Andreia Pizarro

Is walking to school associated with improved metabolic health

BackgroundActive commuting to/from school is an important source of physical activity that has been declining over the past years. Although it is an affordable and simple way of increasing physical activity levels it is still unclear whether it has enough potential to improve health. Therefore, the aim of this cross sectional study was to examine the relationship between active commuting to/from school and metabolic risk factors in 10 to 12 year old children.MethodsParticipants were 229 adolescents, selected through consecutive sampling, (121 girls) with mean age of 11.65 (±0.73) years old from Porto, Portugal. Means of transport to/from school was accessed by asking: ”How do you usually travel to school?” and “How do you usually travel from school?”. Active commuting was considered if children reported at least one of the trips (to or from school) by active means. Total physical activity was obtained with Actigraph accelerometer for 7 consecutive days. Lipid profile measurements were conducted with Cholestech LDX® analyser. Waist circumference and blood pressure were measured by standard methods. The criteria for metabolic syndrome defined by International Diabetes Federation for children and adolescents were used.ResultsAdjusted binary logistic regression analysis suggested that walkers have higher odds to have a better waist circumference (OR = 2.64, 95% CI = 1.63-6.01) and better high density lipoprotein cholesterol (OR = 2.14, 95% CI = 1.01-4.52) profiles than non-active commuters, independent of moderate-to-vigorous physical activity. No associations were found for other metabolic risk factors.ConclusionsExertions to increase and maintain walking to school may be particularly relevant as it is likely to have a positive impact on children’s health and eventually decrease metabolic and cardiovascular diseases.

Modifiable lifestyle behavior patterns, sedentary time and physical activity contexts: a cluster analysis among middle school boys and girls in the SALTA study.

OBJECTIVE To analyze how modifiable health-related variables are clustered and associated with childrens participation in play, active travel and structured exercise and sport among boys and girls. METHODS Data were collected from 9 middle-schools in Porto (Portugal) area. A total of 636 children in the 6th grade (340 girls and 296 boys) with a mean age of 11.64 years old participated in the study. Cluster analyses were used to identify patterns of lifestyle and healthy/unhealthy behaviors. Multinomial logistic regression analysis was used to estimate associations between cluster allocation, sedentary time and participation in three different physical activity (PA) contexts: play, active travel, and structured exercise/sport. RESULTS Four distinct clusters were identified based on four lifestyle risk factors. The most disadvantaged cluster was characterized by high body mass index, low high-density lipoprotein cholesterol and cardiorespiratory fitness and a moderate level of moderate to vigorous PA. Everyday outdoor play (OR=1.85, 95%CI 0.318-0.915) and structured exercise/sport (OR=1.85, 95%CI 0.291-0.990) were associated with healthier lifestyle patterns. There were no significant associations between health patterns and sedentary time or travel mode. CONCLUSION Outdoor play and sport/exercise participation seem more important than active travel from school in influencing childrens healthy cluster profiles.

Which social support and psychological factors are associated to active commuting to school

OBJECTIVE The aim of this study was to investigate the association between self-efficacy, enjoyment, and volitional control with active commuting, as well as to analyze the impact of social support from parents, friends, and teachers with active commuting to school. METHODS Participants in this cross-sectional study were 625 students (male: 46.3%) aged 10 to 15years from Porto, Portugal (2010/2011). A questionnaire was used to assess active commuting to/from school (walk/cycle), self-efficacy, enjoyment, volitional control and social support. Binary logistic regression was performed to identify significant associations between targeted variables and active commuting. RESULTS The results show positive associations in crude analyses for all variables, except for enjoyment for walk/cycle to school. In the adjusted model, higher likelihood of active commuting was found among students who reported having higher self-efficacy (OR=2.10; CI95%: 1.07; 4.11) to walk/cycle to school as well as among adolescents who reported being encouraged by their parents (OR=3.66; CI95%: 1.55; 8.69), and having the partnership of friends in active journeys (OR=4.31; CI95%: 1.79; 10.37). CONCLUSION Self-efficacy, encouragement from parents and companionship from friends were important indicators of active commuting to school among Portuguese adolescents. These findings provide support for further research to identify and understand factors that predict and explain the active commuting.

Fitness and metabolic syndrome in obese fatty liver children

Background: Metabolic Syndrome (MS) is highly prevalent among obese children with fatty liver. However, it is well-known that there is a lower prevalence of MS in individuals with higher cardiorespiratory fitness (CRF). Aim: To analyse the association between CRF with features of the MS in obese children that present fat liver indicators, namely abnormal alanine aminotransferase (ALT) values. Methods: A total of 79 obese students (40 girls), 10–11 year-olds ( ± 0.60), with abnormal serum ALT from Porto public schools comprised the sample. Measurements included CRF (20-metre Shuttle Run Test), Metabolic Risk Factors (MRF), according to MS International Diabetes Federation criteria, ALT values (Cholestech LDX® analyser) and maturational stage (Tanner criteria). Logistic regression analysis was used to determine the influence of CRF on MRF adjusted for sex, maturation, and BMI. Results: The logistic regression showed that, despite being classified as being obese and presenting abnormal levels of ALT, those classified as fit were less likely to have MS than their unfit counterparts (OR = 0.52; p ≤ 0.05). Conclusion: Obese-fit children with abnormal ALT values have a significant reduction in the likelihood to be classified as having MS, even after adjustments for gender, maturation and BMI, Thus, CRF might be an important factor for tackling fatty liver among obese.

Appendicular fat mass is positively associated with femoral neck bone mineral density in older women.

ObjectiveIn this study, we examined the relationships between body fat accumulation and distribution and bone mineral density (BMD) in older women. MethodsA total of 100 healthy white women (mean ± SD age, 68.7 ± 5.5 y) free of medications known to affect bone were enrolled. Lean mass, fat mass (FM), percentage body fat, android FM, gynoid FM, appendicular FM (AFM), appendicular lean mass, and femoral neck BMD were measured by dual-energy x-ray absorptiometry. Dietary intake was assessed by 4-day dietary record, and potential renal acid load was also calculated. Performance measures included knee extension and flexion strength measured on an isokinetic dynamometer. Physical activity was assessed using accelerometers and a questionnaire. Lactase nonpersistence was defined by the C/T-13910 genotype. Sociodemographic information, lifestyle behaviors, and clinical status were also examined. Stepwise multiple linear regression analysis showed that AFM was the most significant positive predictor of femoral neck BMD. ResultsAfter adjustment for confounders (age, height, age at menopause, potential renal acid load, physical activity, and knee muscle strength), AFM had strong and independent associations with femoral neck BMD (26.4% of variance). ConclusionsThese data highlight that in older women, localization of FM is more important for bone mass than obesity per se or lean mass. AFM (subcutaneous adiposity) seems to exhibit an independent protective effect on BMD.

Gender Differences in the Domain-Specific Contributions to Moderate-to-Vigorous Physical Activity, Accessed by GPS

BACKGROUND Identifying where children spend their activity-time may help define relevant domains for effective PA promotion and better understand the relation between PA and environment. Our study aimed to identify how boys and girls allocate their active time in the different domains. METHODS 374 children (201 girls; mean age = 11.7 years) wore an accelerometer and a GPS for 7 days. PALMS software combined data, categorized nonsedentary time and bouts of moderate-to-vigorous physical activity (MVPA). Geographical information system allocated activity into 4 domains: school, leisure, transport and home. RESULTS Overall, a higher proportion of time in MVPA was found in the transport domain (45.5%), school (30.5%), leisure (21.3%), and home (2.7%). Gender differences were found for the proportion of time spent across domains. Girls (54.5%) had more MVPA than boys (35.2%) in the transport domain, whereas boys spent more MVPA time in school (37.0%) and leisure (24.9%) than girls (24.7% and 18.1, respectively). CONCLUSIONS Interventions to increase transport behavior may be relevant for childrens MVPA. School is an important domain for boys PA, while for girls increasing the supportiveness of the school environment for PA should be a priority. Strategies should consider gender differences when targeting each domain.

Meal-exercise challenge and physical activity reduction impact on immunity and inflammation (MERIIT trial)

Background The effect of a pre-exercise meal as countermeasure to exercise induced immunodepression is poorly known. Also, sedentary behavior is associated with increased cardiometabolic risk but studies on immune changes are lacking. Therefore, we aimed to assess: 1) the impact of a pre-exercise Mediterranean meal (MdM) compared with a fast-food type meal (FFM) on exercise-induced immunological changes and 2) the impact of an induced acute period of sedentary behavior on neuro-immune-endocrine status. Methods /Design: This is a two steps clinical trial including: (a) randomized crossover clinical trial, comparing the effect a high-fat/low-nutrient dense meal, FFM, with an isoenergetic similar high-nutrient dense meal, MdM, in the immune response to an exercise challenge (EC) and (b) a pilot trial assessing the neuro-immune-endocrine change induced by acute decreasing by half the usual physical activity level. Results A total of 46 participants (26 females), median aged 25 years were included. Of those 39-completed protocol, including overweight, physical active and inactive and participants with asthma. There were no differences in the EC between interventions. Dietary factors and physical activity were closely monitored during interventions and kept similar. During physical inactivity induction, 31% reached the target of 50% reduction in mean step number and 77% reached a 30% reduction. Conclusion The use of a pre-exercise meal to modulate immune response and the understanding of the immunological impact of physical inactivity might help to establish future recommendations on how to practice exercise in a safer way and to recognize the potential impact of inactivity.

Cardiorespiratory fitness, but not physical activity, is associated with academic achievement in children and adolescents

Abstract Background: Cardiorespiratory fitness (CRF) and physical activity (PA) seem to have positive effects on academic achievement (AA), although in most studies, objective methods of assessment have not been used. Aim: To examine the associations of CRF and PA with AA. Subjects and methods: A sample of 640 youngsters (10–18 years) participated in this cross-sectional study. CRF was estimated with the 20-metre shuttle run test and PA was measured using accelerometers. School grades were used to describe AA using mathematics and native language final grades. The relationship between CRF and PA with AA was analysed using ANCOVA. Results: Results show a significant effect of CRF levels on native language grades, after adjustment for confounders [F(3,414) = 3,99 p < 0.05], but not for mathematics [F(3,360) = 0.95 p > 0.05]. No significant effects of PA levels on AA were found. Conclusions: CRF is associated with moderate-to-vigorous PA (MVPA) and higher levels of CRF may influence AA. CRF is positively correlated with MVPA, suggesting that higher amounts of MVPA might improve CRF and indirectly influence AA. Since CRF is dependent on higher intensities of PA, we can suggest a focus on implementing improvement strategies to increase the intensity of physical education lessons.

Examining the utility of thresholds for aerobic fitness related to resting blood pressure and BMI in portuguese children

This study examined the utility of the Ruiz et al. cut‐points when examining body mass index (BMI) and resting blood pressure in young people.