Perceived neighborhood environment and physical activity among high school students from Curitiba, Brazil

Physical (in)activity, and its predictors, among Brazilian adolescents: a multilevel analysis

Background

Physical activity is a multifactorial trait, determined by both individual and environmental characteristics, it seems relevant to understand the determinants related to youth guidelines accomplishment. The present study aimed to verify the differences between the Brazilian federative units regarding to the prevalence of youth physical activity guidelines accomplishment and to investigate the determinants related to the inter-individual differences in this accomplishment.

Methods

Sample comes from the 2015 Brazilian National School Health Survey (PeNSE), comprising 99,570 adolescents (51,527 girls, 13-17y), enrolled in 3039 schools. Adolescents reported the time they spend in moderate-to-vigorous physical activity daily, and they were categorized as active or inactive, if the guidelines were achieved, or not, respectively, and multilevel statistical analyses were used, including both child and school-level variables. Multilevel Binomial model was computed in the SuperMix software.

Results

The majority of the adolescents did not comply with the physical activity guidelines daily, where Bahian children complied the least, while those from Amazonas, Tocantins, and Mato Grosso do Sul complied the most. Boys (OR: 2.305; 95%CI: 2.277-2.334), older adolescents (OR: 1.044; 95%CI: 1.036-1.051), and those who spent more time in active travelling to/from school (OR: 1.001; 95%CI: 1.001-1.001) complied more the physical activity guidelines. At the school level, adolescents from larger schools (OR: 0.957; 95%CI: 0.928-0.986) tended to comply less with the guidelines.

Conclusion

Significant differences between Brazilian federative units in youth daily physical activity guidelines compliance were observed, highlighting the role of individual but also environmental constraints in the Brazilian adolescents’ engagement in physical activity.

Adolescent's movement behaviors and built environment: a latent class analysis

BACKGROUND

Latent class analysis (LCA) is an alternative and innovative approach to verify the relation of the various combinations of the constructed environment and movement behavior (levels of physical activity, sedentary behavior, and sleep) characteristics. This study aimed to identify latent classes based on the characteristics of the neighborhood environment perceived by adolescents and their association with gender, socioeconomic status (SS), body composition and movement behaviors.

METHODS

This cross-sectional study includes 309 Brazilian adolescents (14 to 16 years old, 57% female). The characteristics of the neighborhood environment perceived were analyzed by the Neighborhood Walkability for Youth Scale. Accelerometers were used for a week to evaluate the movement behaviors. Questionnaires assessed the screen times, total sitting time (TST), and sociodemographic characteristics. LCA was used for modeling the "Perceived Enviroment" variable, having been conducted in the poLCA (Polychromous Variable Latent Class Analysis) package of the R statistical software.

RESULTS

Three classes were recognized: class 1, "Best Perceived Environment" with 23.03% of adolescents; class 2, "Moderate Perceived Environment", 63.33%; and class 3, "Worst Perceived Environment", 13.67%. Light physical activity (LPA), TST, and SS were associated with class prevalence. The adolescents with medium and low SS were, respectively, 3.42 (95% CI 1.62-7.21) and 4.18 (95% CI 1.66-10.50) more likely to belong to class 2, and those with low SS were 5.21 (95% CI 1.35-20.13) more likely to belong to class 3. Class 1 adolescents were associated with a lower chance (OR: 0.09, 95% CI 0.02-0.55) of involvement in 'adequate LPA time' compared to class 3. Class 1 adolescents were associated with a lower chance (OR: 0.31, 95% CI 0.12-0.79) of involvement in 'adequate TST' compared to class 2. There was a difference between the LPA and TST classes; class 3 presented a longer time in LPA than class 1; class 1 had higher TST than the other classes.

CONCLUSION

The findings highlight the influence of neighborhood classes on adolescents' LPA and TST.

Association between neighborhood aesthetics and childhood obesity

The lack of neighbourhood aesthetics (e.g. public art and well-maintained properties) may reduce walkability in the neighbourhood and increase the risk of childhood obesity. In this study, a literature search was conducted in the Cochrane Library, PubMed and Web of Science for articles published before January 1, 2019 to analyse the associations between neighbourhood aesthetics and weight-related behaviours and outcomes among children and adolescents aged <18. One cohort study and 24 cross-sectional studies, conducted in 10 countries with a median sample size of 1124 were identified. Neighbourhood aesthetics was more commonly assessed by self-reported or parent-reported perceptions than objective measurements. Eighteen of the 25 included studies analysed physical activity (PA) as the outcome of interests, eight studies analysed active transport to school (ATS), and eight studies analysed weight status, including body mass index and overweight/obesity status. About two-thirds of studies reported non-significant associations when using PA and weight status as outcomes, and half of studies showed that neighbourhood aesthetics is associated with increased use of ATS. The rest of the studies reported mixed findings with slightly more studies showing neighbourhood aesthetics may promote PA or reduce weight. Better designed studies are necessary to achieve a robust understanding of this epidemiological relationship in the future.

Association between homicide rates and prevalence of cardiovascular risk factors in the municipalities included in the Study of Cardiovascular Risk Factors in Adolescents

OBJECTIVES

In high-income countries, there is a positive relationship between neighborhood-level crime and cardiovascular risk factors (CRFs) in adolescence. A few studies that examined this association in low- and middle-income countries yielded inconsistent results. The aim of our study was to analyze the associations between homicide rates and prevalence rates of CRFs in adolescents living in Brazilian municipalities.

STUDY DESIGN

Cross-sectional ecologic study.

METHODS

An ecologic study was conducted to evaluate associations between homicide rates and CRFs in 122 municipalities included in the Study of Cardiovascular Risk Factors in Adolescents (Portuguese acronym, ERICA). The following CRFs were evaluated: adiposity (overweight/obese), sedentary behavior (screen time ≥3 h per day), high waist circumference (between 10 and 16 years, percentile ≥90; 16-17 years, ≥90 cm for men and ≥80 cm for women), low high-density lipoproteins (HDL) levels (<45 mg/dl), alcohol use (≥1 drink in the last 30 days) and hypertension (≥percentile 95th). In addition to these risk factors, we also evaluated the association of homicides with physical inactivity. Neighborhood homicide data were obtained from the Ministry of Health Mortality Information System (Portuguese acronym, SIM).

RESULTS

The 3-year homicide (115 per 100,000; interquartile range (IQR): 66.1, 150.5.) and CRFs prevalence rates were high (eg, obesity = 7.7%; IQR:6.2,9.5, overweight = 24.7%; IQR:21.6,27.9, sedentary behavior = 54.4%; IQR:47.9,58.9). Crude and adjusted Spearman correlation coefficients between 3-year homicide rate and CRFs were weak, and with the exception of HDL level, in directions contrary to expectation. Prevalence rate ratios (PR) tended toward the null value, even after multiple adjustments. Although the upper limit of the PR expressing the association between the highest homicide category (65-95% percentile range) and physical inactivity in boys barely overlapped the null hypothesis, the point estimate was also very close to one (boys, PR = 0.98, 95% confidence interval 0.95, 1.0).

CONCLUSIONS

In ERICA municipalities, although high prevalence rates of homicides and CRFs are important public health concerns, no significant associations were found between these variables.

Overweight and obese adolescent girls: the importance of promoting sensible eating and activity behaviors from the start of the adolescent period

The adolescent period is associated with changes in eating and activity behaviors in girls. Less reliance on parental provision and choice of food, coupled with a decrease in participation in physical activity and sport, can create an energy imbalance, predisposing to weight gain. Physiological alterations to body composition, reduction in insulin sensitivity, and psychological adjustments may further amplify the risk of becoming overweight and maintaining an unhealthy level of body fat into childbearing years. During pregnancy excess body fat is a risk factor for poor pregnancy outcomes and may predispose an infant to a lifelong heightened risk of being overweight and developing chronic disease. Interventions aimed at preventing the accumulation of body fat in adolescent girls and young women may have far reaching impact and be critically important in reducing intergenerational weight gain. Lifestyle interventions in adolescence have the potential to modify adult obesity risk by switching at-risk individuals from a high to lower obesity risk trajectory. This paper discusses multiple approaches to assist at-risk individuals reduce obesity risk. A key focus is placed on engagement in food preparation and choice, and opportunities for physical activity and sport. Support, education, and opportunity at home and at school, are often associated with the success of lifestyle interventions, and may enable adolescents to make positive choices, and engage in health promoting behaviors during adolescence and childbearing years.