Community violence and internalizing mental health symptoms in adolescents: A systematic review

PURPOSES

Mental disorders are responsible for 16% of the global burden of disease in adolescents. This review focuses on one contextual factor called community violence that can contribute to the development of mental disorders OBJECTIVE: To evaluate the impact of community violence on internalizing mental health symptoms in adolescents, to investigate whether different proximity to community violence (witness or victim) is associated with different risks and to identify whether gender, age, and race moderate this association.

METHODS

systematic review of observational studies. The population includes adolescents (10-24 years), exposition involves individuals exposed to community violence and outcomes consist of internalizing mental health symptoms. Selection, extraction and quality assessment were performed independently by two researchers.

RESULTS

A total of 2987 works were identified; after selection and extraction, 42 works remained. Higher exposure to community violence was positively associated with internalizing mental health symptoms. Being a witnessing is less harmful for mental health than being a victim. Age and race did not appear in the results as modifiers, but male gender and family support appear to be protective factors in some studies.

CONCLUSION

This review confirms the positive relationship between community violence and internalizing mental health symptoms in adolescents and provides relevant information that can direct public efforts to build policies in the prevention of both problems.

Insulin sensitivity as a predictor of longitudinal changes on body mass index in Brazilian adolescents

OBJECTIVES

We aimed to investigate the effect of insulin sensitivity and insulin resistance status at baseline on longitudinal body mass index, and the possible effect modification by sex.

METHODS

This is a secondary analysis of a randomized intervention community trial, in which a subgroup of 84 adolescents, aged between 10 and 12 years, were analyzed. Body weight, height, and body mass index (BMI) were determined before and after 8 months of follow-up. Glucose and serum insulin were examined at baseline and IR was defined based on the homeostasis model assessment-insulin resistance (HOMA-IR), with a cutoff >2.5 for both genders. Linear mixed-effects models were performed to evaluate the influence of HOMA-IR at baseline on BMI changes over time. Models were adjusted for age, pubertal stage, and stratified by sex.

RESULTS

The sample comprised 65.4% of girls and the prevalence of overweight/obesity was 54.7% among girls and 50.0% among boys. The overall prevalence of IR was 75.3%, of which 60.7% for boys and 83.0% for girls. We found an interaction effect by sex (p = .004) for HOMA-IR as a continuous variable, with a decreased BMI rate of change among boys (β = -0.13; p = .03) but not for girls (β = +0.03; p = .36). Longitudinal BMI changes considering IR status at baseline (IR vs. non-IR) did not demonstrate any statistically significant difference for both boys (-0.1 vs. +0.4; p = .28) and girls (+0.7 vs. +1.0; p = .44).

CONCLUSION

Increased HOMA-IR values at baseline were associated with greater BMI reduction over time among boys but not girls, with no influence of IR status.

The compensatory effect of exercise on physical activity and energy intake in young men with overweight: The EFECT randomised controlled trial

BACKGROUND

The compensatory effect of exercise on total volume of physical activity and food intake has been described as a possible explanation for the limited body weight loss observed during exercise interventions.

OBJECTIVE

To investigate the effect of different exercise intensities on total volume of physical activity and energy intake amongst active men with overweight.

DESIGN

Young men with overweight from a naval academy (n = 72; mean ± SD, age 21 ± 2 years, BMI 27.9 ± 2.13 kg/m²) were randomised to a control group (CG), moderate-intensity (MEG), or vigorous-intensity exercise group (VEG). MEG and VEG performed exercise sessions three times per week, for 60 min, during a 2-week period. Physical activity was assessed using triaxial accelerometers for 13 days. Energy intake was assessed at four time-points by 24-hour food recall. Intention-to-treat analyses were performed using linear mixed effect models.

RESULTS

MEG and VEG presented a greater compensatory effect in the total volume of physical activity over time compared to CG, with a significant difference in the rate of change between VEG and CG (∆ = -250,503 counts vs. ∆ = -61,306 counts, respectively; p = 0.01), and MEG and CG (∆ = -253,336 counts vs. ∆ = -61,306 counts, respectively; p = 0.01). There was no difference between MEG and VEG (p = 0.97). Changes in energy intake were not different between groups (p = 0.18); however, MEG presented greater energy intake compared to CG (β=491 kcal/day; p = 0.01) and VEG (β=319 kcal/day; p = 0.07). VEG presented a greater reduction in body weight compared to MEG (-1.3 kg vs. -0.4 kg; p = 0.03) and CG (-1.3 kg vs. -0.6 kg; p = 0.07).

CONCLUSIONS

Two weeks of exercise promoted a compensatory effect in total volume of physical activity in active men with overweight, regardless of exercise intensity. The compensatory effect was not observed for energy intake, although there was a trend for higher absolute energy intake in the MEG. Consequently, individuals in the VEG showed greater reduction in body weight over the intervention period.