A Pilot Study of Cardiorespiratory Fitness, Adiposity, and Cardiometabolic Health in Youth With Overweight and Obesity

The Association between Body Mass Index and Muscular Fitness in Chinese College Freshmen

(1) Background: The present study aimed to investigate the association between body mass index (BMI) and muscular fitness in Chinese college freshmen. (2) Methods: A total of 6425 college freshmen in mainland China were recruited. BMI was classified as underweight (<18.5 kg/m²), normal weight (18.5~23.9 kg/m²), overweight (24~27.9 kg/m²), and obese (≥28 kg/m²), according to the Working Group on Obesity in China. Health-related physical fitness components including cardiorespiratory fitness, lower body explosive power, upper body muscular endurance, abdominal muscular endurance, flexibility, and vital capacity were assessed. Physical fitness index and muscular fitness index were calculated, respectively, as the sum score of the standardized values (z-score) of the corresponding components. Three regression models were used to evaluate the potential associations: a linear regression model, a polynomial regression model, and a restricted cubic spline regression model. Adjust R square was used to compare among models. (3) Results: Significant differences were observed among different BMI categories in nearly all physical fitness components as well as physical fitness z-score and muscular fitness z-score (p < 0.001), regardless of gender. Significant linear associations were found between BMI and physical fitness z-score as well as muscular fitness z-score among total, male, and female groups (p < 0.05). However, the restricted cubic spline regression model showed a better fitting effect (adjust R² was 7.9%, 11.2%, and 4.8% in total, male, and female for physical fitness and 7.7%, 15.7%, and 4.0%, for muscular fitness, respectively), compared with the linear and polynomial regression models, presented by a higher adjusted R². Restricted cubic splines analysis showed that BMI value and physical fitness z-score showed a non-linear relationship with an approximate inverted U curve in all groups, while an approximate reversed J-shaped association was observed between BMI and muscular fitness z-score in all groups. (4) Conclusions: The present study showed a nonlinear negative relationship between BMI and physical fitness with underweight and overweight/obese college freshmen having poorer physical fitness and muscular fitness than their normal BMI peers, which may provide useful evidence to the development of public health recommendations and encourage the health management of young adults. Future studies should further explore the relationship between BMI and muscular fitness with multi-centered large sample size studies.

Predictors of Post-Exercise Energy Intake in Adolescents Ranging in Weight Status from Overweight to Severe Obesity

Exercise may sensitize individuals with overweight and obesity to appetitive signals (e.g., hunger and fullness cues), overriding trait eating behaviors that contribute to overeating and obesity, such as uncontrolled eating. The objective of the current study was to measure predictors of objective ad libitum energy intake at a laboratory-based, post-exercise test-meal in adolescents ranging in weight status from overweight to severe obesity. We hypothesized that appetitive states, rather than appetitive traits, would be the strongest predictors of energy intake at a post-exercise test-meal, after controlling for body size. At Baseline, 30 adolescents (ages 10-16 years, 50% female (F), 43% non-Hispanic white (NHW), 83% with obesity (OB)) completed state and trait appetite measures and an ad libitum dinner meal following intensive exercise. Nineteen of those participants (47% F, 32% NHW, 79% OB) completed identical assessments two years later (Year 2). Energy intake (kcal) at each time point was adjusted for fat-free mass index (i.e., body size). Adjusted energy intake was reliable from Baseline to Year 2 (ICC = 0.84). Multiple pre-meal appetite ratings were associated with test-meal energy intake. In stepwise linear regression models, pre-meal prospective food consumption was the strongest and only significant predictor of test-meal energy intake at both Baseline (R2 = 0.25, p = 0.005) and Year 2 (R2 = 0.41, p = 0.003). Baseline post-exercise energy intake was associated with weight change over two years (R2 = 0.24, p = 0.04), but not with change in fat mass (p = 0.11). Appetitive traits were not associated with weight or body composition change (p > 0.22). State appetite cues were the strongest predictors of post-exercise energy intake, independent of body size. Future studies should examine whether long-term exercise programs enhance responsiveness to homeostatic appetite signals in youth with overweight and obesity, with a goal to reduce excess energy intake and risk for weight gain over time.

Obesity and COVID-19 in children and adolescents: a double pandemic

BACKGROUND AND AIM OF THE STUDY

The high prevalence of obesity and obesity-related comorbidities has reached pandemic proportions, particularly in Western countries. It has been recently recognized as a significant risk factor in severe cases of COVID-19 in children and adolescents. Here, we summarize the existing knowledge regarding the pathophysiology of COVID-19 and consider how its various components may be exacerbated by the presence of obesity to investigate the impact of obesity on disease severity among patients with COVID-19 and collaborate for better clinical care of these patients.

METHODS

The literature search was conducted from March 2020 to January 2022. A review of articles was performed via the online database PubMed, combining the terms "obesity," "weight gain," "COVID-19", "children."

RESULTS

Excessive adipose tissue, insulin resistance, dyslipidemia, hypertension, high levels of proinflammatory cytokines are factors that compromise the functioning of organs and systems in obese patients. In obese patients with COVID-19 these changes can increase the risk of death, need for ventilatory assistance, risk of thromboembolism, and perpetuation of inflammatory response.

CONCLUSIONS

Obesity increases the risk for hospitalization, intensive care admission, mechanic ventilation requirement, and death among children and adolescents with COVID-19. These findings emphasize the need for effective actions by health professionals to increase awareness of the risks resulting from obesity and how these are heightened in the current global pandemic.

COVID-19 in Pediatric Inpatients: A Multi-Center Observational Study of Factors Associated with Negative Short-Term Outcomes

Most cases of COVID-19 in children and adolescents are mild or asymptomatic, but a small number of individuals may develop severe disease, requiring PICU admission and/or mechanical ventilation. We assessed the factors associated with negative short-term outcomes of COVID-19 in 82 pediatric patients at three hospitals within the United States during the spring and summer of 2020 using medical records, laboratory data, and imaging studies of all patients admitted with a positive RT-PCR test for SARS-CoV-2. We found that older patients were more likely to have an extended hospital stay, and those with high BMIs (over 25) were more likely to be admitted to the PICU during the early pandemic. In addition, older patients, those with high BMIs, and those with underlying medical conditions, were more likely to receive respiratory support. Given the association of age, BMI, and underlying medical conditions with more severe COVID-19, clinicians should keep these factors in mind when treating patients.

COVID-19 and obesity in childhood and adolescence: a clinical review

OBJECTIVE

To identify factors that contribute to the increased susceptibility and severity of COVID-19 in obese children and adolescents, and its health consequences.

SOURCES

Studies published between 2000 and 2020 in the PubMed, MEDLINE, Scopus, SciELO, and Cochrane databases.

SUMMARY OF FINDINGS

Obesity is a highly prevalent comorbidity in severe cases of COVID-19 in children and adolescents; social isolation may lead to increase fat accumulation. Excessive adipose tissue, deficit in lean mass, insulin resistance, dyslipidemia, hypertension, high levels of proinflammatory cytokines, and low intake of essential nutrients are factors that compromise the functioning of organs and systems in obese individuals. These factors are associated with damage to immune, cardiovascular, respiratory, and urinary systems, along with modification of the intestinal microbiota (dysbiosis). In severe acute respiratory syndrome coronavirus 2 infection, these organic changes from obesity may increase the need for ventilatory assistance, risk of thromboembolism, reduced glomerular filtration rate, changes in the innate and adaptive immune response, and perpetuation of the chronic inflammatory response.

CONCLUSIONS

The need for social isolation can have the effect of causing or worsening obesity and its comorbidities, and pediatricians need to be aware of this issue. Facing children with suspected or confirmed COVID-19, health professionals should 1) diagnose excess weight; 2) advise on health care in times of isolation; 3) screen for comorbidities, ensuring that treatment is not interrupted; 4) measure levels of immunonutrients; 5) guide the family in understanding the specifics of the situation; and 6) refer to units qualified to care for obese children and adolescents when necessary.