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 ≥ 30 kg/m²) 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/m² (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.     

The Canadian Obesity Epidemic: An Historical Perspective

Objective: To examine temporal trends in stature, body mass, body mass index (BMI), and the prevalence of overweight and obesity in Canada. Research Methods and Procedures: Data for adults 20 to 64 years of age were compared across eight Canadian surveys conducted between 1953 and 1998. Temporal trends in stature and body mass were examined using regression, and changes in weight‐for‐height were expressed as changes from 1953. BMI data were available from 1970 to 1972 to examine changes in overweight and obesity. Qualitative changes in the BMI distribution were examined using Tukey mean‐difference plots. Results: Significant temporal trends in stature and body mass have occurred since 1953 in Canada. Median stature increased 1.4 cm/decade in men and 1.1 cm/decade in women, whereas median body mass increased 1.9 kg/decade in men and 0.8 kg/decade in women. Increases in the 75th percentile of body mass were larger than the median. The average weight‐for‐height increased 5.1% in men and 4.9% in women from 1953. Furthermore, the prevalences of overweight and obesity have increased from 40.0% and 9.7% in 1970–1972 to 50.7% and 14.9% in 1998, respectively. The entire BMI distribution has shifted to the right since 1970–1972 and has become more skewed to the right for men than for women. Discussion: There have been significant increases in stature and body mass in Canada over the last 45 years. Body mass has increased more than stature, particularly in the upper percentiles, which has resulted in the currently observed high prevalences of overweight and obesity.     

Waist Circumference is an Independent Correlate of Errors in Self‐Reported BMI

Although there are issues of reporting bias surrounding the use of self‐reported BMI, it is frequently the method employed to establish the prevalence of obesity. The goal of this study was to assess whether, independently of measured BMI, waist circumference (WC) was associated with the magnitude of the difference between self‐reported and measured BMI within a large sample of European‐American (EA) and African‐American (AA) adults. Self‐reported height and weight, and measured height, weight, and WC were collected on 12,809 adults (61% women, 66% EA) aged 18–65 years. Mean negative BMI differences (self‐reported minus measured BMI) were identified in all race‐by‐sex groups (AA men: ?0.55; EA men: ?0.63; AA women: ?0.91; EA women: ?0.67). WC was negatively associated with the BMI difference such that a higher WC was associated with greater under‐reporting of BMI. However, after adjusting for age and measured BMI, WC was positively associated with the BMI difference in all race‐by‐sex groups. These results suggest that WC could be useful in gaining an insight into people's awareness of their own body size and fatness.     

Comparing Trends in BMI and Waist Circumference

The nature of excess body weight may be changing over time to one of greater central adiposity. The aim of this study is to determine whether BMI and waist circumference (WC) are increasing proportionately among population subgroups and the range of bodyweight, and to examine the public health implications of the findings. Our data are from two cross‐sectional surveys (the US National Health and Nutrition Examination Studies (NHANES) in 1988–1994 (NHANES III) and 2005–2006), from which we have used samples of 15,349 and 4,176 participants aged ≥20 years. Between 1988–1994 and 2005–2006 BMI increased by an average of 1.8 kg/m² and WC by 4.7 cm (adjusted for sex, age, race‐ethnicity, and education). The increase in WC was more than could be attributed simply to increases in BMI. This independent increase in WC (of on average, 0.9 cm) was consistent across the different BMI categories, sexes, education levels, and race‐ethnicity groups. It occurred in younger but not older age groups. Overall in each BMI category, the prevalence of low‐risk WC decreased and the prevalence of increased‐risk or substantially increased‐risk WC increased. These results suggest that the adverse health consequences associated with obesity may be increasingly underestimated by trends in BMI alone. Since WC is closely linked to adverse cardiovascular outcomes, it is important to know the prevailing trends in both of these parameters.     

Forecasting the obesity epidemic in the aging U.S. population

Objective: The objective was to forecast BMI distribution in the U.S. population along with demographic changes based on past race‐, sex‐, and birth cohort‐specific secular trends. Research Methods and Procedures: We compiled data from 44,184 subjects from 4 National Health and Nutrition Examination Surveys (NHANES; 1971 to 2004). By race and sex, we fit regression models to create smoothed mean BMI curves by age for 1970 to 2010. Linking corresponding birth cohorts across age‐ and year‐specific mean BMI projections, we estimated the trajectory of relative BMI throughout each cohort's lifetime. These projections were validated using actual cohorts in the Nurses’ Health Study and Health Professionals Follow‐up Study. Combined with U.S. census, we predicted BMI distributions in 2010 and examined the joint impact of the obesity epidemic and population aging. Results: BMI secular trends in the past 3 decades differ significantly by birth cohort, sex, and race. If these trends continue, the prevalence of obesity is expected to reach 35%, 36%, 33%, and 55% in 2010 among white men, white women, black men, and black women, respectively, far from the Healthy People 2010 goal of 15%. Such forecasts translate into 9.3 million more obese adults 20 to 74 years of age than in 2000, 8.3 million of whom would be 50 years of age or older, and 8.5 million of whom would be white. The mean age among obese men and women is also expected to rise from 47 to 49 years among whites and from 43 to 44 years among blacks. Discussion: As the baby boom generation approaches retirement age, the continuing obesity epidemic signals a likely expansion in the population with obesity‐related comorbidities. A framework to combine BMI and demographic trends is essential in evaluating the burden and disparity associated with the epidemic in the aging U.S. population.     

Variability in Waist Circumference Measurements According to Anatomic Measurement Site

The measurement of waist circumference (WC) is widely advocated as a simple anthropometric marker of health risk; yet there remains no uniformly accepted protocol. This study determined whether the magnitude of WC differs across four measurement sites, and quantified the influence of site on the apparent prevalence of abdominal obesity. The predominantly white sample consisted of 223 men and 319 women (20–67 years). WC was measured using a nonstretching tape at the superior border of the iliac crest, midpoint between the iliac crest and lowest rib, umbilicus, and the minimal waist. Differences in WC across sites were tested using repeated measures ANOVA, adjusted for multiple comparisons. Inter‐ and intraobserver reliabilities across sites were estimated using intraclass correlation. In women, the mean WC for all sites were significantly different from each other, with the exception of the iliac crest and midpoint. In contrast, no significant differences between sites were found in men. Measurement site had an influence on the apparent prevalence of abdominal obesity (>88/102 cm), ranging from 23 to 34% in men and 31 to 55% in women. The reproducibility of WC was high at all sites and was comparable across levels of BMI. In conclusion, the magnitude of WC is influenced by measurement site, particularly in women. Small differences are amplified when dichotomous cut points rather than a continuum are used to define abdominal obesity. Adopting a standard measurement protocol will facilitate the interpretation and clinical utility of WC for obesity‐related risk stratification.     

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.     

First nationwide survey of prevalence of overweight, underweight, and abdominal obesity in Iranian adults

Objective: The goal was to estimate the prevalence of overweight, obesity, underweight, and abdominal obesity among the adult population of Iran. Research Methods and Procedures: A nationwide cross‐sectional survey was conducted from December 2004 to February 2005. The selection was conducted by stratified probability cluster sampling through household family members in Iran. Weight, height, and waist circumference (WC) of 89,404 men and women 15 to 65 years of age (mean, 39.2 years) were measured. The criteria for underweight, normal‐weight, overweight, and Class I, II, and III obesity were BMI <18.5, 18.5 to 24.9, 25 to 29.9, 30 to 34.9, 35 to 39.9, and ≥40 (kg/m²), respectively. Abdominal obesity was defined as WC ≥102 cm in men and ≥88 cm in women. Results: The age‐adjusted means for BMI and WC were 24.6 kg/m² in men and 26.5 kg/m² in women and 86.6 cm in men and 89.6 cm in women, respectively. The age‐adjusted prevalence of overweight or obesity (BMI ≥25) was 42.8% in men and 57.0% in women; 11.1% of men and 25.2% of women were obese (BMI ≥30), while 6.3% of men and 5.2% of women were underweight. Age, low physical activity, low educational attainment, marriage, and residence in urban areas were strongly associated with obesity. Abdominal obesity was more common among women than men (54.5% vs. 12.9%) and greater with older age. Discussion: Excess body weight appears to be common in Iran. More women than men present with overweight and abdominal obesity. Prevention and treatment strategies are urgently needed to address the health burden of obesity.     

Ten-year changes in central obesity and BMI in rural and urban Cameroon

Objective: To compare the 10‐year changes in the distribution of adiposity in rural and urban Cameroonian populations. Methods and Procedures: Two cross‐sectional surveys of populations in the same rural and urban areas of Cameroon, aged ≥24 years, were carried out in 1994 (1,762 subjects) and 2003 (1,398 subjects) using similar methodology. All eligible subjects answered a structured questionnaire on their educational level, alcohol consumption, and tobacco smoking and weight, height, and waist circumference (WC) were measured. Results: Between 1994 and 2003, the age‐standardized prevalence of BMI ≥25 kg/m² increased significantly only in the rural area (+54% for women and +82% for men), while the age‐standardized prevalence of central obesity (WC ≥80 cm (women), ≥94 cm (men)) increased significantly only in the urban population (+32% for women and +190% for men). These differences persisted after adjustments for age group, alcohol consumption, tobacco smoking, and level of education, and within almost all the strata of the studied risk factors. Discussion: Changes in adiposity over time in Cameroon were characterized by an increase of BMI in the rural area and of WC in the urban area.     

Obesity and Its Relationship with Hypertension among Adults 50 Years and Older in Jinan,China

Background

The relationship between obesity and hypertension varies with geographical area, race and definitions of obesity. Our study aimed to investigate the prevalence of obesity using standard Chinese criteria based on the body mass index (BMI) and the waist circumference (WC) and to examine the association between obesity and hypertension among middle-aged and elderly people in Jinan city.

Methods

This cross-sectional study examined 1,870 subjects from the blocks randomly selected from among the 6 communities of Jinan, China in 2011–2012. The Student''s t-test was used to compare numerical data, and the χ² test was used to compare categorical data. Multivariate logistic regression analyses were performed to assess the effects of general and central obesity on hypertension after adjusting for age or for education level, smoking, alcohol consumption, and continuous age.

Results

The prevalence of general obesity among people age 50 years and older was 21.1% (17.0% for males and 23.1% for females), and the prevalence of central obesity was 77.8% for men and 78.7% for women. For men, compared with a normal BMI, the ORs and 95% CIs for overweight and general obesity were 1.853 (1.252, 2.744) and 3.422 (1.894, 6.182), respectively, after adjusting for age, smoking, alcohol consumption and educational level. Compared with a normal WC, the ORs and 95% CIs for central obesity were 2.334 (1.573, 3.465) and 2.318 (1.544, 3.479), respectively, for men. For women, compared with a normal BMI, the ORs and 95% CIs were 1.942 (1.473, 2.599) and 4.011 (2.817, 5.712), respectively, after adjusting for age, smoking, alcohol consumption and educational level. Compared with a normal WC, the ORs and 95% CIs for central obesity were 2.488 (1.865, 3.319) and 2.379 (1.773, 3.192), respectively, for women.

Conclusions

The relationship between hypertension and general obesity was stronger than the relationship between hypertension and either overweight or central obesity in both genders.     

Clinical Utility of Waist Circumference in Predicting All‐cause Mortality in a Preventive Cardiology Clinic Population: A PreCIS Database Study

Although obesity is a risk factor for mortality, it is unclear whether waist circumference (WC) is a better predictor of mortality than BMI in a clinical setting of patients at high risk for coronary artery disease (CAD). Thus, we compared the association between WC and BMI with all‐cause mortality in relation to traditional CAD risk factors in a high‐risk cohort. Study population included 5,453 consecutive new patients seen between 1996 and 2005 for management of CAD risk factors in a preventive cardiology clinic. Mortality was determined from the Social Security Death Index. There were 359 deaths over a median follow‐up of 5.2 years. Mortality was greater in high (>102 cm in men and >88 cm in women) vs. normal WC in both genders (P < 0.01). The unadjusted Cox proportional hazard ratio (HR) for continuous WC (per cm) was 1.02 (P < 0.001) in both genders and remained significant after adjustment for CAD risk factors (HR = 1.01 in men, HR = 1.03 in women, both P < 0.05). BMI did not associate statistically with mortality. WC associated with diabetes mellitus (DM) and CAD prevalence (P < 0.001). BMI associated only with DM (P < 0.001) and this association disappeared when WC was added to the model. We conclude that WC is an independent predictor of all‐cause mortality in a preventive cardiology population. These data affirm the clinical importance of WC measurements for mortality, DM, and CAD risk prediction and suggest that obesity‐specific interventions targeting WC in addition to traditional risk factor management may favorably impact these outcomes.     

Insulin Resistance is the Best Predictor of the Metabolic Syndrome in Subjects With a First‐Degree Relative With Type 2 Diabetes

Although obesity is associated with insulin resistance and the metabolic syndrome (MetS), some obese individuals are metabolically healthy. Conversely, some lean individuals are insulin resistant (IR) and at increased cardiometabolic risk. To determine the relative importance of insulin sensitivity, BMI and waist circumference (WC) in predicting MetS, we studied these two extreme groups in a high‐risk population. One thousand seven hundred and sixty six subjects with a first‐degree relative with type 2 diabetes were stratified by BMI and homeostasis model assessment of insulin resistance (HOMA_IR) into groups. IR groups had higher triglycerides, fasting glucose, and more diabetes than their BMI‐group insulin sensitive (IS) counterparts. Within both IS and IR groups, obesity was associated with higher HOMA_IR and diastolic blood pressure (BP), but no difference in other metabolic variables. MetS (Adult Treatment Panel III (ATPIII)) prevalence was higher in IR groups (P < 0.001) and more subjects met each MetS criterion (P < 0.001). Within each BMI category, HOMA_IR independently predicted MetS (P < 0.001) whereas WC did not. Within IS and IR groups, age and WC, but not BMI, were independent determinants of MetS (P < 0.001). WC was a less meaningful predictor of MetS at higher values of HOMA_IR. HOMA_IR was a better predictor of MetS than WC or BMI (receiver operating characteristic (ROC) area under the curve 0.76 vs. 0.65 vs. 0.59, P < 0.001). In conclusion, insulin sensitivity rather than obesity is the major predictor of MetS and is better than WC at identifying obese individuals with a healthier metabolic profile. Further, as many lean individuals with a first‐degree relative with type 2 diabetes are IR and metabolically unhealthy, they may all benefit from metabolic testing.     

Prevalence of Overweight and Obesity in Elderly People in Spain

Objective: To estimate the prevalence of obesity and overweight in the older adult population in Spain by sex, age, and educational level. Research Methods and Procedures: A cross‐sectional study was carried out in 2001 in a sample of 4009 persons representative of the noninstitutionalized population ≥60 years of age. Anthropometric measurements (BMI and waist circumference) were obtained using standardized techniques and equipment. Overweight was considered at a BMI of 25 to 29.9 kg/m² and obesity at a BMI of ≥30 kg/m². Central obesity was considered at a waist circumference of >102 cm in men and >88 cm in women. Results: The mean BMI was 28.2 kg/m² in men and 29.3 kg/m² in women. The prevalence of overweight and obesity in men was 49% and 31.5%, respectively. The corresponding percentages in women were 39.8% and 40.8%. The prevalence of obesity was higher in persons with no education than in those with third level education (i.e., university studies), especially among women (41.8% vs. 17.5%). The prevalence of central obesity was 48.4% in men and 78.4% in women. Differences by educational level were seen in only women, in whom the prevalence of central obesity was 80.9% in those with no education and 59% in those with third‐level education. Discussion: The prevalence of overweight and obesity in the Spanish adult elderly population is very high. Some other populations show similar prevalences, especially in Mediterranean countries. Socioeconomic conditions in Spain during the years these cohorts were born may partly explain the high‐frequency of obesity.     

Impact of Obesity and Body Fat Distribution on Cardiovascular Risk Factors in Hong Kong Chinese

Objective: Body fat distribution has been reported to differentially contribute to the development of cardiovascular risk. We report the relative associations between general and central obesity and risk factors in 2893 Chinese subjects recruited from the Hong Kong population. Research Methods and Procedures: Anthropometric parameters [waist circumference (WC) and BMI], surrogate measures of insulin resistance (fasting plasma glucose and insulin, oral glucose tolerance test, 2 hours glucose and insulin), fasting lipids (total, low‐density lipoprotein‐cholesterol, high‐density lipoprotein‐cholesterol, and triglycerides) and systolic and diastolic blood pressure were measured. General obesity was classified as BMI ≥25.0 kg/m² and central obesity as a WC ≥80 or ≥90 cm in women and men, respectively. Results: A total of 39.2% of the population was found to be obese. Obesity per se increased the levels of the risk factors, but central adiposity contributed to a greater extent to adverse high‐density lipoprotein‐cholesterol, triglyceride, and insulin resistance levels. There was a continuous relationship between increasing obesity, both general and central, and cardiovascular risk, with lowest risk associated with the lowest indices of obesity. In the 1759 nonobese subjects divided into quartiles of BMI or WC, the levels of the cardiovascular risk factors still significantly increased with increasing quartiles of adiposity. Discussion: Central adiposity appears to contribute to a greater extent than general adiposity to the development of cardiovascular risk in this population. The relationship between obesity parameters and risk is a continuum, with risk factors significantly increasing even at levels usually considered nonobese. These observations support the proposed redefinition of overweight and obesity in Asian populations using lower cut‐off points.     

Central rather than overall obesity is related to diabetes in the Chinese population: the InterASIA study

Objective: The objective was to compare central and overall obesity measurements for identifying diabetes mellitus (DM) and impaired fasting glucose (IFG) level in the Chinese population. Research Methods and Procedures: Data for 15,236 Chinese adults between the ages of 35 and 74 years, obtained by the InterASIA Study in 2000–2001, were used for the current analyses. We analyzed the areas under the receiver operating characteristic (ROC) curves (AUCs) for waist circumference (WC), waist‐to‐hip ratio (WHR), and BMI to determine the ability of these indices to identify DM and IFG in the study sample and bootstrapped samples. WC was used as a measure of central obesity and BMI as a measure of overall obesity. Results: The prevalence rates of central and overall obesity in the study population were 33.97% and 9.78%, respectively. The prevalence rates of IFG and DM were 7.34% and 5.51%, respectively. ROC analysis revealed significant differences between AUCs for WHR (0.666, 95% confidence interval, 0.647 to 0.685) and BMI (0.622, 95% confidence interval, 0.601 to 0.642) and for WC (0.661, 95% confidence interval, 0.643 to 0.682) and BMI for identifying DM (all p < 0.0001). The analysis also revealed significant differences between AUCs for WHR (0.638, 95% confidence interval, 0.619 to 0.655) and BMI (0.607, 95% confidence interval, 0.589 to 0.627) and for WC (0.637, 95% confidence interval, 0.615 to 0.654) and BMI for identifying IFG (all p < 0.001). Discussion: Central obesity is more related to DM and IFG than is overall obesity in the Chinese population, and both WC and WHR are equally able to identify DM.     

Relationships between direct and indirect measures of central and total adiposity in children: What are we measuring?

Objective: The relationship between central and total fat measured by anthropometry, dual energy X‐ray absorptiometry, and magnetic resonance imaging (MRI) with each other and systolic blood pressure (SBP) was examined. Design and Methods: Participants of the Avon Longitudinal Study of Parents and Children were examined at ages 9, 11, 13, and 15 years (n = 3,796‐6,567). MRI was available on a subset of children at 11 (n = 156) and 13 (n = 95). Results: Body mass index (BMI) and waist circumference (WC) were highly correlated (r = 0.84‐0.91, across ages), and total body fat mass (TBFM) and trunk fat mass (TFM) were very strongly correlated (r ≥ 0.98). Among boys, BMI vs. WC explained a similar degree of variation in TBFM and TFM (41‐71% vs. 43‐76%, across age and overweight groups); in girls, BMI accounted for 62‐73% variance and WC 47‐69%. Adiposity measures were generally similarly correlated with SBP within age groups. Further, the relationship between intra‐abdominal adipose tissue (IAAT) volume and adiposity measures did not vary greatly at 11 (0.65‐0.67) and 13 (0.64‐0.67). Conclusions: BMI and WC contain a large amount of overlapping information as evidenced by their high correlation and similarly sized associations with fat mass, SBP, and IAAT. This suggests that WC may be an inadequate marker of central adiposity during childhood.     

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 ≥ 25 kg/m²) and 13.3% in men and 21.0% in women by the Taiwanese definition (BMI ≥ 27 kg/m²). Odds ratios of acquiring various CVD risk factors increased significantly with increment of WC, WHR, and BMI. The areas under the curve predicting metabolic syndrome were all <0.8. The cut‐off values of WC corresponding to the highest sensitivity and the highest specificity in predicting various CVD risk factors were 86.2–88.0 cm in men and 82.0–84.0 cm in women, respectively. Discussion: Obesity was prevalent in the Taiwanese elderly. WC was related to CVD risk factors to a greater extent than BMI and WHR. However, none of them alone was a good screening tool for CVD risk factors. Therefore, how to apply AI prudently to screen elderly for CVD risk factors needs further research.     

Waist circumference and 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 relationship between measures of obesity and incident heart failure: The multi‐ethnic study of atherosclerosis

Objective : To evaluate the strength of association of body mass index (BMI) and waist circumference (WC) with incident heart failure (HF), exploring our associations by ethnicity and age. Design and Methods : 6,809 participants, aged 45‐84 years old, without clinical cardiovascular disease (2000–2002), from the Multi‐Ethnic Study of Atherosclerosis were included. Cox‐Proportional hazards models were used to examine associations of BMI and WC with incident HF. The predictive abilities of BMI and WC were compared using receiver operating characteristic curves. Results : Over a median follow‐up of 7.6 years, there were 176 cases. BMI and WC were associated with incident HF in men (1.33 [1.10‐1.61] and 1.38 [1.18‐1.62], respectively] and women (1.70 [1.33‐2.17] and 1.64 [1.29‐2.08], respectively). These associations became non‐significant after adjusting for obesity‐related conditions (hypertension, dysglycemia, hypercholesterolemia, left ventricular hypertrophy, kidney disease, and inflammation). The associations of BMI and WC did not vary significantly by ethnicity or age‐group, but were inverse in Hispanic men. The area under the curve for BMI and WC was 0.749 and 0.750, respectively, in men and 0.782 and 0.777, respectively, in women. Conclusions : The association between obesity and incident HF is largely mediated by obesity‐related conditions. BMI and WC have similar predictive abilities for incident HF.     

Body fat distribution of children and adolescents in Abeokuta,Southwest Nigeria

Excessive central fat in children and adolescents is a risk factor for cardiovascular and metabolic disorders. This study aimed to compare the body fat distribution patterns of children and adolescents in Abeokuta, Nigeria with international reference standards. Five hundred seventy children aged 5 to 19 years were selected from seven schools using multistage random sampling. Weight, height, triceps and subscapular skinfold thickness (TSF, SSF), and circumference at the waist and hips (WC, HC) were measured. Body mass index (BMI), subscapular:triceps skinfold ratio (STR), waist:hip circumference ratio (WHR), and waist: height ratio (WHtR) were derived. Females had higher mean BMI, TSF, SSF, WC, HC, WHR, and WHtR, while males had significantly higher STR. The mean BMI, WC, TSF, and SSF values were lower for our subjects than for African‐American subjects at all ages. On the other hand, in both sexes, STR was higher among Nigerian than African‐American subjects up to 12 years old. Thereafter the values were similar. The mean WC was similar to those reported for African‐American males up to 8 years, and females up to 7 years of age; thereafter, African‐American had higher values. The prevalence of central obesity using WC and WHtR measures was 4.4% and 5.8%, respectively. There is a need to validate each index against serum lipid profiles and other cardiovascular and metabolic risk factors. Am J Phys Anthropol 150:647–654, 2013. © 2013 Wiley Periodicals, Inc.