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.     

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.     

Prevalence of Overweight and Obesity and Their Associations with Socioeconomic Status in a Rural Han Chinese Adult Population

Background

The purpose of this study is to describe the prevalence of overweight, general obesity, and abdominal obesity and examine their associations with socioeconomic status in a rural Chinese adult population.

Methods

This cross-sectional study was performed on 15,236 participants ≥ 35 years of age (6,313 men [41.4%] and 8,923 women [58.6%]). Each participant’s weight, height, waist circumference (WC), and hipline circumference (HC) were measured, and demographic and socioeconomic data were collected using questionnaires.

Results

The mean body mass index (BMI) values were 23.31 ± 2.96 and 23.89 ± 3.23 kg m^-2 and the mean WC values were 79.13 ± 8.43 and 79.54 ± 8.27 cm for men and women, respectively. The age-standardized prevalence rates of overweight (BMI ≥ 24.0 kg m^-2), general obesity (BMI ≥ 28.0 kg m^-2), and abdominal obesity (WC ≥ 85 cm for men and ≥ 80 cm for women) were 32.0%, 6.7%, and 27.0% for men and 35.1%, 9.7%, and 48.3% for women, respectively. All gender differences were statistically significant (p < 0.001). In addition, the age-specific prevalence rates of general and abdominal obesity slowly decreased among men but sharply increased among women as age increased (p < 0.001). In subsequent logistic regression analysis, educational level was negatively associated with both general obesity and abdominal obesity among women but positively associated with abdominal obesity among men. No significant correlation was found between obesity and income.

Conclusions

These results suggest a high prevalence of obesity which might differ by gender and age, and an inverse association among women and a mixed association among men noted between education and obesity in our locality. Preventive and therapeutic programs are warranted to control this serious public health problem. The gender-specific characteristics of populations at high-risk of developing obesity should be taken into consideration when designing interventional programs.     

Relationship of BMI,Waist Circumference,and Weight Change with Use of Health Services by Older Adults

Objective: To examine the relationship of BMI, waist circumference (WC), and weight change with use of health care services by older adults. Research Methods and Procedures: This was a prospective cohort study conducted from 2001 to 2003 among 2919 persons representative of the non‐institutionalized Spanish population ≥60 years of age. Analyses were performed using logistic regression, with adjustment for age, educational level, size of place of residence, tobacco use, alcohol consumption, and presence of chronic disease. Results: Obesity (BMI ≥ 30 kg/m²) and abdominal obesity (WC >102 cm in men and >88 cm in women) in 2001 were associated with greater use of certain health care services among men and women in the period 2001–2003. Compared with women with WC ≤ 88 cm, women with abdominal obesity were more likely to visit primary care physicians [odds ratio (OR): 1.36; 95% confidence limit (CL): 1.06–1.73] and receive influenza vaccination (OR: 1.30; 95% CL: 1.03–1.63). Weight gain was not associated with greater health service use by either sex, regardless of baseline BMI. Weight loss was associated with greater health service use by obese and non‐obese subjects of both sexes. In comparison with those who reported no important weight change, non‐obese women who lost weight were more likely to visit hospital specialists (OR: 1.45; 95% CL: 1.02–2.06), receive home medical visits (OR: 1.61; 95% CL: 1.06–2.45), be hospitalized (OR: 1.88; 95% CL: 1.29–2.74), and have more than one hospital admission (OR: 2.31; 95% CL: 1.19–4.47). Discussion: Obesity and weight loss are associated with greater health service use among the elderly.     

Trends of Abdominal Adiposity in White,Black, and Mexican‐American Adults, 1988 to 2000

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

Migration Surrogates and Their Association With Obesity Among Within‐Country Migrants

Limited studies have evaluated the link between acculturation and health outcomes of within‐country migrants. The objective of this study was to evaluate whether well‐known acculturation surrogates were associated with obesity among Peruvian rural‐to‐urban migrants. We performed a cross‐sectional survey, the PERU MIGRANT study, using single‐stage random sampling. Evaluation included weight, height, and waist circumference (WC) as well as acculturation surrogates. Obesity was assessed using BMI and WC. Length of residence, age at migration, language proficiency, and language preferences (Spanish or Quechua) were assessed in logistic regression models to calculate odd ratios and 95% confidence intervals adjusting for potential confounders. A total of 589 rural‐to‐urban migrants were enrolled. The mean age was 47.8 (s.d.: 11.7, range: 30–92), and 280 (47.5%) were men. Obesity prevalence assessed using BMI was 30.4% among women and 10.7% among men (P < 0.001), whereas abdominal obesity assessed using WC was 29.1% among women and 19.1% among men (P < 0.01). Obesity was associated with older age at first migration, language speaking proficiency, and language preferences. The association between obesity and acculturation surrogates is variable in this population. Thus, acculturation per se can explore positive channels associated with better health outcomes. The patterns shown in this report suggest a more complex association for these factors.     

Gender‐ethnic Disparity in BMI and Waist Circumference Distribution Shifts in US Adults

While obesity has been increasing in the United States, little is known about the variation in recent BMI and waist circumference (WC) distribution shifts across socio‐demographic groups. We assessed shifts in BMI and WC distributions and compared between‐group differences over the past decade, and projected future BMI and WC distributions and prevalence of obesity and central obesity using National Health and Nutrition Examination Survey (NHANES) 1988–1994 and 1999–2004 data. BMI/WC distributional shifts overall and in percentiles were compared across groups. Average yearly shift was calculated and used for projecting future distributions and prevalence. Both BMI and WC increased more in their uppermost percentile distribution, though BMI shift declined toward the uppermost percentiles among women. Heavier Americans gained more adiposity over the past decade. Ethnic (non‐Hispanic (NH) white vs. black) disparities in mean BMI and WC became wider. Over the survey period, mean BMI increased by 1.3 units vs. 1.8 units among men and women, whereas WC, by 4.2 cm vs. 4.8 cm. Young adults had the largest increase. Shift in women's WC was stable between the 25th and 75th percentiles, but gained pace at higher WC, while women's BMI and men's BMI and WC shifts increased linearly. NH black women had the largest shifts and would have central obesity and obesity prevalence of 90.8 and 70.7% by 2020. Shifts in BMI and WC distribution varied across age‐, gender‐, and ethnic groups. Future rise in the obesity and central obesity prevalence rates are expected, but would vary by demographic groups.     

Independent Associations Between Cardiorespiratory Fitness and Abdominal Obesity With Metabolic Risk in Adolescents and Adults

Our objective was to examine the independent association between abdominal obesity (waist circumference (WC)) and cardiorespiratory fitness (CRF) with metabolic syndrome (MetS) in 2,197 adults (ages 20–49 years) and 3,223 adolescents (ages 12–19 years). Individuals were stratified by CRF and WC using sex‐ and age‐specific MetS criteria for adolescents and adults. Adolescents had a lower prevalence rate of MetS (5.4% vs. 12.8%) and high WC (15.5% vs. 35.7%), but a higher prevalence rate of low CRF (37.6% vs. 15.9%) than adults. As compared to adolescents and adults with low WC, those with a high WC (odds ratio (OR) = 5.5–16.5, P < 0.001) were more likely to have a clustering of MetS factors than those with low WC (OR = 1.2–3.8, P = 0.3 to <0.001), regardless of fitness level. Conversely, the beneficial effects of having moderate/high CRF on MetS were only observed in individuals with low WC, and not high WC. Thus, in conclusion, both high WC and low CRF are associated with increased odds of MetS in adolescents and adults. However, increased abdominal obesity is more strongly associated with MetS in adolescents and adults.     

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.     

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.     

Comparison of Overall Obesity and Body Fat Distribution in Predicting Risk of Mortality

Results of studies comparing overall obesity and abdominal adiposity or body fat distribution with risk of mortality have varied considerably. We compared the relative importance and joint association of overall obesity and body fat distribution in predicting risk of mortality. Participants included 5,799 men and 6,429 women aged 30–102 years enrolled in the third National Health and Nutrition Examination Survey who completed a baseline health examination during 1988–1994. During a 12‐year follow‐up (102,172 person‐years), 1,188 men and 925 women died. In multivariable‐adjusted analyses, waist‐to‐thigh ratio (WTR) in both sexes (P_trend <0.01 for both) and waist‐to‐hip ratio (WHR) in women (P_trend 0.001) were positively associated with mortality in middle‐aged adults (30–64 years), while BMI and waist circumference (WC) exhibited U‐ or J‐shaped associations. Risk of mortality increased with a higher WHR and WTR among normal weight (BMI 18.5–24.9 kg/m²) and obese (BMI ≥30.0 kg/m²) adults. In older adults (65–102 years), a higher BMI in both sexes (P_trend <0.05) and WC in men (P_trend 0.001) were associated with increased survival, while remaining measures of body fat distribution exhibited either no association or an inverse relation with mortality. In conclusion, ratio measures of body fat distribution are strongly and positively associated with mortality and offer additional prognostic information beyond BMI and WC in middle‐aged adults. A higher BMI in both sexes and WC in men were associated with increased survival in older adults, while a higher WHR or WTR either decreased or did not influence risk of death.     

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.     

Alcohol intake, insulin resistance, and abdominal obesity in elderly men

Objective: Moderate and high alcohol intake have been associated with decreased and increased risk of type 2 diabetes, respectively. Insulin resistance, insulin secretion, and abdominal obesity are major predictors of diabetes, but the links with alcohol intake remain contradictory because of limited data. Research Methods and Procedures: In a population‐based cohort of 807 men (age, 70 years), we studied whether alcohol intake was related to insulin sensitivity, measured with the gold standard technique (euglycemic clamp), insulin secretion (early insulin response), or adiposity [BMI, waist circumference (WC), waist‐to‐hip ratio]. Alcohol intake was self‐reported (questionnaire) and was assessed from a validated 7‐day dietary record. The cross‐sectional associations were evaluated using multivariable linear regression, adjusting for smoking, education level, physical activity, dietary total energy intake, hypertension, diabetes, triglycerides, and cholesterol. Results: In multivariable models, self‐estimated alcohol intake was not related to insulin sensitivity, early insulin response, or BMI, but was positively related to WC (β‐coefficient, 0.77; 95% confidence interval, 0.15 to 1.39; p = 0.02) and waist‐to‐hip ratio (0.006 [0.002–0.009], p = 0.003). The association with WC and waist‐to‐hip ratio was most pronounced in men in the lowest tertile of BMI. The results using dietary records were similar. Discussion: Evaluated in a large sample in elderly men, neither insulin sensitivity measured by clamp technique nor insulin secretion was significantly associated with alcohol intake. However, high alcohol intake was associated with abdominal obesity, which might explain the higher diabetes risk previously observed in high alcohol consumers.     

Eleven‐year Prevalence Trends of Obesity in Greek Children: First Evidence that Prevalence of Obesity Is Leveling Off

We examined 11‐year (1997–2007) trends in underweight, overweight, and obesity in Greek children. Population data derived from a yearly, school‐based health survey carried out between 1997 and 2007 in >80% of all Greek schools. Height and weight measurements from 651,582 children, aged 8–9 years (boys: 51.2%) were analyzed. The gender‐ and age‐specific BMI cutoff points by the International Obesity Task Force (IOTF) were used in order to define underweight, normal weight, overweight, and obesity. Trend analysis showed an increase in the prevalence of obesity from 7.2 ± 0.2% in 1997 to 11.3 ± 0.2% in 2004 for girls (P < 0.001) and from 8.1 ± 0.2% in 1997 to 12.3 ± 0.2% in 2004 for boys (P < 0.001). An apparent leveling off in obesity rates was observed during 2004–2007 for both boys and girls. The prevalence of overweight rose between 1997 and 2007 from 20.2 ± 0.2% to 26.7 ± 0.2% for girls (P < 0.001) and from 19.6 ± 0.2% to 26.5 ± 0.2% for boys (P < 0.001). The overall prevalence of thinness in the same period remained constant in both sexes. The presented population‐based data revealed that the prevalence of overweight and obesity among 8‐ to 9‐year‐old Greek children is alarmingly elevated, with the overweight rates rising continuously. However, an apparent leveling off in obesity rates for the past 4 consecutive years was documented for the first time in both genders.     

Abdominal Adiposity in Six Populations of West African Descent: Prevalence and Population Attributable Fraction of Hypertension

OKOSUN, IKE S., TERRENCE E. FORRESTER, CHARLES N. ROTIMI, BABATUNDE O. OSOTIMEHIN, WALINJOM F. MUNA, AND RICHARD S. COOPER. Abdominal adiposity in six populations of West African descent: prevalence and population attributable fraction of hypertension. Obes Res. Objectives: The objective of this investigation was to examine the prevalence of abdominal adiposity and its association with the prevalence of hypertension among African descent populations in Nigeria, Cameroon, Jamaica, St. Lucia, Barbados, and the United States (US). Research Method: The data for this investigation were obtained from the International Collaborative Study on Hypertension in Blacks. Hypertension was defined as mean diastolic blood pressure ≥90 mmHg, systolic blood pressure ≥140 mmHg or current treatment with prescribed anti-hypertension medication. Abdominal overweight was defined as waist circumference (WC) ≥94 and ≥80 cm for men and women, respectively. Abdominal obesity was defined as WC ≥102 and ≥88 cm for men and women, respectively. We estimated the site-specific prevalence of abdominal overweight and obesity across age and body mass index cut-points. We also calculated the population attributable fraction (AF) of hypertension due to abdominal adiposity. Results: The prevalence of hypertension in these populations was tightly linked to abdominal adiposity. Increases in abdominal overweight accompanied an increasing degree of Westernization, rising from 6. 4% and 26. 3% in Nigeria, 16. 5% and 62. 8% in Cameroon, 15. 8% and 58. 6% in Jamaica, 14. 3% and 62. 1% in St. Lucia, 21. 4% and 70. 3% in Barbados to 38. 9%, and 76. 4% in the US for men and women, respectively. The corresponding values for abdominal obesity were 1. 6% and 12. 3% in Nigeria, 5. 1% and 38. 9% in Cameroon, 5. 5% and 34. 0% in Jamaica, 2. 7% and 40. 7% in St. Lucia, 7. 8% and 44. 7% in Barbados to 21. 7% and 54. 1% in the US for men and women, respectively. Body mass index-adjusted estimates of AF suggest that in most of these populations, especially in females, avoidance of abdominal overweight or obesity would help to curb the development of hypertension. Discussion: An important public health challenge is to clarify how lifestyle factors influence risks of abdominal adiposity and ultimately the increased risk of cardiovascular diseases.     

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.     

Trends in obesity and its distribution: data from the Northern Sweden MONICA Survey, 1986-2004

Objective: Obesity, especially abdominal, is a risk factor for many diseases. This study explored trends in the prevalence of general and abdominal obesity, 1986–2004, in northern Sweden. Methods and Procedures: Cross‐sectional population surveys were performed in 1986, 1990, 1994, 1999, and 2004; 250 men and 250 women aged 25–34, 35–44, 45–54, and 55–64 years (from 1994, also 65–74 years) were randomly selected; the overall participation rate was 77%. Anthropometric data were used. Results: Weight and BMI increased in all men, most significantly in men aged 25–64 years (P < 0.0005). Weight increased in women aged 25–64 years (P < 0.005) and BMI in women aged 25–44 years (P < 0.005). Prevalence of obesity (BMI ≥ 30) increased significantly in men aged 25–44 and 55–74 years (P < 0.005; for men 65–74 years old, P < 0.05) and in women aged 25–44 years (P < 0.005). Waist circumference decreased significantly between 1986 and 1990 in all women (P < 0.005) and in men aged 55–64 years (P < 0.05). After 1990 waist circumference increased, most markedly so in women; by 2004 circumference measurements for women, and for men aged 55–64 years, were equal to those of 1986, while for men aged 25–54 years they were higher. Prevalence of abdominal obesity has increased since 1990, most markedly so in women aged 45–64 years (P < 0.0005). Discussion: The rapid increase in both general and central obesity raises concern for the future; increasing abdominal obesity in women is particularly alarming.     

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.     

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.     

Impact of Nightshift Work on Overweight and Abdominal Obesity Among Workers of a Poultry Processing Plant in Southern Brazil

The authors examined the associations of shiftwork with overweight and abdominal obesity through a cross-sectional study of 1206 employees 18 to 50 yrs of age who were working on a production line in a poultry processing plant. Night-shift workers (n?=?800) were considered exposed, whereas day shiftworkers (n?=?406) were considered nonexposed. Overweight was defined as a body mass index ≥25?kg/m² and abdominal obesity as a waist circumference ≥88?cm in women and ≥102?cm in men. The mean age of the workers was 30.5 yrs (standard deviation?=?8.7 yrs), and 65.2% were women. Nightshift workers compared to dayshift workers showed higher prevalences of overweight (42.2% vs. 34.3%; p?=?.020) and abdominal obesity (24.9% vs. 19.5%; p?=?.037). After adjusting for sociodemographics, parental overweight status, behavioral characteristics, and sleep characteristics, including hours of sleep, the prevalence ratios for overweight and abdominal obesity were 1.27 (95% confidence interval [ CI]: 1.00–1.61) and 1.45 (95% CI: 1.10–1.92), respectively, for the nightshift workers compared to the dayshift workers. A consistent finding in our study was the independent contribution of night shiftwork to overweight and abdominal obesity among Brazilian workers. Further studies are needed to understand the biological mechanisms involved and the complex behavioral and social adaptations experienced by night-shift workers. (Author correspondence: mtolinto@gmail.com)