Predicting Incident Diabetes in Jamaica: The Role of Anthropometry

Objective: To evaluate the performance of the body mass index (BMI), waist circumference, waist‐to‐hip ratio (WHR), and waist‐to‐height ratio (WHTR) in predicting incident diabetes in Jamaica. Research Methods and Procedures: A cohort of 728 nondiabetic adults (290 men and 438 women), ages 25 to 74 years and residents of Spanish Town, Jamaica, were followed for a mean of 4 years. Participants had fasting and 2‐hour postchallenge glucose concentrations measured at baseline and follow‐up. Results: There were 51 cases of incident diabetes (17 men and 34 women). All indices were independent predictors of diabetes, and none was clearly superior. The area under the receiver operating characteristics curves (95% confidence interval) for BMI was 0.74 (0.59 to 0.88) for men and 0.62 (0.51 to 0.72) for women. For waist circumference, these values were 0.78 (0.65 to 0.91) in men and 0.61 (0.50 to 0.71) in women. Similar results were obtained for WHR and WHTR. “Optimal” cut‐off points for BMI were 24.8 kg/m² (men) and 29.3 kg/m² (women). For waist circumference, these were 88 cm and 84.5 cm for men and women, respectively. Corresponding values for WHR were 0.87 and 0.80 and for WHTR were 0.51 and 0.54, respectively. Discussion: Cut‐off points for waist circumference and WHR were similar to those proposed in developed countries for women but lower in men. Waist circumference could be useful in health promotion as an alternative to BMI.     

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

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

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

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

The use of BMI and waist circumference as surrogates of body fat differs by ethnicity

Objective: To compare the prediction of percentage body fat using BMI and visceral adipose tissue (VAT) using waist circumference (WC) in individuals of Chinese, European, and South Asian origin. Research Methods and Procedures: Healthy men and women of Chinese, European, and South Asian origin (n = 627) between the ages of 30 and 65 years were recruited to ensure equal distribution of gender and representation across BMI ranges (18.5 to 24.9, 25 to 29.9, and ≥30 kg/m²). Participants were assessed for demographics, anthropometry, lifestyle, and regional adiposity. Percentage body fat and VAT were measured by DXA and computer tomography scan, respectively. Results: BMI and WC were highly correlated with total and regional measures of adiposity in each ethnic group. At any BMI, the percentage body fat of Chinese participants was similar to that of Europeans, but that of South Asians was greater by 3.9% (p < 0.001). Above a WC of 71.0 cm, the Chinese participants had an increasingly greater amount of VAT than the Europeans (p = 0.017 for interaction). South Asians had significantly more VAT than the Europeans at all but the most extreme WC (above 105 cm) (p < 0.05). Discussion: Compared with Europeans, percentage body fat was higher for a given BMI in South Asians, whereas VAT was higher for a given WC in both Chinese and South Asian men and women. These findings support the use of ethnic‐specific anthropometric targets.     

Prospective Investigation of Metabolic Characteristics in Relation to Weight Gain in Older Adults: The Hoorn Study

The objective of this investigation was to determine the relation between baseline glucose, insulin, adiponectin, and leptin levels and subsequent 6‐year weight and waist change in older men and women without diabetes in a prospective cohort study. Participants were 1,198 Dutch men and women without diabetes who were aged 50–77 years when baseline metabolic and anthropometric measurements were evaluated (1989–1991). Approximately 6 years later, body weight and waist circumference were re‐measured at a follow‐up examination (1996–1998). Metabolic variables (fasting plasma glucose, 2‐h postchallenge plasma glucose, homeostasis model assessment of insulin resistance (HOMA‐IR), adiponectin, and leptin) were evaluated as predictors of changes in weight and waist circumference. Postchallenge plasma glucose (mmol/l) significantly predicted less gain in both weight and waist circumference (β = ?0.28 kg, s.e. = 0.11; β = ?0.31 cm, s.e. = 0.14, respectively) during follow‐up. Leptin (µg/l) significantly predicted greater increases in weight (β = 0.29 kg, s.e. = 0.07) and waist (β = 0.16 cm, s.e. = 0.08) among men and in waist among women (β = 0.06 cm, s.e. = 0.02). Fasting plasma glucose (mmol/l) predicted an increase in waist among women (β = 1.59 cm, s.e. = 0.63), but not in men (β = ?0.74 cm, s.e. = 0.55). Adiponectin and insulin did not predict weight or waist change. The authors conclude that lower postchallenge plasma glucose and higher fasting leptin levels significantly predicted long‐term increases in weight and waist circumference. In contrast, measures of insulin resistance and adiponectin were not associated with weight change in this cohort of older persons without diabetes.     

Defining Health‐Related Obesity in Prepubertal Children

Objective: The purpose of this study was to develop percentage of fat and waist circumference cut‐points in prepubertal children with the intention of defining obesity associated with cardiovascular disease (CVD) risk. Research Methods and Procedures: A cross‐sectional analysis of 87 prepubertal children aged 4 to 11 years was used. Percentage of body fat was determined by DXA. Waist circumference was measured to the nearest millimeter. Receiver Operating Characteristic analyses of percentage of fat and waist circumference were used to develop cut‐points for individuals with adverse levels of CVD risk factors. Results: The risk factors selected for analyses (i.e., fasting insulin, high‐density lipoprotein cholesterol, low‐density lipoprotein cholesterol, triglycerides, and total cholesterol/high‐density lipoprotein cholesterol) were significantly related to percentage of body fat and waist circumference. Likelihood ratios were used to identify percentage of fat and waist circumference cut‐points associated with adverse cardiovascular risk profiles. Two cut‐points, an upper cut‐point of 33% body fat and a lower cut‐point of 20% body fat, were derived. Waist circumference cut‐points indicative of adverse and normal risk‐factor profiles were 71 cm and 61 cm, respectively. Discussion: The data indicate that children with ≥33% body fat and children with a waist circumference ≥71 cm were more likely to possess an adverse CVD risk‐factor profile than a normal risk‐factor profile. The likelihood of children with <20% body fat or a waist circumference <61 cm possessing an adverse CVD risk‐factor profile as opposed to a normal risk‐factor profile was small. The cut‐points describe an adequate health‐related definition of childhood obesity.     

Sensitivity and Specificity of Anthropometrics for the Prediction of Diabetes in a Biracial Cohort

Objective: To evaluate the ability of body mass index, waist circumference, waist‐to‐hip ratio, and combinations of these variables to discriminate individuals who will develop diabetes in adulthood. Research Methods and Procedures: Data were from 45‐ to 64‐year‐old men and women who were members of the Atherosclerosis Risk in Communities cohort. The analysis sample consisted of 12,814 African American and white participants who were free of diabetes at baseline. Body mass index, waist circumference, waist‐to‐hip ratio, and diabetes incidence (defined as one glucose measure ≥126 mg/dL after fasting for at least 8 hours, one nonfasting glucose measure ≥200 mg/dL, and self‐report of diabetes or report of taking medication for diabetes). Results: 1515 new cases of diabetes were identified over the 9‐year follow‐up. Areas under receiver operating characteristic curves ranged from 0.66 to 0.73 for single measures. The curves were smooth, with no indication of a threshold. Waist tended to have the highest receiver operating characteristic statistic in all groups, but differences were small. Discussion: The three anthropometric indices tested were approximately equivalent in their ability to predict diabetes. Sensitivity and specificities differed among ethnic and gender groups.     

Defining obesity cut-off points for migrant South Asians

Background

Body mass index (BMI) and waist circumference (WC) are used to define cardiovascular and type 2 diabetes risk. We aimed to derive appropriate BMI and WC obesity cut-off points in a migrant South Asian population.

Methods

4688 White Europeans and 1333 South Asians resident in the UK aged 40–75 years inclusive were screened for type 2 diabetes. Principal components analysis was used to derive a glycaemia, lipid, and a blood pressure factor. Regression models for each factor, adjusted for age and stratified by sex, were used to identify BMI and WC cut-off points in South Asians that correspond to those defined for White Europeans.

Findings

For South Asian males, derived BMI obesity cut-off points equivalent to 30.0 kg/m² in White Europeans were 22.6 kg/m² (95% Confidence Interval (95% CI) 20.7 kg/m² to 24.5 kg/m²) for the glycaemia factor, 26.0 kg/m² (95% CI 24.7 kg/m² to 27.3 kg/m²) for the lipid factor, and 28.4 kg/m² (95% CI 26.5 kg/m² to 30.4 kg/m²) for the blood pressure factor. For WC, derived cut-off points for South Asian males equivalent to 102 cm in White Europeans were 83.8 cm (95% CI 79.3 cm to 88.2 cm) for the glycaemia factor, 91.4 cm (95% CI 86.9 cm to 95.8 cm) for the lipid factor, and 99.3 cm (95% CI 93.3 cm to 105.2 cm) for the blood pressure factor. Lower ethnicity cut-off points were seen for females for both BMI and WC.

Conclusions

Substantially lower obesity cut-off points are needed in South Asians to detect an equivalent level of dysglycemia and dyslipidemia as observed in White Europeans. South Asian ethnicity could be considered as a similar level of risk as obesity (in White Europeans) for the development of type 2 diabetes.     

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.     

BMI and waist circumference as indicators of health among Samoan women

Objective: High rates of obesity and chronic disease make establishment of effective indicators of risk for chronic disease important. The objective was to examine adequacy of anthropometric cut‐off points as indicators of risk for chronic disease among Samoan women in Hawaii. Research Methods and Procedures: A cross‐sectional survey of 55 Samoan women 18 to 28 years of age that included blood lipids, cholesterol, and glucose (including after a 2‐hour oral glucose test); anthropometry (weight, height, waist circumference); and DXA of body composition. Results: Using the Centers for Disease Control and Prevention (CDC)/World Health Organization (WHO) cut‐off points for BMI, 22% of women were overweight and 58% were obese. Cholesterol, lipid, and glucose values were all linearly related to DXA body fat, BMI, and waist circumference. BMI and waist circumference at WHO/NIH cut‐off points predicted levels of blood lipids and glucose that indicate elevated risk for disease. Discussion: WHO/NIH cut‐off points for BMI and waist circumference reflect risk indicators of chronic disease among young Samoan women in Hawaii.     

Amerindians normalized waist circumference and obesity diagnosis standarized by biochemical and HLA data

Metabolic syndrome (MS) and obesity are principal causes of morbidity all over the World, particularly for their association to cardiovascular risk. Amerindians are often living in countries and remote areas with unavailable sophisticated diagnoses methodologies. However, waist-circumference is a reliable and easy to record parameter of visceral obesity and MS. Waist circumference normal values are not yet established in Amerindians: South Asian and Japanese values have been recommended for Amerindian use. The purpose of this study is to objectively define for the first time the waist circumference measure cut-off points for Amerindians. A total of 303 unrelated Amerindian adults recently immigrated to Madrid were studied; they were healthy, since they were questioned and tested as appropriate for blood donation. Waist-circumference was measured in these voluntary blood donors after written consent. Chosen subjects for study had HLA quasi-specific Amerindian genes and not gained weight since their relatively short time living in Spain. Amerindians with Type I or II diabetes or family antecedents were removed from the study. The biochemical parameter used to define normality for MS was the reliable serum HDL-cholesterol levels, whose values are diet independent. A Receiver Operating Characteristic analysis was used to compare the predictive validity and to find out the optimal cut-off points of waist circumference normal values. Cut-off points were ≤88.5 cm in males and ≤82.5 cm in females; these values were close to the median values (88 and 82.2 cm, respectively). Obtained waist circumference values recorded here in normal Amerindians are different to those previously recommended indirectly (those of South Asian/Japanese populations). These parameters may be of great value for American countries health care in order to predict and control MS and its cardiovascular complications. Other countries having a heavy Amerindian immigration (i.e.: USA, Spain) may also benefit for establishing specific Preventive Medicine programs.     

Trends in Waist Circumference among U.S. Adults

Objective: Waist circumference has been proposed as a measure of obesity or as an adjunct to other anthropometric measures to determine obesity. Our objective was to examine temporal trends in waist circumference among adults in the U.S. Research Methods and Procedures: We used data from 15, 454 participants ≥20 years old in National Health and Nutrition Examination Survey (NHANES) III (1988 to 1994) and 4024 participants ≥20 years old from National Health and Nutrition Examination Survey 1999 to 2000. Results: The unadjusted waist circumference increased from 95.3 (age‐adjusted, 96.0 cm) to 98.6 (age‐adjusted, 98.9 cm) cm among men and from 88.7 (age‐adjusted 88.9 cm) to 92.2 (age‐adjusted 92.1 cm) cm among women. The percentiles from the two surveys suggest that much of the waist circumference distribution has shifted. Statistically significant increases occurred among all age groups and racial or ethnic groups except men 30 to 59 years old, women 40 to 59 and ≥70 years old, and women who were Mexican American or of “other” race or ethnicity. Discussion: These results demonstrate the rapid increase in obesity, especially abdominal obesity, among U.S. adults. Unless measures are taken to slow the increase in or reverse the course of the obesity epidemic, the burden of obesity‐associated morbidity and mortality in the U.S. can be expected to increase substantially in future years.     

Larger Hip Circumference Independently Predicts Health and Longevity in a Swedish Female Cohort

Objective: The waist circumference is widely viewed as a simple but effective measure for assessing obesity‐related health risks, whereas measurement of the hip circumference is not currently prioritized. This study examines health risks associated specifically with hip circumference in a cohort of Swedish women, to determine whether information may be lost by excluding the hip circumference from health surveys. Research Methods and Procedures: The subjects described in this report constitute a population‐based sample of 38‐ to 60‐year‐old women who underwent anthropometric examinations in 1968. The 24‐year incidence rates have been ascertained for myocardial infarction, combined cardiovascular diseases, and diabetes. All‐cause, cardiovascular, and myocardial infarction mortality also were evaluated. Results: Hip circumference was a significant independent inverse risk estimator for all endpoints studied. Using Cox regression with adjustment for age, smoking, body mass index, and waist circumference, the remaining variability associated with larger hips was associated with significantly fewer adverse health outcomes. The hip circumference became statistically informative after body mass index adjustment. The strongest protective associations were observed for cardiovascular disease and diabetes endpoints, although significant trends were also seen for total mortality. Considering hip and waist simultaneously, the strength of the inverse association for large hips generally exceeded the positive association for waist. Discussion: Recent interest in the waist circumference as an effective screening tool has taken the focus off of the hip circumference. The present results suggest that collection of hip measurements should not be discontinued in assessment of obesity‐related risk status and health promotion.     

Secular trends of obesity and cardiovascular risk factors in a Mediterranean population

Objective: To evaluate time trends of obesity, abdominal obesity, and cardiovascular risk factors (CRFs) according to BMI and waist circumference (WC) categories in a Mediterranean population. Research Methods and Procedures: Subjects were Spanish men (n = 2383) and women (n = 2525) 25 to 74 years old, examined in 1994 to 1995 and 1999 to 2000 in two independent population‐based cross‐sectional surveys in the northeast of Spain. Lifestyle measures, CRFs, and anthropometric variables were analyzed. Results: Over the 5 years of the study, mean age‐standardized BMI increased by 1.0 units in men and by 0.8 units in women. At the same time the prevalence of obesity increased from 15.4% to 21.9% in men and from 15.4% to 21.4% in women. An upward trend was observed for WC and abdominal obesity (WC > 102 cm in men and WC > 88 cm in women) only in men. The proportion of men and women with hypercholesterolemia, diabetes, and low high‐density lipoprotein‐cholesterol plasma concentration remained stable within BMI and WC categories. The proportion of hypertension and smoking in obese men significantly increased from 1995 to 2000. Discussion: The 5‐year increase in BMI and WC is of considerable magnitude in the present population, although several CRFs remained stable within BMI and WC categories.     

Appropriate Body Mass Index and Waist Circumference Cutoffs for Categorization of Overweight and Central Adiposity among Uighur Adults in Xinjiang

Objective

The current overweight and central adiposity guidelines based on Western populations were not consistent with many studied based on the Asian populations. Uighur people live in Xinjiang Uighur Autonomous Region which is located in the center of Asia. Their overweight and central cutoffs were largely unknown. We aimed to identify cutoffs for body mass index (BMI; in kg/m²) and waist circumference (WC; in cm) for categorization of overweight and central adiposity among Uighur adults in Xinjiang.

Methods

4767 Uighur participants were selected from the Cardiovascular Risk Survey (CRS) which was carried out from October 2007 to March 2010. The age of the participants were from 35 to 101 years old with the mean age of 50.09 years. Anthropometric data, blood pressure, serum concentration of serum total cholesterol, triglyceride, low density lipoprotein (LDL), high density lipoprotein (HDL) and fasting glucose were documented. The prevalence, sensitivity, specificity and distance on the receiver operating characteristic (ROC) curve of each BMI and waist circumference values were calculated.

Results

The prevalence of hypertension, hypercholesterolemia and hypertriglyceridemia were higher with higher BMI for both men and women. The prevalence of hypertension and hypercholesterolemia were higher with higher waist circumference for both men and women. In women, the prevalence of hypertriglyceridemia was noticed to increase as the waist circumference increased. The shortest distance in the receiver operating characteristic curves for hypertension, dyslipidemia, diabetes, or ≥ 2 of these risk factors suggested a BMI cutoff of 26 and a waist circumference cutoff of 90 cm for both men and women.

Conclusions

Higher cutoffs for BMI and waist circumference are needed in the identification of Uighur patients at high risk of cardiovascular disease.     

Relationships of Obesity and Fat Distribution With Atherothrombotic Risk Factors: Baseline Results From the Bypass Angioplasty Revascularization Investigation 2 Diabetes (BARI 2D) Trial

The impact of obesity on cardiovascular disease (CVD) outcomes in patients with type 2 diabetes mellitus (T2DM) and established coronary artery disease (CAD) is controversial; whether BMI and/or waist circumference correlate with atherothrombotic risk factors in such patients is uncertain. We sought to evaluate whether higher BMI or waist circumference are associated with specific risk factors among 2,273 Bypass Angioplasty Revascularization Investigation 2 Diabetes (BARI 2D) study participants with T2DM and documented CAD (baseline data, mean age 62 years, 66% non‐Hispanic white, 71% men). Multiple linear regression models were constructed after adjusting for sex, age, race/ethnicity, US vs. non‐US site, diabetes duration, exercise, smoking, alcohol, and relevant medication use. First‐order partial correlations of BMI with risk factors after controlling for waist circumference and of waist circumference with risk factors after controlling for BMI were also evaluated. Ninety percent of the patients were overweight (BMI ≥25 kg/m²); 68% of men and 89% of women had high‐risk waist circumference measures (≥102 and ≥88 cm, respectively). BMI and waist circumference, in separate models, explained significant variation in metabolic (insulin, lipids, blood pressure (BP)) and inflammatory/procoagulation (C‐reactive protein, PAI‐1 activity and antigen, and fibrinogen) risk factors. In partial correlation analyses BMI was independently associated with BP and inflammatory/procoagulation factors, waist circumference with lipids, and both BMI and waist circumference with insulin. We conclude that, in cross‐sectional analyses, both BMI and waist circumference, independently, are associated with increased atherothrombotic risk in centrally obese cohorts such as the BARI 2D patients with T2DM and CAD.     

Serum 25-hydroxyvitamin D is not related to cardiac natriuretic peptide in nulliparous and lactating women

Background

Visceral obesity is positively related to insulin resistance. The nature of the relationship between waist circumference and insulin resistance has not been known in Japanese populations. This study examined the relationship between waist circumference and insulin resistance and evaluated the optimal cutoff point for waist circumference in relation to insulin resistance in middle-aged Japanese men.

Methods

Study subjects included 4800 Japanese men aged 39 to 60 years. Insulin resistance was evaluated by the homeostasis model assessment of insulin resistance (HOMA-IR). The relationship of waist circumference with HOMA-IR was assessed by use of adjusted means of HOMA-IR and odds ratios of elevated HOMA-IR defined as the highest quintile (≥2.00). Receiver operating characteristics (ROC) curve analysis using Youden index and the area under curve (AUC) was employed to determine optimal cutoffs of waist circumference in relation to HOMA-IR.

Results

Adjusted geometric means of HOMA-IR and prevalence odds of elevated HOMA-IR were progressively higher with increasing levels of waist circumference. In the ROC curve analysis, the highest value of Youden index was obtained for a cutoff point of 85 cm in waist circumference across different values of HOMA-IR. Multiple logistic regression analysis also indicated that the AUC was consistently the largest for a waist circumference of 85 cm.

Conclusion

Waist circumference is linearly related to insulin resistance, and 85 cm in waist circumference is an optimal cutoff in predicting insulin resistance in middle-aged Japanese men.     

Waist Circumference as a Screening Tool for Cardiovascular Risk Factors: Evaluation of Receiver Operating Characteristics (ROC)

To evaluate the receiver operating characteristics (ROC) to determine the cutoffs of waist circumference as a potential population directed screening tool for hypercholesterolaemia (≥6.5 mmol/L), low high density lipoprotein cholesterol (<0.9 mmol/L), and hypertension (treated and/or systolic ≥160 and/or diastolic blood pressure ≥95 mmHg), in 2183 men and 2698 women aged 20 to 59 years selected at random from Dutch civil registries. Main outcome measures: Height, weight, body mass index (BMI), waist circumference, total plasma cholesterol and high density lipoprotein cholesterol concentrations, and blood pressure. Results: ROC curves showed that sensitivity equalled specificity at waist circumferences between 93–95 cm in men and 81–84 cm in women for identifying individual risk factors, and 92 cm in men and 81 cm in women for identifying those with at least one risk factor. Sensitivity and specificity were equal at levels between 61% to 69% for identifying individual risk factors, with positive predictions (56.8% in men and 37.8% in women) within 2% of those using previously defined ‘Action Level 1’ of waist circumference 94 cm in men and 80 cm in women (58.8% in men and 37.4% in women). Risk prediction by anthropometric methods was relatively low: ROC areas for identifying each risk factor by waist varied from 55% to 60%, and reached about 65% for identifying at least one risk factor. Height accounted for less than 03% of variance in waist circumference. Using BMI at 25 kg/m² gave similar prediction to waist, but its combination with waist did not improve predictive values. Conclusions: Measurement of waist circumference ‘Action Level 1’ at 94 cm (37 inches) in men and 80 cm (32 inches) in women could be adopted as a simpler valid alternative to BMI for health promotion, to alert those at risk of cardiovascular disease, and as a guide to risk avoidance by self-weight management     

Relationship of body size and shape to the development of diabetes in the diabetes prevention program

Objective: We report the effects of several different measures of body size at baseline on the subsequent development of diabetes. High levels of body fat predict the onset of diabetes, but this association has not been previously reported in a large multiethnic population of overweight or obese people with impaired glucose tolerance. Research Methods and Procedures: Height, weight, waist circumference, hip circumference, and skinfolds were measured at baseline in 3234 participants enrolled in a randomized clinical trial to treat individuals with impaired glucose tolerance with placebo, metformin, or a lifestyle modification program. Cox proportional hazards models were used to assess the effect of baseline body size variables on the development of diabetes. Results: Over an average of 3.2 years in both the placebo and lifestyle groups, baseline waist circumference had the highest or second highest R² value for predicting diabetes in both sexes. Cox hazard ratios per 1 standard deviation were 1.43 and 1.49 for men in the placebo or lifestyle groups, respectively, and 1.29 and 1.53 for women in the placebo and lifestyle groups, respectively, adjusted for age and self‐reported race/ethnicity. The c‐statistic from the receiver operating characteristic curves also favored the waist circumference in men and women in the lifestyle group and men in the placebo group. No components of body size were predictive in the metformin‐treated group, and metformin compared with the placebo group was effective in preventing diabetes only in individuals with a BMI ≥35 kg/m² or a waist circumference ≥98.0 cm. Discussion: Large waist circumference was a better predictor of risk for developing diabetes than most other measures in the placebo and lifestyle groups. No baseline measure of body size or shape predicted risk of diabetes in the metformin‐treated group.     

BMI Compared With Central Obesity Indicators as a Predictor of Diabetes Incidence in Mauritius

The aim of the study was to compare BMI with waist circumference (WC), waist‐to‐hip ratio (WHR), and waist‐to‐stature ratio (WSR) as a predictor of diabetes incidence. A total of 1,841 men and 2,104 women of Mauritian Indian and Mauritian Creole ethnicity, aged 25–74 years, free of diabetes, hypertension, cardiovascular disease, and gout were seen at baseline in 1987 or 1992, and follow‐up in 1992 and/or 1998. At all time points, participants underwent a 2 h 75 g oral glucose tolerance test. Hazard ratios for diabetes incidence were estimated applying an interval‐censored survival analysis using age as timescale. Six hundred and twenty‐eight individuals developed diabetes during the follow‐up period. Multivariable adjusted hazard ratios for diabetes incidence corresponding to a 1 s.d. increase in baseline BMI, WC, WHR, and WSR for Mauritian Indians were 1.49 (1.31–1.71), 1.58 (1.38–1.81), 1.54 (1.37–1.72), and 1.61 (1.41–1.84) in men and 1.33 (1.17–1.51), 1.35 (1.19–1.53), 1.39 (1.24–1.55), and 1.38 (1.21–1.57) in women, respectively; and for Mauritian Creoles they were 1.86 (1.51–2.30), 2.07 (1.68–2.56), 1.92 (1.62–2.26), and 2.17 (1.76–2.69) in men and 1.29 (1.06–1.55), 1.27 (1.04–1.55), 1.24 (1.04–1.48), and 1.27 (1.04–1.55) in women. Paired homogeneity tests showed that there was no difference between BMI and each of the central obesity indicators (all P > 0.05). The relation of BMI with the development of diabetes was as strong as that for indicators of central obesity in this study population.