Thinness, overweight and obesity in a national sample of Iranian children and adolescents: CASPIAN Study

Background This study was conducted to assess the national prevalence of different grades of nutritional status (underweight, normal weight, overweight and obesity) among Iranian school‐students and to compare the prevalence of overweight and obesity using three different sets of criteria. Methods This cross‐sectional national survey was conducted on a representative sample of 21 111 school students including 10 253 boys (48.6%) and 10 858 girls (51.4%) aged 6–18 years, selected by multistage random cluster sampling from urban (84.6%) and rural (15.4%) areas of 23 provinces in Iran The percentage of subjects in the corresponding body mass index (BMI) categories of the Centers of Disease Control and Prevention (CDC), the International Obesity Task Force (IOTF) and the obtained national percentiles were assessed and compared. Results There was no gender differences in BMI, but was higher in boys living in urban than in rural areas (18.4 ± 3.88 vs. 17.86 ± 3.66 kg/m² respectively, P < 0.05). The prevalence of underweight was 13.9% (8.1% of boys and 5.7% of girls) according to the CDC percentiles, and 5% (2.6% of boys and 2.4% of girls) according to the obtained percentiles. According to the CDC, IOTF and national cut‐offs, the prevalence of overweight was 8.82%, 11.3% and 10.1% respectively; and the prevalence of obesity was 4.5%, 2.9% and 4.79% respectively. The prevalence of overweight was highest (10.98%) in the 12‐year‐old group and that of obesity (7.81%) in the 6‐year‐old group. The kappa correlation coefficient was 0.71 between the CDC and IOTF criteria, 0.64 between IOTF and national cut‐offs, and 0.77 between CDC and national cut‐offs. Conclusions The findings of this study warrant the necessity of paying special attention to monitoring of the time trends in child obesity based on uniform definitions, as well as to design programmes to prevent and control associated factors.     

体重指数与儿童青少年体能指数关联性研究

目的 探讨体重指数(BMI)与儿童青少年体能指数(PFI)之间的关联.方法 以安徽省参加2010年全国学生体质健康调查的7～18岁汉族学生共8941人为研究对象.按性别、年龄分层后,将研究对象依据BMI百分位数分为5组:很低(BMI＜P₅)、较低(P₅≤BMI＜P₁₅)、正常(P₁₅≤BMI＜ P₈₅)、较高(P₈₅≤BMI＜P₉₅)、很高(BMI≥P₉₅).对各体能测试成绩进行标准化,将其Z分相加算出PFI.用方差分析比较不同BMI组PFI的差异.用线性回归模型分析不同性别不同学龄段学生BMI与PFI的关联.结果 8941名学生中BMI很低、较低、正常、较高、很高组的PF1分别为-1.77、-0.91、0.32、-0.17、-0.54,呈倒“U”形分布;BMI正常组的PFI显著高于其他各组(P值均＜0.05).回归分析显示PFI与BMI呈正相关,与BMI²呈负相关,表明PFI是BMI的二次函数,随着BMI的增高PFI呈现先上升后下降的抛物线变化趋势.结论 BMI与儿童青少年PFI呈现抛物线变化趋势.     

体重指数与儿童青少年体能指数关联性研究

目的 探讨体重指数(BMI)与儿童青少年体能指数(PFI)之间的关联.方法 以安徽省参加2010年全国学生体质健康调查的7～18岁汉族学生共8941人为研究对象.按性别、年龄分层后,将研究对象依据BMI百分位数分为5组:很低(BMI＜P5)、较低(P5≤BMI＜P15)、正常(P15≤BMI＜ P85)、较高(P85≤BMI＜P95)、很高(BMI≥P95).对各体能测试成绩进行标准化,将其Z分相加算出PFI.用方差分析比较不同BMI组PFI的差异.用线性回归模型分析不同性别不同学龄段学生BMI与PFI的关联.结果 8941名学生中BMI很低、较低、正常、较高、很高组的PF1分别为-1.77、-0.91、0.32、-0.17、-0.54,呈倒“U”形分布；BMI正常组的PFI显著高于其他各组(P值均＜0.05).回归分析显示PFI与BMI呈正相关,与BMI2呈负相关,表明PFI是BMI的二次函数,随着BMI的增高PFI呈现先上升后下降的抛物线变化趋势.结论 BMI与儿童青少年PFI呈现抛物线变化趋势.     

中国日本儿童青少年体质量指数与体能指数的关系

了解中日两国儿童青少年体质量指数(BMI)与体能指数(PFI)之间的关系,为有效提高中国儿童青少年体能水平提供支持和依据.方法 在中国和日本共测试9 594名7~18岁儿童青少年体能项目,采用随机个案法抽取其中4 800名作为研究对象,比较中日两国不同肥胖程度儿童青少年体能指数存在的差异,并分析不同BMI-Z分与PFI之间的关系.结果 中国男生消瘦、正常、超重和肥胖分组的PFI均值分别为-1.17,-0.03,0.04和0.26,日本男生分别为-2.59,-0.34,-1.46和-2.44,超重和肥胖学生差异均有统计学意义(P值均<0.01);中国不同BMI分组女生的PFI均值分别为-1.18,-0.08,0.01和1.03,日本女生分别为-1.21,0.51,0.11和-1.30,中国正常BMI女生PFI低于日本,肥胖女生则高于日本(P值均<0.05).中国男生、总体和日本男生、女生、总体方面不同BMI-Z值的PFI差异均有统计学意义(F值分别为2.89,3.05,4.81,2.33,5.34,P值均<0.01).结论 中日儿童青少年BMI-Z分与PFI之间存在倒“U”型曲线关系,随着BMI-Z分升高中国男生PFI的下降幅度较日本男生更为显著.应结合中国实际采取有效的干预措施,提高儿童青少年体能水平.     

Association of body mass index to meeting physical activity recommendations

OBJECTIVE: To investigate the association between BMI and physical activity based on the CDC-ACSM recommendation and a more demanding standard consistent with the IOM recommendation. METHODS: A random-digit-dialed survey (n=1810) used 2001 BRFSS questions to measure physical activity. RESULTS: Data revealed a monotonic association between BMI and physical activity level. Lower odds of meeting both recommendations were associated with higher BMI. The proportion meeting the CDC-ACSM recommendation was at least 3 times that of persons meeting the IOM-based recommendation. CONCLUSIONS: Meeting either recommendation was associated with BMI; however, a larger proportion of persons were meeting the less demanding CDC-ACSM recommendation.     

Smoking behavior and its influencing factors in a national-representative sample of Iranian adolescents: CASPIAN study

OBJECTIVES: To determine the national prevalence of smoking among Iranian youths and its environmental influencing factors. METHODS: This study was performed in 2003-2004 among 11,966 school students, ages 11-18 years, selected by multi-stage random cluster sampling from 20 provinces in Iran. The participants filled out self-administered anonymous questionnaires. RESULTS: The prevalence of self-reported cigarette smoking was 14.3%, with a higher prevalence in boys than in girls (18.5% vs. 10.1%, respectively, P < 0.001), and in high school than in middle school students (17.4% vs. 10.6%, respectively, P < 0.001). Overall, 42.2% of smokers were daily smoker, and the rest were occasional smoker. The mean age of the first attempt to smoke was 13.2 +/- 2.5 years with no significant gender difference but was significantly lower in daily than in occasional smokers. The place of the first attempt to smoke was mostly in friend parties (41.6%) and traditional teahouses (23.2%) for boys and the family parties (37.1%) and the traditional teahouses (27.4%) for girls. The higher school level and having a tobacco user at home significantly increased the likelihood of smoking in adolescents, with the highest odds ratio (OR) found for having a smoker sister in girls (OR = 4.5, 95%CI, 2.5, 8.2), and having a smoker brother in boys (OR = 2.4, 95%CI, 2.03, 3.05). CONCLUSION: Smoking is becoming as a major public health threat among Iranian youths. Control measures should be considered not only for cigarette smoking, but also for the socially accepted habit of water pipe use that is revived in traditional teahouses.     

Association of neighborhood design and recreation environment variables with physical activity and body mass index in adolescents

PURPOSE: To examine associations of neighborhood walkability and recreation environment variables with physical activity in adolescents. METHODS: The cross-sectional study was conducted with 98 white or Mexican-American adolescents (mean age = 16.2 years). Physical activity was measured with 7 days of accelerometer monitoring. Height and weight were measured to compute body mass index (BMI). Environmental measures were created using geographic information systems. A neighborhood walkability index was based on land use mix, retail density, street connectivity, and residential density. Proximity to public and private recreation facilities was assessed. RESULTS: In a linear regression, the walkability index within 0.5 mile of homes was related to minutes of moderate to vigorous physical activity, explaining approximately 4% of variance. Recreation variables were not related to physical activity, and BMI was not explained by environmental variables. CONCLUSION: Neighborhood walkability was related to adolescents'physical activity, similar to findings for adults.     

Association of physical activity and body mass index with metabolic syndrome among US adolescents with disabilities

BackgroundAdolescents with disabilities (A-With-D) have shown to be less physically active and more obese compared to adolescents without disabilities (A-Without-D); however, little is known in regards to the impact of physical activity (PA) and body mass index (BMI) on metabolic syndrome (MetS) among A-with-D.ObjectiveThe purpose of this study was to compare the prevalence of MetS, PA levels and BMI percentile between A-With-D and A-Without-D, and to examine the influence of PA and BMI on MetS among A-With-D.MethodsData from the National Health and Nutrition Examination Survey 1999–2010 was used in this study. Inclusion criteria for the study consisted of those who indicated, in the survey, that they had received special education or early intervention service (n = 278). PA level was assessed subjectively by asking the amount of leisure time PA. BMI percentile was obtained using BMI growth charts by age and sex. The continuous MetS (cMetS) score was computed using age and sex standardized residual for mean arterial blood pressure, triglyceride, glucose, waist circumference, and high-density lipoprotein cholesterol.ResultsA-With-D were more likely to be obese and less likely to be engaged in PA compared to A-Without-D. A-With-D were less favorable to MetS with significantly higher cMetS scores than A-Without-D. Lower levels of PA and higher percentile of BMI were significantly associated with higher levels of cMetS scores among A-With-D.ConclusionThis study provided empirical evidence for the importance of promoting a healthy lifestyle (i.e., increasing the level of PA and decreasing the BMI percentile) among A-With-D in order to reduce the risk of MetS.     

Moderate-to-vigorous physical activity and sedentary behaviours in relation to body mass index-defined and waist circumference-defined obesity

The aim of the present study was to investigate the relationships of physical activity types and sedentary behaviour with BMI and waist circumference (WC). The sample comprised 6215 adults (2775 men, 3440 women) aged 16 years and over living in Scotland. Self-reported physical activity of moderate to vigorous intensity (MVIA) included domestic activity, walking, and sports and exercises. MVIA levels were classified as being inactive, being insufficiently active, being sufficiently active for general health benefits and being sufficiently active for obesity prevention. Sedentary time was defined as television and other screen-based entertainment time (TVSE). Dependent variables were BMI-defined obesity (BMI-OB) and WC-defined obesity (WC-OB). TVSE was positively related to both WC-OB (adjusted OR 1.69 (95 % CI 1.39, 2.05) for > or = 4 h of TVSE per d compared with < 2 h/d) and BMI-OB (OR 1.88; 95 % CI 1.51, 2.35) independently of MVIA. Those classified as most active who reported > or = 4 h/d of TVSE had higher prevalence of BMI-OB (18.9 v. 8.3 %; P < 0.05) and WC-OB (28.0 v. 10.0 %; P < 0.01) than those equally active with < 2 h/d of TVSE. Sports and walking were related inversely to WC-OB (OR for no time compared with > or = 30 min/d: 1.55 (95 % CI 1.24, 1.94); 2.06 (95 % CI 1.64, 2.58)), but only walking was related to BMI-OB (OR 1.94; 95 % CI 1.58, 2.37). Domestic physical activity was not related to BMI-OB or WC-OB. In conclusion, physical activity and sedentary behaviour are independently related to obesity. Public health recommendations should both promote physical activity and discourage engagement in sedentary pursuits.     

中国儿童青少年体力活动与体能指数的相关性

  目的  分析中国儿童青少年体力活动(PA)与体能指数(PFI)的相关性,为改善中国儿童青少年体力活动水平以及提升体能素质提供参考。  方法  于2018年9—12月采用整群抽样方式在华东、西北、华北、华中、西南和华南区选取4 269名7~18岁学生,收集体力活动等数据,并完成立定跳远、握力、50 m跑、改良坐位体前屈、30 s仰卧起坐、20 s反复横跨、20 m往返跑测试,采用χ2检验、Wilcoxon秩和检验、线性回归模型分析数据。  结果  在不同体力活动水平儿童青少年PFI的比较中,男生10~12和16~18岁中高强度体力活动(MVPA)达标组的PFI值分别为(0.46±3.58)(0.75±3.00),MVPA不达标组的PFI值分别为(-0.69±3.64)(-0.61±2.87),差异均有统计学意义(t值分别为0.04,0.57,P值均＜0.05);女生4个年龄段MVPA达标组的PFI值与MVPA不达标组相比差异均无统计学意义(P值均＞0.05)。在不同体能等级下儿童青少年体力活动状况比较中,健康体能组MPA和VPA时间、体育锻炼时间高于不健康组(Z值分别为-2.04,-4.93,-7.09,P值均 < 0.05)。线性回归模型分析显示,每日MVPA、体育锻炼与体能指数之间均呈正相关(P值均 < 0.05)。  结论  中高强度体力活动即体育锻炼与体能指数呈正相关,适当提高儿童青少年中高强度体力活动水平尤为重要。     

The association of sleep duration and cardiometabolic risk factors in a national sample of children and adolescents: The CASPIAN III Study

ObjectivesAlthough sleep duration is one of the most important health-related factors, its association with risk factors for chronic diseases has not been completely clarified, especially among children and adolescents. The aim of this study was to evaluate the association between sleep duration and CVD risk factors among a nationally representative sample of Iranian children and adolescents.MethodsThis cross-sectional national study was performed on a representative sample of 5528 Iranian students, ages 10 to 18 y living in central cities of 27 provinces of Iran. Physical examinations and laboratory tests were performed using standard protocols. To determine the association between sleep duration and cardiometabolic risk factors, multivariable logistic regression was used and odds ratios (OR; with 95% confidence intervals) are reported.ResultsThe mean ± SD age was not significantly different among boys (14.69 ± 2.45 y) and girls (14.7 ± 2.38 y). In a crude model, boys who slept > 8 h and 5 to 8 h had lower OR for abdominal obesity compared with those who had slept <5 h in a crude model (ORs, 0.70, 0.80, 1.0, respectively; P = 0.008). A similar result was observed in an age- adjusted model for the prevalence of abdominal obesity (ORs, 0.69, 0.76, 1.0, respectively; P = 0.011). Girls who had slept > 8 h per day had lower OR for high serum low-density lipoprotein levels compared with those who slept < 5 h per day (P = 0.002). These differences remained significant even in the fully adjusted model for all the confounding variables (P = 0.008). Moreover, among boys ages 10 to 14 y, longer sleep duration increased the risk for high total cholesterol in all models.ConclusionShorter sleep duration increased the risk for some cardiometabolic risk factors among adolescents. The clinical significance of our findings should be determined in longitudinal studies.     

Association between junk food consumption and mental health in a national sample of Iranian children and adolescents: The CASPIAN-IV study

ObjectivesThe consumption of high energy and low nutritional content foods, which are known as junk foods, has increased. The aim of this study was to evaluate the association between junk food intake and mental health in a national sample of Iranian children and adolescents.MethodData were obtained from a surveillance system entitled CASPIAN-IV (Childhood and Adolescence Surveillance and Prevention of Adult Non communicable Disease) study of school students, ages 6 to 18 y in Iran. The students and their parents completed two sets of reliable questionnaires obtained from Global School Health Survey translated to Persian. The student questionnaire comprised several questions such as psychiatric distress (worry, depression, confusion, insomnia, anxiety, aggression, and worthless) and violent behaviors (physical fighting, being a victim, and bullying). The junk foods consisted of sweets, sweetened beverages, fast foods, and salty snacks.ResultsIn the sample of 13 486 children and adolescents, the frequency of junk food consumption was significantly associated with psychiatric distress (P < 0.001). There was a significant association between violent behaviors and intake of junk foods (P < 0.001) except for sweets, whereas the association between sweetened beverages consumption and being a victim was not significant (P > 0.05). Additionally, the results of logistic regression showed that daily consumption of sweetened beverages and snacks significantly increased the odds of self-reported psychiatric distress. Also, daily consumption of salty snacks was significantly associated with violent behavior, including physical fighting (odds ratio [OR], 1.39; 95% confidence interval [CI], 1.21–1.60), being a victim (OR, 1.19; 95% CI, 1.04–1.37), and bullying (OR, 1.55; 95% CI, 1.32–1.82).ConclusionJunk food consumption may increase the risk for psychiatric distress and violent behaviors in children and adolescents. Improvement of eating habits toward healthier diets may be an effective approach for improving mental health.     

Sugar-sweetened beverages and body mass index in children and adolescents: a meta-analysis

BACKGROUND: Rates of overweight and obesity have increased. Consumption of sugar-sweetened beverages (SBs) may play a role. OBJECTIVE: The purpose of this meta-analysis was to determine whether the results of original research with the use of longitudinal and randomized controlled trials (RCTs) support the hypothesis that SB consumption is associated with weight gain among children and adolescents. DESIGN: The MEDLINE database was used to retrieve all original studies of SBs and weight gain involving children and adolescents. Twelve (10 longitudinal and 2 RCT) studies were reviewed. Eight of the longitudinal studies and both RCT studies were incorporated into a quantitative meta-analysis. Forest plots and overall estimates and CIs for the association of the difference (Delta) in SB consumption with Deltabody mass index (BMI; in kg/m(2)) were produced. Funnel plots were examined as a diagnostic test for publication bias. Databases of unpublished scientific studies were searched. Sensitivity tests were conducted to examine the robustness of the meta-analysis results. RESULTS: The overall estimate of the association was a 0.004 (95% CI: -0.006, 0.014) change in BMI during the time period defined by the study for each serving per day change in SB consumption with the fixed-effects model and 0.017 (95% CI: -0.009, 0.044) with the random-effects model. The funnel plot is consistent with publication bias against studies that do not report statistically significant findings. The sensitivity tests suggest that the results are robust to alternative assumptions and new studies. CONCLUSION: The quantitative meta-analysis and qualitative review found that the association between SB consumption and BMI was near zero, based on the current body of scientific evidence.     

Objectively measured physical activity, physical activity related personality and body mass index in 6- to 10-yr-old children: a cross-sectional study

Background  

The prevalence and level of overweight in childhood is rapidly increasing. One potential contributor to the rise in overweight is a decline in physical activity (PA). The purpose of this study was to compare levels and patterns of PA and PA related personality in normal-weight (NW) and overweight (OW) 6- to 10-yr-old children.     

Association of body mass index with educational level in Iranian men and women

OBJECTIVE: Investigation of the relationship between educational level, body mass index (BMI), waist-to-hip ratio (WHR), physical activity and parity in a group of Iranian men and women living in Tehran. DESIGN: A cross-sectional study in a group of Iranian men and women. The subjects were classified into two educational levels: low education (< or =12 y schooling) and high education (>12 y schooling); and BMI, WHR, physical activity and parity (in women) were compared in two groups in men and women, separately. SETTING: Metabolic Unit of Tehran University of Medical Sciences in Tehran. SUBJECTS: Three hundred and fifteen men aged 33.1 (22-46) and 403 women aged 27.9 (22-45). RESULTS: After controlling for age and smoking, women with a higher level of education showed a significantly lower mean BMI than less educated women (24.8+/-4.2 vs 28.3+/-4.9, P <0.01), while more educated men had a higher mean BMI than less educated men (28.4+/-4.3 vs 26.7+/-4.5). In multiple regression analysis, physical activity in leisure time in men and years of education in women were the only determinants of BMI. After controlling for BMI, WHR was not related to the level of education in either men or women. CONCLUSION: The present data indicated an educational difference in BMI for the study population. In Iranian women, like the women in developed countries, the level of education was negatively related to BMI, while in men the association was positive. SPONSORSHIP: This work was financially supported by the Institute of Public Health, Tehran University of Medical Sciences.     

Dietary factors and body mass index in a group of Iranian adolescents: Tehran lipid and glucose study--2

OBJECTIVE: To study the prevalence of overweight and obesity in an adolescent population in Tehran and to determine possible association with energy and nutrient intake and distribution of energy over the day. METHOD: A cross-sectional study on 177 boys and 244 girls between 10-19 years old was performed. Overweight and obesity were defined by using recommended body mass index (BMI) cut-off values for adolescents. Total energy intake, percent of energy derived from protein, carbohydrate and fat and percent of energy supplied by each meal and snack were assessed by means of two 24-hour dietary recalls. RESULTS: Prevalence of overweight and obesity was 10.7 and 5.1 in boys and 18.4 and 2.8 in girls, respectively. The composition of diet was not different between overweight/obese and normal weight subjects. BMI was related with breakfast energy percentage in girls (r = -0.18, p < 0.01), with total energy intake in boys (r = 0.23, p < 0.01), and with lunch energy percentage in both sexes. In boys (r = 0.16, p < 0.05) and in girls (r = 0.22, p < 0.01). CONCLUSION: High prevalence of overweight and obesity among adolescents was seen. In boys some relationship between total energy intake, distribution of energy over the day and BMI was seen. In girls BMI was only related with distribution of energy over the day.     

北京海淀区中小学生BMI与素质指标相关性分析

目的探讨北京海淀区中小学生BMI与体质指标之间关系,为客观评价学生体质健康状况提供科学依据。方法采用分层随机整群抽样,抽取海淀区7～18岁中小学生1 100名为研究对象,应用方差分析、相关及偏相关对各项人体测量指标进行统计分析。结果各身体素质指标水平在不同BMI等级中差异有统计学意义,在控制年龄、性别的影响后,BMI与握力(r=0.30)、50 m跑(r=0.17)、50m×8往返跑(r=0.45)、男生1 000 m(r=0.49)、女生800 m跑(r=0.29)呈显著正相关;BMI与斜身引体(r=-0.26)、引体向上(r=-0.28)、立定跳远(r=-0.23)、仰卧起坐(r=-0.13)呈显著负相关。结论随着超重、肥胖学生比例的增加,对身体素质评价的影响也在增大;需要建立更为客观的学生体质健康综合评价体系。