Association between maternal and cord blood thyroid hormones, and urine iodine concentration with fetal growth.

OBJECTIVES: We planned to evaluate the association of fetal and maternal thyroid hormones and maternal iodine status with neonates' anthropometric parameters. METHODS: In this cross-sectional study, levels of thyrotropin were measured in maternal serum in the first trimester of pregnancy, and thyrotropin (TSH) and free thyroxin (fT4) were measured in cord blood serum samples at birth. Urinary iodine concentration (UIC) levels in random urine samples of mothers were measured in the third trimester of pregnancy. The relationship between UIC and thyroid hormone levels of mothers with neonates' anthropometric birth parameters of neonates was evaluated. RESULTS: One hundred eighty-eight mother-newborn pairs completed the study. Mean (SD) of cord blood TSH (CB-TSH), cord blood-free thyroxin (CB-FT4) values, and maternal TSH (M-TSH) levels were 8.8 (7.3) mIU/L, 1.01 (0.2) ng/dL, and 2.2 (0.9) mIU/L, respectively. After adjusting for confounders, there was a positive significant association between female neonate length and maternal TSH and log log-transformed CB TSH (LN_CB-TSH) (p<0.05). Median UIC (Q1-Q3) was 157 (53-241) µg/L, and there was no association between birth weight, birth length, and head circumferences of neonates and mothers' UIC (p>0.05). CONCLUSIONS: We found a positive correlation between maternal TSH in the first trimester of pregnancy and the birth length of newborns, and a negative correlation was observed between CB-TSH and birth length in girls, but it did not provide conclusive evidence for the relationship between maternal and neonatal thyroid hormone levels and birth weight. There was no association between maternal UIC levels in the third trimester and birth anthropometric parameters.

Validity and reliability of parent assessments of pubertal maturation among adolescent girls in Isfahan, Iran.

OBJECTIVES: The current paper presents the steps considered for validation of a questionnaire for assessment of sexual maturity among Iranian adolescent girls. METHODS: This cross-sectional study was performed in 2022 in Isfahan, Iran. Based on the Growth and Development Questionnaire that included both the Pubertal Development Scale (PDS) and Sexual Maturation Scale (SMS), two Persian questionnaires were prepared. The face validity, content validity, criterion validity, and reliability of the questionnaire were assessed. We compared agreement of two parent-reported measures of puberty, SMS and PDS, with clinical Tanner stages (TSs) as the gold standard. Percent agreement, Cohen's kappa coefficient, and Kendall's τ b were used to assess the agreement between maternal assessments with clinical TS. The intraclass correlation coefficient (ICC) and the Cronbach's α coefficient were also calculated to evaluate the reliability of the questionnaire. RESULTS: A total of 150 students aged 6-17 years with mean (SD) age of 10 (2.04) completed this study. The percentages of agreement for the mother-reported SMS in relation to clinical TS for breast stage and pubic hair stage were 60 % and 53.8 %, respectively. The percentages of agreement of the mother-reported PDS in relation to clinical TS for breast stage and pubic hair stage were 55.8 and 66 %, respectively. The weighted kappa coefficients showed moderate agreement, with weighted kappa ranging from 0.52 to 0.61. The mother-reported SMS and PDS showed high reliability. The Cronbach's alpha of the PDS and the SMS was 0.88 and 0.83, respectively. The ICC of the mother-reported SMS and the mother-reported PDS was 0.95 (0.92-0.98) and 0.97 (0.94-0.98), respectively. CONCLUSIONS: This study indicated that a maternal assessment of sexual maturity using the PDS or SMS can reliably estimate pubertal development in adolescent girls in an Iranian population.

Association of Polycyclic Aromatic Hydrocarbons Urine Metabolites with Type 1 Diabetes.

Purpose: Polycyclic aromatic hydrocarbons (PAHs) are believed to be a possible factor in the development of cancer, ischemic heart disease, obesity, and cardiovascular disease. The objective of this study was to explore the association between certain metabolites of urinary PAH and type 1 diabetes (T1D). Methods: In Isfahan City, a case-control study was carried out involving 147 T1D patients and an equal number of healthy individuals. The study measured the levels of urinary metabolites of PAHs, specifically 1-hydroxynaphthalene, 2-hydroxynaphthalene, and 9-hydroxyphenanthrene, in both the case and control groups. The levels of these metabolites were then compared between the two groups to assess any potential association between the biomarkers and T1D. Results: The mean (SD) age of participants in the case and control groups was 8.4 (3.7) and 8.6 (3.7) years old, respectively, (P > 0.05). In terms of gender distribution, 49.7% and 46% of participants in the case and control groups were girls, respectively (P > 0.05). Geometric mean (95% CI) concentrations were: 36.3 (31.4-42) µg/g creatinine for 1-hydroxynaphthalene, 29.4 (25.6-33.8) µg/g creatinine for 2-hydroxynaphthalene, and 72.26 (63.3-82.5) µg/g creatinine for NAP metabolites. After controlling for variables such as the child's age, gender, maternal and paternal education, duration of breastfeeding, exposure to household passive smoking, formula feeding, cow's milk consumption, body mass index (BMI), and five dietary patterns, it was observed that individuals in the highest quartile of 2-hydroxynaphthalene and NAP metabolites had a significantly greater odd ratio for diabetes compared to those in the lowest quartile (P < 0.05). Conclusion: Based on the findings of this study, it is suggested that exposure to PAH might be linked to an increased risk of T1D in children and adolescents. To clarify a potential causal relationship related to these findings, further prospective studies are needed.

Association between Sleep Duration and Early Pubertal Timing in Children and Adolescents: A Systematic Review and Meta-analysis.

BACKGROUND: Early puberty increases the risk of diverse health outcomes during adolescence and beyond. Several studies have explored the links between short sleep duration and early puberty worldwide. OBJECTIVE: The current systematic review and meta-analysis aimed to evaluate the association between sleep duration and early pubertal timing based on published evidence systematically. METHODS: We searched important electronic databases for articles that reported the association between childhood sleep duration and puberty timing up to October 2020. A total of 848 papers were identified from the databases and manual search. Finally, 10 studies including 23752 participants were included in the meta-analysis. We calculated the pooled effect sizes using a random or fixed effects model as appropriate. RESULTS: There was a significant inverse association between sleep duration and the risk of early puberty, longer duration of sleep was associated with 0.34% decreased odds of early puberty (OR = 0.66, 95% CI = 0.58-0.77, I2 = 96.6%). In a subgroup analysis, when pubertal status was assessed by physical examination compared with Pubertal Development Scale (PDS) or Sexual Maturation Scale (SMS), the associations between sleep duration and age of puberty were attenuated. The pooled OR (95% CI) of studies measuring pubertal timing by PDS/SMS and Tanner stage were 0.50(0.37-0.69) and 0.91(0.77-1.09), respectively. When pooling effect sizes was limited to studies that had BMI level adjustment, the association of sleep duration and early puberty was not statistically significant anymore (OR = 0.95, 95% CI = 0.89-1.01). CONCLUSION: Longer sleep duration is associated with a lower risk of early puberty in children. The association between sleep duration and risk of early puberty may be modified by other factors such as BMI. To clarify the effect of sleep duration on the risk of early puberty in children, further prospective studies are needed.

The Association between Exposure to Air Pollution and Type 1 Diabetes Mellitus: A Systematic Review and Meta-Analysis.

Background: This systematic review and meta-analysis aimed to overview the observational studies on the association of exposure to air pollution and type 1 diabetes mellitus (T1DM). Materials and Methods: Based on PRISMA guidelines, we systematically reviewed the databases of PubMed, Scopus, Embase, and Web of Science databases to determine the association of air pollution exposure and T1DM. Quality assessment of the papers was evaluated using the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) checklist for observational studies. The odds ratios (OR) and their 95% confidence intervals (CI) were calculated to assess the strength of the associations between air pollutants (gases and particulate matter air pollutants including PM10, PM2.5, NO2, volatile organic compound, SO4, SO2, O3) and T1DM. Results: Out of 385 initially identified papers, 6 studies were used for this meta-analysis. Fixed effects meta-analysis showed a significant association between per 10 µg/m3 increase in O3 and PM2.5 exposures with the increased risk of T1DM (3 studies, OR = 1.51, 95% CI: 1.26, 1.80, I 2 = 83.5% for O3 and two studies, OR = 1.03, 95% CI: 1.01, 1.05, I 2 = 76.3% for PM2.5). There was no evidence of association between increased risk of T1DM and exposure to PM10 (OR = 1.02, 95% CI: 0.99-1.06, I 2 = 59.4%), SO4 (OR = 1.16, 95% CI: 0.91-1.49, I 2 = 93.8%), SO2 (OR = 0.94, 95% CI: 0.83-1.06, I 2 = 85.0%), and NO2 (OR = 0.995,95% CI: 1.05-1.04, I 2 = 24.7%). Conclusion: Recent publications indicated that exposure to ozone and PM2.5 may be a risk factor for T1DM. However, due to limited available studies, more prospective cohort studies are needed to clarify the role of air pollutants in T1DM occurrence.

Factors related to glycemic control in children and adolescents with type 1 diabetes mellitus in Isfahan, Iran.

PURPOSE: Glycemic control is traditionally evaluated by monitoring of hemoglobin A1c (HbA1c). This study aims to explore factors related to glycemic control among pediatrics with type 1 diabetes mellitus (T1DM). METHODS: This cross-sectional study was conducted among 454 students aged 6-18 years with T1DM in 2018. Demographic and disease related information were collected by a validated questionnaire. Generalized Linear Models (GLM) were used to investigate the association of explanatory variables with HbA1c concentration. RESULTS: The mean (SD) age of the participants was 11.7(± 3.3) years. The overall prevalence of suboptimal glycemic control was 85.5% (HbA1c ≥ 7%). Results showed that post pubertal children experienced a significant decrease in HbA1c levels compared to prepubertal children (ß =-0.83, p = 0.003). Underweight children had an increase of 1.32% in HBA1c concentration compared with normal weight children (ß = 1.32, P = 0.007). We also found that participants with passive smoking had higher HBA1c levels than those without (ß = 0.536, P = 0.022). CONCLUSIONS: The results indicated that age, BMI and passive smoking and were significantly associated with HbA1c levels. It is suggested that glycemic control is related to multiple factors and the interaction of these factors with each other may have positive or negative effects on it which should be investigated in future studies. Improved understanding in this area could lead to prevention of deterioration in glycemic control.

Economic inequality in prevalence of underweight and short stature in children and adolescents: the weight disorders survey of the CASPIAN-IV study.

OBJECTIVE: The aim of this study was to determine the determinants of socio-economic inequality in the prevalence of short stature and underweight in Iranian children and adolescents. METHODS: This cross-sectional nationwide study was conducted on 36,486 participants, aged 6-18 years. This school-based surveillance (CASPIAN- IV) program and its complementary part on weight disorders evaluation was conducted in urban and rural areas of 30 provinces in Iran. In addition to physical examination, a validated questionnaire was completed from students and their parents. Socio-economic status (SES) was determined using principal component analysis, and was classified in quintile scale. Inequality in the prevalence of underweight and short stature was assessed using concentration (C) index and slop index of inequality (SII) by the Oaxaca-Blinder decomposition method. RESULTS: The prevalence (95% CI) of underweight and short stature at national level was 10.89 (10.55, 11.23) and 4.15 (3.94, 4.38), respectively; it had a downtrend from the lowest to highest SES quintile. Furthermore, the value of C for underweight and short stature was negative, i.e. inequality was in favor of high SES groups. Moreover, the prevalence gap of underweight and short stature in the first and fifth quintiles of SES was 6.58% and 5.80%, respectively. The highest proportion of this gap was explained by living area. In the multiple logistic model, odds of underweight and short stature were significantly lower in individuals with higher SES. Compared to boys, odds of underweight were decreased in girls, whereas odds of short stature were increased in them. Odds of underweight and short stature were increased in participants from rural areas than in urban areas. With increasing age, the odds of underweight and short stature decreased significantly. CONCLUSION: The results of this study showed that inequality in the prevalence of short stature and underweight was in favor of high SES groups. Moreover, living area was one of the most important determinants that explained this inequality. Therefore, this issue needs to be considered in health promotion policies.

The Association of Sleep Duration and Quality with Heart Rate Variability and Blood Pressure.

BACKGROUND: The current study was conducted to evaluate the relation of sleep duration and quality with blood pressure (BP) and heart rate variability (HRV). MATERIALS AND METHODS: This cross-sectional study was carried out in 2017 among 260 staff of a university hospital in Isfahan, Iran. They were selected by multi-stage random method from different wards. Time domain spectral analysis was used to measure a number of HRV parameters. The long-term components of the HRV were estimated using the standard deviation of the normal-to-normal interval (SDNN). The square root of the mean squared differences of successive NN intervals (RMSSD) was calculated by statistical time domain measurements; SNN50, and PNN50 were measured. Pittsburg sleep quality index (PSQI) questionnaire was used to assess sleep quality. RESULTS: Higher PSQI score correlated with lower SDANN rise (OR=0.92). Fairly bad to very good subjective sleep quality had association with lower SDANN (OR=0.43). Very high sleep latency to very low sleep latency ratio had association with lower SDANN (OR=0.39) and lower PNN50 (OR= 0.44). Sleep duration and HRV parameters had no significant association. Fairly bad sleep efficiency to very good sleep efficiency ratio was correlated with lower SDANN (OR= 0.29). Very high daytime dysfunction to very low daytime dysfunction ratio had correlation with lower SDANN (OR=0.35). Very bad compared to very good subjective sleep quality had significant correlation with higher Heart rate (HR) (B=0.03). Very high sleep latency compared to no sleep latency was associated with higher HR (B=4.74). Very high compared to very low amount of sleep disturbances correlated with higher SBP levels (B=15.2). Using sleep medication less than once a week compared with no history of taking such drugs was associated with higher HR (B=16.4). CONCLUSION: Our findings showed that poor sleep quality are adversely associated with HRV, HR and BP. This finding should be considered in clinical and preventive recommendations.

Economic inequality in prevalence of underweight and short stature in children and adolescents: the weight disorders survey of the CASPIAN-IV study

ABSTRACT Objective: The aim of this study was to determine the determinants of socio-economic inequality in the prevalence of short stature and underweight in Iranian children and adolescents. Subjects and methods: This cross-sectional nationwide study was conducted on 36,486 participants, aged 6-18 years. This school-based surveillance (CASPIAN- IV) program and its complementary part on weight disorders evaluation was conducted in urban and rural areas of 30 provinces in Iran. In addition to physical examination, a validated questionnaire was completed from students and their parents. Socio-economic status (SES) was determined using principal component analysis, and was classified in quintile scale. Inequality in the prevalence of underweight and short stature was assessed using concentration (C) index and slop index of inequality (SII) by the Oaxaca-Blinder decomposition method. Results: The prevalence (95% CI) of underweight and short stature at national level was 10.89 (10.55, 11.23) and 4.15 (3.94, 4.38), respectively; it had a downtrend from the lowest to highest SES quintile. Furthermore, the value of C for underweight and short stature was negative, i.e. inequality was in favor of high SES groups. Moreover, the prevalence gap of underweight and short stature in the first and fifth quintiles of SES was 6.58% and 5.80%, respectively. The highest proportion of this gap was explained by living area. In the multiple logistic model, odds of underweight and short stature were significantly lower in individuals with higher SES. Compared to boys, odds of underweight were decreased in girls, whereas odds of short stature were increased in them. Odds of underweight and short stature were increased in participants from rural areas than in urban areas. With increasing age, the odds of underweight and short stature decreased significantly. Conclusions: The results of this study showed that inequality in the prevalence of short stature and underweight was in favor of high SES groups. Moreover, living area was one of the most important determinants that explained this inequality. Therefore, this issue needs to be considered in health promotion policies.

Association of Screen Time with Sleep Duration in School-Aged Children; a Nationwide Propensity Score­Matched Analysis: The CASPIAN­V Study.

BACKGROUND: This study aims to determine the association of sleep duration with screen time in children and adolescents. STUDY DESIGN: A matched case-control study. METHODS: This nationwide study was conducted in 2015 among 14,274 students aged 7-18 years, and one of their parents who lived in 30 provinces in Iran. Data collection was performed using questionnaires and physical examination. Watching television and working with computer were categorized into two groups (<2 h/day and ≥2 h). Moreover short sleep duration was defined as sleep duration ≤ 8 h/day. The analysis was conducted based on the propensity score using a matched case-control study design. Data analysis was performed by a conditional logistic regression. RESULTS: Overall, 14,274 students and one of their parents completed the survey (participation rate: 99%). Mean (standard deviation) age of students was 12.3 (3.2) years, and the frequency of short sleep was (4672) 33.5% .In total, 54.3% of students watched TV ≥2 h/day and 9% of those used a computer ≥2 h/day in their leisure time. In the multivariate model, Individuals who watched TV ≥2 h/day had significantly higher odds of short sleep (OR 1.13, 95% CI 1.03, 1.24), and individuals who worked with computer ≥2 h/day had significantly higher odds of short sleep (OR 1.65, 95% CI 1.40, 1.94). CONCLUSION: This study revealed significant association between watching TV and using computer during leisure time with insufficient sleep. Public awareness should be provided regarding the adverse effects of screen use on sleep. Developing special guide lines and educational school programs on restricting screen time and increasing physical activities should be considered as a health priority for children and adolescents.

Association of sleep duration with metabolic syndrome and its components in children and adolescents; a propensity score-matched analysis: the CASPIAN-V study.

OBJECTIVE: This study aims to evaluate the association of sleep duration with metabolic syndrome (MetS) and its components in a pediatric population. METHODS: This multi-centric cross-sectional study was conducted in 2015 in 30 provinces of Iran. Participants consisted of 4200 school students aged 7-18 years, studied in a national school-based surveillance program (CASPIAN-V). Physical examinations and laboratory tests were performed using standard protocols. The analysis was conducted based on the propensity score matching and conditional logistic regression was used to evaluate the association of short sleep (less than 8 h a day) and the onset of sleep with MetS and its components. Results of conditional logistic regression was reported as odds ratios (OR) and 95% confidence intervals (CI). RESULTS: Overall, 3843 of participants completed the survey (response rate: 91.5%). Their mean (SD) age was 12.3 (3.2) years and 50.6% were boys. In the multivariate model, individuals who slept less than 8 h a day had significantly higher odds of MetS (OR 2.05, 95% CI 1.19-3.63) and high blood pressure (BP) (OR 1.46, 95% CI 1.04-2.06). Association between short sleep duration with other MetS components (including abdominal obesity, hypertriglyceridemia, hyperglycemia, and low levels of high-density lipoprotein-cholesterol was not statistically significant (P > 0.05). Moreover, association between the onset of sleep with MetS and its components was not statistically significant (P > 0.05). CONCLUSION: Short sleep duration is associated with increased risk of MetS and high BP in children and adolescents. The clinical impact of current findings should be assessed in future longitudinal studies.

Association of benzene exposure with insulin resistance, SOD, and MDA as markers of oxidative stress in children and adolescents.

Benzene is a ubiquitous environmental pollutant with various health effects. It is reported that benzene exposure might be associated with insulin resistance in elderly adults. The aim of this study is to investigate the association between urinary benzene metabolite, trans, trans-muconic acid (t,t-ma) and markers of oxidative stress and insulin resistance in children and adolescents. This cross-sectional study was conducted in 2017 among 86 children and adolescents, aged 6-18 years, living in Isfahan, Iran. t,t-ma was measured as urinary benzene metabolite and homeostasis model assessment (HOMA-IR) was determined as an index of insulin resistance. Moreover, malondialdehyde (MDA) and superoxide dismutase (SOD) were assessed as oxidative stress markers. We found significant association between insulin resistance, fasting blood glucose, and fasting blood insulin with t,t-ma (p values = 0.002, 0.03, and 0.001, respectively). Results of this study indicate that benzene metabolite in higher concentrations in comparison with lower concentrations is associated with increased risk of insulin resistance. Moreover, after adjustment for age, sex, and household passive smoking, statistically significant increase were documented in SOD and MDA (4.49- and 3.54-fold, respectively) in intermediate levels of t,t-ma vs. low levels of t,t-ma (p values = 0.01 and 0.034, respectively). To the best of our knowledge, this is the first study in its kind in the pediatric age group. It showed that benzene exposures, even in environmental levels, might be associated with insulin resistance and oxidative stress in children and adolescents. Further longitudinal studies are necessary to assess the clinical impacts of this finding.

Association of dietary patterns with continuous metabolic syndrome in children and adolescents; a nationwide propensity score-matched analysis: the CASPIAN-V study.

OBJECTIVE: This study aims to determine the association of dietary patterns with metabolic syndrome (MetS) and its components in children and adolescents. METHODS: This nationwide study was conducted in 2015 among 4200 students aged 7-18 years, who lived in 30 provinces in Iran. The analysis was conducted based on the propensity score using a matched case-control study design. Three dietary patterns were obtained conducting a principal component analysis with a varimax rotation on 16 dietary groups. Continuous MetS score was computed by standardizing the residuals (z-scores) of MetS components by regressing them according to age and sex. The gold standard diagnosis of MetS was considered based on the International Diabetes Federation criteria. Moreover, for the purpose of data analysis, matched logistics analysis was used. RESULTS: The study participants consisted of 3843 children and adolescents (response rate 91.5%) with mean (SD) age of 12.45 (3.04) years. Totally 49.4% of students were girls and 71.4% lived in urban areas. Three dietary patterns were obtained: Healthy, Western, and Sweet. Prevalence of MetS was 5% (boy 5.5 and girl 4.5%). Results of multivariate analysis show that students with Sweet dietary patterns were at higher risk for abdominal obesity (OR 1.29; 95% CI 1.01-1.66), elevated blood pressure (OR 1.35; 95% CI 1.01-1.81) and MetS (OR 1.33; 95% CI 1.02-1.74). The two other dietary patterns were not associated with MetS and its components. CONCLUSION: Sweet dietary pattern increase the risk of MetS and some its components in Iranian children and adolescents. This finding provides valuable information for effective preventive strategies of MetS based on diet rather than medication to maintain healthy lifestyle habits.

Effect of Exposure to Air Pollution on Placental Weight in Isfahan-Iran.

Objective: To determine the effect of Air Quality Index (AQI) in the first trimester of pregnancy on birth weight, placental weight, and the ratio of placental weight to the birth weight (pw-bw) in Isfahan. Materials and methods: This cross-sectional study was done on 312 consecutive pregnant women in Beheshti Hospital in Isfahan city in 2013. Information on air pollution was received from the Environmental department of Isfahan. Average exposure to air pollution in the first trimester of pregnancy was calculated for eachpregnant woman. In order to compare quantitative and qualitative variables, analysis of variance (ANOVA), and chi-square were applied. After that, the multiple linear regression analysis was used to assess the association the Air Quality Index (AQI) on birth weight, placental weight and the ratio of pw-bw. Potential confounders including age, baby gender, smoking of husband, maternal BMI, maternal occupation, and education and mother's residential area were considered. A statistical significant association were considered for P-value less than 0.05. Results: The findings showed that there is inverse relationship between exposure to air pollution and placental weight in the first trimester of pregnancy after controlling potential confounders (ß = -2.57, p-value = 0.008). The inverse relationship between air pollution and the ratio of pw-bw was found. (ß = -0.001, p-value = 0.002). Conclusion: The results of this study suggest that air pollution is associated with newborns' health which in turn is a warning alarm for considering some actions in both sides of reducing the air pollution and teaching the pregnant women about the adverse effects of air pollution on the pregnancy outcomes.

Factors Associated with Screen Time in Iranian Children and Adolescents: The CASPIAN-IV Study.

BACKGROUND: Prolonged screen time is frequent in children and adolescents. Implementing interventions to reduce physical inactivity needs to assess related determinants. This study aims to assess factors associated with screen time in a national sample of children and adolescents. METHODS: This nationwide study was conducted among 14,880 students aged 6-18 years. Data collection was performed using questionnaires and physical examination. The World Health Organization-Global School Health Survey questionnaire was used. Logistic regression analysis was used to examine the relationship between demographic variables, socioeconomic status (SES), family structure, physical activity, unhealthy eating habits, body mass index, and mental distress with screen time. RESULTS: The participation rate was 90.6% (n = 13,486), 50.8% were male, and 75.6% lived in urban areas. Mean (standard deviation) age of participants was 12.47 (3.36) years. The SES, eating junk foods, urban residence, and age had significant association with screen time, watching television (TV), and computer use (P < 0.05). With increasing number of children, the odds ratio of watching TV reduced (P < 0.001). Statistically, significant association existed between obesity and increased time spent watching TV (P < 0.001). Girls spent less likely to use computer and to have prolonged screen time (P < 0.001). Participants in the sense of worthlessness were less likely to watch TV (P = 0.005). Screen time, watching TV, and using computer were higher in students with aggressive behaviors (P < 0.001); screen time was higher in those with insomnia. CONCLUSIONS: In this study, higher SES, unhealthy food habits, and living in urban areas, as well as aggressive behaviors and insomnia increased the risk of physical inactivity.

Is snack consumption associated with meal skipping in children and adolescents? The CASPIAN-IV study.

PURPOSE: The present inquiry set to assess the relationship between snack consumption and meal skipping in Iranian children and adolescents. METHODS: Overall, 14,880 students, aged 6-18 years, were selected via multistage cluster sampling method from rural and urban areas of 30 provinces of Iran. A validated questionnaire of food behaviors including questions on snacks consumption and taking/skipping meals was completed. Consuming and skipping meals and their related factors were reported in both crude and adjusted models. RESULTS: Overall, 13,486 students with a mean age of 12.47 ± 3.36 years completed the study (90.6% participation rate). Among them, 32.08, 8.89, and 10.90% skipped breakfast, lunch, and dinner, respectively. Compared to their counterpart groups, the frequency of meal skipping was higher in girls, urban inhabitants, and students in higher school grades (P < 0.05). Snack consumption was associated with an increased odds ratio of meal skipping in many types of snack groups. CONCLUSIONS: Meal skipping and snack consumption were frequent among Iranian children and adolescents. Evidence based interventions are proposed to improve the students' eating habits.

Association between screen time and snack consumption in children and adolescents: The CASPIAN-IV study.

BACKGROUND: The relationship between screen time (ST) and the frequency of snack consumption in a national sample of Iranian children and adolescents was assessed. The present nationwide survey was conducted on 14,880 school students living in urban and rural areas of 30 provinces in Iran. Trained healthcare providers conducted the physical examination and completed the questionnaire of the World Health Organization - Global School-Based Student Health Survey (WHO-GSHS). METHODS: The association between ST (total time spent watching TV and using a computer in leisure time) and the frequency of snack consumption was determined using ordinal logistic regression analysis. The subjects were 13,486 students out of the 14,880 invited including 50.8% boys. The mean (SD) age of participants was 12.47 (3.36) years. RESULTS: In multivariate models, for students who had prolonged ST (more than 4 h/day), the odds of daily consumption of sweets (odds ratio, OR 1.25; 95% CI 1.14-1.4), salty snacks (OR 1.6; 95% CI 1.5-1.76), soft drinks (OR 1.52; 95% CI 1.4-1.7), canned fruit juice (OR 1.3; 95% CI 1.2-1.4), and fast food (OR 1.53; 95% CI 1.4-1.7) were higher compared to those with low ST. Furthermore, the odds of daily consumption of milk in students who had prolonged ST (more than 4 h/day) were lower compared to those with low ST (OR 0.9; 95% CI 0.8-0.99). CONCLUSIONS: Prolonged time spent watching TV and using a computer during leisure time might be associated with unhealthy dietary habits. Moreover, inactivity induced by prolonged ST may also lead to unhealthy dietary habits and in turn excess weight in children and adolescents.