Effects of an Exercise Program on Cardiometabolic and Mental Health in Children With Overweight or Obesity: A Secondary Analysis of a Randomized Clinical Trial

Importance

Childhood obesity is a risk factor associated with type 2 diabetes, cardiovascular disease, and mental disorders later in life. Investigation of the parallel effects of a defined exercise program on cardiometabolic and mental health in children with overweight or obesity may provide new insights on the potential benefits of exercise on overall health.

Objective

To investigate the effects of a 20-week exercise program on cardiometabolic and mental health in children with overweight or obesity.

Design, Setting, and Participants

This secondary analysis of a parallel-group randomized clinical trial was conducted in Granada, Spain, from November 1, 2014, to June 30, 2016. Data analyses were performed between February 1, 2020, and July 14, 2022. Children with overweight or obesity aged 8 to 11 years were eligible, and the study was performed in an out-of-school context.

Intervention

The exercise program included 3 to 5 sessions/wk (90 min/session) of aerobic plus resistance training for 20 weeks. The wait-list control group continued with their usual routines.

Main Outcomes and Measures

Cardiometabolic outcomes as specified in the trial protocol included body composition (fat mass, fat-free mass, and visceral adipose tissue), physical fitness (cardiorespiratory, speed-agility, and muscular), and traditional risk factors (waist circumference, blood lipid levels, glucose levels, insulin levels, and blood pressure). Cardiometabolic risk score (z score) was calculated based on age and sex reference values for levels of triglycerides, inverted high-density lipoprotein cholesterol, and glucose, the mean of systolic and diastolic blood pressure, and waist circumference. An additional cardiometabolic risk score also included cardiorespiratory fitness. Mental health outcomes included an array of psychological well-being and ill-being indicators.

Results

The 92 participants included in the per-protocol analyses (36 girls [39%] and 56 boys [61%]) had a mean (SD) age of 10.0 (1.1) years. The exercise program reduced the cardiometabolic risk score by approximately 0.38 (95% CI, -0.74 to -0.02) SDs; decreased low-density lipoprotein cholesterol level by -7.00 (95% CI, -14.27 to 0.37) mg/dL (to convert to mmol/L, multiply by 0.0259), body mass index (calculated as weight in kilograms divided by height in meters squared) by -0.59 (95% CI, -1.06 to -0.12), fat mass index by -0.67 (95% CI, -1.01 to -0.33), and visceral adipose tissue by -31.44 (95% CI, -58.99 to -3.90) g; and improved cardiorespiratory fitness by 2.75 (95% CI, 0.22-5.28) laps in the exercise group compared with the control group. No effects were observed on mental health outcomes.

Conclusions and Relevance

In this secondary analysis of a randomized clinical trial, an aerobic plus resistance exercise program improved cardiometabolic health in children with overweight or obesity but had no effect on mental health.

Trial Registration

ClinicalTrials.gov Identifier: NCT02295072.

Sedentarism, Physical Activity, Steps, and Neurotrophic Factors in Obese Children

PURPOSE

This study aimed to examine the associations of sedentary time, physical activity (PA) and step-related behaviors with neurotrophic growth factors.

METHODS

A total of 97 children with overweight/obesity age 8 to 11 yr participated in this study. Sedentary time, PA, and steps were measured by GT3X+ accelerometers in hip and nondominant wrist. Estimates of light, moderate, vigorous, and moderate-to-vigorous PA (MVPA) were obtained. Steps per daytime, peak 60-, 30-, and 1-min cadence were computed. The time accumulated (min·d) in different cadence bands of steps was also computed from hip accelerometer. Plasma levels of brain-derived neurotrophic factor (BDNF), vascular endothelial growth factor (VEGF), and insulin growth factor-1 (IGF-1) were determined by the XMap technology (Luminex IS 100/200 system, Luminex Corporation, Austin, TX).

RESULTS

Light PA, moderate PA, MVPA, and the peak 60-min cadence were positively related with BDNF concentrations (all P < 0.05), and only light PA to VEGF (P = 0.048). No association was observed for IGF-1 (P > 0.05). The associations of light PA with BDNF and VEGF disappeared (all P > 0.05) after performing analyses with nondominant wrist-placement data. However, moderate PA and MVPA remained significantly associated with BDNF (both P < 0.05). The time accumulated in cadence bands of 40 to 59 steps per day and 60 to 79 steps per day (i.e., walking at slow pace) was positively associated with plasma BDNF (all P < 0.05).

CONCLUSIONS

In conclusion, PA is positively related to plasma BDNF, whereas no relationship was observed for VEGF or IGF-1. Higher amounts of time spent in slow walking cadence bands could increment BDNF levels. Exercise-based randomized controlled trials in children with overweight/obesity should be carried out to better understand the influence of PA behaviors on the neurotrophic factors.

Inflammatory biomarkers and brain health indicators in children with overweight and obesity: The ActiveBrains project

INTRODUCTION

Chronic inflammation plays an important role on the pathogenesis of several cardiovascular and metabolic diseases, as well as on brain function and behaviour. The aim of the present study was to examine the associations between inflammatory biomarkers and a wide range of brain health indicators (i.e., academic performance, executive function, behavioural and emotional functioning, and brain volume) in children with overweight/obesity.

METHODS

A total of 107 children (10.0 ± 1.1 years, 41% girls) from the ActiveBrains project were included in the analysis. Five inflammatory biomarkers were analysed in plasma: white blood cell (WBC) count, interleukin-6 (IL-6), interleukin-1β, tumor necrosis factor-α (TNF-α), and C-reactive protein (CRP). Academic performance was assessed by Woodcock-Muñoz Tests of Achievement. Executive function was assessed through the Design Fluency Test for cognitive flexibility, the Stroop test for cognitive inhibition, and the Delayed Non-Match-to-Sample task for working memory. Behavioural and emotional functioning was evaluated through the Behavior Assessment System for Children (BASC) questionnaire. Total and regional brain volume was assessed by magnetic resonance imaging.

RESULTS

IL-6 was inversely associated with adaptive skills (β = -0.228; p = 0.030), while TNF-α was related to mathematics (β = -0.198; p = 0.034). In addition, CRP was positively associated with externalizing (β = 0.246; p = 0.046) and internalizing problems (β = 0.234; p = 0.039), as well as the behavioural symptoms index (β = 0.236; p = 0.047). However, these significant associations disappeared after multiple comparisons correction. Inflammatory biomarkers were not associated with executive function and total brain volumes. Regarding regional brain analyses, WBC was positively associated with gray matter volume in the left middle temporal gyrus (β = 0.387; p < 0.001, k = 44), and CRP was positively associated with gray matter volume in the right superior temporal gyrus (β = 0.439; p < 0.001, k = 29). Additionally, when adjusting by total brain volume, CRP was positively associated with gray matter volume in the right supplementary motor cortex (β = 0.453; p < 0.001, k = 51). Moreover, both, IL-6 (β = 0.366; p < 0.001, k = 81) and TNF-α (β = 0.368; p < 0.001, k = 62) were positively associated with white matter volume around the right inferior frontal gyrus pars opercularis, while CRP was inversely associated with white matter volume around the left superior frontal gyrus (β = -0.482; p < 0.001, k = 82). After adjusting by total brain volume, CRP was also inversely associated with white matter volume in 3 additional clusters (β ranging from -0.473 to -0.404; p < 0.001, k = 87).

CONCLUSIONS

Inflammation was slightly associated with brain health (i.e., academic performance, behavioural and emotional functioning and regional brain volume) in children with overweight or obesity. Further larger longitudinal and interventional studies are warranted to elucidate the short-term and long-term effect of systemic low-grade inflammation on children's brain health.