The Dose-Response Relationship Between Physical Activity and Cardiometabolic Health in Young Adults

Cardiometabolic Risk Factors Associated with Physical Fitness and Activity Levels: An Exploratory Study of US College Students

College students are a vulnerable population at risk of developing and/or experiencing poor physical fitness and insufficient physical activity (PA) levels, both associated with poor cardiometabolic health. Thus, this study assessed the association of physical fitness and domain-specific PA levels on cardiometabolic risk factors (CMRFs) among college students. A volunteer sample of students enrolled in general health and wellness courses at a large, Northeastern U.S. institution from Spring 2023 - Spring 2024 (n=1418, 69.0% male, 89.9% non-Hispanic White) completed an objective health assessment as part of a required course assignment. CMRFs (e.g., cholesterol, blood pressure, fasting blood glucose, triglycerides, waist circumference), cardiorespiratory fitness (e.g., VO2 max), and markers of muscular strength and endurance (e.g., pushups, curl ups, hand grip, sit and reach) were assessed. Participants were then invited to complete a subjective health assessment (e.g., demographics, PA). Separate, unadjusted linear regressions examined the association of physical fitness and domain-specific PA levels (e.g., moderate and vigorous PA, active transportation PA, muscle-strengthening, meeting PA guidelines) on CMRFs, by biological sex. Socio-demographics of race/ethnicity, sexual orientation, semester standing, and grade point average served as covariates in separate, adjusted models to assess potential associations. Among males and females, cardiorespiratory fitness and markers of muscular strength and endurance were significantly associated with CMRFs, while PA levels and socio-demographics were not. Tailored screening approaches may provide students with the required support to reduce later-life adverse coronary events. Future work is required to improve our understanding of the potential role socio-demographics play in CMRFs among young adults.

Dose-Response Relationships of Moderate to Vigorous Physical Activity and Sedentary Time With Renal Function Indices in Adolescents With Reduced Renal Function: A Cross-Sectional Study

BACKGROUND

This study aimed to explore the associations between moderate to vigorous physical activity (MVPA) and sedentary time with renal function indices in adolescents with kidney disease.

METHODS

A cross-sectional study was conducted on 719 adolescents (median age 15 y, 40.6% female) with kidney disease from the National Health and Nutrition Examination Survey 2007-2016. The exposures were MVPA time and sedentary time. Renal metabolic parameters included serum uric acid (SUA), creatinine, blood urea nitrogen, the estimated glomerular filtration rate (eGFR), and the albumin creatinine ratio. Weighted multivariate regression analysis was used to estimate associations between exposures and outcomes.

RESULTS

After stratifying MVPA time, the regression effect values β (95% CI) for MVPA on SUA (Q2: -0.22 [-0.41 to -0.03]; Q3: -0.32 [-0.53 to -0.11]) and creatinine (Q2: -0.08 [-0.15 to -0.01]; Q3: -0.04 [-0.11 to 0.03]) gradually decreased with increasing MVPA time. In males (-0.76 [-1.19 to -0.32]), MVPA time was significantly associated with lower SUA levels compared with females (-0.14 [-0.38 to 0.10]). Notably, female adolescents who had an MVPA time exceeding 420 minutes exhibited lower albumin creatinine ratio (-75.37 [-146.63 to -4.11]). In addition, both recreational MVPA time (-0.26 [-0.45 to -0.06]) and sedentary time (-3.15 [-5.83 to -0.46]) were negatively associated with eGFR.

CONCLUSIONS

Our study found an association between MVPA and lower levels of SUA in male adolescents with kidney disease and albuminuria in female adolescents with kidney disease. In addition, MVPA was also negatively associated with creatinine and eGFR, whereas sedentary time was only associated with eGFR. Further studies are needed to confirm these findings.

Quantifying Physical Activity and Sedentary Behavior in Adults with Intellectual Disability: A Scoping Review of Assessment Methodologies

Background/Objectives: Methodologies for assessing behavior form the foundation of health promotion and disease prevention. Physical activity (PA) and sedentary behavior (SB) assessment methodologies have predominantly been developed for adults without an intellectual disability (ID), raising credibility concerns for adults with ID. The purpose was to synthesize the current state of assessment methodologies for quantifying PA and SB volume in the free-living setting for adults with an ID. Methods: Following PRISMA guidelines, eleven databases were searched through December 2023, yielding 8174 records. Data were extracted in Covidence (v.2.0), obtaining quantified PA and SB volume and assessment methodology characteristics across data collection and analysis, including tool(s) and technique(s) used, preparatory actions taken, instructions provided, and behavioral strategies employed during data collection. Results: Of the 8174 articles screened, 91 met the inclusion criteria. Common metrics included minutes/hours per day/week and steps per day/week. Despite 80% of the studies using objective techniques, substantial variation existed across studies regarding wearable models, sampling frequency and epoch length settings, calibration protocols, wearable placements, and data processing techniques. Limited studies provided instructions that did not exclusively rely on spoken language. Behavioral strategies varied, including self-monitoring, providing assistance or supervision, administering questionnaires verbally, issuing reminders, and offering monetary incentives. Conclusions: This review underscores the need for greater consistency and accessibility in PA and SB assessment methodology for adults with ID. Tailored preparation, instruction, and behavioral strategies may enhance assessment viability and suitability for adults with ID, with or without caregiver or researcher involvement in the free-living setting.

Effects of Adapted Physical Activity on White Matter Integrity in Patients with Schizophrenia

Schizophrenia is associated with changes in white matter (WM) integrity and with reduced life expectancy, in part because of the cardiometabolic side effects of antipsychotics. Physical activity (PA) has emerged as a candidate lifestyle intervention that is safe and effective. The study aimed to assess how an adapted PA program delivered remotely by web (e-APA) improved WM integrity in patients with schizophrenia (SZPs) and healthy controls (HCs) and to evaluate associations among WM integrity, cardiorespiratory fitness, and symptom severity. This longitudinal study was conducted over 16 weeks with 31 participants (18 SZPs and 13 HCs). Diffusion tensor imaging and tract-based spatial statistics were employed to assess WM integrity. Cardiorespiratory fitness was measured by maximal oxygen uptake (VO2max), and assessments for clinical symptoms included the Positive and Negative Syndrome Scale, Self-evaluation of Negative Symptoms and the Brief Negative Syndrome Scale (BNSS). Only the SZPs had significantly increased WM integrity after the e-APA program, with increased fractional anisotropy and decreased radial diffusivity in fasciculi involved in motor functions and language process. Furthermore, decreased negative symptoms assessed with BNSS were associated with greater WM integrity following the program. These findings suggest that e-APA may improve WM integrity abnormalities and support e-APA as a promising therapeutic strategy.

Paving the Way to Active Living for People with Disabilities:: Evaluating Park and Playground Accessibility and Usability in Delaware

Objectives

To evaluate the accessibility and usability of parks and playgrounds in New Castle County, Delaware, for people with disabilities, with a particular focus on identifying environmental barriers that may impede access to these public spaces and potentially affect physical activity (PA) participation for the chronic disease prevention and mitigation.

Methods

Using a cross-sectional observational design, teams of trained University of Delaware students utilized the Community Health Inclusion Index (CHII) Tool to assess the accessibility of ten suburban and urban parks and playgrounds from April to November 2023. The tool evaluated various elements of public spaces, including public transit, parking, pathways and multi-use trails, entrances, playground equipment, and health promotional materials. Descriptive statistics were calculated for the accessibility and usability of each element.

Results

Significant barriers to accessibility and usability were identified. Over half of the sites lacked nearby public transit stops, and many trails and playgrounds were not fully accessible to people with disabilities. While some areas demonstrated good accessibility, such as well-maintained pathways and appropriately designed crosswalks, barriers like uneven surfaces, insufficient curb cuts, and inadequate van-accessible parking spaces were common. Most playgrounds lacked equitable play equipment, with less than half having ground materials suitable for mobility devices.

Conclusions

The study underscores the need for substantial improvements in the design, construction, and maintenance of Delaware parks and playgrounds to better support people with disabilities. Enhancing accessibility is crucial for promoting PA participation. The findings support the development of inclusive recreational and PA environments, aligning with the Americans with Disabilities Act, to reduce chronic disease health disparities faced by people with disabilities.

Policy Implications

This study highlights the need for revised policy measures to enhance park accessibility, advocating for infrastructure improvements and inclusive designs to ensure equitable recreation and physical activity opportunities for people with disabilities.

The association between leisure-time physical activity and blood pressure changes from adolescence to young adulthood: Tehran Lipid and Glucose Study

The effectiveness of long-term leisure time physical activity (LTPA) on blood pressure (BP) changes is still under debate. Since adolescence lifestyle behaviors shape the adulthood health profile, this study aimed to investigate the sex-specific impact of LTPA on BP changes from adolescence to young adulthood. This longitudinal study uses the data of 1412 adolescents (52% females) aged 12-18 years through a median follow-up of 12.2 years in the Tehran Lipid and Glucose Study (TLGS) framework. LTPA was calculated using the reliable and valid Iranian version of the modified activity scale (MAQ), and BP was measured at least twice by trained physicians. The linear mixed model was used to examine the study variables, considering individual and intrapersonal differences during the study. The majority of participants consistently demonstrated insufficient LTPA throughout the follow-up assessments, ranging from 54.7 to 67.1% for males and 77.7-83.4% for females. Despite a declining trend in LTPA (β = - 2.77 for males and β = - 1.43 for females), an increasing trend was noticeable in SBP, DBP, and BMI (β = 1.38, β = 1.81, β = 0.97 for males, and β = 0.10, β = 0.20, β = 0.97 for females, respectively). The unadjusted model revealed a significant trend in all variables for both sexes, except for female BP (P = 0.45 for SBP and P = 0.83 for DBP). Using the adjusted model, no significant association was observed between LTPA and changes in BP over time in both sexes. Our study indicates no association between LTPA and BP changes from adolescence to young adulthood. Insufficient LTPA levels, particularly among Iranian females, are likely the primary factor. Further research is crucial to identify appropriate LTPA levels to promote cardiovascular health and implement targeted interventions to achieve optimal LTPA levels in the Iranian population.

Dose-response associations of Monitor-Independent Movement Summary with health-related fitness in youth

The purpose of this study was to determine the dose-response associations between Monitor-Independent Movement Summary (MIMS) units and health-related fitness in youth. The sample comprised US children and adolescents who participated in the 2012 National Youth Fitness Survey (NNYFS; N = 1158, 48.9% female). Health-related fitness domains were assessed using tests of cardiorespiratory endurance (timed maximal and graded treadmill tests), muscular strength (modified pull-up and grip tests), and muscular endurance (plank test). Movement data were collected using wrist-worn ActiGraph accelerometers with raw data processed using MIMS and the calculated metrics of average MIMS/day, Peak 60-min MIMS, and Peak 30-min MIMS. Weighted regression models examined linear associations between MIMS metrics and fitness test scores. Nonlinear associations were examined using weighted spline models with knots placed at the 10th, 50th, and 90th percentiles. Models were adjusted for covariates and fit was examined using the coefficient of determination (R2 ). The strongest adjusted linear relationships included a positive association between MIMS/day (per every 1000 units) and maximal endurance times (b = 5.5 s, p < 0.001) and between Peak 60-min MIMS (per every 10 units) and estimated aerobic capacity (b = 1.7 mL/kg/min, p < 0.001), modified pull-ups (b = 0.7 reps, p < 0.001), and plank test scores (b = 5.0 s, p < 0.001). Linear spline models had slightly higher R2 values (R2 range = 16.9%-74.8%) compared to linear models (R2 range = 15.0%-74.5%). The relationship between MIMS metrics and fitness test scores was best modeled as piecewise linear functions. Although all MIMS metrics associated with cardiorespiratory endurance, Peak 60-min MIMS showed stronger associations with tests of muscular strength and endurance.

High-fiber diet and rope-skipping benefit cardiometabolic health and modulate gut microbiota in young adults: A randomized controlled trial

Previous studies have shown that high intake of dietary fiber (DF) and efficient levels of physical activity are beneficial for cardiometabolic health in middle-aged and elderly populations with cardiometabolic disease. However, evidence from young adults with low cardiometabolic risk is lacking. This study aimed to investigate the effects of various interventions including a high-fiber (HF) diet and the rope-skipping (RS) exercise on cardiometabolic risk factors (CRFs) and the composition of the gut microbiota in young adults. A 12-week parallel-designed randomized controlled trial was conducted in undergraduates (n = 96), who were randomly assigned to the HF group (≥20 g/d DF), the RS group (2000 jumps/week), and the control (CON) group. Among the 84 people who completed the trial, measurements of anthropometric characteristics, biochemical parameters, and gut microbiota were taken at the beginning and end of the intervention. After the intervention, the RS exercise led to a significant decrease in the heart rate and triglyceride levels compared to the CON group (all P < 0.05), but there was no significant difference in CRFs between the HF and CON groups. When compared to baseline, the 12-week HF diet intervention resulted in an increase in fat-free mass, and a decrease in the percentage of body fat and waist circumference (all P < 0.05). With regard to gut microbiota alterations after intervention, we found that compared with the CON group, the relative abundance of Lactobacillus decreased significantly in both the HF group and the RS group, Muribaculaceae decreased in the RS group, and Eubacterium_coprostanoligenes_group decreased in the HF group (all P < 0.05). Finally, shifts in 7 metabolic pathways were detected in the RS group using predictive functional profiling, while only one pathway was altered in the HF group (all P < 0.05). In conclusion, the RS exercise improved body composition compared to the CON group in young adults, while the HF diet just enhanced CRFs in contrast to baseline. Furthermore, both RS and HF interventions altered Lactobacillus and various other gut microbiota. The results indicated that the HF diet and RS exercise could partly benefit cardiometabolic health and modulate gut microbiota in young adults. Trial registration: ClinicalTrials.gov, NCT04834687.

Objectively-measured movement behaviors, systemic low-grade inflammation, and plasma neurofilament light chain in older adults: a population-based study

BACKGROUND

Evidence has linked self-reported sedentary behavior (SB) and physical activity (PA) with cognitive impairment; however, the underlying mechanisms are poorly understood. We examined the associations of the accelerometer-measured movement behaviors with plasma neurofilament light chain (NfL) among older adults and the role of systemic low-grade inflammation in the associations.

RESULTS

This population-based study included 1,029 dementia-free older adults (age ≥ 60 years, range 60-88 years; 59.48% women) who undertook the ActiGraph substudy (March 2018-December 2020) in MIND-China. There were nonlinear relationships of daily SB and PA time with plasma NfL concentration, such that more daily SB time or less time spent in daily light-intensity physical activity (LPA) and moderate-to-vigorous-intensity physical activity (MVPA) was significantly associated with increased plasma NfL only when SB time ≥ 8.00 h/day or LPA time < 5.00 h/day or MVPA time < 2.00 h/day. Furthermore, more daily SB time or less daily LPA and MVPA time was significantly associated with higher serum low-grade inflammation score, a composite measure generated from serum IL-6, IL-8, TNF-α, and ICAM-1 (P < 0.05). Finally, low-grade inflammation score accounted for 14.5% to 17.8% of the associations between movement behaviors and plasma NfL.

CONCLUSIONS

More daily SB and less PA time are associated with neurodegeneration and systemic low-grade inflammation in older adults. The association of movement behaviors with neurodegeneration is partially mediated by low-grade inflammation.

Perspectives of US Youths on Participation of Transgender Individuals in Competitive Sports: A Qualitative Study

Importance

Rights and access for transgender individuals, including the participation of transgender athletes in sports, have long been debated. These discussions often center around fairness and mental health impacts on youths associated with identity-based inclusion in sports.

Objective

To assess the experiences and perspectives of adolescents and young adults on the inclusion of transgender individuals in competitive sports.

Design, Setting, and Participants

In this qualitative study, 5 open-ended survey questions were sent to the MyVoice cohort from December 10 to 17, 2021. MyVoice is a nationwide text-message polling platform of US youths aged 14 to 24 years. All coding and subsequent analysis was completed between January 10 and December 11, 2022.

Main Outcomes and Measures

Qualitative perspectives of youths regarding transgender athlete participation in sports as measured by survey responses. Responses were reviewed using an inductive approach to qualitative thematic analysis to develop a codebook. The codes were independently applied to all responses by 2 investigators; discrepancies were resolved with discussion. Summary statistics were calculated for demographic characteristics and code frequencies, and χ2 tests (α = .05, 2-tailed) were used to evaluate differences in opinion based on gender identity and participation in competitive sports.

Results

A total of 905 of 1199 youths (75%) responded to the survey. Respondents had a mean (SD) age of 20 (2) years; 482 (53%) identified as male, 29 (3%) identified as transgender, and 306 (34%) reported having participated in high school and/or collegiate athletics. Three themes emerged: (1) youths differed regarding the inclusion of transgender athletes based on gender identity vs sex assigned at birth, (2) many youths did not have personal experience related to the inclusion of transgender athletes, and (3) youths were uncertain about the impacts of gender identity-based participation on cisgender individuals but perceived positive impacts for transgender individuals. Nearly half of respondents (327 of 691 [47%]) thought that transgender athletes should participate based on their gender identity or personal preference, whereas 240 (35%) favored participation based on sex assigned at birth or in a transgender-only category. Respondents mentioned concern about the fairness of identity-based participation, specifically for cisgender women, but many (410 of 697 [59%]) also reported that it would be affirming for transgender athletes to participate based on gender identity.

Conclusions and Relevance

The youths in our study differed in their opinions regarding sports participation of transgender youths, but many felt that inclusive policies would affirm and support the mental health of transgender individuals. Negative impacts on fairness were noted by some respondents. These findings suggest that nuanced policies are needed to address the participation of transgender athletes in competitive sports and should consider the impacts on and perspectives of youths most affected.

The association between metabolic equivalent and visceral adiposity index among children and adolescents: Ten-cycle cross-sectional study on NHANES (1999-2018)

Metabolic disorder is globally prevalent in children and adolescents, and physical activity may have a protective role against metabolic disorder. However, the association between metabolic equivalent (MET) and visceral adiposity index (VAI) among children and adolescents remains unclear. This study aimed to address this concern. Data were retrieved from the National Health and Nutrition Examination Survey (NHANES), which used the Global Physical Activity Questionnaire to assess the physical activity levels. VAI was calculated according to body mass index (BMI), waist circumference (WC), triglyceride (TG), and high-density lipoprotein (HDL). Linear regression was adopted to assess the association between MET and VAI. Restricted cubic spline regression was used to further explore the nonlinear relationship, Interaction effect analysis was conducted to identify whether the sample characteristic could modify the effect of MET on VAI. After data cleansing, a total of 3402 participants aged <18 years were enrolled. In the fully adjusted linear regression model, the β for VAI was 0.01 (95% confidence interval [CI]: -0.08, 0.09) for the second tertile and -0.11 (95% CI: -0.20, -0.03) for the third tertile. A linear downward trend was found in the restricted cubic spline regression (overall P < .05). Interaction effect analysis revealed no significant effects of age, gender, race, income poverty ratio, and insurance (all P for interaction >0.05). High physical activity intensity is associated with decreased VAI scores in children and adolescents.

Very low calorie ketogenic diet combined with physical interval training for preserving muscle mass during weight loss in sarcopenic obesity: A pilot study

Background

The prevalence of sarcopenic obesity (SO) is increasing worldwide, posing important challenges to public health and national health care system, especially during the COVID pandemic. In subjects with SO, it is essential to reduce body weight, and to preserve lean mass, to avoid worsening of muscle function. Adequate nutrition and correct physical activity is essential to counteract SO progression. Very Low Calorie Ketogenic Diet (VLCKD), a well-established nutritional intervention for obesity, has been also indicated for the treatment of SO. To date, the effects of physical training during VLCKD have not been investigated.

Aim

This pilot study aims to determine the efficacy of VLCKD combined with interval training, compared to a VLCKD alone, on weight-loss, body composition, and physical performance in participants with SO.

Materials and methods

Twenty-four participants with SO, aged between 50 and 70 years, who met the inclusion criteria, accepted to adhere to a VLCKD (<800 Kcal/die) and to give informed consent, were enrolled in the study. Twelve participants followed a structured VLCKD protocol (VLCKD group) and twelve followed the same VLCKD protocol combined with interval training (IT), twice per week (VLCKD + IT group). Data were collected at baseline (T0) and after 6-week of treatment (T6). Anthropometric indexes, body composition analysis by Bioelectrical Impedance Analysis (BIA), muscle strength and physical performance analysis were assessed at baseline and at the end of treatment.

Results

At the end of the study, body mass index (BMI), body weight, waist circumference, and hip circumference were significantly reduced in both VLCKD group and VLCKD + IT group. Interestingly, a significant improvement in muscle strength and physical performance was observed in both groups. A multiple comparison of delta variations in all parameters between groups was performed. No differences were observed for the majority of anthropometric and biochemical parameters, with the exception of fat free mass (FFM) and fat mass (FM): notably, participants who followed a VLCKD combined with IT preserved FFM (p < 0.001) and reduced FM (p = 0.001) to a greater extent than what observed in VLCKD group. Moreover, high density lipoprotein (HDL) cholesterol plasma levels were significantly higher in the VLCKD + IT group compared to the VLCKD group.

Conclusion

This pilot study confirms that VLCKD is effective in terms of body weight reduction, particularly FM; moreover, the combination of VLCKD and interval training could determine a better preservation of FFM.