Detrimental effects of physical inactivity on peripheral and brain vasculature in humans: Insights into mechanisms, long-term health consequences and protective strategies

Sociodemographic and lifestyle determinants of blood pressure in adult Nigerians

BACKGROUND

Blood pressure (BP) trends are influenced by genetic, sociodemographic and lifestyle factors, with notable population-specific variations. This study assessed the impact of these determinants on BP in urban Nigerians to identify high-risk subgroups and inform targeted interventions.

METHODS

We conducted a cross-sectional study of 5076 adults ages 18-92 y (51.1% female) from Lagos, Nigeria. Data were collected using a modified World Health Organization STEPS protocol, including standardized BP measurements. Multiple linear regression models evaluated the effects of sociodemographic (age, sex, education, marital status and occupation) and lifestyle factors (tobacco/alcohol use, physical activity and fruit/vegetable consumption) on systolic BP (SBP) and diastolic BP (DBP) trends.

RESULTS

Age and marital status (married/cohabiting) significantly predicted higher SBP and DBP. Male sex, previously married, low physical activity and current tobacco use independently predicted elevated SBP, while alcohol consumption and employment type (salaried and self-employment) predicted higher DBP. The impacts of these factors on SBP and DBP ranged from β=0.03 to 0.28. Low fruit/vegetable consumption was not a significant independent predictor.

CONCLUSIONS

Sociodemographic and lifestyle factors exhibit unique patterns in influencing BP among urban Nigerians. Tailored public health strategies, including alcohol/tobacco risk awareness, access to health screening and socio-economic/marital support, are essential for effective hypertension prevention in this population.

Increased sedentary behavior is associated with neurodegeneration and worse cognition in older adults over a 7-year period despite high levels of physical activity

INTRODUCTION

Sedentary behavior may be a modifiable risk factor for Alzheimer's disease (AD). We examined how sedentary behavior relates to longitudinal brain structure and cognitive changes in older adults.

METHODS

Vanderbilt Memory and Aging Project participants (n = 404) completed actigraphy (7 days), neuropsychological assessment, and 3T brain MRI over a 7-year period. Cross-sectional and longitudinal linear regressions examined sedentary time in relation to brain structure and cognition. Models were repeated testing for effect modification by apolipoprotein E (APOE) ε4 status.

RESULTS

In cross-sectional models, greater sedentary time related to a smaller AD-neuroimaging signature (β = -0.0001, p = 0.01) and worse episodic memory (β = -0.001, p = 0.003). Associations differed by APOE-ε4 status. In longitudinal models, greater sedentary time related to faster hippocampal volume reductions (β = -0.1, p = 0.008) and declines in naming (β = -0.001, p = 0.03) and processing speed (β = -0.003, p = 0.02; β = 0.01, p = 0.01).

DISCUSSION

Results support the importance of reducing sedentary time, particularly among aging adults at genetic risk for AD.

HIGHLIGHTS

Greater sedentary behavior is related to neurodegeneration and worse cognition. Associations differed by APOE-ε4 carrier status in cross-sectional models. Sedentary behavior is an independent risk factor for Alzheimer's disease.

Dietary patterns and physical activity in young South Asians and white Europeans and their potential implications for cardiovascular risk

Individuals of South Asian (SA) ethnicity have greater risk of developing cardiovascular disease (CVD) relative to white Europeans (WEs). Factors which generally contribute to increased CVD risk include physical inactivity and poor dietary habits, including high intake of salt and saturated fat. Contrastingly, diets rich in fibre, antioxidants and polyphenols are considered cardioprotective. The current questionnaire-based study aimed to examine whether the dietary habits and physical activity levels of young adult SAs living in the UK may contribute to their increased CVD risk in comparison to age-matched WEs. All participants (80 healthy individuals, 40 SA/ 40 WE (gender-balanced, aged 18-26 years) completed questionnaires to assess: general health; habitual physical activity levels, assessed by the International Physical Activity Questionnaire; and dietary patterns, assessed by EPIC-food frequency questionnaire and three-day food diaries. SAs had higher sitting times (SA: 469 ± 19.4, WE: 387 ± 21.5 min/day, p = 0.0107) and were less physically active (SA: 2050 ± 1110, WE: 4850 ± 2810 MET mins/day, p < 0.0001) than WEs. Further, SAs had lower consumption of cardioprotective nutrients, such as fibre (p = 0.0183), folate (p = 0.0242), vitamin C (p = 0.0105) and phytochemicals, such as flavonoids (p = 0.0644). SAs also consumed less alcohol (p < 0.0001), fat (p = 0.0066), sugar (p = 0.0218) and sodium (p = 0.0011) compared to WEs. These findings suggest that lower consumption of nutrients and phytochemicals that are cardioprotective, rather than excess consumption of fat, sugar and sodium, amongst young SAs may contribute to their increased CVD risk. Young SA individuals may also reduce their future CVD risk by increasing their physical activity.

Influence of sedentary behavior on sleep quality in postmenopausal women in high-altitude regions of China: a cross-sectional study

Objective

This study investigates the association between sedentary behavior and sleep quality among postmenopausal women residing in China's plateau regions. Particular attention is given to moderating effects of age, body mass index (BMI), and sleep environment. This study aims to identify modifiable risk factors influencing sleep quality in this high-altitude population.

Methods

This cross-sectional study focused on postmenopausal women (aged ≥50 years, ≥12 months post-menopause) across four primary plateau regions in China: Qinghai-Tibet, Yunnan-Guizhou, Inner Mongolia, and the Loess Plateau. Sedentary behavior was evaluated with the Older Adults Sedentary Behavior Questionnaire, and sleep quality was assessed with the Pittsburgh Sleep Quality Index. Data analysis encompassed descriptive statistics, correlation analysis, multiple linear regression, and subgroup analyses.

Results

Among the 151 participants (mean age 58.5 years), sedentary behavior was positively correlated with poorer sleep quality (r = 0.36, p < 0.001). Improvements in the sleep environment were similarly associated with better sleep quality (r = 0.29, p < 0.001). Multiple linear regression identified sedentary behavior and sleep environment as significant predictors of sleep quality, while other variables showed no significant associations. Subgroup analysis revealed age-specific effects: sedentary behavior had a strong influence on sleep quality in women under 60 years (r = 0.36, p < 0.01) but demonstrated a weaker, non-significant association in those aged 60 years or older (p = 0.062).

Conclusion

Prolonged sedentary behavior is an independent risk factor for reduced sleep quality among postmenopausal women residing in high-altitude regions, while improvements in the sleep environment are positively associated with better sleep quality. The influence of sedentary behavior on sleep quality varies by age groups. These findings highlight the importance of tailored interventions and health policies to improving sleep quality in postmenopausal women living at high altitudes.

Variability of flow-mediated dilation across lower and upper limb conduit arteries

Endothelial dysfunction is an early predictor of atherosclerosis and cardiovascular disease. Flow-mediated dilation (FMD) is the gold standard to assess endothelial function in humans. FMD reproducibility has been mainly assessed in the brachial artery (BA) with limited research in lower limb arteries. The purpose of this study was to compare FMD reproducibility in the upper limb BA and lower limb superficial femoral artery (SFA) in young healthy adults.Fifteen young healthy adults (nine males; six females) underwent FMD, resting diameter, velocity, and shear rate measurements on three occasions to determine intra-and inter-day reproducibility in both BA and SFA, assessed by coefficient of variation (CV), intraclass correlation coefficient (ICC), and Bland-Altman plots.BA FMD CVs (intra-day: 4.2%; inter-day: 8.7%) and ICCs (intra-day: 0.967; inter-day: 0.903) indicated excellent reproducibility and reliability, while for SFA FMD, both CVs (intra-day: 11.6%; inter-day: 26.7%) and ICCs (intra-day: 0.898; inter-day: 0.651) showed good/moderate reproducibility and reliability. BA FMD was significantly more reproducible than SFA FMD (p < 0.05). Diameter reproducibility was excellent and similar between arteries, while resting velocity and shear rate have lower reproducibility in the BA compared to SFA. Bland-Altman plots displayed no proportional and fixed bias between measurements.In summary, SFA FMD is less reproducible than BA FMD, with identical volume of ultrasound training. Given the increasing interest in using SFA FMD to test the efficacy of interventions targeting lower limb's vascular health and as a potential biomarker for peripheral arterial disease risk, future studies should ensure higher levels of training for adequate reproducibility.

Breaking up Sitting Time With Isometric Wall Squat Exercise During Occupational Activities: A Feasibility Randomized Trial

OBJECTIVE

The aim of to analyze the feasibility of isometric wall squat exercise (IWSE) over a 12-week period as a method of breaking up sitting time during occupational activities in sedentary adults.

METHODS

This feasibility randomized study involved sedentary adults. Participants in the IWSE group ( n = 12) performed isometric wall squats, while participants in the STAND group ( n = 12) were recommended to stand up for 12 weeks. Feasibility was assessed through online questionnaires in the eighth week regarding adherence, safety, satisfaction, and acceptability.

RESULTS

Adherence to weekly breaks was similar between groups ( P > 0.05). No serious side effects have been reported in the groups. Dropout rates (IWSE: 40% vs STAND: 40%, P = 1.000), satisfaction (IWSE +3.4 [1.2] vs STAND +3.0 [1.7], P = 0.709), and intention to continue with the intervention (IWSE: 75% vs STAND: 83%, P = 0.368) were similar between groups.

CONCLUSIONS

The IWSE is as feasible as stand up as a strategy to breaking up sedentary time in workplace.

Acute Effects of Breaking up Sitting Time With Isometric Wall Squat Exercise on Vascular Function and Blood Pressure in Sedentary Adults: Randomized Crossover Trial

PURPOSE

The World Health Organization has recommended breaking up sitting time to improve cardiovascular health. However, whether isometric exercise can be effectively used as a strategy to break up sitting time remains unclear. Thus, the aim of this study was to analyze the acute effects of breaking up prolonged sitting with isometric wall squat exercise (IWSE) on vascular function and blood pressure (BP) in sedentary adults.

METHODS

This randomized crossover trial included 17 adults (53% male, 26 ± 6 yr, 22.4 ± 3.6 kg/m 2 ) with high sedentary behavior (≥ 6 hr/d). The participants completed 2 experimental sessions in a randomized order, both sharing a common sitting period of 180 min: Breaks (2-min breaks were incorporated into the IWSE, with participants maintaining their knees at the angle determined by the incremental test, which occurred every 30 min) and Control (sitting for 180 min continuously). Popliteal artery flow-mediated dilation (FMD) and brachial BP were measured before and at 10 and 30 min after the experimental sessions.

RESULTS

The results did not indicate significant session vs time interaction effects on popliteal FMD and brachial BP ( P > .05). A subanalysis including only participants with popliteal FMD reduction after the Control session (n = 11) revealed that Breaks enhanced popliteal FMD after 10 min (1.38 ± 6.45% vs -4.87 ± 2.95%, P = .002) and 30 min (-0.43 ± 2.48% vs -2.11 ± 5.22%, P = .047).

CONCLUSION

Breaking up prolonged sitting with IWSE mitigates impaired vascular function resulting from prolonged sitting but has no effect on BP in sedentary adults.

Acute effects of energy drink consumption on microvascular reactivity in young male volunteers at rest: a randomized trial

Energy drinks are nonalcoholic beverages whose main ingredients are sugar, taurine, and caffeine. The consumption of energy drinks is increasing worldwide, but only a few conflicting studies have investigated the vascular effects of energy drinks in young adults. The aim of this study was to evaluate microvascular reactivity before and after energy drinks consumption in young healthy male volunteers. This was a cross-sectional prospective study. Microvascular reactivity signals were evaluated in the skin of the forearm using laser speckle contrast imaging with acetylcholine (ACh) iontophoresis before and 90 and 180 min after the randomized consumption of one ED or the same volume of water (control), followed by a postocclusive reactive hyperemia (PORH) test. Thirty-two volunteers were evaluated (age: 25.4±4.3 years). Energy drink consumption prevented the rest-induced reduction in cutaneous vascular conductance over time that was observed in the control group. In the control group, there were significant reductions in microvascular vasodilation at 90 and 180 min compared to baseline (P=0.004), but this was not the case in the energy drink group (P=0.76). Our results demonstrated that the reduction in microvascular conductance associated with prolonged immobility can be prevented by the consumption of one energy drink, highlighting the vasodilator effects of this beverage in young individuals at rest. The between-study variability in terms of the brand of energy drinks and the ingested volume, as well as the method of vascular evaluation and the inclusion criteria, may explain the discrepancies among previous studies on the vascular effects of energy drinks.

Association between inflammatory biomarkers and hypertension among sedentary adults in US: NHANES 2009-2018

Our study focuses on the relationship between inflammatory biomarkers and hypertension among sedentary adults in the United States, using data from the National Health and Nutrition Examination Survey (NHANES) from 2009 to 2018. We categorized 24,614 participants into two groups based on their daily sedentary time: 9607 individuals in the sedentary group (≥7 h) and 15,007 in the non-sedentary group (<7 h). We found that the sedentary group had a significantly higher prevalence of hypertension than the non-sedentary group. Using weighted multiple logistic regression and smoothing curves, we assessed the correlation between inflammatory biomarkers and hypertension among the sedentary adults. The odds ratios for hypertension were 1.92 for the monocyte to high-density lipoprotein ratio (MHR), 1.15 for the systemic inflammation response index (SIRI), and 1.19 for the natural logarithm of the systemic immune-inflammation index (lnSII), all showing nonlinear associations. Furthermore, a significant positive correlation was found between sedentary time and inflammatory biomarkers (MHR, SIRI, and lnSII). Our findings suggest that prolonged sedentary behavior in the US significantly increases hypertension risk, likely due to marked increases in inflammation markers.

Sit less and move more! A cross-sectional study of the associations between physical activity and sedentary behaviors with inhibitory control in Brazilian adults

OBJECTIVE

To investigate the independent and joint associations between sedentary behaviors (SB) and physical activity (PA) with inhibitory control (IC) in adults.

METHODS

A total of 111 participants (median age = 30 years; 60% women), completed the Stroop Color-Words test to assess IC. They also wore accelerometers for seven days to measure SB, light PA, moderate-to-vigorous PA (MVPA), and daily steps. We previously set cutoff points for SB and PA measurements and tested them to determine their association with IC. All analyses were adjusted for potential confounding factors including age, gender, post-secondary education, income, body mass index, and accelerometer wear time.

RESULTS

Low SB, high MVPA, and high daily steps were independently associated with a better IC compared to their respective counterparts. Adults with low levels of SB and light PA demonstrated better IC performance (β = -227.67, 95%CI = -434.14 to -21.20) compared to those with high SB and low light PA. Conversely, individuals with high SB and high light PA exhibited worse performance (β = 126.80, 95%CI = 2.11 to 251.50) than those in the high SB and low light PA group. Furthermore, the joint association of low SB with high MVPA (β = -491.12, 95%CI = -689.23 to -293.01) or low SB with high daily steps (β = -254.29, 95%CI = -416.41 to -92.16) demonstrated better IC performance compared to those with high SB and low MVPA or low daily steps.

CONCLUSION

Our findings highlight independent and joint associations between low SB, high MVPA, and high daily steps with enhanced IC in adults.

Cerebrovascular Reactivity Following Spinal Cord Injury

Background

Spinal cord injuries (SCI) often result in cardiovascular issues, increasing the risk of stroke and cognitive deficits.

Objectives

This study assessed cerebrovascular reactivity (CVR) using functional magnetic resonance imaging (fMRI) during a hypercapnic challenge in SCI participants compared to noninjured controls.

Methods

Fourteen participants were analyzed (n = 8 with SCI [unless otherwise noted], median age = 44 years; n = 6 controls, median age = 33 years). CVR was calculated through fMRI signal changes.

Results

The results showed a longer CVR component (tau) in the grey matter of SCI participants (n = 7) compared to controls (median difference = 3.0 s; p < .05). Time since injury (TSI) correlated negatively with steady-state CVR in the grey matter and brainstem of SCI participants (RS = -0.81, p = .014; RS = -0.84, p = .009, respectively). Lower steady-state CVR in the brainstem of the SCI group (n = 7) correlated with lower diastolic blood pressure (RS = 0.76, p = .046). Higher frequency of hypotensive episodes (n = 7) was linked to lower CVR outcomes in the grey matter (RS = -0.86, p = .014) and brainstem (RS = -0.89, p = .007).

Conclusion

Preliminary findings suggest a difference in the dynamic CVR component, tau, between the SCI and noninjured control groups, potentially explaining the higher cerebrovascular health burden in SCI individuals. Exploratory associations indicate that longer TSI, lower diastolic blood pressure, and more hypotensive episodes may lead to poorer CVR outcomes. However, further research is necessary to establish causality and support these observations.

Peripheral vascular dysfunction and the aging brain

Aging is the greatest non-modifiable risk factor for most diseases, including cardiovascular diseases (CVD), which remain the leading cause of mortality worldwide. Robust evidence indicates that CVD are a strong determinant for reduced brain health and all-cause dementia with advancing age. CVD are also closely linked with peripheral and cerebral vascular dysfunction, common contributors to the development and progression of all types of dementia, that are largely driven by excessive levels of oxidative stress (e.g., reactive oxygen species [ROS]). Emerging evidence suggests that several fundamental aging mechanisms (e.g., "hallmarks" of aging), including chronic low-grade inflammation, mitochondrial dysfunction, cellular senescence and deregulated nutrient sensing contribute to excessive ROS production and are common to both peripheral and cerebral vascular dysfunction. Therefore, targeting these mechanisms to reduce ROS-related oxidative stress and improve peripheral and/or cerebral vascular function may be a promising strategy to reduce dementia risk with aging. Investigating how certain lifestyle strategies (e.g., aerobic exercise and diet modulation) and/or select pharmacological agents (natural and synthetic) intersect with aging "hallmarks" to promote peripheral and/or cerebral vascular health represent a viable option for reducing dementia risk with aging. Therefore, the primary purpose of this review is to explore mechanistic links among peripheral vascular dysfunction, cerebral vascular dysfunction, and reduced brain health with aging. Such insight and assessments of non-invasive measures of peripheral and cerebral vascular health with aging might provide a new approach for assessing dementia risk in older adults.

The Impact of Physical Exercise on microRNAs in Hemodialysis Patients: A Review and a Protocol for an Ancillary Study

Physical inactivity is considered a significant risk factor for mortality and morbidity among chronic hemodialysis (HD) patients. Therefore, physical exercise is recommended in the treatment of HD patients. Although the beneficial effects of physical exercise in HD patients are well-described in the literature, the underlying physiological mechanisms still need to be fully understood. Recently, microRNAs (miRNAs) have emerged as potential mediators of the therapeutic effects of physical exercise in healthy individuals. miRNAs are short, single-stranded, noncoding RNAs involved in gene expression regulation. Specifically, upon forming the RNA-induced silencing complex, miRNAs selectively bind to specific miRNAs within cells, reducing gene expression. miRNAs can be secreted by cells in an accessible form or enclosed within exosomes or extracellular vesicles. They can be detected in various body fluids, including serum (circulating miRNAs), facilitating the study of their diverse expression. Currently, there is no available data regarding the impact of physical exercise on the expression of miRNAs involved in osteogenic differentiation, a fundamental mechanism in the development of vascular calcification, for HD patients. Therefore, we have designed an observational and longitudinal case-control study to evaluate the expression of miR-9 and miR-30b in HD patients participating in a 3-month interdialytic physical exercise program. This paper aims to present the study protocol and review the expression of circulating miRNAs in HD patients and their modulation through physical exercise.

A novel vascular health index: Using data analytics and population health to facilitate mechanistic modeling of microvascular status

The study of vascular function across conditions has been an intensive area of investigation for many years. While these efforts have revealed many factors contributing to vascular health, challenges remain for integrating results across research groups, animal models, and experimental conditions to understand integrated vascular function. As such, the insights attained in clinical/population research from linking datasets, have not been fully realized in the basic sciences, thus frustrating advanced analytics and complex modeling. To achieve comparable advances, we must address the conceptual challenge of defining/measuring integrated vascular function and the technical challenge of combining data across conditions, models, and groups. Here, we describe an approach to establish and validate a composite metric of vascular function by comparing parameters of vascular function in metabolic disease (the obese Zucker rat) to the same parameters in age-matched, "healthy" conditions, resulting in a common outcome measure which we term the vascular health index (VHI). VHI allows for the integration of datasets, thus expanding sample size and permitting advanced modeling to gain insight into the development of peripheral and cerebral vascular dysfunction. Markers of vascular reactivity, vascular wall mechanics, and microvascular network density are integrated in the VHI. We provide a detailed presentation of the development of the VHI and provide multiple measures to assess face, content, criterion, and discriminant validity of the metric. Our results demonstrate how the VHI captures multiple indices of dysfunction in the skeletal muscle and cerebral vasculature with metabolic disease and provide context for an integrated understanding of vascular health under challenged conditions.