Gender Differences in Respiratory Health of School Children Exposed to Rail Yard-Generated Air Pollution: The ENRRICH Study.

Studies about environmental burdens often explore overall community risk. Increasing evidence suggests, however, differential burdens by gender and age. The purpose of the authors' research was to determine if gender-related difference exists among children in a region plagued with poor air quality and if increased exposure to pollutants from a major goods movement rail yard influences the relationship. Using a cross-sectional study design, the authors provided respiratory screening for children at two elementary schools. Compared to females, males were at significantly greater odds of exhibiting elevated fractional exhaled nitric oxide (FeNO) but less likely to exhibit reduced lung volume. Even in an area of overall poor air quality, the authors found that male children were a vulnerable subpopulation for greater elevated FeNO, while females were at increased risk for reduced lung capacity. Understanding differential burdens in vulnerable subpopulations is critical to providing timely and responsive strategies targeted towards health-based prevention and intervention activities.

Early-life influences on obesity: from preconception to adolescence.

The double burden of under- and overnutrition profoundly affects human health globally. According to the World Health Organization, obesity and diabetes rates have almost doubled worldwide since 1980, and, in 2011, more than 40 million children under 5 years of age were overweight. Ecologic factors, parental genetics and fitness, and the intrauterine environment significantly influence the likelihood of offspring developing the dysmetabolic diathesis of obesity. This report examines the effects of these factors, including preconception, intrauterine and postnatal energy balance affecting programming of transgenerational transmission, and development of chronic diseases later in life-in particular, diabesity and its comorbidities.

Associations of season and region on objectively assessed physical activity and sedentary behaviour.

Seasonal and regional variation may influence physical activity (PA) patterns. These associations are in need of further investigation. The objective of the current study was to examine the association of season and region on objectively measured PA. The study was designed as a cross-sectional study with 1172 participants living in Sweden. Data on PA were collected throughout a calendar year using accelerometry. Regions were categorised as south (Götaland), central (Svealand) and north (Norrland). Outcome variables included accelerometer-measured mean counts per minute, sedentary time and time in low intensity and moderate-intensity physical activity (MVPA) or greater. ANCOVA was used to determine the associations of season and region with PA, adjusting for sex, age, body mass index (BMI) and education. The results showed that during the Spring season more time was spent in MVPA than during the Autumn. For participants living in the south of Sweden, a significant trend for season was found for MVPA, with Spring having the highest MVPA (P = 0.025). Season had a borderline significant association with MVPA or higher intensity activities (P = 0.051). No significant effects of region or season on total PA, low-intensity PA and sedentary periods of time were observed. The results indicate that studies conducted in a population living in high latitudes, may not be significantly affected by seasonality or region when assessing PA.

Nutrient profiles of vegetarian and nonvegetarian dietary patterns.

BACKGROUND: Differences in nutrient profiles between vegetarian and nonvegetarian dietary patterns reflect nutritional differences that can contribute to the development of disease. OBJECTIVE: Our aim was to compare nutrient intakes between dietary patterns characterized by consumption or exclusion of meat and dairy products. DESIGN: We conducted a cross-sectional study of 71,751 subjects (mean age=59 years) from the Adventist Health Study 2. Data were collected between 2002 and 2007. Participants completed a 204-item validated semi-quantitative food frequency questionnaire. Dietary patterns compared were nonvegetarian, semi-vegetarian, pesco vegetarian, lacto-ovo vegetarian, and strict vegetarian. Analysis of covariance was used to analyze differences in nutrient intakes by dietary patterns and was adjusted for age, sex, and race. Body mass index and other relevant demographic data were reported and compared by dietary pattern using χ(2) tests and analysis of variance. RESULTS: Many nutrient intakes varied significantly between dietary patterns. Nonvegetarians had the lowest intakes of plant proteins, fiber, beta carotene, and magnesium compared with those following vegetarian dietary patterns, and the highest intakes of saturated, trans, arachidonic, and docosahexaenoic fatty acids. The lower tails of some nutrient distributions in strict vegetarians suggested inadequate intakes by a portion of the subjects. Energy intake was similar among dietary patterns at close to 2,000 kcal/day, with the exception of semi-vegetarians, who had an intake of 1,707 kcal/day. Mean body mass index was highest in nonvegetarians (mean=28.7 [standard deviation=6.4]) and lowest in strict vegetarians (mean=24.0 [standard deviation=4.8]). CONCLUSIONS: Nutrient profiles varied markedly among dietary patterns that were defined by meat and dairy intakes. These differences are of interest in the etiology of obesity and chronic diseases.

Vegetarian dietary patterns are associated with a lower risk of metabolic syndrome: the adventist health study 2.

OBJECTIVE: The study objective was to compare dietary patterns in their relationship with metabolic risk factors (MRFs) and the metabolic syndrome (MetS). RESEARCH DESIGN AND METHODS: Cross-sectional analysis of 773 subjects (mean age 60 years) from the Adventist Health Study 2 was performed. Dietary pattern was derived from a food frequency questionnaire and classified as vegetarian (35%), semi-vegetarian (16%), and nonvegetarian (49%). ANCOVA was used to determine associations between dietary pattern and MRFs (HDL, triglycerides, glucose, blood pressure, and waist circumference) while controlling for relevant cofactors. Logistic regression was used in calculating odds ratios (ORs) for MetS. RESULTS: A vegetarian dietary pattern was associated with significantly lower means for all MRFs except HDL (P for trend < 0.001 for those factors) and a lower risk of having MetS (OR 0.44, 95% CI 0.30-0.64, P < 0.001) when compared with a nonvegetarian dietary pattern. CONCLUSIONS: A vegetarian dietary pattern is associated with a more favorable profile of MRFs and a lower risk of MetS. The relationship persists after adjusting for lifestyle and demographic factors.

Associations between physical activity, fitness, and academic achievement.

OBJECTIVES: To explore the associations between objectively assessed intensity levels of physical activity and academic achievement and test whether cardiovascular fitness mediates the association between physical activity and academic achievement. STUDY DESIGN: Cross-sectional data were gathered in Swedish 9th-grade students (n = 232; mean age = 16 years; 52% girls). School grades, pubertal phase, skinfold thickness, cardiovascular fitness, and physical activity were measured objectively. Mother's education, family structure, and parental monitoring were self-reported. Data were analyzed with linear regression analyses. RESULTS: After controlling for confounding factors, academic achievement was associated with vigorous physical activity in girls (beta = .30, P < .01; explained variance of the model 26%), which remained after inclusion of fitness (beta = .23, P < .05; explained variance 29%). The association was not mediated by fitness. In boys, academic achievement was associated with pubertal phase (beta = .25, P < .05). After inclusion of fitness, it was only associated with fitness (beta = .25, P < .05; explained variance of the model 30%). CONCLUSION: In girls, academic achievement was associated with vigorous physical activity and not mediated by fitness, whereas in boys only fitness was associated with academic achievement. Further studies are necessary to investigate the potential longitudinal effect of vigorous physical activity on academic achievement, the role of fitness herein and the implications of these findings for schools.

Associations between physical activity, body fat, and insulin resistance (homeostasis model assessment) in adolescents: the European Youth Heart Study.

BACKGROUND: More and better data are needed to understand the action of physical activity (PA) on insulin resistance and the concomitant relation with body fat in adolescence. OBJECTIVE: We examined the relation between total PA and intensity levels with insulin resistance under special consideration of waist circumference and skinfold thickness. DESIGN: This was a cross-sectional study of 613 adolescents (352 girls, 261 boys) with a mean (+/-SD) age of 15.5 +/- 0.5 y from Sweden and Estonia. Total, low, moderate, and vigorous PA was measured by accelerometry. Body fat estimators included waist circumference and the sum of 5 skinfold thicknesses. Fasting insulin and glucose were measured, and insulin resistance was calculated according to the homeostasis model assessment (HOMA). Linear regression analysis and analysis of covariance were used to determine the association between PA and insulin resistance while considering body fat. All estimates were adjusted for sex, country, pubertal status, and indicators of body fat when applicable. RESULTS: Total, moderate, and vigorous PA were inversely correlated with HOMA. Body fat estimators were positively correlated with HOMA. Significant contrasts in HOMA concentrations were seen when comparing the lower 2 tertiles with the upper tertile of PA indicators. Repeating the analysis with body fat estimators showed significant contrasts in HOMA concentrations when comparing the lower tertiles with the upper tertile. CONCLUSION: In view of an increase in obesity in young people, the results accentuate the role of PA in sustaining metabolic balance in adolescence and the potential benefit of an increase of time spent at higher PA levels for youth with relatively elevated amounts of body fat.

Relationship of physical activity, fitness, and fatness with clustered metabolic risk in children and adolescents: the European youth heart study.

OBJECTIVES: To examine the associations of physical activity (PA) at different levels and intensities and cardiorespiratory fitness (CRF) with a clustering of metabolic risk factors in children and adolescents with special consideration of body fat. STUDY DESIGN: Total PA and intensity levels were measured by accelerometry in children (9 years, n = 273) and adolescents (15 years, n = 256). CRF was measured with a maximal ergometer bike test. Measured outcomes included fasting insulin, glucose, triglycerides, total and high-density lipoprotein cholesterol, blood pressure, and body fat. A metabolic risk score (MRS) was computed as the mean of the standardized outcome scores. A "non-obesity-MRS" was computed omitting body fat from the MRS. Analysis of variance and multiple regressions were used in the analysis. RESULTS: Total and vigorous PA was inversely significantly associated with MRS in adolescent girls, the group with lowest PA, becoming insignificant when CRF was introduced in the analysis. Significant regression coefficients of total PA and CRF on non-obesity-MRS diminished when body fat was entered in the analysis. CONCLUSIONS: CRF is more strongly correlated to metabolic risk than total PA, whereas body fat appears to have a pivotal role in the association of CRF with metabolic risk.

High cardiovascular fitness is associated with low metabolic risk score in children: the European Youth Heart Study.

The aim of the present study was to examine the associations of cardiovascular fitness (CVF) with a clustering of metabolic risk factors in children, and to examine whether there is a CVF level associated with a low metabolic risk. CVF was estimated by a maximal ergometer bike test on 873 randomly selected children from Sweden and Estonia. Additional measured outcomes included fasting insulin, glucose, triglycerides, HDLC, blood pressure, and the sum of five skinfolds. A metabolic risk score was computed as the mean of the standardized outcomes scores. A risk score <75th percentile was considered to indicate a low metabolic risk. CVF was negatively associated with clustering of metabolic risk factors in children. Receiver operating characteristic curve analysis showed a significant discriminatory accuracy of CVF in identifying the low/high metabolic risk in girls and boys (p < 0.001). The CVF level for a low metabolic risk was 37.0 and 42.1 mL/kg/min in girls and boys, respectively. These levels are similar to the health-related threshold values of CVF suggested by worldwide recognized organizations. In conclusion, the results suggest a hypothetical CVF level for having a low metabolic risk, which should be further tested in longitudinal and/or intervention studies.

Relations of total physical activity and intensity to fitness and fatness in children: the European Youth Heart Study.

BACKGROUND: It is unclear how the amount and intensity of physical activity (PA) are associated with cardiovascular fitness (CVF) and body fatness in children. OBJECTIVE: We aimed to examine the associations of total PA and intensity levels to CVF and fatness in children. DESIGN: A cross-sectional study of 780 children aged 9-10 y from Sweden and Estonia was conducted. PA was measured by accelerometry and was expressed as min/d of total PA, moderate PA, and vigorous PA. CVF was measured with a maximal ergometer bike test and was expressed as W/kg. Body fat was derived from the sum of 5 skinfold-thickness measurements. Multiple regression analysis was used to determine the degree to which variance in CVF and body fat was explained by PA, after control for age, sex, and study location. RESULTS: Lower body fat was significantly associated with higher levels of vigorous PA, but not with moderate or total PA. Those children who engaged in >40 min vigorous PA/d had lower body fat than did those who engaged in 10-18 min vigorous PA/d. Total PA, moderate PA, and vigorous PA were positively associated with CVF. Those children who engaged in >40 min vigorous PA/d had higher CVF than did those who accumulated <18 min vigorous PA/d. CONCLUSIONS: The results suggest that PA of vigorous intensity may have a greater effect on preventing obesity in children than does PA of lower intensity, whereas both total and at least moderate to vigorous PA may improve children's CVF.