receiver operating curve analyses were performed to derive cutoffs for identifying high predicted CVD risk (PCE score ≥7.5%).ResultsAmong men, WC (adjusted Odds Ratio (aOR): 2.25, 95% CI; 1:50–3:37) was strongly associated with CVD risk. Among women, WC (aOR: 1.69, 95% CI: 1:33–2:14) also displayed the strongest association with CVD risk in the BMI-adjusted model but WHR displayed the strongest fit. All variables were superior discriminators of high CVD risk in men (c-statistic range: 0.887–0.891) than women (c-statistic range: 0.677–0.707). The optimal WC cutoff for identifying participants at high CVD risk was 89 cm among men and identified the most cases (64%). Among women, the recommended WC cutoff of 94 cm or WHR cutoff of 0.90 identified the most cases (92%).ConclusionsAnthropometric variables were stronger discriminators of high CVD risk in African men than women. Greater WC was associated with high CVD risk in men while WHR and WC were associated with high CVD risk in women.     

Application of obesity treatment algorithms to Canadian adults

OBJECTIVE: The purpose of this study was to apply obesity treatment algorithms to a representative sample of Canadians to determine their potential impact on the population. DESIGN: The Canadian Heart Health Surveys (1986-1992) were used to describe the prevalence of adults (18-64 y) that would be eligible for weight loss treatment according to the US NIH algorithm, which uses body mass index (BMI), waist circumference (WC), and the presence of two or more cardiovascular disease (CVD) risk factors. Similar algorithms based on CVD risk factors and a single measure of either BMI or WC alone were also evaluated. RESULTS: Using the NIH algorithm, 24% of Canadians (28% men, 19% women) would be identified for weight loss treatment. Virtually, all subjects received the same treatment recommendations when using BMI and CVD risk factors only, while 22% (23% men, 21% women) would meet the criteria for treatment using WC and CVD risk factors only. CONCLUSIONS: Approximately one in four Canadians would be eligible for weight loss treatment using the NIH obesity treatment algorithm. However, the algorithm may be improved through the incorporation of more sensitive WC thresholds.     

Derivation of anthropometric cut-off levels to define CVD risk in Sri Lankan adults

Obesity is associated with increased cardiovascular risk. Anthropometric cut-off values derived for Caucasians may not be applicable to other populations. The main objective of the present study was to derive population-specific anthropometric cut-off values to define high CVD risk for Sri Lankan adults. A nationally representative sample of 4474 non-institutionalised adults aged ≥?18 years was analysed. Cut-off values to provide optimum sensitivity and specificity were derived using receiver-operating characteristic curve analysis. BMI, waist circumference (WC), waist-to-hip ratio (WHR), blood pressure and overnight fasting venous blood samples were collected to measure glucose, HDL-cholesterol and TAG. An oral glucose tolerance test was also performed. The results suggested that the age-adjusted BMI, WC and WHR were significantly associated with all cardiovascular risk factors (P?相似文献   

不同体重指数和腰围水平与其他心血管病危险因素聚集的关系

目的探讨不同体重指数(BMI)和腰围水平对人群中其他心血管病危险因素聚集的影响.方法将1992～1994年和1998年在我国不同地区中年人群中进行的2次心血管病危险因素调查资料合并共30 561人,比较不同BMI和腰围分组的研究对象其他心血管病危险因素聚集率和聚集的相对危险,其中危险因素聚集定义为同一研究对象具有高血压、高血清总胆固醇、低高密度脂蛋白胆固醇或空腹血糖异常之中的任意2项或2项以上者.结果随着BMI和(或)腰围的增加,人群其他心血管病危险因素的聚集率呈明显上升趋势, 按BMI分层各组中,男女两性腰围与其他心血管病危险因素的聚集率均呈明显的线性上升趋势,同样在不同的腰围分组中,BMI均与其他心血管病危险因素的聚集率呈明显的线性趋势.男性和女性年龄调整心血管病危险因素聚集率在BMI<24 kg/m2、腰围(男/女)<85/80 cm组分别为11.1%和10.4%,BMI<24 kg/m2、腰围(男/女)85～95.9/80～89.9 cm组分别为24.2%和16.9%, BMI 24.0～27.9 kg/m2、腰围(男/女)<85/80 cm组分别为24.0%和17.0%,BMI 24～27.9 kg/m2、腰围(男/女)85～95.9 /80～89.9 cm组分别为34.3%和24.0%. BMI 24.0～27.9 kg/m2、腰围(男/女)≥95/90 cm组分别为40.8%和29.6%,BMI≥28 kg/m2、腰围(男/女)85～95.9/80～89.9 cm组分别为44.2%和29.9%,BMI≥28 kg/m2、腰围(男/女)≥95/90 cm组分别为54.7%和35.4%.结论 BMI和腰围水平均与其他心血管病危险因素的聚集有独立的正相关性.保持BMI和腰围均在正常范围对心血管健康是很重要的.     

成人代谢综合征适宜体质指数切点的研究

目的:探讨成人诊断代谢综合征的适宜体质指数切点。方法:以2008-2009年南京地区参加健康体检成人27822人为研究对象,测量身高、体重、血压,采集空腹静脉血测定葡萄糖、血甘油三酯、高密度脂蛋白胆固醇,通过对体质指数和各代谢异常危险因素的分析,建立受试者工作特征曲线(ROC曲线),探讨适宜的体质指数诊断切点。结果:男性出现代谢异常危险因素的比例高于女性;根据ROC曲线分析,在男性BMI为24.32、女性BMI为23.06时,预测≥2项代谢异常危险因素的Youden指数最大。结论:南京地区成人代谢综合征的体质指数切点,以男性BMI=24,女性BMI=23比较合适。     

Obesity, abdominal obesity, and clustering of cardiovascular risk factors in South Korea

The aim of this study was first, to investigate the prevalence of obesity, abdominal obesity, and clustering of cardiovascular (CVD) risk factors, and secondly, to identify the BMI or waist circumference (WC) level at which clustering increases in South Koreans. A population-based, cross-sectional National Health Examination Survey was carried out in 1998. A total of 8,816 subjects (4,029 men and 4,787 women) aged 15-79 y were selected by stratified multistage probability sampling design. The measurements taken of the subjects included: height, weight, waist and hip circumference, blood pressure, fasting glucose, and lipids. The prevalence of BMI > or = 25 kg/m2 was 25.3% for men and 28.3% for women. The prevalence of WC >90 cm in men, and >80 cm in women was 18.5%, and 38.5%, respectively. Clustering of 3 or more CVD risk factors was 22.7% in men ad 21.7% in women. Using <21 kg/m2; as a referent, subjects with BMI of 23 kg/m2; and 27 kg/m2; had an odds ratio of 3.5 and 10.2 in men, and 3.1 and 6.7 in women, respectively for clustering of CVD risk factors. Using <65 cm as a referent, subjects with a WC of > or = 90 cm in men and > or = 85 cm in women had an odds ratio of 13.4, and 13.6, respectively for clustering of CVD risk factors. Considering the significant associations between clustering of CVD risk factors and BMI or WC, the present study suggests that high prevalence of overweight may have important implications for the health care system, even at a lower level of BMI or WC.     

中国成年人代谢异常相关的体质指数和腰围切点研究

目的 研究中国成年人BMI和腰围与各项代谢危险因素之间的相关性,确定超重肥胖的适宜BMI和腰围切点。方法 中国慢性病前瞻性研究于2004-2008年进行基线调查,并于2013-2014年随机抽取了5%的研究对象进行第2次重复调查。本研究剔除体格指标或代谢危险因素变量缺失或极端值、自报患有恶性肿瘤者,基线纳入501 201人,第2次重复调查纳入19 201人。比较不同BMI和腰围下代谢危险因素异常率,通过受试者工作特征（ROC）曲线分析,确定预测高血压、糖尿病、血脂异常和危险因素聚集的适宜BMI和腰围切点。结果 随BMI或腰围的增加,高血压、糖尿病、血脂异常和危险因素聚集患病率均呈现上升的趋势。依据正确指数最大的原则选取BMI超重切点和腰围切点,男性和女性BMI超重切点均接近24.0 kg/m²,男性腰围切点接近85 cm,女性腰围切点约为80~85 cm。男性和女性中,检出各项代谢危险因素特异度达到90%的BMI切点范围为27.0~28.9 kg/m²,多数接近28.0 kg/m²,以28.0 kg/m²作为肥胖切点。结论 本研究在更新开展的大样本调查中进一步验证了中国肥胖问题工作组2002年推荐的超重和肥胖标准,超重和肥胖的BMI切点分别为24.0和28.0 kg/m²;中心性肥胖的腰围适宜切点男性为85 cm,女性为80~85 cm。     

Body mass index and waist circumference independently contribute to the prediction of nonabdominal, abdominal subcutaneous, and visceral fat

BACKGROUND: It is unknown whether the ability of waist circumference (WC) to predict health risk beyond that predicted by body mass index (BMI) alone is explained in part by the ability of WC to identify those with elevated concentrations of total or abdominal fat. OBJECTIVE: We sought to determine whether BMI and WC independently contribute to the prediction of non-abdominal (total fat - abdominal fat), abdominal subcutaneous, and visceral fat. DESIGN: Fat distribution was measured by magnetic resonance imaging in 341 white men and women. Multiple regression analysis was performed to measure whether the combination of BMI and WC explained a greater variance in non-abdominal, abdominal subcutaneous, and visceral fat than did BMI or WC alone. These fat depots were also compared after a subdivision of the cohort into 3 BMI (normal, overweight, and class I obese) and 3 WC (low, intermediate, and high) categories according to the classification system used to identify associations between BMI, WC, and health risk. RESULTS: Independent of age and sex, the combination of BMI and WC explained a greater variance in non-abdominal, abdominal subcutaneous, and visceral fat than did either BMI or WC alone (P < 0.05). For non-abdominal and abdominal subcutaneous fat, BMI was the strongest correlate; thus, by adding BMI to WC, the variance accrued was greater than when WC was added to BMI. However, when WC was added to BMI, the added variance explained for visceral fat was greater than when BMI was added to WC. Furthermore, within each of the 3 BMI categories studied, an increase in the WC category was associated with an increase in visceral fat (P < 0.05). CONCLUSIONS: BMI and WC independently contribute to the prediction of non-abdominal, abdominal subcutaneous, and visceral fat in white men and women. These observations reinforce the importance of using both BMI and WC in clinical practice.     

Preferred clinical measures of central obesity for predicting mortality

OBJECTIVE: To define the clinical measures of obesity that best predict all cause mortality and cardiovascular disease (CVD) mortality. DESIGN AND SETTING: Eleven-year mortality follow-up of an Australian urban population sample of 9309 adults aged 20-69 years in 1989. Baseline measures of obesity included body mass index (BMI), waist circumference (WC), waist-to-stature ratio and the waist-to-hip ratio. The age-standardized hazard ratios for mortality were calculated for 1 s.d. above the mean for each measure of obesity using Cox regression analysis. We constructed receiver operator characteristic (ROC) curves to assess sensitivity and specificity of the measures and to identify approximate cut-points for the prediction of risk. RESULTS: Waist-to-hip ratio was superior by magnitude and significance in predicting all cause mortality (male hazard ratio 1.25, P=0.003, female hazard ratio 1.24, P=0.003) and CVD mortality (male hazard ratio 1.62, P<0.001, female hazard ratio 1.59, P<0.001). Waist-to-stature ratio and WC were highly significant but less powerful predictors for CVD mortality. ROC analysis showed higher 'area under the curve' values for waist-related measures in males, with similar less marked trends in females. The ROC cut-points yielded values that corresponded to current promulgated criteria. CONCLUSIONS: The waist-to-hip ratio is the preferred clinical measure of obesity for predicting all cause and CVD mortality. WC is a practical alternative. Waist-to-stature ratio is not more useful than WC alone.     

A composite score combining waist circumference and body mass index more accurately predicts body fat percentage in 6- to 13-year-old children

Purpose

Body mass index (BMI) and waist circumference (WC) are widely used to predict % body fat (BF) and classify degrees of pediatric adiposity. However, both measures have limitations. The aim of this study was to evaluate whether a combination of WC and BMI would more accurately predict %BF than either alone.

Methods

In a nationally representative sample of 2,303 6- to 13-year-old Swiss children, weight, height, and WC were measured, and %BF was determined from multiple skinfold thicknesses. Regression and receiver operating characteristic (ROC) curves were used to evaluate the combination of WC and BMI in predicting %BF against WC or BMI alone. An optimized composite score (CS) was generated.

Results

A quadratic polynomial combination of WC and BMI led to a better prediction of %BF (r ² = 0.68) compared with the two measures alone (r ² = 0.58–0.62). The areas under the ROC curve for the CS [0.6 * WC-SDS + 0.4 * BMI-SDS] ranged from 0.962 ± 0.0053 (overweight girls) to 0.982 ± 0.0046 (obese boys) and were somewhat greater than the AUCs for either BMI or WC alone. At a given specificity, the sensitivity of the prediction of overweight and obesity based on the CS was higher than that based on either WC or BMI alone, although the improvement was small.

Conclusion

Both BMI and WC are good predictors of %BF in primary school children. However, a composite score incorporating both measures increased sensitivity at a constant specificity as compared to the individual measures. It may therefore be a useful tool for clinical and epidemiological studies of pediatric adiposity.     

不同类型肥胖与心血管疾病危险因素关联的比较

目的 比较不同类型肥胖与心血管疾病(CVD)危险因素的关联,为预防和控制心血管疾病提供科学依据.方法 利用"2002年中国居民营养与健康状况调查"资料,按照<中国成人超重和肥胖症预防控制指南>中判定肥胖的界值点[体重指数(BMI):24kg/m2和28 kg/m2;腰围:男性85 cm和95 cm,女性80 cm和90 cm]判定肥胖类型,比较不同类型肥胖人群与罹患CVD危险因素的关联;用logistic回归和多元线性回归分析BMI和腰围与CVD危险因素的关系.结果 与体重和腰围均在正常范围的人群(OR=1)相比,正常体重并高腰围Ⅰ(男性85～95 cm,女性80～90 cm)的人群、超重但腰围正常的人群罹患CVD危险因素的风险为1～2倍,超重并高腰围Ⅰ、肥胖但腰围正常的人群为2～3倍,超重并高腰围Ⅱ(男性≥95 cm,女性≥90 cm)、肥胖并高腰围Ⅰ或Ⅱ(男性≥85 cm,女性≥80 cm)的人群为≥3倍;同一腰围组中,随着BMI增加罹患CVD危险因素的风险也呈逐渐增加趋势;BMI和腰围同时解释CVD危险因素变异的1.7%～9.4%,大于BMI或腰围单独解释的比例(1.5%～9.0%);BMI对于收缩压的标化回归系数为0.129,略大于腰围(0.123),腰围对甘油三酯、总胆固醇和高密度脂蛋白胆同醇标化回归系数的绝对值大于BMI.结论 BMI和腰围与CVD危险因素独立相关,建议评估疾病危险时同时使用BMI和腰围两项指标.     

Are waist circumference and body mass index independently associated with cardiovascular disease risk in Chinese adults?

BACKGROUND: In Western populations, waist circumference (WC) is more predictive of cardiovascular disease (CVD) risk than is body mass index (BMI). It is unclear whether the same is true in Asian populations. OBJECTIVE: The objective was to examine the independent effects of WC and BMI on CVD risk factors in China. DESIGN: CVD risk factors, BMI, and WC were measured in a nationally representative cross-sectional study of 15 540 Chinese adults aged 35-74 y. RESULTS: Higher WC tertiles were associated with higher blood pressure and higher cholesterol, triacylglycerol, and glucose concentrations within each tertile of BMI and vice versa. In men, the odds of hypertension, dyslipidemia, and the metabolic syndrome (MS) increased with successive WC tertiles (1.0, 1.1, and 1.8, respectively, for hypertension; 1.0, 1.4, and 2.0, respectively, for dyslipidemia; and 1.0, 2.3, and 4.8, respectively, for MS; P for trend < 0.001 for all), even after adjustment for BMI. Similarly, the odds of hypertension, dyslipidemia, and MS increased with successive BMI tertiles (1.0, 1.5, and 2.6, respectively, for hypertension; 1.0, 1.3, and 1.8, respectively, for dyslipidemia; 1.0, 1.3, and 2.9, respectively for MS; P for trend < 0.001 for all), even after adjustment for WC. However, BMI tertiles were not associated with the odds of diabetes after adjustment for WC (P for trend = 0.67), whereas tertiles of WC were significantly associated with the odds of diabetes after adjustment for BMI (1.0, 1.6, and 2.1, respectively; P for trend = 0.002). The results were similar in women. CONCLUSIONS: These data show that WC adds additional risk information to that of BMI in Chinese adults. Measurement of both WC and BMI in Chinese adults may enhance CVD risk stratification.     

Adiposity measurements in association with metabolic syndrome in older men have different clinical implications

Obesity is a major public health problem, and measuring adiposity accurately and predicting its future comorbidities are important issues. Therefore, we hypothesized that 4 adiposity measurements, body mass index (BMI), waist circumference (WC), waist-to-height ratio, and body fat percentage, have different physiological meanings and distinct associations with adverse health consequences. This study aimed to investigate the relationship of these 4 measurements with metabolic syndrome (MetS) components and identify the most associated factor for MetS occurrence in older, non-medicated men. Cross-sectional data from 3004 men, all 65 years of age and older, were analyzed. The correlation and association between adiposity measurements and MetS components were evaluated by Pearson correlation and multiple linear regression. Based on multivariate logistic regression, BMI and WC were significantly associated with MetS and were selected to build a combined model of receiver operating characteristic curves to increase the diagnosis accuracy for MetS. The results show that BMI is independently associated with systolic and diastolic blood pressure; WC and body fat percentage are associated with fasting plasma glucose and log transformation of triglyceride; BMI and WC are negatively associated with high-density lipoprotein cholesterol (HDL-C); and WC is a better discriminate for MetS than BMI, although the combined model (WC + BMI) is not significantly better than WC alone. Based on these results, we conclude that the 4 adiposity measurements have different clinical implications. Thus, in older men, BMI is an important determinant for blood pressure and HDL-C. Waist circumference is associated with the risk of fasting plasma glucose, HDL-C, triglyceride, and MetS occurrence. The combined model did not increase the diagnosis accuracy.     

上海市35-74岁成人代谢综合征腰围切点的研究

［目的］ 探寻上海市35-74 岁人群中代谢综合征（metabolic syndrome,MS）相关肥胖程度的腰围切点。 ［方法］采用多阶段随机抽样方法,在上海市35~74 岁居民中进行横断面调查,共调查7 414 名个体。分析男性和女性不同腰围水平与MS 其他因素的关系,以获得检出2 个及以上危险因素敏感性和特异性均较好的腰围切点。 ［结果］ 随腰围增大,MS 危险因素聚集的比值比（OR）也随之升高,检出2 个及以上MS 危险因素的特异度和阳性预测值逐渐增高,而敏感度和阴性预测值逐渐下降。当男性腰围≥ 85 cm、女性腰围≥ 80 cm,检出2 个及以上MS 危险因素的敏感度为68.33%（男性）、70.17%（女性）,特异度为58.48%（男性）、58.36%（女性）,受试者工作特征曲线（ROC）距离最短,分别为男性0.522 1、女性0.512 2。 ［结论］ 当男性腰围≥ 85 cm、女性腰围≥ 80 cm时,能较好反映MS 危险因素的聚集,为本研究人群代谢综合征肥胖的腰围切点。     

Waist circumference, body mass index and health risk factors among middle aged Thais

Body mass index (BMI) and waist circumference (WC) are important contributors to major causes of health risk factors such as high blood cholesterol, high fasting blood sugar and high blood pressure. This analysis was designed to assess the associations between WC, BMI and each health risk factor in suitable cut-off points for WC and BMI among middle aged men and women of Thai population. Cross sectional data from the Second National Health Survey in Thailand was analysed. This set of data collected by the Ministry of Public Health from 1996 to 1997 was obtained from a total of 998 subjects (comprising 396 men and 602 women) aged 45-50. Results from the Receiver Operating Characteristic curve (ROC curve) identified those with health risk factors demonstrating cut-off points for WC between 81.5-84 centimeters for men and 76-80.5 centimeters for women and BMI between 23.3-23.9 kg/m2 for both genders, respectively. Results from the Multiple logistic regression analysis demonstrated lower risks of having high blood cholesterol, high fasting blood sugar and high blood pressure with cutoff points 84 cm for men, 80 cm for women and BMI 23 kg/m2 for both genders compared to cut-off points 102 cm for men, 88 cm for women and BMI 25 kg/m2 for both genders as specified for the population in Western countries. This study has proposed a waist circumference of 84 cm (33.6 inches) for middle aged Thai men and 80 cm (32 inches) for middle aged Thai women and BMI of 23 kg/m2 for both genders. Monitoring changes in the waist circumference over time along with BMI may be convenient and useful for middle aged Thais to prevent health risk conditions, even in the absence of a change in BMI.     

Evaluation of waist circumference to predict cardiova scular risk factors in an overweight Tehranian population: findings from Tehran Lipid and Glucose Study

This study was conducted to evaluate the waist circumference (WC) cut-off points to predict cardiovascular risk factors in the overweight Tehranian population. Anthropometric measures, blood pressure, and biochemical analyses were evaluated for the 15,005 participants of the Tehran Lipid and Glucose Study. Three thousand sixty-five subjects aged 18-74 years with a body mass index of 25-29.9 were enrolled in this study. Abdominal obesity was defined as WC > or =102 cm for men and > or =88 cm for women. Sensitivity of WC > or =102 cm to detect various cardiovascular risk factors for men aged 35-54 years was between 5% and 14%, and for men aged 55-74 years, was between 12% and 19%. The specificity of this cut-off point was between 93% and 98% and between 86% and 96% for corresponding age-categories, respectively. WC > or =88 cm had a sensitivity of between 28% and 41 % for identifying cardiovascular risk factors in women aged 18-34 years. Sensitivity tended to increase with age and specificity tended to decrease with age in both genders. These cut-off points had the highest positive predictive value for the more prevalent risk factors in both genders. The negative predictive values were different for various risk factors among age groups. The classic cut-off points of WC failed to provide adequate evidence for the use of WC in detecting cardiovascular risk factors. Further studies should be conducted to determine optimal WC cut-off points for Iranians.