Background Waist circumference (WC), a representative of abdominal visceral fat, is strongly associated with cardiovascular disease (CVD) and its outcomes. We aimed to define body mass index (BMI)-specific WC thresholds as predictors of CVD and all-cause mortality. Methods In this prospective cohort study in the context of the Tehran Lipid and Glucose Study (TLGS), a total of 3344 men and 4068 women were followed up for 18 years. Based on BMI, the participants were categorized into three groups: BMI < 25, 25 < BMI < 30, and BMI > 30. In each BMI category, sex-specific WC thresholds were estimated by the maximum value of Youden’s index to predict based on incident CVD events and all-cause mortality prediction. Results Overall 667 and 463 CVD events (the incidence rate of 3.1 to 4.5 in men and 1.1 to 2.6 in women per 1,000 person-years within BMI categories) and 438 and 302 mortalities (the incidence rate of 2.1 to 2.7 in men and 1.2 to 1.4 in women per 1,000 person-years within BMI categories) were recorded in men and women, respectively. WC thresholds in the BMI categories of < 25, 25–30, and BMI > 30 kg/m2 with regard to CVD events were 82, 95, and 103 cm in men and 82, 89, and 100 cm in women, and regarding all-cause mortality, the respective values were 88, 95, and 103 cm in men and 83, 90, and 99 cm among women. Conclusion BMI-specific WC thresholds observed here can help to better identify individuals at high risk of developing CVDs.

Background The prevalence of obesity among children and adolescences have been increased, which can consequently increase the prevalence of metabolic and cardiovascular diseases later in life. The objective of this study is to compare the ability of different childhood body mass index cut-offs in prediction of carotid intima media thickness (CIMT) as an indicator of subclinical atherosclerosis. Methods Participants were categorized into normal weight, overweight and obesity group, based on world health organization (WHO), center for disease control and prevention (CDC), international obesity task force (IOTF) and local IOTF cut-offs. After 18 years of follow up CIMT was measured. Akaike’s information criterion and relative efficiency were measured in order to compare regression models on the role of obesity on CIMT. Results In this prospective cohort study, 1295 subjects aged 3 to 18 years old were enrolled. The overall prevalence of overweight was 15.4, 11.5, 16.3 and 14.1 along with obesity prevalence of 6.6, 8.5, 7.7 and 5.0% based on WHO, CDC, local IOTF and international IOTF criteria, respectively. CIMT was higher in obese compare to normal groups across all classification criteria. After regression analysis, international IOTF was the best to predict adulthood CIMT, followed by local IOTF and WHO. CDC had the least discriminatory ability. Conclusion Due to the results of this study, IOTF could be a better tool in national and international surveillances of children in order to define overweight and obesity, which can help us to intervene more effectively in reducing the burden of cardiovascular diseases.

Background: The prevalence of obesity among children and adolescences have been increased, which can consequently increase the prevalence of metabolic and cardiovascular diseases later in life. The objective of this study is to compare the ability of different childhood body mass index cut-offs in prediction of carotid intima media thickness (CIMT) as an indicator of subclinical atherosclerosis. Methods: Participants were categorized into normal weight, overweight and obesity group, based on world health organization (WHO), center for disease control and prevention (CDC), international obesity task force (IOTF) and local IOTF cut-offs. After 18 years of follow up CIMT was measured. Akaike’s information criterion and relative efficiency were measured in order to compare regression models on the role of obesity on CIMT.Results: In this prospective cohort study, 1295 subjects aged 3 to 18 years old were enrolled. The overall prevalence of overweight was 15.4, 11.5, 16.3 and 14.1 along with obesity prevalence of 6.6, 8.5, 7.7 and 5.0 percent based on WHO, CDC, local IOTF and international IOTF criteria, respectively. CIMT was higher in obese compare to normal groups across all classification criteria. After regression analysis, international IOTF was the best to predict adulthood CIMT, followed by local IOTF and WHO. CDC had the least discriminatory ability. Conclusion: Due to the results of this study, IOTF could be a better tool in national and international surveillances of children in order to define overweight and obesity, which can help us to intervene more effectively in reducing the burden of cardiovascular diseases.