Optimal Waist Circumference Research Articles

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.

Centralna gojaznost kod normalno uhranjenih odraslih pacijenata u primarnoj zdravstvenoj zaštiti

Introduction: There are people with optimal body weight and exceeding waist circumference and they`ve got a 20% higher risk of developing the disease as compared to people with optimal weight and waist circumference. Objective: Examine the nutritional status and the prevalence of central obesity in optimally fed adult patients of Primary Health Center (PHC) Novi Sad and find out whether there were differences when age and sex were taken into account. Method: Retrospective analysis of the anthropometric data recorded in the electronic health records (EHR) of 39.751 adult patients. Results: We analyzed the data of 23.264 women and 16.487 men. The average age of the participants was 53.8 years (SD 15.419). The average body mass index (BMI) was 26,5 kg/m2 (SD 4,73), and waist circumference 90,1 cm (SD 14,25001). There were 28.8% of the male patients and 46.1% of the female patients with optimal body weight. There was a significant statistical difference in the nutritional status levels with respect to sex and age (p<0.005). Central obesity was found in 21.1% of optimally fed males and 37.0% of females. In the group of optimally fed patients with central obesity, 79.7% were females and 21.3% males. In this group of patients, central obesity was the most frequent in the 60-69 age group. There is a statistically significant difference in relation to gender and age group (p<0.005). Conclusion: We found a third of patients with normal body weight had central obesity. In order to calculate the risk for chronic non-communicable diseases, besides BMI, we should also take into account a routine measurement of the waist circumference.

The discriminatory power of visceral adipose tissue area vs anthropometric measures as a diagnostic marker for metabolic syndrome in South African women

BackgroundA number of studies have shown central adiposity, in particular visceral adipose tissue (VAT) accumulation to be a hallmark of metabolic syndrome (MetS). In clinical practice, waist circumference (WC) is used as a proxy for VAT.AimTo compare the ability of dual energy x-ray absorptiometry (DXA)-derived VAT area and anthropometric measures of adiposity for diagnosing MetS in a sample of high risk South African women.MethodsMetS was quantified using the Joint Interim Statement (JIS) criteria. Fasting glucose, insulin and lipid profile were measured in 204 post-menopausal women. Anthropometry measures included body mass index (BMI), WC, waist-to-hip ratio (WHR), waist-to-height ratio (WHtR) and a body shape index (ABSI). The area under the curve (AUC) was used to assess their performance in detecting any two components of MetS (excluding WC). Optimal WC and VAT area cut-points were derived to compare their performance for diagnosing MetS and to compare to internationally recognised cut-points.ResultsThe highest AUC for the prediction of MetS was recorded for VAT, followed by WHtR and WC (AUC, 0.767, 0.747 and 0.738 respectively), but these did not differ significantly (all p ≥ 0.192). In contrast, VAT was significantly better than BMI (p = 0.028), hip (p = 0.0004) and ABSI (p < 0.0001). The optimal WC (94.4 cm) and VAT area (174 cm2 based on the Youden’s index method and 175.50 cm2 based on the CTL approach) cut-points performed similarly in detecting MetS.ConclusionDXA-derived VAT and WC had the same overall performance in discriminating the presence of any 2 MetS components in high risk South African women. These findings support the current recommendations of using WC rather than VAT for MetS risk screening, as it is cheap, accessible and easy to measure.

A study of the correlation of waist circumference with metabolic risks among non-obese populations.

To investigate the correlation of waist circumference with metabolic risks among non-obese populations. A retrospective analysis was conducted for the clinical information of 13,145 non-obese subjects who received physical examinations in the hospital from January 2015 to January 2018. Among them, 1,971 subjects were definitely diagnosed with diabetes mellitus, hypertension, and metabolic syndrome and set as the metabolic disorder group, with the remaining 11,174 cases as the control group. All metabolism-related indicators were compared between the patients in the two groups, the analysis was performed for the prevalence of diabetes, hypertension, and metabolic syndrome in patients with different waist circumference as well as males and females with different waist circumferences. Finally, the optimal cut-off points of waist circumference were determined. According to the comparison, there were no statistically significant differences in subjects with low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and total cholesterol between the metabolic disorder group and the control group (p>0.05). The subjects in the metabolic disorder group had higher waist circumference, waist-to-hip ratio, triglyceride, fasting insulin, fasting blood glucose, and insulin resistance index than those in the control group, displaying statistically significant differences (p<0.05). When waist circumference was more than 70 cm, as it increased, the prevalence rates of diabetes, hypertension, and metabolic syndrome gradually elevated. When waist circumference was 60-90 cm, hypertension took the leading place in metabolic disorders, so did the metabolic syndrome and diabetes, with a waist circumference of more than 90 cm. There were no remarkable differences in the prevalence rates of diabetes, hypertension, and metabolic syndrome among male and female patients with different waist circumferences ((p>0.05). The patients with the waist circumference of over 90 cm exhibited gradually declined prevalence rates of diabetes, hypertension, and metabolic syndrome, while those in the patients with a waist circumference of 60-90 cm were gradually increased. The optimal cut-off points of waist circumference were calculated according to the prevalence rates of diabetes, hypertension, and metabolic syndrome among patients, and the calculation results were 78 cm, 79 cm, and 77 cm for male patients and 73 cm, 78 cm, and 73 cm for female patients. Based on the weight combined with the optimal cut-off points of waist circumference, the optimal waist circumference cut-off points for males and females were 78 cm and 74 cm, respectively. There is a correlation between the waist circumference and metabolic risks among non-obese populations, but the screening for metabolic diseases should be conducted among males with a waist circumference of over 78 cm and females with a waist circumference of over 74 cm. The treatment measures are supposed to be taken promptly to improve the prognosis.

Optimal waist circumference cutoff values for predicting metabolic syndrome among older adults in Ecuador

AimsTo determine optimal waist circumference cutoff values for predicting metabolic syndrome (MetS) among adults aged 60 years and older in Ecuador. Material and methodsThe National Survey of Health, Wellbeing, and Aging survey was used to describe the prevalence of MetS according to standard definitions. Receiver operating characteristics (ROC) curve analyses and the Younden index J (YI) were performed to examine optimal waist circumference cutoff values for predicting MetS. Moreover, the prevalence of MetS according to country-specific waist circumference cutoff values was compared with those using standard definitions. ResultsAmong 2306 participants with a mean age of 70.6 years, the optimal waist circumference cutoff value for predicting MetS was 90.7 cm in women with a sensitivity of 66.1%, specificity of 65.6% and YI of 0.31. In men, a waist circumference of 91.2 cm with a sensitivity of 73.2%, specificity of 62.8%, and YI of 0.36 was the optimal cutoff point for predicting MetS. In general, applying country-specific cutoff values decreased the prevalence of MetS among older Ecuadorian women. In men, except with the ATP III definition, similar MetS prevalence rates were seen whether the country-specific or standard waist circumference cutoff values were applied. ConclusionsThe optimal waist circumference cutoff values for predicting metabolic syndrome among older Ecuadorians adults were 90.7 cm for women and 91.2 cm for men. Moreover, current standard definitions of abdominal obesity may overestimate the prevalence of MetS, particularly in Latin American women.

Waist circumference cutoff points for predicting metabolic abnormalities in Lebanese adults

IntroductionCentral obesity, as measured by waist circumference, performs differently across diverse localities, and there is a need to optimize gender-based cutoff points to specific ethnic and population groups.Material and methodsA total of 1,528 asymptomatic individuals free from cardiac disease aged 40 years and above and attending 25 primary health care centers distributed over the entire Lebanese territory were recruited for a cardiovascular risk screening service implemented by the Ministry of Public Health in 2012. Using receiver operating characteristics curve analyses, we evaluated different waist circumference cutoff points for the optimal combination of sensitivity and specificity that distinguish men and women with concomitant presence of impaired blood sugar and hypertension.ResultsThe optimal waist circumference cutoffs for prediction of the outcome were 98.5 cm in men and 91.5 cm in women, yielding better predictive characteristics than those recommended by the International Diabetes Federation (IDF). Based on the study values, the prevalence rates of central obesity in our sample (36.2% in males and 40.2% in females) were lower than those estimated using the IDF cutoff values (55.2% and 79.7%, respectively).ConclusionsFindings from this first examination of optimal central obesity cutoff points in Lebanon confirm the need for nation-wide studies with more inclusive cardio-metabolic outcomes for the development of appropriate screening protocols.

The Risk of Myocardial Infarction and Ischemic Stroke According to Waist Circumference in 21,749,261 Korean Adults: A Nationwide Population-Based Study.

BackgroundWaist circumference (WC) is a well-known obesity index that predicts cardiovascular disease (CVD). We studied the relationship between baseline WC and development of incident myocardial infarction (MI) and ischemic stroke (IS) using a nationwide population-based cohort, and evaluated if its predictability is better than body mass index (BMI).MethodsOur study included 21,749,261 Koreans over 20 years of age who underwent the Korean National Health Screening between 2009 and 2012. The occurrence of MI or IS was investigated until the end of 2015 using National Health Insurance Service data.ResultsA total of 127,289 and 181,637 subjects were newly diagnosed with MI and IS. The incidence rate and hazard ratio of MI and IS increased linearly as the WC level increased, regardless of adjustment for BMI. When the analyses were performed according to 11 groups of WC, the lowest risk of MI was found in subjects with WC of 70 to 74.9 and 65 to 69.9 cm in male and female, and the lowest risk of IS in subjects with WC of 65 to 69.9 and 60 to 64.9 cm in male and female, respectively. WC showed a better ability to predict CVD than BMI with smaller Akaike information criterion. The optimal WC cutoffs were 84/78 cm for male/female for predicting MI, and 85/78 cm for male/female for predicting IS.ConclusionWC had a significant linear relationship with the risk of MI and IS and the risk began to increase from a WC that was lower than expected.

The Potential Role of Dietary Antioxidant Capacity in Preventing Age-Related Macular Degeneration

Objectives: Age-related macular degeneration (AMD) is a progressive disorder among people aged ≥50 years. Some dietary factors associated with the susceptibility to AMD include dietary glycemic index and glycemic load, as well as intake of antioxidants and other nutrients, such as vitamins, minerals, and dietary fatty acids.Methods: This case-control study was conducted between July 2015 and February 2016 on 100 case subjects with AMD and 100 healthy controls without AMD. The participants were recruited from the Department of Ophthalmology of Hacettepe University Hospitals in Ankara, Turkey. Dietary intake was estimated from a 3-day food intake record and food frequency questionnaire, and anthropometric measurements were recorded. The relationship between nutritional factors and AMD was assessed using logistic regression.Results: Dietary total antioxidant intake of AMD group was found to be lower (p < 0.05) than that of healthy individuals. In a multivariate analysis, smoking, daily red meat intake, omega-6 intake, and higher glycemic index were identified as risk factors for AMD development. Meanwhile, daily fruit intake, daily fish intake, omega-3 intake, and zinc intake were associated with a protective effect. However, no difference was found in dietary total antioxidant capacity.Conclusions: In this study, a high dietary intake of carotenoids, vitamins C and E, zinc, and omega-3, as well as maintaining optimal waist circumference, were found to substantially reduce the risk of developing AMD in people aged >50 years. By contrast, in addition to smoking and old age, obesity, high red meat intake, and omega-6 intake might increase the risk of developing AMD. Therefore, a better understanding of nutritional risk factors is necessary for preventing AMD.

Optimal cut-off for obesity and markers of metabolic syndrome for Ethiopian adults

BackgroundMetabolic syndrome (MetS) is defined as the presence of central obesity plus any two of the following markers: high triglycerides (> 150 mg/dl), low high density lipoprotein (HDL) cholesterol < 40 mg/dl in men and < 50 mg/dl in women, hypertension (blood pressure > 130/85 mmHg or use of antihypertensive medication), high fasting blood glucose (> 100 mg/dl or use of treatment for diabetes mellitus). Since recently, metabolic syndrome and obesity have become emerging problems of both low and middle income countries, although they have been the leading cause of morbidity and mortality in high income countries for the past decades. It has been indicated that the international anthropometric cut-off for detecting obesity is not appropriate for Ethiopians. This study developed optimal cut off values for anthropometric indicators of obesity and markers of metabolic syndrome for Ethiopian adults to enhance preventive interventions.MethodsA total of 704 employees of Jimma University were randomly selected using their payroll as a sampling frame. Data on socio-demographic, anthropometry, clinical and blood samples were collected from February to April 2015. Receiver Operating Characteristic Curve analyses were used to determine optimal anthropometric cut-off values for obesity and markers of the metabolic syndrome. WHO indicators of obesity based on body fat percent (> 25% for males and > 35% for females) were used as binary classifiers for developing anthropometric cut-offs. Optimal cut-off values were presented using sensitivity, specificity and area under the curve.ResultsThe optimal cut-off for obesity using body mass index was 22.2 k/m2 for males and 24.5 kg/m2 for females. Similarly, the optimal waist circumference cut-off for obesity was 83.7 cm for males and 78.0 cm for females. The cut-off values for detecting obesity using waist to hip ratio and waist to height ratio were: WHR (0.88) and WHtR (0.49) for males, while they were 0.82 and 0.50 for females, respectively. Anthropometric cut-off values for markers of metabolic syndrome were lower compared to the international values. For females, the optimal BMI cut-offs for metabolic syndrome markers ranged from 24.8 kg/m2 (triglycerides) to 26.8 kg/m2 (fasting blood sugar). For WC the optimal cut-off ranged from of 82.1 cm (triglyceride) to 96.0 cm(HDL); while for WHtR the optimal values varied from 0.47(HDL) to 0.56(fasting blood sugar). Likewise, the optimal cut-offs of WHR for markers of metabolic syndrome ranged from 0.78(fasting blood sugar) to 0.89(HDL and blood pressure). For males, the optimal BMI cut-offs for metabolic syndrome markers ranged from 21.0 kg/m2 (HDL) to 23.5 kg/m2 (blood pressure). For WC, the optimal cut-off ranged from 85.3 cm (triglyceride) to 96.0 cm(fasting blood sugar); while for WHtR the optimal values varied from 0.47(BP, FBS and HDL) to 0.53(Triglyceride). Similarly, the optimal cut-offs of WHR form markers of metabolic syndrome ranged from 0.86(blood pressure) to 0.95(fasting blood sugar).ConclusionThe optimal anthropometric cut-offs for obesity and markers of metabolic syndrome in Ethiopian adults are lower than the international values. The findings imply that the international cut-off for WC, WHtR, WHR and BMI underestimate obesity and metabolic syndrome markers among Ethiopian adults, which should be considered in developing intervention strategies. It is recommended to use the new cut-offs for public health interventions to curb the increasing magnitude of obesity and associated metabolic syndrome and diet related non-communicable diseases in Ethiopia.

Do current guidelines for waist circumference apply to black Africans? Prediction of insulin resistance by waist circumference among Africans living in America

BackgroundTo lower the risk of diabetes and heart disease in Africa, identification of African-centred thresholds for inexpensive biomarkers of insulin resistance (IR) is essential. The waist circumference (WC) thresholds that...

Is waist circumference more strongly associated with metabolic risk factors than waist-to-height ratio in Asians?

Differential distribution of fats can vary among ethnic groups and thus have varying effects on metabolic risk. Measuring metabolic risk of individuals using simple anthropometric measurements is essential to replace current invasive methods of obtaining blood samples. Waist-to-height ratio (WHtR) has been advocated as the best simple anthropometric measurement, but, because of the high visceral fat of Asians, there has been speculation as to the possibility of using only waist circumference (WC) to measure metabolic risk. The aim of this study was to compare the performance of WC and WHtR in terms of their association with measures of obesity and metabolic risk factors (e.g., homeostasis model assessment for insulin resistance, low-density lipoprotein, triacylglycerol, and ratio of triacylglycerol to high-density lipoprotein) and to obtain an optimal cutoff value for one anthropometric measurement. The study was performed on healthy Asian Chinese (N = 527) men (n = 209) and women (n = 318) who participated in a cross-sectional study conducted at the Clinical Nutrition Research Centre located in Singapore. Association of WC and WHtR with metabolic risk factors was obtained using Spearman's rank correlation coefficient. Optimal cutoff value was obtained using receiver operating characteristic curve. WC and WHtR performed equally well in both sexes in terms of their strength of association between metabolic risk factors. Receiver operating characteristic curve analysis showed that 73.5 cm (in women) and 82.5 cm (in men) were the optimal WC cutoff values to identify insulin resistance. It is suggested that WC is a simpler anthropometric measurement that has strong association with an individual's metabolic risk level.

Differential relationship between waist circumference and mortality according to age, sex, and body mass index in Koreans with age of 30\u201390 years; a nationwide health insurance database study

BackgroundA recent concept is that obesity, assessed by body mass index (BMI), is not always a sign of poor health. Thus, in order to use obesity metrics in clinical decision making, it is important to clarify the relationship between waist circumference (WC), a proxy for abdominal obesity, and mortality.MethodsData were used from 8,796,759 subjects aged between 30 and 90 years, who had participated in the Korea National Health Screening Examination between January 1, 2009 and December 31, 2009 and survived at least 1 year post screening. Data from a mean follow-up time of an additional 5.3 years (time at risk) were analyzed for the relationship between WC and mortality according to age, sex, and BMI category.ResultsAn increased WC of more than 90 cm in men and 85 cm in women showed a definite negative influence on mortality. However, the detailed relationship between WC and mortality was J-shaped or U-shaped according to age, sex, and BMI category. In the normal BMI group, the optimal WC range with the lowest mortality was < 70 cm in men and 70–75 cm in women, whereas in obese individuals a WC between 80 and 90 cm in men and 75 and 85 cm in women showed the lowest mortality. The association between increased WC and higher mortality tended to be more obvious in normal-weight women than in normal-weight men or obese women. Furthermore, in normal-weight and obese women, the effect of increased WC on mortality was more critical for subjects aged < 60 years rather than those aged ≥ 60 years.ConclusionsAbdominal obesity, as measured by WC, showed a significant negative association on mortality, and its association with mortality was different according to age, sex, and BMI category. Therefore, WC should be considered in the assessment of obesity-related health risks, and individualized cut-off points for the definition of a healthy WC according to age, sex, and BMI category are necessary.

Optimum cutoff values of anthropometric indices of obesity for predicting hypertension: more than one decades of follow-up in an Iranian population.

We determined cutoff points of body mass index (BMI), waist circumference (WC), waist-to-hip ratio (WHR), and waist-to-height ratio (WHtR), for predicting hypertension in an Iranian population. Study sample included 6359 (3678 female) participants aged ≥20 and <60 years of a prospective cohort. The sex stratified multivariate hazard ratios (HRs) for all indices were estimated using Cox regression in two age groups (20-39 and 40-59 years). Receiver operating characteristic (ROC) was used to evaluate the predictive ability and determine the optimal cut-off values of the indices. In both genders and two age groups, the confounders adjusted HRs were significant for general and central obesity measures indices. AUCs of the indices were similar in men; however, among women 40-59 years, WC and WHtR had significantly higher AUC compared to BMI. Generally, the optimal cut-off values were higher in the 40-59 year age group. Optimal BMI, WC and WHR and WHtR cut-off values were 24.15 kg/m2, 90.5 cm, 0.90 and 0.49 among men, aged 20-39 years; the corresponding values were 28.41 kg/m2, 86.5 cm, 0.96 and 0.50 in men aged 40-59 years, respectively. In women, the aforementioned values were 26.38 kg/m2, 83.5 cm, 0.79 and 0.51 in the age group of 20-39 years, and 29.57 kg/m2, 90.5 cm, 0.88 and 0.59 in the 40-59 year age group, respectively. Our results suggest that gender and age differences in the association between anthropometric indices and hypertension should be considered.

Should Waist Circumference Cutoffs in the Context of Cardiometabolic Risk Factor Assessment be Specific to Sex, Age, and BMI?

A sex-specific standard waist circumference (WC) is widely used to determine cardiometabolic risk across ages even though aging impacts the link between fat distribution and cardiometabolic risk. The objective was to propose WC thresholds that better predict metabolic abnormalities according to sex, age, and body mass index (BMI) categories. First, receiver operating characteristic analyses were performed to identify optimal age (20-49, 50-64, and 65-80 years) and BMI (normal weight, overweight, obese I, and obese II+) specific WC thresholds to correctly identify at-risk individuals, that is, presenting ≥2 cardiometabolic risk factors of metabolic syndrome (n = 23,482; NHANES 2007-2014). Second, cross-validation analyses (n = 18,686; NHANES 1999-2006) were used to validate these WC optimal thresholds. Univariate logistic regression models with WC as an independent predictor were performed to quantify odds of being at-risk for each age and BMI subgroups. When age and BMI categories were considered in the identification of optimal WC thresholds, sensitivity to correctly identify at-risk individuals significantly improved. Our results indicate that the use of WC thresholds that are specific to age and BMI subcategories significantly increases the capacity to accurately identify at-risk individuals. They would thus be highly appropriate for clinicians in the context of efficient cardiometabolic risk assessment and intervention recommendations.

Cut-Off Values for Visceral Fat Area Identifying Korean Adults at Risk for Metabolic Syndrome.

BackgroundCut-off values for visceral fat area (VFA) measured by computed tomography (CT) for identifying individuals at risk of metabolic syndrome (MetS) have not been clearly established in Korean adults, particularly for large populations. We aimed to identify optimal VFA and waist circumference (WC) cut-off values and compare the ability of VFA and WC to predict the presence of ≥2 metabolic risk factors.MethodsWe included 36,783 subjects aged 19–79 years undergoing abdominal fat CT during regular health checkups between January 2007 and February 2015 in Seoul. The risk factors for MetS except WC were based on the International Diabetes Federation criteria. Receiver operating characteristic curve analyses were used to determine the appropriate VFA and WC cut-off values for MetS.ResultsVFA was a more significant predictor of metabolic risk factors than WC and body mass index (BMI). The optimal cut-off values for VFA and WC were 134.6 cm2 and 88 cm for men and 91.1 cm2 and 81 cm for women, respectively. We estimated age-specific cut-off values for VFA, WC, and BMI. VFA cut-off values increased with age, particularly among women.ConclusionThis large population study proposed the cut-off values for VFA and WC for identifying subjects at risk of MetS among Korean adults. For more accurate diagnosis, different age-specific cut-off values for VFA and WC may be considered.

The Waist Circumference That Predicts Insulin Resistance in Africans Is Higher in Women than Men—A Population-Specific Study

Waist circumference (WC) is an inexpensive marker of both insulin resistance (IR) and visceral adipose tissue (VAT). As Africa is experiencing a rapid rise in diseases related to IR such as diabetes and heart disease, identifying the WC of risk in Africans would have great clinical utility. Yet the WC which predicts IR in Africans is unknown. Further WC varies by race and gender and cannot distinguish between VAT and subcutaneous adipose tissue (SAT). Nonetheless the International Diabetes Federation states until more data is available, WC thresholds determined in whites (men 94 cm; women 80 cm) should be applied to Africans. However, data from South Africa suggests that the WC threshold which best predicts IR in black women is between 90 and 100 cm and higher in women than men. Whether this is true in Africans from other regions is unknown. Our goals were to determine in Africans (a) the WC which best predicts IR and (b) whether sex differences in VAT and SAT distribution contribute to sex differences in the WC of risk. Therefore, 360 blacks born in Africa (West 52%, Central 23%, East 25%) and living in the United States (men 68%, age 38±10y (mean±SD)) had CT scans to measure VAT and SAT. OGTT were performed to determine glucose tolerance status. IR was defined by the lowest quartile of the Matsuda Index. AUC-ROC and Youden Index were used to determine the WC which best predicted IR. Compared to women, men had lower BMI (27.2±3.9 vs. 28.6±5.4, P&amp;lt;0.001), higher VAT and lower SAT (both P&amp;lt;0.001). The optimal WC for the prediction of IR in men and women were 91 cm and 96 cm, respectively. Regression analyses with VAT and sex as independent variables and either SAT or WC as dependent variables revealed an interaction (P&amp;lt;0.001) between sex and VAT. So at the same VAT, both SAT and WC were higher in women than men. Overall, in Africans the WC which optimally predicts IR is 91 cm in men and 96 cm in women. Higher SAT at the same level of VAT explains why the WC which predicts IR is higher in African women than men. Disclosure J. Kabakambira: None. S.M. Briker: None. R.L. Baker: None. A.B. Courville: None. L. Mabundo: None. C. DuBose: None. S.T. Chung: None. M. Rahman: None. A.E. Sumner: None.

Associations of Body Mass Index and Waist Circumference with 3-Year All-Cause Mortality Among the Oldest Old: Evidence from a Chinese Community-Based Prospective Cohort Study

ObjectiveCurrent international and national guidelines for body mass index (BMI) and waist circumference (WC) have been recommended to all adults. However, whether recommendations applied to the oldest old (aged 80+) is poorly known. The study objective was to investigate the relation of BMI and WC with 3-year all-cause mortality among the oldest old. Design, Setting, and ParticipantsA total of 4361 Chinese oldest old (mean age 91.8) participated in this community-based prospective cohort study. MeasurementsBMI and WC were measured at baseline in 2011 and were used as continuous variables and as categorized variables by recommendations or by tertiles. Adjusted, sex-stratified Cox models with penalized splines and Cox models were constructed to explore the association. ResultsGreater BMI and WC were linearly associated with lower mortality risk in both genders. The mortality risk was the lowest in overweight or obese participants (BMI ≥ 24.0) and was lower in participants with abdominal obesity. Compared to the upper tertile, those in the middle and lower tertile of BMI had a higher risk of mortality for men [hazard ratio (HR): 1.23 (1.02-1.48) and 1.53 (1.28-1.82)] and for women [HR: 1.21 (1.03-1.41) and 1.35 (1.15-1.58)]; it was also found in participants in the middle and lower tertile of WC for men [HR: 1.21 (1.01-1.46) and 1.41 (1.18-1.69)] and for women [HR: 1.35 (1.15-1.58) and 1.55 (1.32-1.81)] (all the P values for trend <.001). These findings were robust in further sensitivity analyses or when using propensity score matching, in subgroup analyses, or in octogenarians, nonagenarians, and centenarians. ConclusionsIn Chinese oldest old, both higher BMI and higher WC predict better survival in both genders. The finding suggests optimal BMI and WC may be sensitive to age, thus, the current recommendations for the oldest old may need to be revisited.

Cohort study to determine the waist circumference cutoffs for predicting type 2 diabetes mellitus in rural China.

Limited information is available on the cutoffs of waist circumference (WC) for predicting type 2 diabetes mellitus (T2DM). We aimed to define the optimal WC cutoffs for predicting T2DM among rural Chinese people. A cohort of 11968 participants (732 new-onset T2DM) from a rural area in China with age 18 to 87years was established at baseline during July to August of 2007 and 2008 and followed up during July to August of 2013 and 2014. Scatterplot, X-tile plot, and receiver operating characteristic (ROC) curve analyses were used to determine WC cutoffs for predicting T2DM. The WC cutoffs for males and females were 84 and 86cm (scatterplot), 83 and 88cm (X-tile plot), and 87 and 88cm (ROC curve). According to the highest risk score, the optimal WC cutoffs were 87cm for males and 88cm for females. With the optimal WC cutoffs, the sensitivity, specificity, positive likelihood ratio, area under the ROC curve, and population-attributable risk proportions were 67.9%, 67.0%, 2.06%, 0.70%, and 46%, respectively, for males and 52.5%, 75.0%, 2.10%, 0.69%, and 34%, respectively, for females; the corresponding adjusted hazard ratio for WC predicting T2DM was 3.66 (95% confidence interval 2.80-4.78) for males and 2.55 (2.08-3.12) for females. The optimal WC cutoffs for predicting T2DM were similar between males and females. As well, the criteria of WC for central obesity are no longer practical for predicting T2DM.

Study on the prevalence rate and optimal waist circumference cut-off points of obesity for the components of metabolic syndrome in Uygur from Xinjiang

Objective To investigate the prevalence of metabolic syndrome and appropriate cut-off point of waist circumference of abdominal obesity for components of metabolic syndrome in Uygur population in Xinjiang. Methods A questionnaire-based survey, physical examination, and blood testing were conducted according to cluster random sampling in Uygur residents above 18 years old in Xinjiang. There were 3 542 samples collected, based on the International Diabetes Federation (IDF) standard of metabolic syndrome, the relativities of clustering of metabolic syndrome components and different strata of waist circumference for Uygur were analyzed, and looking for the appropriate cut-off points for identifying two or more components of metabolic syndrome within the shortest distance of receiver operating characteristic (ROC) curve. Results According to IDF standard, the waist circumference (85 cm for men, 82 cm for women) corresponded to the shortest distance in ROC curve, at these cut-offs of abdominal obesity for component of metabolic syndrome, the prevalences of metabolic syndrome were 21.3%, 19.5% in men, while 23.0% in women, the prevalence of women was higher than that of men (P<0.05). The prevalences of ≥1, ≥2 components of metabolic syndrome were shown an increasing trend with the increasing size of waist circumference, and the odds ratio of clustering of metabolic syndrome components were also increased significantly. Conclusion The prevalence of metabolic syndrome among Xinjiang Uygur population was higher than that of national level. The cut-off points of waist circumference (85 cm for men, 82 cm for women) combining other components definition of IDF standard were recommended for identifying metabolic syndrome of Uygurs. (Chin J Endocrinol Metab, 2018, 34: 211-216) Key words: Metabolic syndrome; Uygur; Component of obesity; Cut-off points of waist circumference; Prevalence rate

Abstract P141: Detection of Abnormal Glucose Tolerance in Africans: International Diabetes Federation Waist Circumference Thresholds Perform Better in Africans Than the Higher Thresholds Used in America

Introduction: In the 21 st century, Africans are experiencing an epidemic of diabetes and heart disease. Key to addressing this public health challenge is the identification of thresholds for risk factors for diabetes and heart disease which are valid in Africans. For example, central obesity indicates both insulin resistance (IR), a risk factor for heart disease, and abnormal glucose tolerance (abnl-GT), a term which encompasses both prediabetes and diabetes. There are two major standards for diagnosing central obesity by waist circumference (WC): the European standard of the International Diabetes Federation (IDF) (men: 94 cm, women: 80 cm) and the American standard of the AHA/NHLBI (men: 102 cm, women: 88 cm). It is unknown if either the IDF or higher AHA/NHLBI thresholds are appropriate for Africans. Objectives: Our goals were to determine in Africans the WC that best predicts IR and abnl-GT and then compare these thresholds to the standards put forward by the IDF and AHA/NHLBI. Methods: We measured WC and determined glucose tolerance status by the OGTT in 348 subSaharan Africans (male 69%, age 39±10y (mean±SD) range 20 to 64y, BMI 27.6±0.2, (range 18.2 to 42.4) who were living in America, born in Africa (West: 51%, Central: 23%, East: 26%) and self-identified as healthy. The area under the receiver operating characteristic curve (AUC-ROC) and the Youden Index were used to determine the WC which best predicts IR and abnl-GT. IR was defined by the lowest tertile of the Matsuda Index. Visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) were measured by computerized tomographic scan. Prior to analyses, the participants were divided into 4 groups: (1) normal glucose tolerant (NGT), (2) NGT and IR, (3) abnl-GT and IR, (4) abnl-GT and no IR. Results: The prevalence of these 4 groups did not differ by sex and their overall frequency were: 47% with NGT; 13% with NGT and IR ;19% with abnl-GT and IR; and 21% with abnl-GT and no IR. BMI was higher in women than men (28.5±5.4 vs. 27.2±3.9, P=0.01). After adjusting for BMI, women had lower WC and VAT and higher SAT than men (all P &lt; 0.001). According to the Youden Index, the optimal WC in men which predicted IR and abnl-GT were: 91 cm (AUC-ROC±SE 0.78±0.03) and 92 cm (0.67±0.04), resp. In women, the optimal WC which predicted IR and abnl-GT were: 96 cm (0.75±0.05) and 82 cm (0.67±0.06), resp. Conclusions: Gender differences in body fat distribution may explain why in women, but not men, the WC which predicts IR was higher than the WC which predicts abnl-GT. However, and most importantly, the WC thresholds which optimally predict abnl-GT in African men and women were much more similar to the IDF(men: 94 cm, women: 80 cm) than the higher AHA/NHLBI (men: 102 cm, women: 88 cm) thresholds. Therefore, we recommend that WC thresholds from the IDF be used to screen African men and women for abnl-GT.