Anthropometric cutoff points for predicting chronic diseases in the Mexican National Health Survey 2000

OBJECTIVE: To determine optimum anthropometric cutoffs for predicting the likelihood ratios of type 2 diabetes mellitus (DM) and hypertension (HT) in Mexicans. RESEARCH METHODS AND PROCEDURES: Data from a randomly selected, nationally representative health survey (2000) with 11,730 men [37.4 (+/- 12.9) years] and 26,647 women [37.3(+/- 12.9) years] were assessed for values of body mass index (BMI) and waist circumference (WC) for predicting DM or HT by receiver operating characteristic curve analyses. Likelihood ratios for DM and HT were calculated, and BMIs or WCs for public-health screening were developed. Subanalyses included regional data. RESULTS: Likelihood ratios of DM and HT increased from BMI values of 22 to 24 kg/m(2) in both sexes and with WC values of 75 to 80 cm in men and 70 to 80 cm in women. The best BMI cutoffs for predicting DM were 26.3 to 27.4 kg/m(2) in men and 27.7 to 28.9 kg/m(2) in women, with similar values for HT, i.e., 26.2 to 27.0 kg/m(2) and 27.7 to 28.5 kg/m(2), for men and women, respectively; WC cutoffs for DM were 93 to 98 cm in men and 94 to 99 cm in women, and cutoffs for HT were 92 to 96 cm and 93 to 96 cm for men and women, respectively. The WC cutoffs had higher sensitivity and specificity than those of BMI. DISCUSSION: The risk for DM and HT starts at lower levels of BMI and WC than those suggested by WHO. WC is a better discriminator than BMI measures for use in public health.     

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 and obesity-related metabolic disorders in Taiwanese and US whites and blacks: implications for definitions of overweight and obesity for Asians

BACKGROUND: Recommendations based on scanty data have been made to lower the body mass index (BMI; in kg/m(2)) cutoff for obesity in Asians. OBJECTIVE: The goal was to compare relations between BMI and metabolic comorbidity among Asians and US whites and blacks. METHODS: We compared the prevalence rate, sensitivity, specificity, predictive values, and impact fraction of comorbidities at each BMI level and the BMI-comorbidity relations across ethnic groups by using data from the third National Health and Nutrition Examination Survey and the Nutrition and Health Survey in Taiwan (1993-1996). RESULTS: For most BMI values, the prevalences of hypertension, diabetes, and hyperuricemia were higher for Taiwanese than for US whites. In addition, increments of BMI corresponded to higher odds ratios in Taiwanese than in US whites for hypertriglyceridemia (P = 0.01) and hypertension (P = 0.075). BMI-comorbidity relations were stronger in Taiwanese than in US blacks for all comorbidities studied. BMIs of 22.5, 26, and 27.5 were the cutoffs with the highest sum of positive and negative predictive value for Taiwanese, US white, and US black men, respectively. The same order was observed for women. For BMIs >27, >85% of Taiwanese, 66% of whites, and 55% of blacks had at least one of the studied comorbidities. However, a cutoff close to the median of the studied population was often found by maximizing sensitivity and specificity. Reducing BMI from >25 to <25 in persons in the United States could eliminate 13% of the obesity comorbidity studied. The corresponding cutoff in Taiwan is slightly <24. CONCLUSION: These data suggest a possible need to set lower BMI cutoffs for Asians, but where to draw the line is a complex issue.     

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

OBJECTIVE: BMI (kilograms per meters squared) and waist circumference (WC) (measured in centimeters) are each associated with the risk of developing cardiovascular disease (CVD). Therefore, a combination of the two may be more effective in identifying subjects at risk than either alone. The present study sought to identify the combination of BMI and WC that has the strongest association with CVD risk factors in whites. RESEARCH METHODS AND PROCEDURES: Subjects were 8712 white men and women from the Third National Health and Nutrition Examination Survey. The optimal combination of BMI and WC was developed using logistic regression models with BMI and WC as predictors and CVD risk factors as outcomes. The combined measure of BMI and WC using current cut-off points was also examined. Sensitivity, specificity, and receiver operating characteristics curves were compared between the combined measures and BMI alone. RESULTS: For white men, the optimal combination of BMI and WC for identifying CVD risk factors was 0.68 x BMI + 0.32 x WC. This combination generated a score that better estimated the odds of having CVD risk factors than either alone. For white women, WC alone largely determined the likelihood of having CVD risks. The combination of BMI and WC using current cut-off points may provide an improved measure of CVD risk. Combined measures showed a higher sensitivity or a shorter distance in receiver operating characteristic curves in the identification of CVD risk factors. DISCUSSION: Combined measures of BMI and WC may provide a higher overall test performance for CVD risk factors and may be useful in some ethnic groups as an improved means of screening subjects for further evaluation in the clinical setting.     

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.     

Total and central obesity among elderly Hispanics and the association with Type 2 diabetes

OBJECTIVE: To report the prevalence of total and central obesity in a representative sample of Puerto Rican and Dominican elders in Massachusetts, to compare them with a neighborhood-based group of non-Hispanic white elders, and to examine associations of obesity indices with the presence of type 2 diabetes. RESEARCH METHODS AND PROCEDURES: We examined the prevalence of overweight, obesity, and central obesity in 596 Hispanics of Caribbean origin, ages 60 to 92 years, and 239 non-Hispanic whites, and tested linear and logistic regression models to determine associations among body mass index (BMI), waist circumference (WC), and diabetes. RESULTS: Obesity (BMI > or = 30 kg/m(2)) was prevalent among all ethnic groups, ranging from 17% to 29% for Dominican and Puerto Rican men, respectively, and from 29% to 40% for non-Hispanic white and Dominican women, respectively. These differences were not statistically significant. Among Hispanic men and women, diabetes was prevalent across all BMI and WC categories but tended to be greatest among those with BMI of 25 to 29 kg/m(2) (41% to 43%). In contrast, diabetes was most prevalent in the obese group (36% to 45%) of non-Hispanic whites. Both BMI and WC were associated with the presence of diabetes, but the coefficients were greater for non-Hispanic whites than for Hispanics. DISCUSSION: Caribbean Hispanics and non-Hispanic whites living in the same Massachusetts localities had high prevalences of overweight and obesity. Total and central obesity exerted a differential effect on the presence of diabetes among ethnic groups; for Hispanics, diabetes was prevalent even among non-obese individuals, whereas for non-Hispanic white women, the prevalence of diabetes was strongly associated with total and central obesity. Additional research is needed to investigate the factors associated with the differential effect of obesity on the prevalence of type 2 diabetes among Hispanic and non-Hispanic white elders.     

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.     

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.     

Fitness alters the associations of BMI and waist circumference with total and abdominal fat

OBJECTIVE: We tested the following hypotheses in black and white men and women: 1) for a given BMI or waist circumference (WC), individuals with moderate cardiorespiratory fitness (CRF) have lower amounts of total fat mass and abdominal subcutaneous and visceral fat compared with individuals with low CRF; and 2) exercise training is associated with significant reductions in total adiposity and abdominal fat independent of changes in BMI or WC. RESEARCH METHODS AND PROCEDURES: The sample included 366 sedentary male (111 blacks and 255 whites) and 462 sedentary female (203 blacks and 259 whites) participants in the HERITAGE Family Study. The relationships between BMI and WC with total fat mass (determined by underwater weighing) and abdominal subcutaneous and visceral fat (determined by computed tomography) were compared in subjects with low (lower 50%) and moderate (upper 50%) CRF. The effects of a 20-week aerobic exercise training program on changes in these adiposity variables were examined in 86% of the subjects. RESULTS: Individuals with moderate CRF had lower levels of total fat mass and abdominal subcutaneous and visceral fat than individuals with low CRF for a given BMI or WC value. The 20-week aerobic exercise program was associated with significant reductions in total adiposity and abdominal fat, even after controlling for reductions in BMI and WC. With few exceptions, these observations were true for both men and women and blacks and whites. DISCUSSION: These findings suggest that a reduction in total adiposity and abdominal fat may be a means by which CRF attenuates the health risk attributable to obesity as determined by BMI and WC.     

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.     

Percentage body fat ranges associated with metabolic syndrome risk: results based on the third National Health and Nutrition Examination Survey (1988-1994)

BACKGROUND: Increasing attention has focused on the association between body fatness and related metabolic risk factors. The quantitative link between percentage body fat (%BF) and the risk of metabolic syndrome is unknown. OBJECTIVES: The objectives were to determine the risk [odds ratios (ORs)] of metabolic syndrome based on %BF in black and white men and women in the United States and to provide corresponding ranges of %BF associated with a risk equivalent to body mass index (BMI; in kg/m(2)). DESIGN: The subjects were participants in the third National Health and Nutrition Examination Survey and were divided into those with and without the metabolic syndrome. OR equations were derived from logistic regression models for %BF and BMI, with the 25th percentile in the study population as the reference. Ranges were developed by associating %BF with the equivalent risk of metabolic syndrome based on established BMI cutoffs. RESULTS: Four sets (men, women, black, and white) of OR curves were generated for %BF and for BMI by using data from 8259 adults. The ORs for metabolic syndrome were lower in blacks than in whites at any given %BF or BMI. The developed cutoffs for %BF differed between men and women but showed only small race and age effects. A simplified set of sex-specific %BF ranges for the risk of metabolic syndrome were developed. CONCLUSIONS: The risk of metabolic syndrome can be established from measured %BF by using either the developed OR curves or %BF thresholds at traditional BMI cutoffs. This information should prove useful in both clinical and research settings.     

Prospective study of optimal obesity index cutoffs for predicting development of multiple metabolic risk factors: the korean genome and epidemiology study

Background: In this prospective cohort study, we estimated the risk of developing more than 1 metabolic risk factor, using different obesity indices. In addition, we investigated the relative usefulness of the obesity indices for predicting development of such risk factors and calculated optimal cutoffs for the obesity indices.Methods: The cohort comprised 10 038 representative residents of a small city and a rural county who were recruited in 2001-2002. Follow-up examinations were conducted every 2 years. Among the 3857 participants without metabolic syndrome at baseline, 1102 new cases occurred during the 6-year follow-up. Receiver operating characteristic (ROC) curves for the obesity indices were plotted to compare the usefulness of the obesity indices.Results: The numbers of new cases of multiple metabolic risk factors among people in the highest quintiles of body mass index (BMI), waist circumference (WC), waist-hip ratio (WHR), and waist-height ratio at the baseline examination were 2 to 3 times those in the lowest quintiles. The area under the ROC curve for WHR was significantly higher than that for BMI. The optimal BMI cutoff was 24 kg/m(2) in men and women, and the optimal WC cutoffs were 80 cm and 78 cm in men and women, respectively.Conclusions: Both overall obesity and central obesity predicted risk of developing multiple metabolic risk factors, and WHR appeared to be a better discriminator than BMI. To prevent development of metabolic diseases among Koreans, it might be useful to lower the cutoff for abdominal obesity, as defined by WC.     

Leptin concentrations in the United States: relations with demographic and anthropometric measures

BACKGROUND: Leptin is a peptide that is strongly correlated with adiposity and is a potential determinant of obesity and its complications. OBJECTIVE: Leptin concentrations from a representative sample of the US population were examined in relation to demographic and anthropometric measures. DESIGN: Fasting serum leptin concentrations were measured in 6303 women and men aged > or =20 y in the third National Health and Nutrition Examination Survey. Anthropometric measures included body mass index, 4 skinfold thicknesses, and 4 body circumferences. Ethnic groups included non-Hispanic whites and blacks and Mexican Americans. RESULTS: The mean serum leptin concentration was much higher in women (12.7 microg/L) than in men (4.6 microg/L). In a multivariate analysis, leptin concentrations were associated with the sum of 4 skinfold thicknesses, waist and hip circumferences, ethnicity, and age. These measures explained most of the variance in leptin concentrations in women (R2 = 0.69) and in men (R2 = 0.67). Triceps skinfold thickness, when substituted for the sum of skinfold thicknesses, performed nearly as well in women (R2 = 0.68) and men (R2 = 0.67). Leptin concentrations were slightly but significantly higher in non-Hispanic blacks than in non-Hispanic whites of both sexes when these anthropometric measures and age were controlled for; Mexican Americans had concentrations that were intermediate compared with the concentrations of non-Hispanic whites and blacks. CONCLUSIONS: In this large, representative sample of the US population, demographic and anthropometric measures predicted serum leptin concentrations in women and men.     

Trends of abdominal adiposity in white,black, and Mexican-American adults, 1988 to 2000

OBJECTIVE: To describe changes in the distribution of waist circumference (WC) and abdominal obesity (AO) in white, black, and Mexican-American adults from 1988 through 2000. RESEARCH METHODS AND PROCEDURES: Nationally representative cross-sectional surveys of adults 20 to 79 years of age were examined using data from U.S. National Health and Nutrition Examination Surveys of 1988 to 1994 and 1999 to 2000. AO was defined as WC > or =102 cm in men and > or 88 cm in women. RESULTS: There was a gradient of increasing WC and AO with increasing age in both study periods in whites and blacks. In men, the average increase between the study periods in overall WC in whites, blacks, and Mexican Americans were 3, 3.3, and 3.4 cm, respectively. The corresponding values in women were 2.4, 5.3, and 3.7 cm, respectively. In men, the percentage change in prevalence of AO between 1988 and 2000 ranged from 5.5% in Mexican-American men to 8.2% in white men. In women, there was a 1.7% decrease in AO in Mexican Americans, whereas there was an increase of 6.3% for whites and 7% for blacks. DISCUSSION: Despite increased understanding of the need for screening and treatment for obesity, this study indicates increasing prevalence of AO in white and black Americans. Without concerted effort to reduce the prevalence of overall obesity, the increasing prevalence of AO is likely to lead to increased prevalence of metabolic syndromes in the United States. Our results highlight the need to design evidence-based programs that show promise for long-term health behavior changes to facilitate the prevention of AO and related comorbidities.     

Population reference values for plasma total homocysteine concentrations in US adults after the fortification of cereals with folic acid

BACKGROUND: Folic acid fortification has resulted in a dramatic increase in folate intake in the United States. Folate intake is inversely associated with circulating total homocysteine (tHcy). Elevated tHcy is directly associated with cardiovascular disease risk. OBJECTIVE: The aim of this study was to present the distribution of plasma concentrations of tHcy in US adults by using data from nationally representative sample surveys conducted since folic acid fortification was implemented. DESIGN: Data from the National Health and Nutrition Examination Surveys from 1999-2001 and 2001-2002 were used to study tHcy distribution by age, sex, and race-ethnicity in 9196 persons. RESULTS: Plasma concentrations of tHcy were higher in men than in women and in older persons than in younger persons. In those aged 19-30, 31-50, and 51-70 y but not in those aged >70 y, men had significantly (P < 0.0001) higher mean plasma concentrations of tHcy than did women. A race-ethnicity difference in plasma tHcy existed only in persons aged >70 y. Non-Hispanic blacks aged >70 y had significantly (P < 0.05) higher tHcy concentrations than did non-Hispanic white or Mexican American or Hispanic subjects in the same age group. Age-adjusted plasma tHcy concentrations did not differ significantly between non-Hispanic white (8.39 micromol/L), non-Hispanic black (8.92 micromol/L), and Mexican American or Hispanic (8.12 micromol/L) subjects. The rate of increase in plasma tHcy was greater in non-Hispanic blacks aged >/=50 y than in persons of similar age but of other races-ethnicities. CONCLUSIONS: These plasma tHcy data reflect the effects of folic acid fortification. Sex, age, and race-ethnicity differences persist in plasma tHcy concentrations.     

Ethnic Disparities in the Association of Body Mass Index with the Risk of Hypertension and Diabetes

Despite having lower body mass index (BMI) compared to other ethnic groups, Asians continue to develop significant metabolic diseases such as hypertension and diabetes. To evaluate the disparate association of BMI and risk of hypertension and diabetes in Asians. We retrospectively studied 150,753 adults from the 1985–2011 California Behavioral Risk Factor Survey. Trends in prevalence of obesity, hypertension, and diabetes were stratified by ethnicity. Multivariate logistic regression models evaluated the incremental effect of one unit BMI increase on risk of hypertension and diabetes and the disparate risks of hypertension and diabetes at different BMI thresholds. Asians had the lowest BMI among all groups. However, the impact of increasing BMI on risk of hypertension and diabetes was significantly greater in Asians. For each one unit increase in BMI, Asians were significantly more likely to have hypertension (OR 1.15; 95 % CI 1.13–1.18) compared to non-Hispanic whites, blacks, and Hispanics. Similar trends were seen for diabetes (Asians: OR 1.15; 95 % CI 1.13–1.18). The risk of hypertension in Asians with BMI ≥ 22 was similar to non-Hispanic whites with BMI ≥ 27 and blacks with BMI ≥ 28. The risk of diabetes in Asians with BMI ≥ 28 was similar to non-Hispanic whites with BMI ≥ 30. Despite lower overall BMI compared to other groups, weight gain in Asians is associated with significantly higher risks of hypertension and diabetes. Compared to other ethnic groups, similar risks of hypertension and diabetes are seen in Asians at much lower BMI.     

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.     

Body mass index, waist circumference, and risk of coronary heart disease: a prospective study among men and women

OBJECTIVE: The purpose of the study was to assess the risk of CHD associated with excess weight measured by BMI and waist circumference (WC) in two large cohorts of men and women. DESIGN, SETTING, SUBJECTS: Participants in two prospective cohort studies, the Health Professionals Follow-up Study (N = 27,859 men; age range 39-75 years) and the Nurses' Health Study (N = 41,534 women; 39-65 years) underwent 16-year follow-up through 2004. RESULTS: 1,823 incident cases of CHD among men and 1,173 cases among women were documented. Compared to men with BMI 18.5 to 22.9 kg/m2, those with a BMI > 30.0 kg/m2 had a multivariate-adjusted RR of CHD of 1.81 (95% CI 1.48 - 2.22). Among women, those with a BMI > 30.0 kg/m2 had a RR of CHD of 2.16 (95% CI 1.81 - 2.58). Compared to men with a WC < 84.0 cm, those with WC of greater than 102.0 cm had a RR of 2.25 (95% CI 1.77 - 2.84). Among women, the RR of CHD was 2.75 (95% CI 2.20 - 3.45) for those with WC of greater than 88.0 cm. CONCLUSIONS: In these analyses from two large ongoing prospective cohort studies, both BMI and WC strongly predicted future risk of CHD. Furthermore, WC thresholds as low as 84.0 cm in men and 71.0 cm in women may be useful in identifying those at increased risk of developing CHD. The findings have broad implications in terms of CHD risk assessment in both clinical practice and epidemiologic studies.     

Comparison of abdominal adiposity and overall obesity in predicting risk of type 2 diabetes among men

BACKGROUND: Obesity is a strong risk factor for type 2 diabetes. However, few studies have compared the predictive power of overall obesity with that of central obesity. The cutoffs for waist circumference (WC) and waist-to-hip ratio (WHR) as measures of abdominal adiposity remain controversial. OBJECTIVE: The objective was to compare body mass index (BMI), WC, and WHR in predicting type 2 diabetes. DESIGN: A prospective cohort study (Health Professionals Follow-Up Study) of 27 270 men was conducted. WC, WHR, and BMI were assessed at baseline. Covariates and potential confounders were assessed repeatedly during the follow-up. RESULTS: During 13 y of follow-up, we documented 884 incident type 2 diabetes cases. Age-adjusted relative risks (RRs) across quintiles of WC were 1.0, 2.0, 2.7, 5.0, and 12.0; those of WHR were 1.0, 2.1, 2.7, 3.6, and 6.9; and those of BMI were 1.0, 1.1, 1.8, 2.9, and 7.9 (P for trend < 0.0001 for all). Multivariate adjustment for diabetes risk factors only slightly attenuated these RRs. Adjustment for BMI substantially attenuated RRs for both WC and WHR. The receiver operator characteristic curve analysis indicated that WC and BMI were similar and were better than WHR in predicting type 2 diabetes. The cumulative proportions of type 2 diabetes cases identified according to medians of BMI (>/=24.8), WC (>/=94 cm), and WHR (>/=0.94) were 82.5%, 83.6%, and 74.1%, respectively. The corresponding proportions were 78.9%, 50.5%, and 65.7% according to the recommended cutoffs. CONCLUSIONS: Both overall and abdominal adiposity strongly and independently predict risk of type 2 diabetes. WC is a better predictor than is WHR. The currently recommended cutoff for WC of 102 cm for men may need to be reevaluated; a lower cutoff may be more appropriate.     

Development of health-related waist circumference thresholds within BMI categories

OBJECTIVE: To develop and cross-validate waist circumference (WC) thresholds within BMI categories. The utility of the derived values was compared with the single WC thresholds (women, 88 cm; men, 102 cm) recommended by NIH and Health Canada. RESEARCH METHODS AND PROCEDURES: The sample included adults classified as normal weight (BMI = 18.5 to 24.9), overweight (BMI = 25 to 29.9), obese I (BMI = 30 to 34.9), and obese II+ (BMI > or = 35) from the Third U.S. National Health and Nutrition Examination Survey (NHANES III; n = 11,968) and the Canadian Heart Health Surveys (CHHS; n = 6286). Receiver operating characteristic curves were used to determine the optimal WC thresholds that predicted high risk of coronary events (top quintile of Framingham scores) within BMI categories using the NHANES III. The BMI-specific WC thresholds were cross-validated using the CHHS. RESULTS: The optimal WC thresholds increased across BMI categories from 87 to 124 cm in men and from 79 to 115 cm in women. The validation study indicated improved sensitivity and specificity with the BMI-specific WC thresholds compared with the single thresholds. DISCUSSION: Compared with the recommended WC thresholds, the BMI-specific values improved the identification of health risk. In normal weight, overweight, obese I, and obese II+ patients, WC cut-offs of 90, 100, 110, and 125 cm in men and 80, 90, 105, and 115 cm in women, respectively, can be used to identify those at increased risk.