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.