Association between maximal oxygen consumption and physical performance tests among older adults with cognitive frailty

INTRODUCTION

Cardiorespiratory fitness has an inverse relationship with cognitive impairment and frailty in older adults. Direct assessment of maximal oxygen consumption (VO2 max) is the gold standard to assess cardiorespiratory fitness. However, it is costly and requires a laboratory setting. Therefore, VO2 max estimation among older adults with cognitive frailty (CF) will allow the assessment of aerobic capacity, which is commonly overlooked due to the complexity of the test.

AIM

This study aims to determine the use of one of three physical performance tests (2-minute step, 2-minute walk, and 1-minute sit to stand) to effectively estimate cardiorespiratory fitness among older adults with CF.

METHODS

In this cross-sectional study, community-dwelling individuals aged 60 years old and above in Klang Valley were screened for CF. The participants performed three physical performance tests (2-minute walk, 2-minute step, and 1-minute sit to stand) followed by treadmill-based maximal exercise testing on another day.

RESULTS

A total of 32 older adults with cognitive frailty (mean age; SD: 67.1;4.7 years) participated in this study. Nearly half of them had hypertension (43.5 %), hypercholesterolemia (43.5 %), and multimorbidity (47.8 %). Among the endurance tests performed, only the 2-minute walk test independently predicted VO2 max by sex-specific with men (R2 = 0.58, p = 0.03) and women (R2 = 0.34, p = 0.01). The 2-minute walk test had good agreement with VO2 max (ICC = 0.77, 95 % CI: -3.1-2.4).

CONCLUSION

The 2-minute walk test is a valid tool for estimating cardiorespiratory fitness among older adults with CF. However, it should be further tested across a larger population.

The association of increased body mass index on cardiorespiratory fitness, physical activity, and cognition in adults with down syndrome

BACKGROUND

Obesity is a significant risk factor for Alzheimer's disease; however, this association has not been explored in adults with Down syndrome.

OBJECTIVE

To examine the association of obesity, assessed by body mass index (BMI), with factors related to Alzheimer's disease risk including cardiorespiratory fitness, physical activity, and cognition in adults with Down syndrome.

METHODS

Adults with Down syndrome attended a laboratory visit where BMI, cardiorespiratory fitness (VO2 peak), and cognitive function (CANTAB® DS Battery) were obtained. Physical activity (accelerometer) was collected over the week following the laboratory visit. Wilcoxon rank sum tests were used to evaluate differences in cardiorespiratory fitness, sedentary time, moderate-to-vigorous physical activity (MVPA), and cognition between adults with obesity (BMI≥ 30 kg/m2) and those with healthy weight or overweight (BMI <30 kg/m2). Spearman correlations and linear regressions were used to measure the impact of BMI on cardiorespiratory fitness, MVPA, sedentary time, and cognition.

RESULTS

Data was collected for 79 adults with Down syndrome (26.7 ± 9.0 years of age, 54% female, 54% with obesity). VO2 peak was significantly lower in participants with obesity (18.4 ± 2.5 ml/kg/min) compared to those with healthy weight or overweight (22.9 ± 4.0 ml/kg/min, p < 0.001). BMI was negatively associated with cardiorespiratory fitness (rho = -0.614, p < 0.001). No associations were observed between BMI and physical activity or cognition.

CONCLUSIONS

Lower BMI was associated with improved cardiorespiratory fitness. However, no associations were observed between BMI and cognition or physical activity.

NCT REGISTRATION

NCT04048759.

Exercise intensity and cardiovascular health outcomes after 12 months of football fitness training in women treated for stage I-III breast cancer: Results from the football fitness After Breast Cancer (ABC) randomized controlled trial

PURPOSE

To examine the exercise intensity and impact of 12 months of twice-weekly recreational football training on cardiorespiratory fitness (CRF), blood pressure (BP), resting heart rate (HR_rest), body fat mass, blood lipids, inflammation, and health-related quality of life in women treated for early-stage breast cancer (BC).

METHODS

Sixty-eight women who had received surgery for stage I-III BC and completed adjuvant chemo- and/or radiation therapy within 5 years were randomized in a 2:1 ratio to a Football Fitness group (FFG, n = 46) or a control group (CON, n = 22). Football Fitness sessions comprised a warm-up, drills and 3-4 × 7 min of small-sided games (SSG). Assessments were performed at baseline, 6 months and 12 months. Outcomes were peak oxygen uptake (VO₂peak), blood pressure (BP), HR_rest, total body fat mass, and circulating plasma lipids and hs-CRP, and the 36-Item Short Form Health Survey (SF36). Intention-to-treat (ITT) analyses were performed using linear mixed models. Data are means with SD or 95% confidence intervals.

RESULTS

Adherence to training in participants completing the 12-months follow-up (n = 33) was 47.1% (22.7), and HR during SSG was ≥80% of HR_max for 69.8% (26.5) of total playing time. At baseline, VO₂peak was 28.5 (6.4) and 25.6 (5.9) ml O₂/kg/min in FFG and CON, respectively, and no significant changes were observed at 6- or 12 months follow-up. Systolic BP (SBP) was 117.1 (16.4) and 116.9 (14.8) mmHg, and diastolic BP (DBP) was 72.0 (11.2) and 72.4 (8.5) mmHg in FFG and CON, respectively, at baseline, and a 9.4 mmHg decrease in SBP in CON at 12 months resulted in a between-group difference at 12 months of 8.7 mmHg (p = .012). Blood lipids and hs-CRP were within the normal range at baseline, and there were no differences in changes between groups over the 12 months. Similarly, no differences between groups were observed in HR_rest and body fat mass at 6- and12-months follow-up. A between-group difference in mean changes of 23.5 (0.95-46.11) points in the role-physical domain of the SF36 survey favored FFG at 6 months.

CONCLUSION

Football Fitness training is an intense exercise form for women treated for breast cancer, and self-perceived health-related limitations on daily activities were improved after 6 months. However, 1 year of Football Fitness training comprising 1 weekly training session on average did not improve CRF, BP, blood lipids, fat mass, or HR_rest.

TRIAL REGISTRATION NUMBER

The trial was registered at ClinicalTrials.gov with identifier NCT03284567.

Homeostatic effects of exercise and sleep on metabolic processes in mice with an overexpressed skeletal muscle clock

Brain and muscle-ARNT-like factor (Bmal1/BMAL1) is an essential transcriptional/translational factor of circadian clocks. Loss of function of Bmal1/BMAL1 is highly disruptive to physiological and behavioral processes. In light of these previous findings, we examined if transgenic overexpression of Bmal1/BMAL1 in skeletal muscle could alter metabolic processes. First, we characterized in vivo and ex vivo metabolic phenotypes of muscle overexpressed mice (male and female) compared to wild-type littermates (WT). Second, we examined in vivo and ex vivo metabolic processes in the presence of positive and negative homeostatic challenges: high-intensity treadmill running (positive) and acute sleep deprivation (negative). In vivo measures of metabolic processes included body composition, respiratory exchange ratio (RER; VCO2/VO2), energy expenditure, total activity counts, and food intake collected from small animal indirect calorimetry. Ex vivo measure of insulin sensitivity in skeletal muscle was determined from radioassays. RER was lower for muscle overexpressed females compared to female WTs. There were no genotype-dependent differences in metabolic phenotypes for males. With homeostatic challenges, muscle overexpressed mice had lower energy expenditure after high-intensity treadmill running. Acute sleep deprivation reduced insulin sensitivity in skeletal muscle in overexpressed male mice, but not male WTs. The present study contributes to a body of evidence showing pleiotropic, non-circadian, and homeostatic effects of altered Bmal1/BMAL1 expression on metabolic processes, demonstrating a critical need to further investigate the broad and complex actions of Bmal1/BMAL1 on physiology and behavior.

Obesity, fitness, and brain integrity in adolescence

OBJECTIVE

We set out to ascertain the relationship between insulin resistance, fitness, and brain structure and function in adolescents.

DESIGN AND METHODS

We studied 79 obese and 51 non-obese participants who were recruited from the community, all without type 2 diabetes mellitus. All participants received medical, endocrine, neuropsychological, and MRI evaluations as well as a 6-minute walk test that was used to estimate fitness (maximal oxygen consumption).

RESULTS

Obese adolescents had significantly thinner orbitofrontal cortices and performed significantly worse on Visual Working Memory tasks and the Digit Vigilance task. Insulin sensitivity and maximal oxygen consumption (VO2 max) were both highly correlated with central obesity and orbitofrontal cortical thickness, although insulin sensitivity was the stronger predictor for orbitofrontal cortical thickness. We also found that VO2 max was the only significant physiological variable related to visual working memory.

CONCLUSIONS

This is the first study to report positive associations between insulin resistance, VO2 max, and frontal lobe brain integrity in adolescents. Given the importance of brain health for learning and school performance, we conclude that schools should also emphasize physical fitness in order to maintain structural and functional brain integrity and facilitate academic achievement.

Hearts and minds: linking vascular rigidity and aerobic fitness with cognitive aging

Human aging is accompanied by both vascular and cognitive changes. Although arteries throughout the body are known to become stiffer with age, this vessel hardening is believed to start at the level of the aorta and progress to other organs, including the brain. Progression of this vascular impairment may contribute to cognitive changes that arise with a similar time course during aging. Conversely, it has been proposed that regular exercise plays a protective role, attenuating the impact of age on vascular and metabolic physiology. Here, the impact of vascular degradation in the absence of disease was investigated within 2 groups of healthy younger and older adults. Age-related changes in executive function, elasticity of the aortic arch, cardiorespiratory fitness, and cerebrovascular reactivity were quantified, as well as the association between these parameters within the older group. In the cohort studied, older adults exhibited a decline in executive functions, measured as a slower performance in a modified Stroop task (1247.90 ± 204.50 vs. 898.20 ± 211.10 ms on the inhibition and/or switching component, respectively) than younger adults. Older participants also showed higher aortic pulse wave velocity (8.98 ± 3.56 vs. 3.95 ± 0.82 m/s, respectively) and lower VO₂ max (29.04 ± 6.92 vs. 42.32 ± 7.31 mL O2/kg/min, respectively) than younger adults. Within the older group, faster performance of the modified Stroop task was associated with preserved aortic elasticity (lower aortic pulse wave velocity; p = 0.046) and higher cardiorespiratory fitness (VO₂ max; p = 0.036). Furthermore, VO₂ max was found to be negatively associated with blood oxygenation level dependent cerebrovascular reactivity to CO₂ in frontal regions involved in the task (p = 0.038) but positively associated with cerebrovascular reactivity in periventricular watershed regions and within the postcentral gyrus. Overall, the results of this study support the hypothesis that cognitive status in aging is linked to vascular health, and that preservation of vessel elasticity may be one of the key mechanisms by which physical exercise helps to alleviate cognitive aging.

Impact of exercise training on redox signaling in cardiovascular diseases

Reactive oxygen and nitrogen species regulate a wide array of signaling pathways that governs cardiovascular physiology. However, oxidant stress resulting from disrupted redox signaling has an adverse impact on the pathogenesis and progression of cardiovascular diseases. In this review, we address how redox signaling and oxidant stress affect the pathophysiology of cardiovascular diseases such as ischemia-reperfusion injury, hypertension and heart failure. We also summarize the benefits of exercise training in tackling the hyperactivation of cellular oxidases and mitochondrial dysfunction seen in cardiovascular diseases.