A comparison between body mass index and waist circumference for identifying continuous metabolic syndrome risk score components in Iranian school-aged children using a structural equation modeling approach: the CASPIAN-V study.

PURPOSE: The purpose of this study was to investigate the association of anthropometric indices with continuous metabolic syndrome (cMetS) risk score components in a large population-based sample of children and adolescents. METHODS: This multi-centric study was performed on 3843 students aged 7-18 years who were selected by multistage, stratified cluster sampling method from 30 provinces of Iran. Demographic, anthropometric and biochemical factors were obtained and standardized residuals (z-scores) were calculated for MetS components. A structural equation modeling approach was applied to evaluate the relationships among the study variables and to implement the subsequent structural modeling. RESULTS: The mean age of the participants (52.3% boys) was 12.4 ± 3.05 years. Standardized scores of body mass index (ZBMI) and waist circumference (ZWC) had a direct effect on standardized scores of mean arterial pressure (ZMAP) (0.23 and 0.24 in boys and 0.22 and 0.23 in girls, respectively) and triglyceride (ZTG) (0.07 and 0.04 in boys and 0.02 and 0.06 in girls, respectively), but the effect of ZWC was stronger than ZBMI on these variables. Age, socioeconomic status and sedentary behaviors showed a positive direct effect on ZWC (0.01, 0.05 and 0.07 in boys and 0.05, 0.08 and 0.002 in girls, respectively). These variables induced indirect effects on cMets risk score components through ZWC. CONCLUSION: The magnitude of association between WC and continuous metabolic syndrome risk score components was higher compared to BMI in school-aged children, emphasizing on paying more attention to central obesity in childhood. LEVEL OF EVIDENCE: Level V, cross-sectional descriptive study.

Association of Sunlight Exposure with Sleep Hours in Iranian Children and Adolescents: The CASPIAN-V Study.

We aimed to assess the association of sunlight exposure with sleep duration and sleep onset time in children. Data were obtained from the fifth survey of a national school-based surveillance program in Iran. Sunlight exposure time, sleep duration, sleep onset time, physical activity time, mental health status and frequency of consuming coffee and tea were recorded. Overall, 14 274 students aged 7-18 years were recruited. Sleep duration was associated positively with sex, age, body mass index and physical activity, as well as with sunlight exposure and negatively with the consumption of coffee and tea. Higher physical activity, exposure to sunlight and mental status score in children exposed to sunlight via their face, hands, arms and feet, reduced the likelihood of sleep onset time after midnight (odds ratio (OR) = 0.909, 0.741 and 0.554 respectively). Daily exposure to sunlight may increase sleep duration and advance the sleep onset time in children and adolescents.

Association between junk food consumption and cardiometabolic risk factors in a national sample of Iranian children and adolescents population: the CASPIAN-V study.

AIMS: Only a few studies have attempted to assess the relationship between junk food consumption and cardiometabolic risk factors in Iranian children and adolescents; therefore, the aim of our study was to determine the association between junk food intake and cardiometabolic risk factors in this population. STUDY DESIGN: This is a cross-sectional study. METHODS: A total of 14,400 students were selected from 30 provinces of Iran using multistage, stratified cluster sampling method. Information about student's lifestyle, health behaviors and health status was obtained through a validated questionnaire. Blood pressure was measured and anthropometric indices were calculated. Blood samples were drawn from 3,303 students for biochemical tests. In our study, sugar-sweetened beverages, salty snacks, sweets and fast foods were considered as junk foods. RESULTS: The mean age of participants was 12.42 ± 2.97 years. Those with metabolic syndrome were more likely to live in urban areas (P = 0.004) and have higher BMI (P < 0.0001). Junk food intake was not related to metabolic syndrome; however, it was associated with increased odds of high BP (OR 1.23, 95% CI 1.09, 1.39), high SBP (OR 1.38, 95% CI 1.09, 1.75), and high DBP (OR 1.18, 95% CI 1.04, 1.35), overweight (OR 1.22, 95% CI 1.08, 1.39) and excess weight (OR 1.14, 95% CI 1.04, 1.25). CONCLUSIONS: Junk food consumption plays an important role in childhood overweight and is related to high blood pressure in this population. LEVEL OF EVIDENCE: Level III, case-control analytic studies.

Association of meal skipping with subjective health complaints in children and adolescents: the CASPIAN-V study.

PURPOSE: Few studies have assessed the relationship between meal skipping with subjective health complaints in children and adolescents. The aim of our study was to determine the association between meal skipping and subjective health complaints in this population. METHODS: A total of 14,400 students aged 7-18 years were selected using multistage stratified cluster sampling method from 30 provinces of Iran. Data were collected as a part of the fifth national school-based surveillance program (CASPIAN-V) in Iran. Information about students' lifestyle, health behaviours, health status and health complaints were gathered through a validated questionnaire. RESULTS: The mean (standard deviation) age of participants was 12.3 (3.2) years old. Breakfast skipping was associated with increased odds of stomachache (OR 1.77, 95% CI 1.56, 2.00), backache (OR 1.68, 95% CI 1.46, 1.92), difficulty in getting to sleep (OR 1.66, 95% CI 1.48, 1.86), feeling nervous (OR 1.59, 95% CI 1.43, 1.76) and irritability (OR 1.29, 95% CI 1.02, 1.25). There were 27, 63, 58 and 107% increase in odds of headache, stomachache, backache and difficulty in getting to sleep by lunch skipping, respectively. While dinner skipping was related to 39, 59 and 52% increase in odds of headache, feeling low and difficulty in getting to sleep, respectively, it was associated with decreased odds of stomachache (OR 0.33, 95% CI 0.25, 0.44). CONCLUSIONS: Our study suggests that meal skipping is associated with some somatic and psychological health complaints among children; therefore, regular meal consumption, at least three times a day, is highly recommended in this population. LEVEL OF EVIDENCE: V, cross-sectional descriptive study.

Association of fruit and vegetable intake with meal skipping in children and adolescents: the CASPIAN-V study.

BACKGROUND: There are few studies on the association of main meal consumption with fruit and vegetable intake. This study aims to assess the relation between skipping main meals and fruit and vegetable intake in children and adolescents. METHODS: This multi-centric cross-sectional study was conducted in 30 provinces of Iran. This study was conducted in the framework of the fifth survey of a national surveillance program entitled Childhood and Adolescence Surveillance and Prevention of Adult Non-communicable Disease study (CASPIAN- V). 14,440 school students aged 7-18 years were assessed. Logistic regression analyses were used to evaluate the association between frequency of fruit and vegetable intake with skipping main meals. RESULTS: Overall, 14,274 students completed the study (99% participation rate). Their mean (SD) age was 12.3 (3.2) (53% were aged 6-12), 50.6% of them were boys, and 71.3% lived in urban area. In multivariate logistic regression model, statistically significant associations were found between skipping main meals and low fruits and vegetables intake. Skipping breakfast was associated with vegetables intake [OR = 1.19(95% CI 1.02-1.38)] and fruits intake [OR = 5.33(95% CI 4.46-6.37)]. Skipping lunch was associated with vegetables intake [OR = 1.61(95% CI 1.29-1.96)] and fruit intake [OR = 9.11(95% CI 6.55-12.67)]. Skipping dinner was associated with vegetables intake [OR = 1.52 (95% CI 1.15-2.01)] and fruits intake [OR = 2.21(95% CI 1.64-2.97)]. CONCLUSIONS: In this study, low frequency of fruit and vegetable intake was associated with skipping main meals. The results highlight the importance of promoting regular meal consumption with increase in the intake of fruit and vegetables among children and adolescents. LEVEL OF EVIDENCE: Level V.

Utility of waist circumference-to-height ratio as a screening tool for generalized and central obesity among Iranian children and adolescents: The CASPIAN-V study.

BACKGROUND: Waist-to-height ratio (WHtR) is regarded as a simple anthropometric index for evaluating central adiposity because of its independence of age, gender, and ethnicity. OBJECTIVE: The purpose of this study was to determine the optimal WHtR cutoff value in screening obesity and to compare it with other obesity indicators including body mass index (BMI) and waist circumference (WC) in Iranian children and adolescents. METHODS: This large survey was conducted on 14 274 Iranian children and adolescents as a national school-based surveillance study (CASPIAN) in 2015. The receiver operating characteristic curve analysis was performed to estimate the optimal cut-off points of WHtR for the prediction of general and central obesity. The area under curve (AUC) was used to compare the ability of WHtR cut-off points, BMI and WC percentiles to discriminate students with and without obesity according to age and sex. RESULTS: The optimal WHtR cutoff value for predicting general obesity was 0.49 and 0.48 for boys and girls, respectively and for central obesity according to WC ≥ 90th percentile was 0.50 for both genders. AUC values of WHtR for predicting general and central obesity were 87% and 96%, which indicates its strong predictive ability. For central obesity, the AUCs of WHtR were superior to those of WC percentiles. The kappa agreement coefficient was 0.55 between WC ≥ 90th percentile and WHtR ≥ 0.5. CONCLUSIONS: The WHtR ≥ 0.5 as a simple and useful screening tool is better than WC, for predicting general and central obesity in different age and sex groups of Iranian children and adolescents.

Is single-child family associated with cardio-metabolic risk factors: the CASPIAN-V study.

BACKGROUND: In the present study, the association of the cardio-metabolic risk factors and the status of single-child family were studied in a national representative sample of Iranian children and adolescents. METHODS: This cross sectional study was conducted as the fifth round of "Childhood and Adolescence Surveillance and PreventIon of Adult Non- communicable disease" surveys. The students' questionnaire was derived from the World Health Organization-Global School Student Health Survey. Using survey data analysis methods, data from questionnaires'; anthropometric measures and biochemical information analyzed by logistic regression analysis. RESULTS: Overall, 14,274 students completed the survey (participation rate: 99%); the participation rate for blood sampling from students was 91.5%. Although in univariate logistic regression model, single child students had an increased risk of abdominal obesity [OR: 1.37; 95% CI: 1.19-1.58)], high SBP [OR: 1.58; 95% CI:1.17-2.14)], high BP [OR: 1.21; 95% CI:1.01-1.45)] and generalized obesity [OR: 1.27; 95% CI:1.06-1.52)], in multiple logistic regression model, only association of single child family with abdominal obesity remained statistically significant [OR: 1.28; 95% CI:1.1-1.50)]. Also in multivariate logistic regression model, for each increase of a child in the family the risk of abdominal obesity [OR: 0.95; 95% CI: 0.91-0.97), high SBP [OR: 0.88; 95% CI: 0.81-0.95)] and generalized obesity [OR: 0.95; 95% CI: 0.91-0.99)] decreased significantly. CONCLUSION: The findings of this study serve as confirmatory evidence on the association of cardio-metabolic risk factors with single-child family in children and adolescents. The findings of study could be used for better health planning and more complementary research.

Validity of triglyceride-glucose index as an indicator for metabolic syndrome in children and adolescents: the CASPIAN-V study.

PURPOSE: The purpose of this study was to determine the cut-off values of triglycerides and glucose (TyG) index as one of the indirect indices for metabolic syndrome (MetS) in a pediatric population. METHODS: This national study was conducted in 2015 on 14400 students, aged 7-18 years. They were selected by random cluster sampling from 30 provinces of our country during the fifth survey of a national school-based surveillance program. MetS was defined based on the Adult Treatment Panel III (ATP III) criteria modified for the pediatric age group. The cut-off values of TyG index for MetS were obtained using the receiver operation characteristic (ROC) curve analysis by gender and age groups. RESULTS: Totally, 3843 students (52.3% boys) with mean (SD) age of 12.45 (3.04) years were assessed. The area under the ROC curve of TyG index for MetS was 0.83 in total participants. According to the ATP III criteria the cut-off values of the TyG index were 8.33 (8.21-8.45) in total students, 8.47 (8.36-8.58) in boys, and 8.33 (8.18-8.48) in girls. In the 7-12 and 13-18 years' age groups, these values were 8.47 (8.32-8.63) and 8.34 (8.22-8.45) in total, 8.39 (8.26-8.52) and 8.47 (8.33-8.61) in boys, 8.33 (8.11-8.55) and 8.35 (8.22-8.47) in girls, respectively. CONCLUSION: The findings of this study can be clinically helpful for screening MetS in children and adolescents but the effectiveness of these criteria needs to be evaluated by further longitudinal surveys. LEVEL OF EVIDENCE: Level V, cross-sectional descriptive study (National surveillance study).

Association of anthropometric indices with continuous metabolic syndrome in children and adolescents: the CASPIAN-V study.

PURPOSE: This study aims to examine the association of anthropometric indices with continuous metabolic syndrome (cMetS) among Iranian children and adolescents. METHODS: This multicentric study was conducted on 14138 students aged 7-18 years, who participated in a national surveillance program. Fasting blood sample was obtained from a subsample of 3843 randomly selected students. Physical examination including the measurement of anthropometric indices and blood pressure was conducted; fasting blood glucose and lipid profile were measured; and cMetS score was computed. Standardized residuals (z-scores) were calculated for MetS components. A higher cMetS score indicates a less favorable metabolic profile. Linear regression models were applied to determine the association between cMetS and anthropometric indices. RESULTS: The study participants consisted of 3843 children and adolescents (52.3% boys) with mean (SD) age of 12.45 ± 3.04 years. All anthropometric indices had positive correlation with standardized scores of mean arterial pressure, waist circumference and cMetS (P < 0.05). Standardized scores of triglycerides were positively correlated with weight and body mass index (P < 0.05). In multivariate model, general and abdominal obesity, as well as high circumferences of neck, wrist, and hip circumferences increased the standardized cMetS risk score to 1.8, 1.9, 1.6, 1.5 and 1.5, respectively (P < 0.05 for all variables). CONCLUSION: The results demonstrated that higher anthropometric indices are associated with higher cMetS risk score in children and adolescents. This information could be valuable for screening and prevention of MetS at population level. LEVEL OF EVIDENCE: V, cross-sectional descriptive study (National surveillance study).

Socioeconomic difference in physical activity in children and their parents: The childhood and adolescence surveillance and prevention of adult noncommunicable disease study.

Background: As a health-related behavior, physical activity (PA) differs according to individual's socioeconomic status (SES). This study aimed to assess the socioeconomic difference in leisure-time PA among Iranian students and their parents at national and regional levels. Study Design: Nationwide cross-sectional study. Methods: This study was conducted as part of a national survey conducted in 2015 among 14400 Iranian students and their parents. Total PA level was measured as the average hours spent on PA per week. Nonlinear principal component analysis was used to construct the households' SES based on household's assets, type of house ownership, occupation of fathers and the educational levels of fathers and mothers. Concentration index was applied to measure the inequality in the PA level in parents and students. Results: Complete data of 13313 students and their parents were available. At the national level, students spent more hours of PA per week (3.753 h per week [h/w]) as compared to their parents. Moreover, PA h/w was higher in fathers (3.488 h/w) as compared to mothers (2.763 h/w). The lowest means of mother's and student's PA were found in the highest SES region. At national level, the concentration indices (CI) of father's and mother's PA were -0.050 (95% CI = -0.067 ~ -0.030) and -0.028 (95% CI = -0.044 ~ -0.012), respectively, indicating pro-poor inequality, but the CI value of student PA was non-significant (CI = -0.007, 95% CI = -0.023-0.008). Conclusions: Given that the mother's and student's PA level was low in the high SES regions, it is suggested that focused PA planning may further increase the level of PA across higher SES regions and might be effective in reducing the PA inequality.

Tri-ponderal mass index and body mass index in prediction of pediatric metabolic syndrome: the CASPIAN-V study.

Objective Body mass index (BMI) and tri-ponderal mass index (TMI) are anthropometric measures to evaluate body adiposity in the various age groups. The present study aims to compare the predictive value of TMI and BMI for metabolic syndrome (Mets) in children and adolescents of both genders. Subjects and methods A cross-sectional study conducted on 3731 Iranian children and adolescents aged 7-18 years obtained from the fifth survey of 'Childhood and Adolescence Surveillance and Prevention of Adult Non-communicable Disease' (CASPIAN-V) study. The predictive value of BMI and TMI for MetS were determined using Receiver-operator curves. Logistic regression analysis was used to assess the relationship between these indices with MetS. Results 52.6% of participants were boys. The mean (standard deviations) age for boys and girls were 12.62 (3.02) and 12.25 (3.05) years, respectively. In boys, the area under the curve (AUC) of TMI was greater than BMI for all age groups. AUC of TMI was also greater than BMI for age group of 11-14 years (AUC = 0.74; 95% CI (0.67, 0.81)) in girls. Furthermore, our findings showed that odds ratio of Mets for TMI was greater than BMI in age groups of 11-14 years (OR = 1.33 vs 1.22) and 15-18 years (1.16 vs 1.15) in girls and boys, respectively. Conclusion TMI and BMI had moderate predictive value for identifying MetS. However, TMI was a better predictor of MetS than BMI in both genders, especially in age groups of 11-14 and 15-19 years for girls and boys.

Association of Alanine Aminotransferase With Different Metabolic Phenotypes of Obesity in Children and Adolescents: The CASPIAN-V Study.

Aim: To determine the association of alanine aminotransferase with different metabolic phenotypes of obesity in a nationally- representative sample of Iranian children and adolescents. Methods: This national study was conducted in the framework of the fifth survey of a national surveillance program entitled Childhood and Adolescence Surveillance and Prevention of Adult Non-communicable Disease study. Participants consisted of 4,200 subjects aged 7-18 years, who were recruited by multistage random cluster sampling from 30 provinces in Iran. They were categorized to normal weight and obese groups and in each group those with and without MetS components. Results: Overall, 3,843 of participants completed the survey (response rate: 91.5%). Their mean (SD) age was 12.58 (3.15) years; 52.6% were boys, and 72.7% lived in urban areas. Mean of alanine aminotransferase (ALT) in subjects with abdominal obesity and general obesity was 8.81 (95% CI: 7.99-9.62) (IU/L) and 8.87 (95% CI: 7.28-10.46) (IU/L), respectively. According to the adjusted model, one unit increment in ALT increased odds of being metabolically non-healthy obese (MNHO) by 2% compared to metabolically healthy non-obese (MHNO) [adj.OR (95% CI): 1.02 (1.01-1.04)]. Also, subjects in the third and fourth quartiles of serum ALT had significantly greater odds of being MNHO than those in its first quartile [Q3/Q1: adj. OR (95% CI): 3.85 (1.70-8.71); Q4/Q1: Adj. OR (95% CI): 3.63 (1.51-8.73)]. Conclusion: This large population-based study revealed significant associations between metabolic phenotypes of obesity and ALT level.

Factors Associated with Tendency for Weight Loss in a Representative Sample of Children and Adolescents: The CASPIAN-V Study.

BACKGROUND: This study aims to determine the factors affecting the tendency to lose weight (TLW) and its methods in Iranian children and adolescents. METHODS: In this cross-sectional nationwide study 14800 students, aged 7-18 years, living in 30 provinces of Iran were selected via multistage cluster random sampling method. The dietary and physical activity habits and TLW as well as psychosocial health status, anxiety, self-satisfaction, and change in dietary behaviors were assessed by the global school-based student health survey (WHO-GSHS) questionnaire. Multivariate logistic regression model was used to identify factors influencing TLW. RESULTS: Overall, 14274 students (participation rate of 99%), consisting of 51% boys and 71.4% urban residents, completed the study. Of them, 37.7% (51.4% Girls and 48.6% boys) tended to lose weight. In multivariate model, the odds for TLW was 12% higher in students aged 13-18 years than those aged 6-12 years (OR = 1.12, 95% CI: 1.02 to 1.23; P < 0.001). Students with high anxiety level were 43% more likely to have TLW (OR = 1.43, 95% CI: 1.28-1.59; P < 0.001). The odds of increasing physical activity for weight loss was 22% lower in obese than in normal weight students (OR = 0.78, 95% CI: 0.66 to 0.93; P < 0.001). CONCLUSIONS: TLW was significantly higher in girls, as well as in those with higher anxiety level. In addition to dietary change, increasing physical activity should be encouraged among children and adolescents with excess weight. Public education regarding proper lifestyle change for reaching healthy weight should be underscored.

Association of sleep duration and snack consumption in children and adolescents: The CASPIAN-V study.

OBJECTIVES: The relationship between sleep deprivation and the risk of overweight and obesity is somewhat known in children and adolescents. This study aimed to investigate the relationship between sleep duration and eating snacks in a national sample of children and adolescents aged 6-18 years old. METHODS: This cross-sectional study was carried out on the data of the fifth survey of the national school-based surveillance system entitled the "Childhood and Adolescence Surveillance and PreventIon of Adult Non-communicable Disease" (CASPIAN-V) study. Short sleeping duration was defined 10 hr per day for children under 10 years and 9 hr per day for children ≥ 10 years. To assess food habits, the consumption frequency of some food groups including sweets, salty snacks, carbonated beverages, diet soft drinks, soft beer, fresh fruits, dried fruits, fresh juices, vegetables, packed juices, dairy products (milk, yogurt, and cheese), fast foods, tea, sugar along with tea, and coffee was asked using Likert scale ( never, rarely, weekly, and daily). RESULTS: In multivariate model, short sleep versus long sleep in students was associated with increased chance of eating salty snacks (OR = 1.49 [95% CI: 1.38-1.61]; p = .001), soft drinks (OR = 1.12 [95% CI: 1.04-1.20]; p = .002), fast foods (OR = 1.66 [95% CI: 1.54-1.79]; p < .001), tea (OR = 1.49 [95% CI: 1.39-1.61]; p < .001), and tea with sugar (OR = 1.13 [95% CI: 1.05-1.22]; p < .001). In addition, short sleep in students was associated with a decreased odds of daily intake of soft drinks without sugars (OR = 0.64 [95% CI: 0.58-0.70]; p < .001), soft beer (OR = 0.92 [95% CI: 0.85-0.99]; p < .001), fresh fruit (OR = 0.83 [95% CI: 0.76-0.90]; p < .001), dried fruit (OR = 0.43 [95% CI: 0.39-0.46]; p < .001), fresh fruit juice (OR = 0.66 [95% CI: 0.62-0.72]; p < .001), packed juice (OR = 0.91 [95% CI: 0.84-0.98]; p < .009), milk (OR = 0.51 [95% CI: 0.47-0.55]; p < .001), yogurt (OR = 0.86 [95% CI: 0.79-0.93]; p ≤ .001), and coffee (OR = 0.82 [95% CI: 0.76-0.89]; p ≤ .001). CONCLUSIONS: The findings of this study indicate a significant relationship between sleep duration and unhealthy food habits. Therefore, increasing awareness of families in this area may reduce obesity and its complications.

Comparing the validity of continuous metabolic syndrome risk scores for predicting pediatric metabolic syndrome: the CASPIAN-V study.

Background The aim of this study was to compare the validity of various approaches to pediatric continuous metabolic syndrome (cMetS) scores including siMS scores (2 waist/height + fasting blood glucose [FBG]/5.6 + triglycerides [TG]/1.7 + systolic blood pressure [BP]/130 + high-density lipoprotein [HDL]/1.02), Z-scores, principal component analysis (PCA) and confirmatory factor analysis (CFA) for predicting metabolic syndrome (MetS). Methods This nationwide cross-sectional study was conducted on 4200 Iranian children and adolescents aged 7-18 years. The cMetS was computed using data on HDL, cholesterol, TGs, FBG, mean arterial pressure (MAP) and waist circumference (WC). The areas under the receiver operating characteristic curves (AUCs) were used to compare the performances of different cMetS scores. Results Data of 3843 participants (52.4% boys) were available for the current study. The mean (standard deviation [SD]) age was 12.6 (3) and 12.3 (3.1) years for boys and girls, respectively. The differences in AUC values of cMetS scores were significant based on the Delong method. The AUCs (95% confidence interval [CI]) were for Z-scores, 0.94 (0.93, 0.95); first PCA, 0.91 (0.89, 0.93); sum PCA, 0.90 (0.88, 0.92), CFA, 0.79 (0.76, 0.3) and also for siMS scores 1 to 3 as 0.93 (0.91, 0.94), 0.92 (0.90, 0.93), and 0.91 (0.90, 0.93), respectively. Conclusions The results of our study indicated that the validity of all approaches for cMetS scores for predicting MetS was high. Given that the siMS scores are simple and practical, it might be used in clinical and research practice.

Decomposition of passive smoking inequality in Iranian children and adolescents: the CASPIAN-V Study.

To investigate the socioeconomic inequality in passive smoking in Iranian children and adolescents. Through a multistage random cluster sampling method, a representative sample of 14,400 school students, aged 6-18 years, were enrolled from urban and rural areas of 30 provinces of Iran. Using a non-linear principal component analysis (NLPCA), the correlated variables were summarized as socioeconomic status (SES). Normalized concentration index (NCI) was used to measure inequality in passive smoking at national and regional SES levels. We decomposed total socioeconomic inequality in passive smoking into explanatory variables to identify the main contributors of inequality in passive smoking in the population studied. Data of 12,327 students and parents were complete for the current study. The response rate was 85.6% (50.9% boys, 71.2% urban residents). About 44% of Iranian students were exposed to passive smoking. The NCI for passive smoking at a national level was - 0.043 (95% confidence interval - 0.035, - 0.012), indicating that passive smoking was more concentrated among poorer children and adolescents. This inequality was statistically significant at a national level and in all regions except for regions with lower middle- and lowest SES levels. Considering the decomposition analysis, the household SES (63%), mothers' educational level (37%), fathers' educational level (29%), and school type (18%) made the largest positive contribution to inequality in passive smoking of children and adolescents. Passive smoking was distributed unequally among Iranian children and adolescents; it was more concentrated among socioeconomically disadvantaged families. Public health policies attentions should be given to reduce passive smoking among low SES children and adolescents living with illiterate or low-educated parents.

Association of Anthropometric Indices With Metabolic Phenotypes of Obesity in Children and Adolescents: The CASPIAN-V Study.

Background: Obesity, particularly in the upper part of the body, is a major health problem. Measuring the neck circumference (NC) and wrist circumference (WrC) is a relatively new method of differentiating between normal and abnormal fat distributions. This study aimed to evaluate the association of NC, hip circumference (HC), and WrC with different phenotypes of obesity and their metabolic status. Methods: In this multi-centric cross-sectional study, 4,200 students aged 7-18 years were selected from 30 provinces in Iran in 2014 by using a multistage cluster random sampling method. Metabolic syndrome (MetS) was defined based on the ATP III criteria modified for the pediatric age group. The subjects were classified into four groups according to their weight and metabolic status: metabolically healthy obese (MHO), metabolically non-healthy non-obese (MNHNO), metabolically non-healthy obese (MNHO), and metabolically healthy non-obese (MHNO). Results: Significant but different associations of NC, HC, and WrC with obesity phenotypes were documented in the entire population. Significant but different associations of NC, HC, and WrC with metabolic phenotypes were also found in the entire population. In the multinomial logistic regression, the association of the different obesity phenotypes with the study anthropometric indices increased significantly with increasing NC, WrC, and HC. Also, per one unit increment in NC, HC, and WrC, the odds of MHO, MNHNO, and MNHO increased compared to that of the MHNO phenotype. Conclusion: In children and adolescents, HC, NC, and WrC are significantly associated with obesity phenotypes and their metabolic status, and these metrics are suggested to be innovative, low-cost, and alternative tools for assessing them in different age and sex pediatric age groups.

Passive smoking and cardiometabolic risk factors in Iranian children and adolescents: CASPIAN-V study.

BACKGROUND: Smoking behavior as a harmful trend among adolescents and young adults has increased over last two decades. Many children and adolescents are at the risk of "second-hand" smoking at home due to their exposure to parents' or siblings' smoking. These second hand smokers are called "passive smokers" and are at risk of several health complications like cardiometabolic risk factors. OBJECTIVES: The present study aims to evaluate the association between passive smoking and increase of cardiometabolic risk factors in a sample of Iranian's children and adolescents, aged 7-18 years. METHODS: This multicenter cross-sectional study was carried out over 14,400 students (aged 7-18 years). Blood sampling were randomly collected from a sub-sample of 4200 selected pupils. According to their degree of exposure to smoke for both cigarette and hookah, water pipes that are used to smoke specially made tobacco that comes in different flavors, all participants were divided to the two separate groups of positive and negative exposure. Metabolic syndrome (MetS) is defined as a constellation of at least three out of five cardiometabolic risk factors, including abdominal obesity, elevated blood pressure, elevated fasting plasma glucose concentration, high serum levels of triglycerides (TG), and depressed high-density cholesterol (HDL-C) levels. RESULTS: The mean and standard deviation (SD) age of participants was 12.3 ± 2.24 years. 49.4% were girls and 71.4% of them were urban residents. The mean SD for BMI of participants was 18.5 (4.7) Kg/m2. The mean TG levels were considerably higher among passive smoker children and adolescents. MetS and being overweight were found to have a major association with passive smoking (OR 1.63 CI 95% 1.17-2.29 P Value 0.004 and OR 1.21 95% CI 1.06-1.37 P Value 0.004, respectively). CONCLUSION: This study confirms that passive smoking or second-hand smoking is linked with the increased prevalence of cardiometabolic risk factors and places children and adolescents at a higher risk of being overweight. Preventive strategies could be incorporated against passive smoking to recognize it as a health priority among children and adolescents.

Determinants of taking dietary supplements in Iranian children and adolescents: the CASPIAN-V study.

AIM: Tendency for taking dietary supplements is dramatically increasing. However, limited studies exist in this regard. We aimed to assess the frequency and determinants of dietary supplement use among a nationally-representative sample of Iranian children and adolescents. METHODS: This population-based cross-sectional study (the CASPIAN V) was conducted in students aged 7 to 18 years old in 2015. Multistage, stratified cluster sampling method was used to select participants from thirty provinces in Iran. Data regarding taking vitamin and mineral supplements were collected. Demographic information, anthropometric indices, physical activity, screen time and body image were also evaluated. Multivariate logistic regression model was used for analyses. RESULTS: The prevalence of dietary supplements use was 34.1% and the most popular dietary supplement was Iron (12.9%). Multivariate logistic regression showed that boys (0.84, 95%CI: 0.78, 0.91) and body image perception (OR: 0.84, 95%CI: 0.75, 0.94) used less dietary supplements compared to others. Children aged 11 to 14 years (OR: 1.15, 95%CI: 1.06, 1.26) and those with moderate family socioeconomic status (OR: 1.12, 95%CI: 1.007, 1.25) used more supplement compared to other groups. Moreover, those with higher paternal educational level (OR: 0.77, 95%CI: 0.64, 0.93) used less supplements. However, living area, family size, paternal occupation, children BMI, Intended weight loss, and body image by student did not indicate any significant association. CONCLUSION: Our findings indicated that about one-third of Iranian children and adolescents used dietary supplements; iron supplements were the most frequent ones. Children aged 11 to 14 years, those with higher educated mothers and moderate family socioeconomic status used more supplements compared to others. However, boys, children with excess weight and those with high-educated parents used less supplements compared to others. More studies are needed to clarify the efficacy and safety of dietary supplements in different age groups in various societies.

Discriminatory ability of visceral adiposity index as an indicator for modeling cardio-metabolic risk factors in pediatric population: the CASPIAN-V study.

Introduction: The purpose of this study was to obtain the cutoff points of visceral adiposity index (VAI), a new marker of indirect evaluation of visceral fat, to assess its association with metabolic syndrome (MetS) in a population of children and adolescents. Methods: This cross sectional study was conducted on children and adolescents aged 7-18 years attended in the fifth phase of a national school-based surveillance survey. The odds ratio (OR) of cardiometabolic risk factors across tertile categories of VAI was determined using the logistic regression models and the valid cut-off values of VAI for predicting MetS was obtained using the receiver operation characteristic (ROC) curve analysis. Results: A total of 3843 students (52.3% boys, 12.3 [12.2-12.4] years) were included in the analysis. The mean of VAI was significantly higher in participants who had MetS (2.60 [2.42-2.78] vs 1.22 [1.19-1.25]; P <0.001). Participants in the third tertile compared to the first tertile category of VAI had higher odds of abdominal obesity (OR: 1.77, 95% CI: 1.43-2.20), impaired fasting blood glucose (OR: 2.00, 95% CI: 1.28-3.13) and low high-density lipoprotein cholesterol (OR: 15.93, 95% CI: 12.27-20.66). The cut-off points of the VAI for predicting MetS were 1.58, 1.30 and 1.78 in total population, boys and girls, respectively. Conclusion: We determined the cut-off points of VAI as an easy tool for detecting MetS in children and adolescents and demonstrated that VAI is strongly associated with MetS. Prospective longitudinal studies are suggested to show the possible efficiency of the VAI as a predictor of MetS in pediatrics.