Function In Healthy Young Adults Research Articles

Test-Retest Reliability and Reliable Change Estimates for Sensorimotor Concussion Assessments in Healthy Young Adults.

Sensorimotor impairments are common sequela following concussion, but recovery following a concussion is often determined through examiner scored clinical testing. There are emerging technologies that provide objective methods to determine physiological impairment after concussion, but the psychometrics of these tools are lacking and must be established for use in clinical practice. The purpose of this study was to examine the test-retest reliability and provide reliable change estimates in healthy young adults for outcomes from 3 emerging technologies providing objective assessments of sensorimotor function in healthy young adults. Test-retest reliability design in a laboratory setting. Healthy, young adults completed testing at 2 time points 4weeks apart on the Bertec Vision Trainer, the Concussion Balance Test (COBALT), and the Neurolign Dx-100eye-tracking system. We determined test-retest reliability using intraclass correlation coefficients with a 2-way mixed-effects model absolute agreement. Reliable change estimates were calculated for 70%, 80%, 90%, and 95% CIs. Participants included 30 healthy young adults (age = 25 [5]y, interquartile range = 20-29; range = 18-38; 17% [57%] women). Test-retest reliability for the Bertec Vision Trainer outcomes ranged from 0.56 to 0.88, with 45% of the outcomes being classified as clinically acceptable (>.70 intraclass correlation coefficients ); for COBALT conditions, sway velocity ranged from 0.50 to 0.95, 95% ellipse area ranged from -0.22 to 0.88, and Sway Score ranged from 0.07 to 0.85, with 50% of COBALT metrics being clinically acceptable; and for the Dx-100,outcomes ranged from -0.20 to 0.89, with 52% being clinically acceptable. Overall, test-retest reliability was moderate-to-good for the Bertec Vision Trainer assessment outcomes but were highly variable for outcomes of postural control using the COBALT and eye-tracking metrics using the Dx-100. This study adds clinically relevant test-retest reliability and reliable change estimates in healthy adults for 3 commercially available sensorimotor assessments.

Vigorous Exercise Enhances Verbal Fluency Performance in Healthy Young Adults.

We examined the effects of cardiovascular exercise on verbal fluency using a between-groups design. Within our experimental (i.e., exercise) group, participants performed phonemic and semantic verbal fluency tasks (VFTs) before, during, and after a vigorous 30 min bout of cycling. Participants within our control group also completed these VFTs before, during, and after a non-physical activity. We compared the VFT performance of the experimental (exercise) and control (no-exercise) groups of participants in terms of the characteristics of the words that they produced within the VFTs. In addition, we examined these aspects of VFT performance for each participant group across time within the experiment session. From these comparisons, we see that exercise influenced VFT performance. Most notably, participants engaged in exercise changed their VFT performance over time, while control group participants did not. Exercising participants produced more words over the course of their exercise session that contained fewer letters over time and were lower in frequency during and after exercise as compared to before exercise. Additionally, topic switches in the VFTs increased after exercise as compared to before exercise. Participants in the control group did not change their VFT performance over time according to any of these measures. These findings indicate that exercise impacted participants' lexical access and that these VFT performance changes were not due to practice effects.

The Effect of Free Weight Resistance Training on Cognitive Function Explored Through Eye Tracking: A Randomized Double-Blind Clinical Trial.

In this study, we investigated the impact of a 10-week free weight resistance training (RT) program on cognitive function in healthy young adults. In this randomized controlled trial, 18 participants were assigned to either an experimental or control group. We assessed cognitive function by using eye-tracking (ET) technology during text processing tasks. First-pass reading times (FPRTs) and total reading times (TRTs) were measured. Results revealed a significant three-way interaction between group, moment, and syntactic complexity in FPRTs, demonstrating training effects on cognitive processing. The experimental group showed a distinctive shift in processing patterns: from longer times in low complexity pre-intervention to increased times in high complexity post-intervention, particularly in early processing measures (FPRTs). Complementary analyses of strength improvements showed that increased strength was associated with enhanced attention allocation to complex structures and improved processing efficiency for simpler texts, suggesting RT's potential to modulate cognitive function.

Effects of Foot Somatosensory Training on Plantar Somatosensory Function.

Background Declines in foot somatosensory function can negatively impact balance and daily activities, particularly in older adults and individuals with neurological conditions. Despite this, effective physical therapeutic interventions to improve foot sensory function are limited. This study assessed the effects of targeted foot somatosensory training on plantar sensory function in healthy young adults. Methods Thirty-three healthy young adults (mean age 21.2 ± 0.7 years) were randomly assigned to one of three groups: (1) Discrimination group, (2) Attention group, or (3) Control group. The Discrimination group performed spatial attention tasks to identify weight positions on an instability board; the Attention group focused on timing tasks; and the Control group watched a video. Tactile pressure sensitivity and two-point discrimination of the plantar surface were measured before and after the intervention. Statistical analyses included Wilcoxon signed-rank tests and two-way repeated measures of analysis of variance (ANOVA). Results No significant differences were found in tactile pressure sensitivity. However, two-point discrimination thresholds for the big toe and the ball of the little toe were significantly reduced in the Discrimination group, indicating enhanced sensitivity. Conclusion Foot sensory training, particularly through discrimination tasks, may effectively improve plantar sensory function, suggesting potential clinical applications in individuals with sensory impairments.

Effect of chewing hard material on boosting brain antioxidant levels and enhancing cognitive function.

Chewing has been reported to enhance cognitive function through the increase in cerebral blood flow. However, the mechanisms linking cerebral blood flow increase to metabolic changes in the brain affecting cognition remain unclear. We hypothesized that glutathione (GSH) plays a pivotal role in these mechanisms. Therefore, this study aimed to investigate changes in brain GSH levels following chewing and their association with cognitive function in healthy young adults. A total of 52 university students were recruited, and the Korean version of the Repeatable Battery for the Assessment of Neuropsychological Status was used for the neurocognitive evaluations. Brain GSH levels following chewing gum or wood blocks were measured using MEscher-GArwood Point RESolved Spectroscopy (MEGA-PRESS) sequence, and their relevance to neurocognitive evaluation results was investigated. Chewing significantly increased brain GSH concentration, particularly in the wood-chewing group compared to the gum-chewing group, as observed in the anterior cingulate cortex. Furthermore, the rise in GSH concentration in the wood-chewing group was positively correlated with memory function. Chewing moderately hard material elevates brain antioxidant levels such as GSH, potentially influencing cognitive function.

Effects of different exposures to normobaric hypoxia on cognitive performance in healthy young adults.: Normobaric hypoxia and cognitive performance

Normobaric hypoxia has become an innovative non-pharmacological therapy to treat cognitive dysfunction. Nevertheless, the acute effects of exposure to hypoxia on cognitive performance remain unclear. We aimed to determine the effects of different normobaric hypoxic exposures on cognitive function in healthy young adults. Nineteen participants (13 men and 6 women; 23.7 ± 3.9 years; 172.0 ± 8.4 cm; 69.1 ± 12.2 kg) completed a cross-over randomized control trial with the following doses of fraction of inspired oxygen (FiO2): a) 21 %, b) 15 %, c) 13 % or d) 11 %. During experimental trials, the physiological response (blood oxygen saturation and heart rate) and the following cognitive abilities were evaluated: memory, sustained attention, anticipation, and reaction time. Sustained attention improved under hypoxia at 15 % FiO2 (mean difference (MD) 0.024, 95 % confidence intervals (CI) 0.005 to 0.044 s; p = 0.018) compared to 11 % and 21 % FiO2. During 11 % and 15 % FiO2, participants showed improved anticipation ability compared to normoxia (MD -0.023, 95 % CI -0.042 to -0.003 s, p = 0.020, and MD -0.009, 95 % CI -0.016 to -0.001 s, p = 0.022, respectively). However, reaction time was impaired under 11 % compared to 21 % FiO2 (MD 0.033, 95 % CI 0.008 to 0.059 s, p = 0.013). Finally, we did not find significant effects of hypoxia on memory (p > 0.05). Severe normobaric hypoxic exposure (11 % FiO2) produces detrimental effects on reaction time, although anticipation seems to be improved, compared to normoxia. In addition, cognitive processes of attention and anticipation appear to improve with moderate hypoxic exposure (15 % FiO2).

An observational study: Correlation between self-perceived readiness and physical performance in healthy individuals

IntroductionIn complex environments, individuals need to anticipate and react to stimuli by integrating complex systems and skills. Identifying the perceptual-cognitive, physical, and health characteristics that afford effective performance is necessary for developing training and readiness strategies. Measuring readiness by establishing a relationship between the Acute Readiness Monitoring Scale (ARMS) and performance during perceptual-cognitive tasks is essential. Therefore, this study aimed to determine the relationship between self-perceived readiness, physical performance, and perceptual-cognitive performance in healthy young adults. Materials and methodsCross-sectional design with healthy and physically active young adults (n = 35). Participants completed a measure of self-perceived readiness (the ARMS), physical performance (i.e., Vertical Jump (VJ) and Ballistic Push-Up), and perceptual-cognitive exercises (i.e., Single Leg Memory Hop (SLMH), Reactive VJ, Reactive Ballistic Push-Up, Reactive Agility Run Decide, and Upper and Lower Extremity Reaction Tests). Data was analyzed using Pearson's r (r) correlation to identify associations. ResultsStatistically significant moderate correlations were detected between ARMS Total and VJ (Peak Power Normalized and Flight Time) (r = 0.434, p = 0.010) and (r = 0.420, p = 0.013), and SLMH Distance Normalized (r = 0.409, p = 0.016). Moderate negative correlations between the ARMS Total and Reactive VJ Reaction Time (r = −0.473, p = 0.005). ConclusionThe ARMS can be an effective tool for measuring acute self-perceived readiness. This suggests that individuals who work in dynamic environments may benefit from training that targets perceptual-cognitive skills. Although moderate, self-perceived readiness was associated with better resilience, health, and performance exercises. Results highlight the importance of protocols targeting populations who work in complex environments for increased performance.

Concentric exercise-induced fatigue of the shoulder impairs proprioception but not motor control or performance in healthy young adults

ObjectivesTo investigate the effect of concentric fatigue on proprioception, motor control and performance of the shoulder in healthy young adults. DesignTest-retest experimental design. SettingHuman performance laboratory. Participants20 healthy adults. Main outcome meausure(s)Proprioception was assessed using the joint repositioning sense (JRS) and the threshold to detection of passive movement (TTDPM). Motor control was assessed using the Y-balance Upper Quarter test (YBT-UQ) and performance using the Athletic Shoulder test (ASH test). All tests were conducted before and immediately after fatigue intervention (CON/CON protocol). ResultsFollowing fatigue, absolute angular error (AAE) was significantly increase by 160.27 %. Moreover, there was a significant increase (48.41 %) in TTDPM after fatigue. Furthermore there was no significant differences in motor control and performance before and after fatigue intervention. ConclusionsSince muscular fatigue negatively affects shoulder proprioception, it is essential to assess proprioception before and after fatigue to detect any dysfunctions that may arise as a result of fatigue. To address these dysfunctions, it is recommended to engage in proprioceptive exercises under situations of fatigue in order to enhance the sensitivity of the mechanoreceptors.

Effects of low and high dietary nitrate intake on human saliva, plasma and skeletal muscle nitrate and nitrite concentrations and their functional consequences

Dietary nitrate (NO3−) supplementation has been shown to reduce blood pressure (BP), improve exercise performance, and alter the oral microbiome. Following a “control” diet (CON), we manipulated dietary NO3− intake to examine the effect of a short-term (7-day) low NO3− diet (LOW) followed by a 3-day high NO3− diet (HIGH), compared to a 7-day standard (STD) NO3− diet followed by HIGH, on saliva, plasma, and muscle [NO3−] and nitrite ([NO2−]), BP, and cycling exercise performance in healthy young adults. We also examined the effect of LOW on the oral microbiome. Saliva [NO3−] and [NO2−], and plasma [NO3−] were significantly lower than CON following LOW (all P < 0.05) but there was no change in plasma [NO2−] or muscle [NO3−] and [NO2−] (all P > 0.05). Following HIGH, saliva and plasma [NO3−] and [NO2−], and muscle [NO3−], were significantly elevated above CON, LOW and STD (all P < 0.05), but there was no difference between CON-LOW-HIGH and CON-STD-HIGH (P < 0.05). BP and exercise performance were not altered following LOW (P > 0.05). HIGH significantly reduced systolic and diastolic BP compared to CON when preceded by STD (both P < 0.05) but not when preceded by LOW (P > 0.05). Peak (+4 %) and mean (+3 %) power output during sprint cycling was significantly improved following HIGH (both P < 0.05), with no differences between CON-LOW-HIGH and CON-STD-HIGH (both P > 0.05). LOW altered the oral microbiome composition, including decreases in relative abundances of phylum Proteobacteria and genus Neisseria. The findings indicate that a short-term low NO3− diet lowers plasma but not skeletal muscle [NO3−]. The maintenance of plasma [NO2−] and muscle [NO3−] and [NO2−] following LOW may be indicative of their importance to biological functions, including BP regulation and exercise performance.

Mediated relationship between Vitamin D deficiency and reduced pulmonary function by copper in Taiwanese young adults

BackgroundVitamin D deficiency is prevalent worldwide and associated with worse outcomes in various lung diseases. This study examines the association between vitamin D deficiency and pulmonary function in healthy young adults. MethodsThis prospective cohort study (2017–2019) explored the impact of vitamin D deficiency on pulmonary function in a community-based young adult population. Pulmonary function was assessed via spirometry, with serum 25-hydroxyvitamin D [25(OH)D] and urinary copper levels quantified. Multivariate regression was used to estimate the relationship between vitamin D levels and lung function, with mediation analysis evaluating copper's role. ResultsThe study included 1034 participants, average age 33.45 years, 41.93 % male. The median 25(OH)D level was 19.20 ng/mL (Interquartile Range: 13.48–24.90 ng/mL). Over half (54.74 %) had 25(OH)D levels below 20 ng/mL. Higher 25(OH)D levels were associated with better forced vital capacity (FVC) and forced expiratory volume in one second (FEV₁). Trends suggested subgroup differences, but these were not statistically significant, indicating a consistent effect of 25(OH)D on pulmonary function across groups. SEM analysis suggested urinary copper as a mediator between 25(OH)D levels and FVC. ConclusionVitamin D deficiency is significantly associated with reduced pulmonary function in young adults in Taiwan.

Effect of Lower Limb Muscle Fatigue on Dynamic Balance Performance in Healthy Young Adults: Role of Arm Movement.

There is evidence that balance performance deteriorates due to exercise-induced muscle fatigue. However, it is unknown if free arm movement during balance testing can compensate for, or restricted arm movement can amplify these performance degradations. Thus, the objective of this study was to compare the effects of free versus restricted arm movement on balance performance under non-fatigued and fatigued conditions. Fifty-two healthy participants (men=31, women=21; age=22.6±1.6 years) were assessed for their dynamic balance (reach distances for the Y Balance Test - Lower Quarter) under non-fatigued and fatigued (repetitive vertical bipedal box jumps until failure) conditions using two different arm positions: free (move the arms freely) and restricted (keep the arms akimbo) arm movement. Restriction of arm movement (all p< 0.001; 0.48≤ η p 2 ≤0.79) and application of fatigue ( p≤ 0.003; 0.16≤ η p 2 ≤0.28) independently, but not the interaction between the two (except for the posteromedial reach direction: p= 0.046; η p 2 =0.08) , resulted in significantly deteriorated lower limb reach distances. These findings suggest that free arm movement and thus the use of an 'upper body strategy' has no compensatory effect on muscle fatigue-induced balance deteriorations.

A systematic review and Bayesian meta-analysis provide evidence for an effect of acute physical activity on cognition in young adults

Physical exercise is a potential intervention for enhancing cognitive function across the lifespan. However, while studies employing long-term exercise interventions consistently show positive effects on cognition, studies using single acute bouts have produced mixed results. Here, a systematic review and meta-analysis was conducted to determine the impact of acute exercise on cognitive task performance in healthy young adults. A Bayesian hierarchical model quantified probabilistic evidence for a modulatory relationship by synthesizing 651 effect sizes from 113 studies from PsychInfo and Google Scholar representing 4,390 participants. Publication bias was mitigated using the trim-and-fill method. Acute exercise was found to have a small beneficial effect on cognition (g = 0.13 ± 0.04; BF = 3.67) and decrease reaction time. A meta-analysis restricted to executive function tasks revealed improvements in working memory and inhibition. Meta-analytic estimates were consistent across multiple priors and likelihood functions. Physical activities were categorized based on exercise type (e.g., cycling) because many activities have aerobic and anaerobic components, but this approach may limit comparison to studies that categorize activities based on metabolic demands. The current study provides an updated synthesis of the existing literature and insights into the robustness of acute exercise-induced effects on cognition. Funding provided by the United States Army Research Office.

Towards optimized methodological parameters for maximizing the behavioral effects of transcranial direct current stimulation.

Transcranial direct current stimulation (tDCS) administers low-intensity direct current electrical stimulation to brain regions via electrodes arranged on the surface of the scalp. The core promise of tDCS is its ability to modulate brain activity and affect performance on diverse cognitive functions (affording causal inferences regarding regional brain activity and behavior), but the optimal methodological parameters for maximizing behavioral effects remain to be elucidated. Here we sought to examine the effects of 10 stimulation and experimental design factors across a series of five cognitive domains: motor performance, visual search, working memory, vigilance, and response inhibition. The objective was to identify a set of optimal parameter settings that consistently and reliably maximized the behavioral effects of tDCS within each cognitive domain. We surveyed tDCS effects on these various cognitive functions in healthy young adults, ultimately resulting in 721 effects across 106 published reports. Hierarchical Bayesian meta-regression models were fit to characterize how (and to what extent) these design parameters differentially predict the likelihood of positive/negative behavioral outcomes. Consistent with many previous meta-analyses of tDCS effects, extensive variability was observed across tasks and measured outcomes. Consequently, most design parameters did not confer consistent advantages or disadvantages to behavioral effects-a domain-general model suggested an advantage to using within-subjects designs (versus between-subjects) and the tendency for cathodal stimulation (relative to anodal stimulation) to produce reduced behavioral effects, but these associations were scarcely-evident in domain-specific models. These findings highlight the urgent need for tDCS studies to more systematically probe the effects of these parameters on behavior to fulfill the promise of identifying causal links between brain function and cognition.

Age-related changes in the effects of induced positive affect on executive control in younger and older adults—evidence from a task-switching paradigm

ABSTRACT Positive affect has been shown to promote task-switching performance in healthy young adults. Given the well-documented age-related decline in executive functioning, we asked whether induced positive affect also helps to improve task-switching performance in older adults. Sixty-eight younger and older adults performed a switching task before and after they had watched cartoon clips (positive affect group) or documentaries (neutral affect group). Positive affect was associated with reduced error rates across all trial types in both age groups. In older adults, the increase in accuracy came at the expense of slower response times for task-switch trials, resulting in greater switch costs. This pattern of findings is inconsistent with the popular notion that positive affect supports greater cognitive flexibility. Instead, positive affect may trigger adjustments in response control settings – such as a shift in the speed-accuracy trade-off toward more cautious responding – depending on the experienced level of task difficulty.

Effects of Short-term Repeated Sprint Exercise Training and Moderate Intensity Continuous Exercise Training on Vascular Function in Healthy Young Adults

Effects of Short-term Repeated Sprint Exercise Training and Moderate Intensity Continuous Exercise Training on Vascular Function in Healthy Young Adults

Blood Pressure Variability is Better Associated with Acute Relative Hyperglycemia Than the Heart Rate Variability in Healthy Young Adults.

Deranged cardiovascular autonomic functions are well-reported complications of diabetes mellitus, where chronic hyperglycemia is an important factor. The role of acute relative hyperglycemia on cardiovascular autonomic functions, particularly on blood pressure variability in healthy subjects, has been rarely explored. Therefore, this study aimed to examine the effect of acute relative hyperglycemia on cardiovascular autonomic functions in healthy young adults. Beat-to-beat blood pressure and electrocardiogram were recorded to assess the heart rate variability and blood pressure variability in 42 young, healthy subjects during fasting and relative hyperglycemic states. Recorded cardiovascular parameters were analyzed in time and frequency domains. Correlations among analyzed parameters of cardiovascular autonomic variabilities were explored during fasting and relative hyperglycemic state. A few of the systolic, mean, and diastolic blood-pressure-variability parameters were significantly altered during acute relative hyperglycemia when compared to the fasting state. However, no significant changes were observed in any of the heart-rate-variability parameters. Also, novel significant correlations were found among many of the parameters of cardiovascular autonomic variabilities during fasting and relative hyperglycemic states. The blood pressure variability is affected significantly during acute relative hyperglycemia in healthy young adults; however, the heart rate variability does not show such changes. Also, many blood pressure variability parameters show significant correlations with heart rate variability and baroreflex sensitivity. It may be hypothesized that although the variabilities in heart rate and blood pressure assess cardiovascular autonomic functions, blood pressure variability is a better indicator of cardiovascular autonomic effects of acute relative hyperglycemia.

The Effects of High-Intensity Interval Training and Moderate Alcohol Consumption on Cognitive Performance-A Multidisciplinary Intervention in Young Healthy Adults.

The main purpose of this study was to determine the effects of a high-intensity interval training (HIIT) intervention in the context of moderate alcohol consumption on cognitive performance in healthy young adults. We conducted a 10-week HIIT program along with four types of beverages with/without alcohol content. A total of 75 healthy adults (18-40 years old; 46% female) were allocated to either a control Non-Training group or an HIIT program group (2 days/week). Using block randomization, participants in the HIIT group were further allocated to an HIIT-Alcohol group (alcohol beer or sparkling water with vodka added, 5.4%) or an HIIT-NonAlcohol group (sparkling water or non-alcohol beer, 0.0%). The control group was instructed to maintain an active lifestyle but did not undergo any regular training. A comprehensive neuropsychological battery was used to evaluate cognitive performance (i.e., memory, working memory, processing speed, inhibitory control, and verbal fluency). Changes from baseline to week 10 were included in the main analyses. All groups improved in all neuropsychological measures (all p ≤ 0.001), independent of sex and alcohol consumption, with no statistical differences between groups (all p > 0.05). Furthermore, larger increases in maximal oxygen uptake were associated with greater improvements in processing speed, inhibitory control, and verbal fluency (all p < 0.050). Although the improvements found in cognitive performance cannot be attributed to the HIIT intervention, no significant impairments in cognitive functions were noted due to moderate alcohol intake. Furthermore, our results confirmed that exercise-induced physical fitness improvements were associated with cognitive performance enhancements in young healthy adults.

How do visual, auditory and motor dual-tasking each affect swallowing and chewing function?

It can be challenging to perform a second task at the same time as swallowing. The study aimed to investigate the effect of visual, auditory and motor dual-tasking on swallowing and chewing function in healthy young adults. Right-handed healthy adults without any psychological and cognitive problems were included in the study. Swallowing was evaluated based on the dysphagia limit in different liquid textures such as water and nectar consistencies, and chewing was evaluated by the Test of Masticating and Swallowing Solids. For the second task, visual and auditory performance was assessed using reaction time, and the motor performance was assessed using a bilateral tapping task. Assessments were performed in two steps: baseline and dual-task. For baseline, all evaluation methods were applied individually. After completing the baseline assessment, dual-task assessment were carried out the following day. For dual-task assessment, the swallowing and chewing tasks were performed simultaneously with visual, auditory and motor tasks. Results showed a significant decrease in dysphagia limit in the nectar consistency, and significant increase in chewing time, visual reaction time and tapping rate (right-left) when compared to baseline and dual-task conditions (χ2(3) = 9.61, p = .02; χ2(3) = 9.02, p = .02; χ2(3) = 28.09, p < .001; χ2(3) = 28.97, p < .001; χ2(3) = 21.56, p < .001, respectively). However, there were no differences in dysphagia limit in the water and auditory reaction time compared to baseline and dual-task conditions (χ2(3) = 3.18, p = .36; χ2(3) = 2.56, p = .50, respectively). Results shedding light on how simultaneous dual tasks can influence swallowing and chewing. Dual-tasking cause a decrease in both swallowing/chewing and the visual/motor performances. These results may provide valuable information for designing interventions or strategies aimed at improving or maintaining optimal swallowing and chewing during in various populations during daily life.

Night Screen Time is Associated with Cognitive Function in Healthy Young Adults: A Cross-Sectional Study.

In recent years, a significant shift toward remote work, virtual education, and social distancing measures was witnessed, thereby leading people to increasingly depend on digital devices for communication, work, and entertainment. This increased exposure to screens has raised concerns regarding its potential impact on cognitive function. This study investigated the relationship between screen time and cognitive function among healthy young adults. One hundred forty-five healthy individuals (mean age 21.55 ± 2.84 years) participated in this cross-sectional study. Sociodemographic information including age, sex, height, weight, and level of education were obtained. Participants reported screen time using a screen time questionnaire. Cognitive function tests including, Paced Auditory Serial Addition Task (PASAT), Montreal Cognitive Assessment (MoCA) and Symbol Digit Modalities Test (SDMT) were conducted. Multilinear regression analyses were used to examine the associations between age, sex, level of education, screen time, and cognitive function. One hundred thirty-nine participants (76 women) completed the study. Increased night screen time, bachelor's educational level, and women were associated with lower PASAT scores (R2=0.258; p≤0.047). Moreover, increased night screen time was associated with lower MoCA scores (R2=0.029; p=0.035). However, no associations were found between night screen time and SDMT scores. Participants who had higher night screen exposure had lower cognitive scores in the information speed processing, working memory, calculation, and attention domains. Considering these findings, this study emphasizes on the importance of setting a future recommended screen time guidelines for young adults as well as to promote healthy cognitive habits in order to preserve cognitive function and reduce the risk of developing neurodegenerative disease in the future. Future prospective cohort studies involving a more diverse age range is needed.

The effects of prolonged sitting with a mild hypercapnic environment on vascular function in elderly adults: A pilot study

Introduction: Prolonged Sitting (PS), defined a sitting for 2+ hours at a time, has been identified as an independent risk factor for cardiovascular disease (CVD). We previously reported that an acute bout of PS can attenuate macrovascular function in healthy young adults. Additionally, we reported that PS in mild hypercapnic environments (elevated CO2 concentrations) can further exacerbate these impairments in healthy young adults, and these impairments can be partially prevented by intermittent bouts of passive and active leg movements. However, the effects of prolonged sitting with a mild hypercapnic environment in the elderly population have not been studied. Therefore, the purpose of this study was to examine the impact of prolonged sitting with a mild hypercapnic condition on macrovascular function, arterial stiffness, and leg muscle metabolism. Additionally, we have further examined the effects of passive and active movements to negate the negative effects of prolonged sitting in elderly adults. Hypothesis: We hypothesized that 1) prolonged sitting in a hypercapnic environment will attenuate vascular function and leg metabolism, 2) both passive and active leg movements will preserve endothelial function and leg metabolism. Methods: Healthy elderly adults (n=2, 2 males, 69 ± 2.83 yrs) participated in three experimental visits consisting of 2.5h of prolonged sitting in a mild hypercapnic condition (CO2 = 1500ppm): control (CON), passive (PASS, passive leg movement), and active (ACT, active leg movement). Popliteal and brachial artery endothelial function was measured using flow-mediated dilation (FMD). Peripheral and central arterial stiffness was assessed using pulse wave velocity. Leg muscle metabolism was assessed using near infrared spectroscopy and a thermal camera. All measurements were taken pre- and post-siting. Results: Popliteal FMD was reduced in the CON condition compared to both the PASS and ACT (Δ -3.559 ± 0.499 vs Δ -1.799 ± 0.824 vs Δ 0.601 ± 1.958, respectively). Brachial FMD was attenuated in the CON condition compared to both compared to both the PASS and ACT (Δ -2.368 ± 0.215 vs Δ -0.285 ± 1.578 vs Δ 1.116 ± 1.174, respectively). The CON condition showed a greater reduction in leg temperature compared to both the PASS and ACT (Δ -2.4 vs Δ -1.6 ± 0.599 vs Δ 0.1 ± 0.224, respectively). No changes in central or peripheral arterial stiffness were observed. Conclusion: This preliminary data shows that uninterrupted prolonged sitting induces impairments in both local and systemic vascular function, leg muscle metabolism, but not arterial stiffness. Additionally, intermittent bouts of passive and active movements can partially preserve leg vascular function and metabolism during PS. This research was supported by the UNO Graduate Research and Creative Activity Grant, National Institutes of Health (RO1HD106911) and the Great Plains IdeaA-CTR (U54 GM115448). This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.