Effect of Cardiorespiratory Fitness on Vascular Regulation and Oxidative Stress in Postmenopausal Women

Effects of physical exercise during adjuvant chemotherapy for breast cancer on long-term tested and perceived cognition: results of a pragmatic follow-up study

PURPOSE

Cancer-related cognitive impairment (CRCI) following chemotherapy is commonly reported in breast cancer survivors, even years after treatment. Data from preclinical studies suggest that exercise during chemotherapy may prevent or diminish cognitive problems; however, clinical data are scarce.

METHODS

This is a pragmatic follow-up study of two original randomized trials, which compares breast cancer patients randomized to exercise during chemotherapy to non-exercise controls 8.5 years post-treatment. Cognitive outcomes include an online neuropsychological test battery and self-reported cognitive complaints. Cognitive performance was compared to normative data and expressed as age-adjusted z-scores.

RESULTS

A total of 143 patients participated in the online cognitive testing. Overall, cognitive performance was mildly impaired on some, but not all, cognitive domains, with no significant differences between groups. Clinically relevant cognitive impairment was present in 25% to 40% of all participants, regardless of study group. We observed no statistically significant effect of exercise, or being physically active during chemotherapy, on long-term cognitive performance or self-reported cognition, except for the task reaction time, which favored the control group (β = -2.04, 95% confidence interval: -38.48; -2.38). We observed no significant association between self-reported higher physical activity levels during chemotherapy or at follow-up and better cognitive outcomes.

CONCLUSION

In this pragmatic follow-up study, exercising and being overall more physically active during or after adjuvant chemotherapy for breast cancer was not associated with better tested or self-reported cognitive functioning, on average, 8.5 years after treatment. Future prospective studies are needed to document the complex relationship between exercise and CRCI in cancer survivors.

Association of Physical Activity and Parkinson Disease in Women: Long-term Follow-up of the E3N Cohort Study

BACKGROUND AND OBJECTIVES

Previous cohort studies reported that a single measure of physical activity (PA) assessed at baseline was associated with lower Parkinson disease (PD) incidence, but a meta-analysis suggested that this association was restricted to men. Because of the long prodromal phase of the disease, reverse causation could not be excluded as a potential explanation. Our objective was to study the association between time-varying PA and PD in women using lagged analyses to address the potential for reverse causation and to compare PA trajectories in patients before diagnosis and matched controls.

METHODS

We used data from the Etude Epidémiologique auprès de femmes de la Mutuelle Générale de l'Education Nationale (1990-2018), a cohort study of women affiliated with a national health insurance plan for persons working in education. PA was self-reported in 6 questionnaires over the follow-up. As questions changed across questionnaires, we created a time-varying latent PA (LPA) variable using latent process mixed models. PD was ascertained using a multistep validation process based on medical records or a validated algorithm based on drug claims. We set up a nested case-control study to examine differences in LPA trajectories using multivariable linear mixed models with a retrospective timescale. Cox proportional hazards models with age as the timescale and adjusted for confounders were used to estimate the association between time-varying LPA and PD incidence. Our main analysis used a 10-year lag to account for reverse causation; sensitivity analyses used 5-, 15-, and 20-year lags.

RESULTS

Analyses of trajectories (1,196 cases and 23,879 controls) showed that LPA was significantly lower in cases than in controls throughout the follow-up, including 29 years before diagnosis; the difference between cases and controls started to increase ∼10 years before diagnosis (p interaction = 0.003). In our main survival analysis, of 95,354 women free of PD in 2000, 1,074 women developed PD over a mean follow-up of 17.2 years. PD incidence decreased with increasing LPA (p trend = 0.001), with 25% lower incidence in those in the highest quartile compared with the lowest (adjusted hazard ratio 0.75, 95% CI 0.63-0.89). Using longer lags yielded similar conclusions.

DISCUSSION

Higher PA level is associated with lower PD incidence in women, not explained by reverse causation. These results are important for planning interventions for PD prevention.

Monocyte Phenotypes and Physical Activity in Patients with Carotid Atherosclerosis

Atherosclerosis is associated with low-grade inflammation involving circulating monocytes. It has been shown that the levels of intermediate pro-inflammatory monocytes are associated with cardiovascular mortality and risk of ischemic stroke. It also has been shown that physical activity (PA) decreases inflammation markers, incidence of strokes, and mortality. In this cross-sectional study, we tested the effect of PA on circulating monocytes phenotype rate. A total of 29 patients with a carotid stenosis > 50% were recruited. Levels of physical activity (MET.min/week) were measured by the GPAQ questionnaire, arterial samples of blood were collected to analyze monocyte phenotype (classical, intermediate and non-classical) assessed by flow cytometry, and venous blood samples were used to dose antioxidant activity and oxidative damage. Antioxidant capacity was reduced and oxidative damage increased in patients. There was a significant decrease in the percentage of classical and intermediate monocytes in moderately active patients as compared with non-active and highly active patients. Inversely, the rate of non-classical monocytes increased in moderately active patients. Intense PA appears to blunt the beneficial effects of moderate PA. Our study also suggests that PA could be beneficial in such patients by reducing the rate of intermediate monocytes known to predict the risk of ischemic stroke and by increasing the non-classical monocytes involved in lesions’ healing. Nevertheless, a longitudinal study would be necessary to confirm this hypothesis.

Body fat percentage, cardiorespiratory fitness and arterial blood pressure in children and adolescents: a longitudinal analysis

Background

A better understanding of how cardiorespiratory fitness (CRF) and adiposity interact to associate with arterial blood pressure over time remains inconclusive. Thus, the aim of the present study was to examine whether changes in CRF moderates the association between body fat percentage (BF%) and arterial blood pressure in children and adolescents.

Methods

This is an observational longitudinal study with 407 children and adolescents aged 8–17 years followed-up for three years from a city in Southern Brazil. Participants were evaluated in 2011 and 2014. CRF was measured by validated field-based tests following the Projeto Esporte Brazil protocols and peak oxygen uptake (VO_2peak) was estimated. BF% was determined by the measures of tricipital and subscapular skinfolds using equations according to sex. Systolic and diastolic blood pressure (SBP, DBP) were measured with a sphygmomanometer according to standard procedures. Moderation analyses included multiple linear regression models adjusted for sex, age, pubertal status, height, socioeconomic level, skin color, and the arterial blood pressure variable itself at baseline.

Results

It was observed a significant inverse association between VO_2peak at baseline with SBP (β = − 0.646 CI95% = − 0.976  − 0.316) and DBP (β = − 0.649 CI95% = − 0.923  − 0.375) at follow-up and a positive association between BF% at baseline with SBP (β = 0.274; CI95% = 0.094 0.455) and DBP (β = 0.301; CI95% = 0.150 0.453) at follow-up. In addition, results indicated a significant interaction term between changes in VO_2peak and BF% at baseline with both SBP (p = 0.034) and DBP at follow-up (p = 0.011), indicating that an increase of at least 0.35 mL/kg/min and 1.78 mL/kg/min in VO_2peak attenuated the positive relationship between BF% with SBP and DBP.

Conclusion

CRF moderates the relationship between BF% and SBP and DBP in children and adolescents.

Exercise, Arterial Stiffness, and Cerebral Vascular Function: Potential Impact on Brain Health

Exercise is associated with higher cognitive function and is a promising intervention to reduce the risk of dementia. With advancing age, there are changes in the vasculature that have important clinical implications for brain health and cognition. Primary aging and vascular risk factors are associated with increases in arterial stiffness and pulse pressure, and reductions in peripheral vascular function.

OBJECTIVE

The purpose is to discuss the epidemiological, observational, and mechanistic evidence regarding the link between age-related changes in vascular health and brain health.

METHODS

We performed a literature review and integrated with our published data.

RESULTS

Epidemiological evidence suggests a link between age-related increases in arterial stiffness and lower cognitive function, which may be mediated by cerebral vascular function, including cerebral vasoreactivity and cerebral pulsatility. Age-associated impairments in central arterial stiffness and peripheral vascular function have been attenuated or reversed through lifestyle behaviors such as exercise. Greater volumes of habitual exercise and higher cardiorespiratory fitness are associated with beneficial effects on both peripheral vascular health and cognition. Yet, the extent to which exercise directly influences cerebral vascular function and brain health, as well as the associated mechanisms remains unclear.

CONCLUSION

Although there is evidence that exercise positively impacts cerebral vascular function, more research is necessary in humans to optimize experimental protocols and address methodological limitations and physiological considerations. Understanding the impact of exercise on cerebral vascular function is important for understanding the association between exercise and brain health and may inform future intervention studies that seek to improve cognition.

Impact of Physical Activity on Oxidative Stress Markers in Patients with Metastatic Breast Cancer

Purpose

Regular physical activity (PA) can affect oxidative stress, known to be involved in carcinogenesis. The objective of this study was to evaluate the associations between a six-month PA intervention and oxidative stress biomarkers, PA, and clinical outcomes in patients with metastatic breast cancer.

Methods

Forty-nine newly diagnosed patients with metastatic breast cancer were recruited for a single-arm, unsupervised, and personalized six-month walking intervention with activity tracker. PA level and PA fitness, plasma concentrations of DNA oxidation (8OhdG), lipid peroxidation (MDA), and protein oxidation (AOPP), plasma activities of superoxide dismutase (SOD), glutathione peroxidase (GPX), and catalase, plasma and leucocyte activities of myeloperoxidase (MPO) and NADPH oxidase (NOX), and clinical markers of tumor progression (RECIST criteria) were measured at baseline and after the six-month intervention.

Results

GPX activity (+17%) and MDA (+9%) significantly increased between baseline and the end of the intervention. Changes in PA level and fitness were significantly positively correlated with changes in plasma GPX and significantly negatively with changes in NOX in the leucocytes. Plasma MDA was significantly higher (+20%) whereas plasma AOPP was lower (-46%) for patients with tumor progression or that died during the six months as compared to patients without progression.

Conclusion

A six-month PA intervention may be potentially beneficial in metastatic breast cancer patients for enhancing antioxidant enzyme activity and decreasing prooxidant enzyme activity. Moreover, AOPP and MDA could also be favorable and unfavorable biomarkers, respectively, since they are associated with disease progression and fitness level in this population. This trial is registered with NCT number: NCT03148886.

Associations Among Physical Activity Level and Skeletal Muscle Antioxidants in Older Adults

BACKGROUND

Endogenous antioxidants are critical to limiting cellular oxidative damage.

METHODS

The authors determined if habitual physical activity (PA) and cardiorespiratory fitness were associated with skeletal muscle expression of endogenous antioxidants (superoxide dismutase, catalase, and glutathione peroxidase) and circulating oxidative stress markers (serum 8-hydroxy-2'-deoxyguanosine [8-OHdG]; oxidized low-density lipoprotein [LDL]) in older adults. Moderate to vigorous PA (MVPA) was estimated using a validated PA questionnaire in 26 older adults (mean [SD]; M/F = 9/17, age = 68 [4] y, body mass index = 26 [3] kg·m-2). Maximal oxygen consumption was estimated using the YMCA submaximal cycle test. Skeletal muscle endogenous antioxidants and serum 8-OHdG and oxidized LDL were measured. Bivariate and partial correlations (controlling for body mass index) were utilized to determine associations among variables.

RESULTS

MVPA (1640 [1176] kcal·wk-1) was correlated with superoxide dismutase 2 (r = .55), catalase (r = .55), glutathione peroxidase 1 (r = .48), and 8-OHdG (r = -.41) (all Ps < .05), but not oxidized LDL. MVPA and 8-OHdG were not significantly correlated when controlling for body mass index (r = -.29). Estimated maximal oxygen consumption was correlated with glutathione peroxidase 1 (r = .48; P < .05).

CONCLUSIONS

These data show that skeletal muscle endogenous antioxidant expression and circulating oxidative damage are associated with habitual MVPA in older adults. Thus, MVPA in older adults may be protective against reactive oxygen species damage due to higher expression of endogenous antioxidants.

Cerebral tissue pO2 response to treadmill exercise in awake mice

We exploited two-photon microscopy and Doppler optical coherence tomography to examine the cerebral blood flow and tissue pO₂ response to forced treadmill exercise in awake mice. To our knowledge, this is the first study performing both direct measure of brain tissue pO₂ during acute forced exercise and underlying microvascular response at capillary and non-capillary levels. We observed that cerebral perfusion and oxygenation are enhanced during running at 5 m/min compared to rest. At faster running speeds (10 and 15 m/min), decreasing trends in arteriolar and capillary flow speed were observed, which could be due to cerebral autoregulation and constriction of arterioles in response to blood pressure increase. However, tissue pO₂ was maintained, likely due to an increase in RBC linear density. Higher cerebral oxygenation at exercise levels 5–15 m/min suggests beneficial effects of exercise in situations where oxygen delivery to the brain is compromised, such as in aging, atherosclerosis and Alzheimer Disease.

Impact of aerobic exercise, sex, and metabolic syndrome on markers of oxidative stress: results from the Brain in Motion study

Oxidative stress may be involved in disease pathology and dependent on both modifiable and nonmodifiable factors. This study aimed to assess exercise-induced changes in markers of oxidative stress among older, sedentary adults and to determine the effects of metabolic syndrome (MetS) status, aerobic capacity, age, sex, and weight on these biomarkers. Two hundred and six participants (means ± SE; 66.8 ± 6.4 yr, 104 women) of the Brain in Motion study underwent a 6-mo aerobic exercise intervention. At three time points, venous blood samples were collected and analyzed for markers of oxidative stress [advanced oxidation protein products (AOPP), malondialdehyde (MDA), 3-nitrotyrosine (3-NT) and antioxidant status: catalase, uric acid (UA), superoxide dismutase (SOD), and ferric-reducing ability of plasma (FRAP)]. AOPP levels significantly decreased after 6 mo of aerobic exercise (P = 0.003). This decrease was not modified by MetS status (P = 0.183). Subjects with MetS possessed significantly higher levels of AOPP (P < 0.001), MDA (P = 0.004), and FRAP (P = 0.049) across the intervention (months 0-6). Men possessed significantly higher levels of FRAP (P < 0.001), catalase (P = 0.023), and UA (P = 0.037) across the intervention (months 0-6). Sex-MetS status interaction analyses revealed that the effect of MetS is highly sex dependent. These findings are multifaceted because the effect of MetS status seems distinctly different between sexes, pointing to the importance of acknowledging modifiable and nonmodifiable factor differences in individuals who possess conditions where oxidative stress may be part of the etiology.NEW & NOTEWORTHY Oxidative stress is implicated in a myriad of conditions, namely cardiovascular disease risk factors. This article details the effect of aerobic exercise, sex, and metabolic syndrome on markers of oxidative stress. We conclude that 6 mo of aerobic exercise significantly decreased oxidative stress, and further, that there is an effect of metabolic syndrome status on oxidative stress and antioxidant status levels, which are highly dependent on the sex of the individual.

Hypertension accelerates cerebral tissue PO2 disruption in Alzheimer's disease

This study measured stimulus-evoked brain tissue oxygenation changes in a mouse model of Alzheimer disease (AD) and further explored the influence of exercise and angiotensin II-induced hypertension on these changes. in vivo two-photon phosphorescence lifetime microscopy was used to investigate local changes in brain tissue oxygenation following whisker stimulation. During rest periods, PO₂ values close to the arteriolar wall were lower in the AD groups and the PO₂ spatial decay as a function of distance to arteriole was increased by hypertension. During stimulation, tissue PO₂ response had a similar spatial dependence across groups. Tissue PO₂ response in post-stimulation period was larger in AD groups (e.g., AD6 and ADH6) than in the controls (WT6 and WTH6). After a 3-month voluntary exercise period, some of these changes were reversed in AD mice. This provides novel insight into tissue oxygen delivery and the impact of blood pressure control and exercise on brain tissue oxygenation in AD.

Impacts of exercise interventions on different diseases and organ functions in mice

Background

In recent years, much evidence has emerged to indicate that exercise can benefit people when performed properly. This review summarizes the exercise interventions used in studies involving mice as they are related to special diseases or physiological status. To further understand the effects of exercise interventions in treating or preventing diseases, it is important to establish a template for exercise interventions that can be used in future exercise-related studies.

Methods

PubMed was used as the data resource for articles. To identify studies related to the effectiveness of exercise interventions for treating various diseases and organ functions in mice, we used the following search language: (exercise [Title] OR training [Title] OR physical activity [Title]) AND (mice [title/abstract] OR mouse [title/abstract] OR mus [title/abstract]). To limit the range of search results, we included 2 filters: one that limited publication dates to "in 10 years" and one that sorted the results as "best match". Then we grouped the commonly used exercise methods according to their similarities and differences. We then evaluated the effectiveness of the exercise interventions for their impact on diseases and organ functions in 8 different systems.

Results

A total of 331 articles were included in the analysis procedure. The articles were then segmented into 8 systems for which the exercise interventions were used in targeting and treating disorders: motor system (60 studies), metabolic system (45 studies), cardio-cerebral vascular system (58 studies), nervous system (74 studies), immune system (32 studies), respiratory system (7 studies), digestive system (1 study), and the system related to the development of cancer (54 studies). The methods of exercise interventions mainly involved the use of treadmills, voluntary wheel-running, forced wheel-running, swimming, and resistance training. It was found that regardless of the specific exercise method used, most of them demonstrated positive effects on various systemic diseases and organ functions. Most diseases were remitted with exercise regardless of the exercise method used, although some diseases showed the best remission effects when a specific method was used.

Conclusion

Our review strongly suggests that exercise intervention is a cornerstone in disease prevention and treatment in mice. Because exercise interventions in humans typically focus on chronic diseases, national fitness, and body weight loss, and typically have low intervention compliance rates, it is important to use mice models to investigate the molecular mechanisms underlying the health benefits from exercise interventions in humans.

Exercise-Induced Regulation of Redox Status in Cardiovascular Diseases: The Role of Exercise Training and Detraining

Although low levels of reactive oxygen species (ROS) are beneficial for the organism ensuring normal cell and vascular function, the overproduction of ROS and increased oxidative stress levels play a significant role in the onset and progression of cardiovascular diseases (CVDs). This paper aims at providing a thorough review of the available literature investigating the effects of acute and chronic exercise training and detraining on redox regulation, in the context of CVDs. An acute bout of either cardiovascular or resistance exercise training induces a transient oxidative stress and inflammatory response accompanied by reduced antioxidant capacity and enhanced oxidative damage. There is evidence showing that these responses to exercise are proportional to exercise intensity and inversely related to an individual’s physical conditioning status. However, when chronically performed, both types of exercise amplify the antioxidant defense mechanism, reduce oxidative stress and preserve redox status. On the other hand, detraining results in maladaptations within a time-frame that depends on the exercise training intensity and mode, as high-intensity training is superior to low-intensity and resistance training is superior to cardiovascular training in preserving exercise-induced adaptations during detraining periods. Collectively, these findings suggest that exercise training, either cardiovascular or resistance or even a combination of them, is a promising, safe and efficient tool in the prevention and treatment of CVDs.

Effects of hypoxia-reoxygenation stimuli on renal redox status and nuclear factor erythroid 2-related factor 2 pathway in sickle cell SAD mice

NEW FINDINGS

What is the central question of this study? What are the effects of repeated subclinical vaso-occlusions on nuclear factor erythroid 2 related factor 2 (Nrf2) and oxidative stress balance regulation in the kidney of transgenic SAD mice? What is the main finding and its importance? In response to hypoxia-reoxygenation, nuclear Nrf2 protein expression decreased in the kidney of SAD mice while haem oxygenase transcripts were increased. This suggest that in SAD mice, other transcription factors than Nrf2 could be involved in renal antioxidant gene regulation in response to hypoxia-reoxygenation.

ABSTRACT

Hypoxia-reoxygenation (H/R) stress is known to increase oxidative stress in transgenic sickle mice and can cause organ failure. Here we described the effects of H/R on nuclear factor erythroid 2-related factor 2 (Nrf2) as a putative regulator of redox status in the kidneys of SAD mice investigating Nrf2-regulated antioxidant enzymes. Transgenic SAD mice and healthy C57Bl/6J mice were exposed to 4 h of hypoxia followed by various times of reoxygenation at ambient air (2 or 6 h). Regardless of the conditions (i.e. normoxia or H/R), SAD mice expressed higher renal oxidative stress levels. Nuclear Nrf2 protein expression decreased after 2 h post-hypoxia only in the medulla region of the kidney and only in SAD mice. Simultaneously, haem oxygenase transcripts were affected by H/R stimulus with a significant enhancement after 2 h post-hypoxia. Similarly, hypoxia inducible factor-1α staining increased after 2 h post-hypoxia in SAD mice in both cortex and medulla areas. Our data confirm that the kidneys are organs that are particularly sensitive to H/R stimuli in sickle cell SAD mice. Also, these results suggest an effect of the duration of recovery period (short vs. long) and specific responses according to kidney areas, medulla vs. cortex, on Nrf2 expression in response to H/R stimuli in SAD mice.

The role of exercise in the reversal of IGF-1 deficiencies in microvascular rarefaction and hypertension

Hypertension has been linked with peripheral and central reductions in vascular density, and with devastating effects on brain function. However, the underlying mechanisms in the relationship between blood pressure and cognitive impairment have yet to be fully elucidated. Here, we review compelling evidence from two lines of inquiry: one that links microvascular rarefaction with insulin-like growth factor 1 (IGF-1) deficiencies, and another which posits that vascular dysfunction precedes hypertension. Based on the findings from experimental and clinical studies, we propose that these lines of evidence converge, and suggest that age-related declines in IGF-1 concentrations precede microvascular rarefaction, initiate an increase in vascular resistance, and therefore are causally linked to onset of hypertension. Physical exercise provides a relevant model for supporting our premise, given the well-established effects of exercise in attenuating vascular dysfunction, hypertension, IGF-1 deficiency, and cognitive decline. We highlight here the role of exercise-induced increases in blood flow in improving vascular integrity and enhancing angiogenesis via the actions of IGF-1, resulting in reversal of rarefaction and hypertension, and enhancement of cerebral blood flow and cognition.

A Pilot Study Investigating Changes in Capillary Hemodynamics and Its Modulation by Exercise in the APP-PS1 Alzheimer Mouse Model

Dysfunction in neurovascular coupling that results in a mismatch between cerebral blood flow and neuronal activity has been suggested to play a key role in the pathogenesis of Alzheimer's disease (AD). Meanwhile, physical exercise is a powerful approach for maintaining cognitive health and could play a preventive role against the progression of AD. Given the fundamental role of capillaries in oxygen transport to tissue, our pilot study aimed to characterize changes in capillary hemodynamics with AD and AD supplemented by exercise. Exploiting two-photon microscopy, intrinsic signal optical imaging, and magnetic resonance imaging, we found hemodynamic alterations and lower vascular density with AD that were reversed by exercise. We further observed that capillary properties were branch order-dependent and that stimulation-evoked changes were attenuated with AD but increased by exercise. Our study provides novel indications into cerebral microcirculatory disturbances with AD and the modulating role of voluntary exercise on these alterations.

Laparoscopic Approach in Management of Renal Cell Carcinoma During Pregnancy: State of the Art

Renal cell carcinoma (RCC) is extremely rare in pregnant women. However, this is one of the most reported urologic tumors during pregnancy. The aim of this review was to evaluate RCC during pregnancy in terms of epidemiology, risk factors, diagnosis, natural history of disease, and the safety of laparoscopic approach in the management of this tumor. RCC presentation is frequently made incidentally during an ultrasonography performed for other reasons, such as hydronephrosis owing to non-neoplastic causes. The optimal time for surgery during pregnancy and the consequences of surgery on the maternal and fetal well-being are major considerations. Risks for adverse pregnancy outcomes should be explained, and the patient's decision about pregnancy termination should be considered. Ultrasound is good in diagnosing renal masses, with a sensitivity comparable to that of computed tomography only for exophytic masses larger than 3 cm. Magnetic resonance imaging is reproducible and a good, though expensive, alternative to computed tomography scans for the evaluation of renal lesions in pregnant women. Radical nephrectomy or nephron-sparing surgery are essential treatments for management of RCC. Laparoscopic surgery has historically been considered dangerous during pregnancy and avoided whenever possible, because of concerns regarding surgery-related risks, such as uterine injury, miscarriage, teratogenesis, preterm birth, and hypercapnia. The laparoscopic treatment during pregnancy is becoming increasingly accepted where feasible with low morbidity. However, the combination of a multidisciplinary approach, multi-specialty communication, and skilled surgeons can give the best possible outcomes for mother and fetus.

Longitudinal associations between 4-hydroxynonenal and depression in coronary artery disease patients

Depressive symptoms in patients with coronary artery disease (CAD) attenuate the cardiovascular benefits of cardiac rehabilitation (CR). Given that oxidative stress may be an important mechanism underlying depression, this study aimed to understand the longitudinal relationship between lipid peroxidation markers and depression in CAD. Serum levels of early (lipid hydroperoxides, LPH) and late (4‑hydroxy‑2-nonenal, 4-HNE; 8-isoprotane, 8-ISO) lipid peroxidation markers were measured in 120 CAD patients undergoing CR. The Structured Clinical Interview for DSM Axis I Disorders - Depression Module (SCID) was used to diagnose depression at baseline and the Center for Epidemiological Studies Depression Scale (CES-D) was used to measure depressive symptom severity. Multivariate mixed models compared the trajectories of serum LPH, 4-HNE, and 8-ISO between depressed and non-depressed CAD patients undergoing 6 months of CR. Similar models evaluated the associations between serum LPH, 4-HNE, and 8-ISO and CES-D score over the course of CR. Serum 4-HNE decreased less in CAD patients with depression compared to those without. In addition, a decrease in 4-HNE concentrations was significantly associated with a decrease in CES-D scores over 6 months. These findings suggest that 4-HNE may be an important marker of depressive symptoms in CAD and may be involved in its progression.

Detectable levels of eHSP72 in plasma are associated with physical activity and antioxidant enzyme activity levels in hypertensive subjects

Previous studies reported that extracellular HSP72 (eHSP72) correlates with poor prognosis, markers of vascular dysfunction, and the severity of cardiovascular diseases, associated with a systemic oxidative and inflammatory profile. On the other hand, eHSP72 may represent immune-regulatory signaling that is related to exercise benefits, but the association between physical activity levels and eHSP72 levels is not established. Thus, since regular physical activity may avoid oxidative stress and inflammation, we investigate whether detectable levels of eHSP72 in plasma are associated with physical activity and antioxidant enzyme activity levels in hypertensive subjects. Physical activity levels of hypertensive subjects (n = 140) were measured by tri-axial movement sensor pedometer for 24 h during 5 consecutive days. One day after, blood was collected into heparinized tubes for oxidative stress analyses (catalase-CAT and superoxide dismutase-SOD activities and malondialdehyde levels) or in disodium EDTA tubes for eHSP72 assays. Thus, hypertensive subjects were classified as physically inactive (< 10,000 footsteps/day) or active (> than 10,000 footsteps/day) and according detectable or not detectable eHSP72 levels in plasma, performing the inactive/eHSP72-, active/eHSP72-, inactive/eHSP72+, and active/eHSP72+ groups. We found that detectable levels of eHSP72 in plasma were associated with physical activity levels and low oxidative stress profile (Higher CAT and SOD activities and low malondialdehyde levels). eHSP72 levels can be used as a biomarker of the amount of physical activity necessary to improve antioxidant defense and thus cardiovascular health in hypertensive subjects.

Executive dysfunction and blockage of brain microvessels in a rat model of vascular cognitive impairment

Most research focuses on overt stroke caused by blockage of major blood vessels. Less attention has been paid to small vessel disease which gives rise to covert stroke that often leads to vascular cognitive impairment (VCI). One reason for this may be the relative lack of relevant animal models. Herein, we describe, a model of VCI induced in middle-aged Sprague-Dawley rats exposed to a diet high in saturated fats, salt and refined sugar (HFSS). In Experiment 1, rats were fed HFSS and subjected to a small mediodorsal (MD) thalamic stroke with or without concomitant permanent bilateral carotid artery occlusion. MD lesions produce significant executive dysfunction in an attention set-shift task ( p = 0.012). In Experiment 2, rats were exposed to either HFSS or control diet and functional effects assessed. We found significant hypertension ( p = 0.013), blockage of brain microvessels ( p = 0.018) and white matter atrophy ( p = 0.039) in HFSS diet animals. As in Experiment 1, profound, specific set-shifting executive dysfunction was noted ( p = 0.003) following both small MD infarcts (0.332 mm³) and the HFSS diet. In summary, these data describe a middle-aged animal model of VCI that includes clinically relevant metabolic disturbances and small vessel disease and as such may be helpful in developing new cognitive therapies.

Effects of exercise intensity and cardiorespiratory fitness on the acute response of arterial stiffness to exercise in older adults

PURPOSE

Increased arterial stiffness is observed with ageing and in individuals with low cardiorespiratory fitness ([Formula: see text]O_2peak), and associated with cardiovascular risk. Following an exercise bout, transient arterial stiffness reductions offer short-term benefit, but may depend on exercise intensity. This study assessed the effects of exercise intensity on post-exercise arterial stiffness in older adults with varying fitness levels.

METHODS

Fifty-one older adults (72 ± 5 years) were stratified into fitness tertiles ([Formula: see text]O_2peak: low-, 22.3 ± 3.1; mid-, 27.5 ± 2.4 and high-fit 36.3 ± 6.5 mL kg^-1 min^-1). In a randomised order, participants underwent control (no-exercise), moderate-intensity continuous exercise (40% of peak power output; PPO), and higher-intensity interval exercise (70% of PPO) protocols. Pulse wave velocity (PWV), augmentation index (AIx75) and reflection magnitude (RM) were assessed at rest and during 90 min of recovery following each protocol.

RESULTS

After control, delta PWV increased over time (P < 0.001) and delta RM was unchanged. After higher-intensity interval exercise, delta PWV (P < 0.001) and delta RM (P < 0.001) were lower to control in all fitness groups. After moderate-intensity continuous exercise, delta PWV was not different from control in low-fit adults (P = 0.057), but was lower in the mid- and higher-fit older adults. Post-exercise AIx75 was higher to control in all fitness groups (P = 0.001).

CONCLUSIONS

In older adults, PWV increases during seated rest and this response is attenuated after higher-intensity interval exercise, regardless of fitness level. This attenuation was also observed after moderate-intensity continuous exercise in adults with higher, but not lower fitness levels. Submaximal exercise reveals differences in the arterial stiffness responses between older adults with higher and lower cardiorespiratory fitness.

Preterm birth and oxidative stress: Effects of acute physical exercise and hypoxia physiological responses

Preterm birth is a global health issue that can induce lifelong medical sequela. Presently, at least one in ten newborns are born prematurely. At birth, preterm newborns exhibit higher levels of oxidative stress (OS) due to the inability to face the oxygen rich environment in which they are born into. Moreover, their immature respiratory, digestive, immune and antioxidant defense systems, as well as the potential numerous medical interventions following a preterm birth, such as oxygen resuscitation, nutrition, phototherapy and blood transfusion further contribute to high levels of OS. Although the acute effects seem well established, little is known regarding the long-term effects of preterm birth on OS. This matter is especially important given that chronically elevated OS levels may persist into adulthood and consequently contribute to the development of numerous non-communicable diseases observed in people born preterm such as diabetes, hypertension or lung disorders. The purpose of this review is to summarize the current knowledge regarding the consequences of preterm birth on OS levels from newborn to adulthood. In addition, the effects of physical activity and hypoxia, both known to disrupt redox balance, on OS modulation in preterm individuals are also explored.

Higher Daily Physical Activity Level Is Associated with Lower RBC Aggregation in Carotid Artery Disease Patients at High Risk of Stroke

Aim: Carotid artery disease (CAD) is an atherosclerotic inflammatory disease that affects the arterial wall, specifically at points of bifurcation where blood flow is disturbed. Abnormal blood rheology could participate in the pathophysiology of ischemic cardiovascular disease. Physical activity (PA) is known to improve blood rheology in several chronic disorders. This study aims to (i) compare the hemorheological profile of CAD patients and controls and (ii) investigate the associations between daily PA and hemorheological parameters in CAD patients. Methods: Blood viscosity, red blood cell (RBC) aggregation and RBC deformability were assessed in 80 patients (15 symptomatic and 65 asymptomatic) and 14 age-matched controls. Patients' PA levels were evaluated using questionnaires. Results: Symptomatic patients showed increased blood viscosity and RBC aggregation compared to healthy controls. RBC aggregation was significantly lower in the most physically active patients compared to the least physically active ones. Blood viscosity and RBC deformability did not vary according to physical activity level. Conclusions: Our results showed greater hemorheological abnormalities (blood hyper-viscosity and hyper-aggregation of red blood cells) in the most severe CAD patients, which could exacerbate the risk of stroke in patients with stenosis. As the most physically active patients had lower RBC aggregation than those who were less physically active, it is possible that regular PA may limit hemorheological alterations in CAD patients.

Human cerebral blood flow control during hypoxia: focus on chronic pulmonary obstructive disease and obstructive sleep apnea

The brain is a vital organ that relies on a constant and adequate blood flow to match oxygen and glucose delivery with the local metabolic demands of active neurons. Thus exquisite regulation of cerebral blood flow (CBF) is particularly important under hypoxic conditions to prevent a detrimental decrease in the partial pressure of oxygen within the brain tissues. Cerebrovascular sensitivity to hypoxia, assessed as the change in CBF during a hypoxic challenge, represents the capacity of cerebral vessels to respond to, and compensate for, a reduced oxygen supply, and has been shown to be impaired or blunted in a number of conditions. For instance, this is observed with aging, and in clinical conditions such as untreated obstructive sleep apnea (OSA) and in healthy humans exposed to intermittent hypoxia. This review will 1) provide a brief overview of cerebral blood flow regulation and results of pharmacological intervention studies which we have performed to better elucidate the basic mechanisms of cerebrovascular regulation in humans; and 2) present data from studies in clinical and healthy populations, using a translational physiology approach, to investigate human CBF control during hypoxia. Results from studies in patients with chronic obstructive pulmonary disease and OSA will be presented to identify the effects of the disease processes on cerebrovascular sensitivity to hypoxia. Data emerging from experimental human models of intermittent hypoxia during wakefulness will also be reviewed to highlight the effects of intermittent hypoxia on the brain.

Role of Exercise-Induced Oxidative Stress in Sickle Cell Trait and Disease

Sickle cell disease is a class of hemoglobinopathy in humans, which is the most common inherited disease in the world. Although complications of sickle cell disease start from polymerization of red blood cells during its deoxygenating phase, the oxidative stress resulting from the biological processes associated with this disease (ischaemic and hypoxic injuries, hemolysis and inflammation) has been shown to contribute to its pathophysiology. It is widely known that chronic exercise reduces oxidative stress in healthy people, mainly via improvement of antioxidant enzyme efficiency. In addition, recent studies in other diseases, as well as in sickle cell trait carriers and in a mouse model of sickle cell disease, have shown that regular physical activity could decrease oxidative stress. The purpose of this review is to summarize the role of oxidative stress in sickle cell disease and the effects of acute and chronic exercise on the pro-oxidant/antioxidant balance in sickle cell trait and sickle cell disease.

Effects of voluntary exercise on structure and function of cortical microvasculature

Aerobic activity has been shown highly beneficial to brain health, yet much uncertainty still surrounds the effects of exercise on the functioning of cerebral microvasculature. This study used two-photon fluorescence microscopy to examine cerebral hemodynamic alterations as well as accompanying geometric changes in the cortical microvascular network following five weeks of voluntary exercise in transgenic mice endogenously expressing tdTomato in vascular endothelial cells to allow visualization of microvessels irrespective of their perfusion levels. We found a diminished microvascular response to a hypercapnic challenge (10% FiCO₂) in running mice when compared to that in nonrunning controls despite commensurate increases in transcutaneous CO₂ tension. The flow increase to hypercapnia in runners was 70% lower than that in nonrunners (p = 0.0070) and the runners' arteriolar red blood cell speed changed by only half the amount seen in nonrunners (p = 0.0085). No changes were seen in resting hemodynamics or in the systemic physiological parameters measured. Although a few unperfused new vessels were observed on visual inspection, running did not produce significant morphological differences in the microvascular morphometric parameters, quantified following semiautomated tracking of the microvascular networks. We propose that voluntary running led to increased cortical microvascular efficiency and desensitization to CO₂ elevation.

Relationship between exercise capacity and urinary liver-type fatty acid-binding protein in middle-aged and older individuals

BACKGROUND

The underlying mechanism linking the decline in exercise capacity with renal dysfunction remains unclear. Urinary liver-type fatty acid-binding protein (L-FABP) levels reflect the degree of peritubular capillary blood flow, an important factor for renal dysfunction with aging. The aim of this study was to examine the relationship between exercise capacity and urinary L-FABP levels.

METHODS

This was a cross-sectional study of 187 middle-aged and older individuals (aged 50-83 years) without chronic kidney disease (CKD). We assessed urinary L-FABP levels, peak oxygen consumption ([Formula: see text]), and grip strength.

RESULTS

Urinary L-FABP levels inversely correlated with both [Formula: see text] (r _s  = -0.349) and grip strength (r _s  = -0.485). When the participants were divided into four groups according to the median values of aerobic fitness and muscular strength ([Formula: see text] and grip strength), urinary L-FABP levels were the highest in participants with lower levels of aerobic fitness and muscular strength (2.95 ± 1.43 μg/g creatinine) and the lowest in the participants with higher levels of aerobic fitness and muscular strength (1.33 ± 0.76 μg/g creatinine). The difference between the two groups was significant (P < 0.001).

CONCLUSION

Our results demonstrate that both [Formula: see text] and grip strength were inversely associated with urinary L-FABP levels in middle-aged and older individuals without CKD. This suggests that a decline in exercise capacity is associated with a reduction in peritubular capillary blood flow, providing a novel insight into the underlying mechanism linking the decline in exercise capacity to the development of renal dysfunction.

Oxidative Stress Function in Women over 40 Years of Age, Considering Their Lifestyle

Aging is dependent on biological processes that determine the aging of the organism at the cellular level. The Oxidative Stress Theory of Aging might explain some of the age-related changes in cell macromolecules. Moreover, exposome and lifestyle may also induce changes in cell damage induced by oxidative stress. The aim of the present study was to analyze the related redox changes in lymphocyte function of healthy women over 40 years old. Three groups: younger (YG: 40-49 years), middle aged (MAG: 50-59 years), and older (OG: ≥60 years) were evaluated on anthropometric variables, blood pressure, cardiovascular fitness, lifestyle habits, perceived stress, DNA damage, malondialdehyde, catalase activity, and total antioxidant capacity. Physical activity and cardiovascular fitness were significantly higher in YG and MAG as compared to the OG. Systolic blood pressure increased significantly with group age. Frequency and total amount of alcohol intake were lower in the OG and higher in the MAG. No significant differences were observed between the three groups in oxidative stress parameters. Only alcohol consumption was associated with the higher DNA FPG-sensitive sites, and only in the YG (p < 0.05). Healthy lifestyle is critical to avoiding major ailments associated with aging. This may be inferred from the lack of significant differences in the various oxidative stress parameters measured in the healthy women over the age of 40 who took part in the study. Conscious lifestyle behaviors (decrease in alcohol and smoking habits) could have impaired the expected age-related oxidative stress increase.

Magnetic resonance imaging biomarkers of exercise-induced improvement of oxidative stress and inflammation in the brain of old high-fat-fed ApoE-/- mice

KEY POINTS

Vascular brain lesions and atherosclerosis are two similar conditions that are characterized by increased inflammation and oxidative stress. Non-invasive imaging in a murine model of atherosclerosis showed vascular brain damage and peripheral inflammation. In this study, exercise training reduced magnetic resonance imaging-detected abnormalities, insulin resistance and markers of oxidative stress and inflammation in old ApoE-/- mice. Our results demonstrate the protective effect of exercise on neurovascular damage in the ageing brain of ApoE-/- mice.

ABSTRACT

Vascular brain lesions, present in advanced atherosclerosis, share pathological hallmarks with peripheral vascular lesions, such as increased inflammation and oxidative stress. Physical activity reduces these peripheral risk factors, but its cerebrovascular effect is less documented, especially by non-invasive imaging. Through a combination of in vivo and post-mortem techniques, we aimed to characterize vascular brain damage in old ApoE-/- mice fed a high-cholesterol (HC) diet with dietary controlled intake. We then sought to determine the beneficial effects of exercise training on oxidative stress and inflammation in the brain as a treatment option in an ageing atherosclerosis mouse model. Using in vivo magnetic resonance imaging (MRI) and biological markers of oxidative stress and inflammation, we evaluated the occurrence of vascular abnormalities in the brain of HC-diet fed ApoE-/- mice >70 weeks old, its association with local and systemic oxidative stress and inflammation, and whether both can be modulated by exercise. Exercise training significantly reduced both MRI-detected abnormalities (present in 71% of untrained vs. 14% of trained mice) and oxidative stress (lipid peroxidation, 9.1 ± 1.4 vs. 5.2 ± 0.9 μmol mg-1 ; P < 0.01) and inflammation (interleukin-1β, 226.8 ± 27.1 vs. 182.5 ± 21.5 pg mg-1 ; P < 0.05) in the brain, and the mortality rate. Exercise also decreased peripheral insulin resistance, oxidative stress and inflammation, but significant associations were seen only within brain markers. Highly localized vascular brain damage is a frequent finding in this ageing atherosclerosis model, and exercise is able to reduce this outcome and improve lifespan. In vivo MRI evaluated both the neurovascular damage and the protective effect of exercise.

Effects of exercise on markers of oxidative stress: an Ancillary analysis of the Alberta Physical Activity and Breast Cancer Prevention Trial

BACKGROUND

Oxidative stress may contribute to cancer aetiology through several mechanisms involving damage to DNA, proteins and lipids leading to genetic mutations and genomic instability. The objective of this study was to determine the effects of aerobic exercise on markers of oxidative damage and antioxidant enzymes in postmenopausal women.

METHODS

The Alberta Physical Activity and Breast Cancer Prevention Trial (ALPHA) was a two-centre, two-armed randomised trial of 320 inactive, healthy, postmenopausal women aged 50-74 years. Participants were randomly assigned to a year-long exercise intervention (225 min/week) or a control group while being asked to maintain a normal diet. Fasting blood samples were obtained and plasma concentrations of two oxidative damage markers (8-hydroxy-2'-deoxyguanosine (8-OHdG) and 8-isoprostaglandin F2α (8-Iso-PGF2α)) and two antioxidant enzymes (superoxide dismutase and catalase) were measured at baseline, 6 months and 12 months. Intention-to-treat (ITT) and per-protocol analyses were performed using linear mixed models adjusted for baseline biomarker concentrations. A further exercise adherence analysis, based on mean minutes of exercise per week, was also performed.

RESULTS

In the ITT and per-protocol analyses, the exercise intervention did not have any statistically significant effect on either oxidative damage biomarkers or antioxidant enzyme activity.

CONCLUSIONS

A year-long aerobic exercise intervention did not have a significant impact on oxidative stress in healthy, postmenopausal women.

TRIAL REGISTRATION NUMBER

NCT00522262.

Exercise Does Not Protect against Peripheral and Central Effects of a High Cholesterol Diet Given Ad libitum in Old ApoE-/- Mice

Aim: Advanced atherosclerosis increases inflammation and stroke risk in the cerebral vasculature. Exercise is known to improve cardio-metabolic profiles when associated with a caloric restriction, but it remains debated whether it is still beneficial without the dietary control. The aim of this study was to determine both the peripheral and central effects of exercise training combined with a cholesterol-rich diet given ad libitum in old ApoE^−/− mice.

Methods: Forty-five-weeks old obese ApoE^−/− mice fed with a high cholesterol diet ad libitum were divided into Exercise-trained (EX; running wheel free access) and Sedentary (SED) groups. Insulin tolerance and brain imaging were performed before and after the twelve-weeks training. Tissue insulin resistance, oxidative stress, and inflammation markers in plasma, aorta, and brain were then assessed.

Results: In EX ApoE^−/− mice, no beneficial effect of exercise was observed on weight, abdominal fat, metabolic parameters, oxidative stress, or inflammation compared to SED. Despite the regular exercise training in ApoE^−/− EX mice (mean of 12.5 km/week during 12 weeks), brain inflammation imaging score was significantly associated with increased blood brain barrier (BBB) leakage evaluated by imaging follow-up (r² = 0.87; p = 0.049) with a faster evolution compared to SED ApoE^−/−mice.

Conclusion: We conclude that in a context of high cardio-metabolic risk, exercise does not provide any protective effect in old ApoE^−/− animals under high cholesterol diet given ad libitum. Peripheral (insulin sensitivity and oxidative/inflammatory status) but also central features (BBB preservation and protection against inflammation) did not show any benefits of exercise. Indeed, there was a fast induction of irreversible brain damage that was more pronounced in exercise-trained ApoE^−/− mice.

Resistance or aerobic training decreases blood pressure and improves cardiovascular autonomic control and oxidative stress in hypertensive menopausal rats

We investigated whether resistance training (RT) vs. aerobic training (AT) differentially impacts on arterial pressure and related mechanisms in ovariectomized spontaneously hypertensive rats (SHRs). Female SHRs were ovariectomized and assigned to one of the following groups: sedentary, AT, or RT; sham sedentary SHR were used as control group. AT was performed on a treadmill, whereas RT was performed on a vertical ladder. Both exercise protocols were performed for 8 wk, 5 days/wk. Arterial pressure, baroreflex sensitivity, autonomic modulation, and cardiac oxidative stress parameters (lipid peroxidation, protein oxidation, redox balance, NADPH oxidase, and antioxidant enzymes activities) were analyzed. Ovariectomy increased mean arterial pressure (∼9 mmHg), sympathetic modulation (∼40%), and oxidative stress in sedentary rats. Both RT and AT reduced mean arterial pressure (∼20 and ∼8 mmHg, respectively) and improved baroreflex sensitivity compared with sedentary ovariectomized rats. However, RT-induced arterial pressure decrease was significantly less pronounced than AT. Lipid peroxidation and protein oxidation were decreased while antioxidant enzymes were increased in both trained groups vs. sedentaries. The reduced gluthatione was higher after AT vs. other groups, whereas oxidized gluthatione was lower after RT vs. AT. Moreover, sympathetic and parasympathetic modulations were highly correlated with cardiac oxidative stress parameters. In conclusion, both RT and AT can decrease arterial pressure in a model of hypertension and menopause; although, at different magnitudes this decrease was related to attenuated autonomic dysfunction in association with cardiac oxidative stress improvement in both exercise protocols.

Promoting brain health through exercise and diet in older adults: a physiological perspective

The rise in incidence of age-related cognitive impairment is a global health concern. Ageing is associated with a number of changes in the brain that, collectively, contribute to the declines in cognitive function observed in older adults. Structurally, the ageing brain atrophies as white and grey matter volumes decrease. Oxidative stress and inflammation promote endothelial dysfunction thereby hampering cerebral perfusion and thus delivery of energy substrates and nutrients. Further, the development of amyloid plaques and neurofibrillary tangles contributes to neuronal loss. Of interest, there are substantial inter-individual differences in the degree to which these physical and functional changes impact upon cognitive function as we grow older. This review describes how engaging in physical activity and cognitive activities and adhering to a Mediterranean style diet promote 'brain health'. From a physiological perspective, we discuss the effects of these modifiable lifestyle behaviours on the brain, and how some recent human trials are beginning to show some promise as to the effectiveness of lifestyle behaviours in combating cognitive impairment. Moreover, we propose that these lifestyle behaviours, through numerous mechanisms, serve to increase brain, cerebrovascular and cognitive reserve, thereby preserving and enhancing cognitive function for longer.

Oxidative Stress State Is Associated with Left Ventricular Mechanics Changes, Measured by Speckle Tracking in Essential Hypertensive Patients

The oxidative stress state is characterized by an increase in oxygen reactive species that overwhelms the antioxidant defense; we do not know if these pathological changes are correlated with alterations in left ventricular mechanics. The aim was correlating the oxidative stress state with the left ventricular global longitudinal strain (GLS) and the left ventricular end diastolic pressure (LVEDP). Twenty-five patients with essential hypertension and 25 controls paired by age and gender were studied. All of the participants were subjected to echocardiography and biochemical determination of oxidative stress markers. The hypertensive patients, compared with control subjects, had significantly (p < 0.05) higher levels of oxidized proteins (5.03 ± 1.05 versus 4.06 ± 0.63 nmol/mg), lower levels of extracellular superoxide dismutase (EC-SOD) activity (0.045 ± 0.02 versus 0.082 ± 0.02 U/mg), higher LVEDP (16.2 ± 4.5 versus 11.3 ± 1.6 mm Hg), and lower GLS (−12% versus −16%). Both groups had preserved ejection fraction and the results showed a positive correlation of oxidized proteins with GLS (r = 0.386, p = 0.006) and LVEDP (r = 0.389, p = 0.005); we also found a negative correlation of EC-SOD activity with GLS (r = −0.404, p = 0.004) and LVEDP (r = −0.347, p = 0.014).

Relation of C-reactive protein, fibrinogen, and cardiorespiratory fitness to risk of systemic hypertension in men

We investigated the relation between inflammation and incident hypertension, independent of obesity, and tested the associations of cardiorespiratory fitness (fitness) and indexes of inflammation for the development of hypertension in 2,475 normotensive men. Inflammatory markers were C-reactive protein (CRP) and fibrinogen. Fitness was directly measured by peak oxygen uptake during sign/symptom-limited treadmill exercise testing to volitional fatigue; 266 men (10.7%) developed hypertension during an average of 4 years follow-up. After adjusting for potential confounding variables, the relative risk (RR) and 95% confidence interval (CI) for incident hypertension in those in the upper tertile versus lower tertile were 1.55 (95% CI 1.15 to 2.09) for CRP and 1.51 (95% CI 1.10 to 2.06) for fibrinogen. Although the association between fibrinogen and incident hypertension persisted after adjusting for body mass index (p = 0.049), the relation between CRP and incident hypertension was no longer statistically significant (p = 0.08). Fit men had a 27% decreased (RR 0.73, 95% CI 0.56 to 0.94) risk of incident hypertension compared with unfit men in a multivariable adjusted model. In the joint analysis, unfit men with upper CRP had 1.81 times (95% CI 1.21 to 2.70) and unfit men with upper fibrinogen had 2.03 times (95% CI 1.33 to 3.12) greater risks of incident hypertension compared with fit men with low CRP and fibrinogen, respectively. However, these risks did not significantly increase in fit men with upper CRP (RR 1.12, 95% CI 0.76 to 1.63) and fibrinogen (RR 1.26, 95% CI 0.86 to 1.85) groups. In conclusion, these results suggest that heightened levels of fibrinogen, but not CRP, are associated with incident hypertension, independent of body weight, and that high fitness attenuates the risk of incident hypertension across upper levels of inflammatory markers in men.

Moderate exercise blunts oxidative stress induced by normobaric hypoxic confinement

PURPOSE

Both acute hypoxia and physical exercise are known to increase oxidative stress. This randomized prospective trial investigated whether the addition of moderate exercise can alter oxidative stress induced by continuous hypoxic exposure.

METHODS

Fourteen male participants were confined to 10-d continuous normobaric hypoxia (FIO2 = 0.139 ± 0.003, PIO2 = 88.2 ± 0.6 mm Hg, ∼4000-m simulated altitude) either with (HCE, n = 8, two training sessions per day at 50% of hypoxic maximal aerobic power) or without exercise (HCS, n = 6). Plasma levels of oxidative stress markers (advanced oxidation protein products [AOPP], nitrotyrosine, and malondialdehyde), antioxidant markers (ferric-reducing antioxidant power, superoxide dismutase, glutathione peroxidase, and catalase), nitric oxide end-products, and erythropoietin were measured before the exposure (Pre), after the first 24 h of exposure (D1), after the exposure (Post) and after the 24-h reoxygenation (Post + 1). In addition, graded exercise test in hypoxia was performed before and after the protocol.

RESULTS

Maximal aerobic power increased after the protocol in HCE only (+6.8%, P < 0.05). Compared with baseline, AOPP was higher at Post + 1 (+28%, P < 0.05) and nitrotyrosine at Post (+81%, P < 0.05) in HCS only. Superoxide dismutase (+30%, P < 0.05) and catalase (+53%, P < 0.05) increased at Post in HCE only. Higher levels of ferric-reducing antioxidant power (+41%, P < 0.05) at Post and lower levels of AOPP (-47%, P < 0.01) at Post + 1 were measured in HCE versus HCS. Glutathione peroxidase (+31%, P < 0.01) increased in both groups at Post + 1. Similar erythropoietin kinetics was noted in both groups with an increase at D1 (+143%, P < 0.01), a return to baseline at Post, and a decrease at Post + 1 (-56%, P < 0.05).

CONCLUSIONS

These data provide evidence that 2 h of moderate daily exercise training can attenuate the oxidative stress induced by continuous hypoxic exposure.

Nitric oxide concentrations in gas emanating from the tails of obese rats

This study was undertaken to investigate the effects of oral L-arginine administration and exercising training on the NO concentration emanating from rat tail and NOx in plasma. Obese (fa/fa) Zucker rats (n = 22) were divided into four groups: (1) oral L-arginine administration (A) (n = 6), (2) exercise training (E), (3) exercise training + L-arginine administration (E + A) (n = 5), and (4) non-exercise training + non-L-arginine administration (N) (n = 6). The control (+/+) Zucker rats (n = 22) were also divided into the same four groups. The body weight of the E + A and the A groups was significantly lower than that of the N group. The NO concentration emitted from the tail was higher in the L-arginine (E + A and A) groups than in the non-L-arginine (E and N) groups in both obese and control rats. Exercise training did not affect the skin gas NO concentration in either obese or control rats. Plasma NOx concentrations in four obese rats were significantly higher than those observed in control rats. Exercise training did not influence the level of plasma NOx in obese or control rats. In conclusion, this study confirmed that L-arginine administration increases the skin gas NO concentration and obesity increases the plasma NOx level. The plasma NOx concentrations were not affected by L-arginine administration or exercise training in obese or control rats.

Obstructive sleep apnea and risk of cardiovascular events and all-cause mortality: a decade-long historical cohort study

BACKGROUND

Obstructive sleep apnea (OSA) has been reported to be a risk factor for cardiovascular (CV) disease. Although the apnea-hypopnea index (AHI) is the most commonly used measure of OSA, other less well studied OSA-related variables may be more pathophysiologically relevant and offer better prediction. The objective of this study was to evaluate the relationship between OSA-related variables and risk of CV events.

METHODS AND FINDINGS

A historical cohort study was conducted using clinical database and health administrative data. Adults referred for suspected OSA who underwent diagnostic polysomnography at the sleep laboratory at St Michael's Hospital (Toronto, Canada) between 1994 and 2010 were followed through provincial health administrative data (Ontario, Canada) until May 2011 to examine the occurrence of a composite outcome (myocardial infarction, stroke, congestive heart failure, revascularization procedures, or death from any cause). Cox regression models were used to investigate the association between baseline OSA-related variables and composite outcome controlling for traditional risk factors. The results were expressed as hazard ratios (HRs) and 95% CIs; for continuous variables, HRs compare the 75th and 25th percentiles. Over a median follow-up of 68 months, 1,172 (11.5%) of 10,149 participants experienced our composite outcome. In a fully adjusted model, other than AHI OSA-related variables were significant independent predictors: time spent with oxygen saturation <90% (9 minutes versus 0; HR = 1.50, 95% CI 1.25-1.79), sleep time (4.9 versus 6.4 hours; HR = 1.20, 95% CI 1.12-1.27), awakenings (35 versus 18; HR = 1.06, 95% CI 1.02-1.10), periodic leg movements (13 versus 0/hour; HR = 1.05, 95% CI 1.03-1.07), heart rate (70 versus 56 beats per minute [bpm]; HR = 1.28, 95% CI 1.19-1.37), and daytime sleepiness (HR = 1.13, 95% CI 1.01-1.28).The main study limitation was lack of information about continuous positive airway pressure (CPAP) adherence.

CONCLUSION

OSA-related factors other than AHI were shown as important predictors of composite CV outcome and should be considered in future studies and clinical practice.

Ethanolic extract of rhizome of Ligusticum chuanxiong Hort. (chuanxiong) enhances endothelium-dependent vascular reactivity in ovariectomized rats fed with high-fat diet

Rhizome of Ligusticum chuanxiong Hort. (LC), also known as chuanxiong, is a very common herb widely used to treat cardiovascular and cerebrovascular diseases.

The relationship between aerobic fitness level and metabolic profiles in healthy adults

SCOPE

Application of metabolomics to nutrition and health research is increasing and while much effort has been invested in understanding factors that influence the metabolomic profile there is relatively little known about the impact of fitness level. This study aimed to examine the relationship between fitness level, substrate oxidation rates, and the metabolic profile.

METHODS AND RESULTS

Two hundred and fourteen healthy adults (18-60 years) were recruited and 65 subjects were selected based on their estimated maximal oxygen consumption levels. Metabolomic analysis was performed. The subjects were split into fitness groups according to their maximal oxygen consumption levels (mL/kg/min) and analysis revealed significant differences in normalized fat and carbohydrate oxidation levels between the groups. Urinary metabolomic analysis revealed significantly different profiles in the groups with 15 amino acids significantly higher in the low fitness groups. Effects of fitness level in the plasma metabolic profiles were also demonstrated.

CONCLUSION

This study demonstrates a relationship between fitness level and the amino acid profile. Moreover, the metabolite changes show that a reduced excretion of amino acids in adults is associated with increased fitness levels and an increased fat oxidation rate during exercise. Interestingly, higher levels of branched chain amino acids were associated with lower fitness levels and higher insulin resistance.

The brain-in-motion study: effect of a 6-month aerobic exercise intervention on cerebrovascular regulation and cognitive function in older adults

BACKGROUND

Aging and physical inactivity are associated with declines in some cognitive domains and cerebrovascular function, as well as an elevated risk of cerebrovascular disease and other morbidities. With the increase in the number of sedentary older Canadians, promoting healthy brain aging is becoming an increasingly important population health issue. Emerging research suggests that higher levels of physical fitness at any age are associated with better cognitive functioning and this may be mediated, at least in part, by improvements in cerebrovascular reserve. We are currently conducting a study to determine: if a structured 6-month aerobic exercise program is associated with improvements or maintenance of both cerebrovascular function and cognitive abilities in older individuals; and, the extent to which any changes seen persist 6 months after the completion of the structured exercise program.

METHODS/DESIGN

Two hundred and fifty men and women aged 55-80 years are being enrolled into an 18-month combined quasi-experimental and prospective cohort study. Participants are eligible for enrollment into the study if they are inactive (i.e., not participating in regular physical activity), non-smokers, have a body mass index <35.0 kg/m(2), are free of significant cognitive impairment (defined as a Montreal Cognitive Assessment score of 24 or more), and do not have clinically significant cardiovascular, cerebrovascular disease, or chronic obstructive pulmonary airway disease. Repeated measurements are done during three sequential six-month phases: 1) pre-intervention; 2) aerobic exercise intervention; and 3) post-intervention. These outcomes include: cardiorespiratory fitness, resting cerebral blood flow, cerebrovascular reserve, and cognitive function.

DISCUSSION

This is the first study to our knowledge that will examine contemporaneously the effect of an exercise intervention on both cerebrovascular reserve and cognition in an older population. This study will further our understanding of whether cerebrovascular mechanisms might explain how exercise promotes healthy brain aging. In addition our study will address the potential of increasing physical activity to prevent age-associated cognitive decline.