Association between total and leisure time physical activity and risk of myocardial infarction and stroke - a Swedish cohort study

Examining the alignment between subjective effort and objective force production

Ratings of Perceived Exertion (RPE) are frequently used to prescribe exercise intensity. A central assumption of using RPE scales is that the subjective perception of effort maps onto objective performance in a consistent way. However, the degree and shape of how RPE aligns with objective performance is not fully understood. Here, we investigate the degree and shape of alignment, as well as how time (i.e., how frequently an effort needs to be performed) and mental effort (i.e., if one has to invest mental effort and physical effort) correspond with the alignment. In a randomized within-subjects experiment, we used a grip-to-scale method that asked participants (N = 43) to repeatedly squeeze a handgrip dynamometer with four to-be-produced RPE target levels relative to their subjective maximum strength (representing 20%, 40%, 60%, or 80%). We found that the RPE-force alignment was not the same across RPE-levels: Whereas subjective differences from 20-40% and 40-60% were met by comparable differences in produced force, a substantially larger difference was observed for the 60-80% interval. Interestingly, exploratory post-hoc analyses revealed that this was mirrored by an increase in variance at the higher effort levels. In addition, at constant RPE-levels, participants produced less force over time, and this effect was more pronounced at lower RPE target levels. Lastly, anticipating mental effort after the physical effort slightly altered the alignment as a function of the to-be-produced RPE-level and experimental duration. Taken together, our results indicate that the mapping of perceived effort on objective performance is intricate, and several factors affect the degree and shape of how RPE and performance align. Understanding the dynamic adjustment of RPE-performance alignment across different RPE levels is particularly relevant for contexts that use RPE as a tool for training load prescription.

Risk of stroke with different levels of leisure-time physical activity: a systematic review and meta-analysis of prospective cohort studies

BACKGROUND

Leisure-time physical activity (LTPA) protects against vascular diseases. Whether and to what extent different levels of LTPA, including lower ones, benefit stroke prevention is still unclear.

METHODS

We searched prospective cohort studies, indexed on PubMed and Scopus, published in English up to 22 April 2023, that investigated, in a general healthy population, the relationship between different predefined LTPA levels, compared with inactivity, and the risk of any type of stroke. We applied random effect modelling for meta-analyses and meta-regression to control for the impact of age and sex.

RESULTS

Out of 3064 screened articles, 15 articles on 16 cohorts of subjects were included in meta-analyses, with a total of 752 050 followed-up subjects. Mean follow-up was 125.7±77.5 months. Included studies identified three (none, below target and ideal) to five (none, insufficient, low, moderate and intense) levels of LTPA. In the five studies identifying three levels of LTPA, compared with no LTPA, below target (risk ratio (RR)=0.82, 95% CI=0.75 to 0.88) and ideal LTPA significantly reduced stroke risk (RR=0.71, 95% CI=0.58 to 0.86).Lower levels of LTPA also mitigated stroke risk in studies reporting on four (n=6; RR=0.73, 95% CI=0.62 to 0.87 favouring moderate LTPA over no LTPA) and five levels (n=2; RR=0.71, 95% CI=0.58 to 0.88 favouring moderate LTPA over no LTPA). The benefits of LTPA were independent of age and sex.

CONCLUSIONS

According to our results, all levels of LTPA can be beneficial for stroke prevention, including levels currently regarded as low or insufficient. People should be encouraged to be physically active even at the lowest levels.

PROSPERO REGISTRATION NUMBER

CRD42023425302.

Association between physical activity changes and incident myocardial infarction after ischemic stroke: a nationwide population-based study

BACKGROUND

The impact of changes in physical activity after ischemic stroke (IS) on the subsequent myocardial infarction (MI) risk is not fully understood. We aimed to investigate the effects of changes in physical activity on the risk of MI after acute IS using data from the Korean National Health Insurance Services Database.

METHODS

224,764 patients newly diagnosed with IS between 2010 and 2016 who underwent two serial biannual health checkups were included. The participants were divided into four categories according to changes in their physical activity: persistent non-exercisers, new exercisers, exercise dropouts, and exercise maintainers. The primary outcome was a new diagnosis of incident MI. Multivariable Cox proportional models were used to assess the effects of changes in exercise habits on the risk of MI.

RESULTS

After a median of 4.25 years of follow-up, 6,611 (2.94%) MI cases were observed. After adjusting for confounders, new exercisers and exercise maintainers were significantly associated with a lower risk of incident MI than persistent non-exercisers (aHR, 0.849; 95% CI, 0.792-0.911; P-value < 0.001; and aHR, 0.746; 95% CI, 0.696-0.801; P-value < 0.001, respectively). Effects were consistent across sexes, more pronounced in those > 65 years. Notably, any level of physical activity after stroke was associated with a reduced MI risk compared to no exercise.

CONCLUSIONS

In this nationwide cohort study, commencing or sustaining physical activity after an IS corresponded to a diminished likelihood of subsequent MI development. Advocating physical activity in ambulatory stroke survivors could potentially attenuate the prospective risk of MI.

Leisure-time and occupational physical activity and risk of cardiovascular disease incidence: a systematic-review and dose-response meta-analysis of prospective cohort studies

BACKGROUND AND OBJECTIVE

Physical activity has benefits for the cardiovascular system, however, what levels and types of activity provide optimal cardiovascular health is unclear. We aimed to determine the level of physical activity that has the most benefits against cardiovascular diseases (CVD).

METHODS

PubMed, Scopus, and Web of Science were searched for prospective cohort studies on leisure-time (LTPA) or occupational physical activity (OPA) as the exposure and major types of CVD (total CVD, coronary heart disease [CHD], stroke, and atrial fibrillation [AF]) incidence as the outcome. Risk of bias of studies was evaluated using the ROBINS-I tool. Summary hazard ratios (HR) were calculated using random-effects pairwise model.

RESULTS

A total of 103 studies were included in the analysis. The highest versus the lowest LTPA was associated with a lower risk of overall CVD (HR = 0.81; 95% CI: 0.77-0.86), CHD (HR = 0.83; 0.79-0.88), and stroke (HR = 0.83; 0.79-0.88), but not AF (HR = 0.98; 0.92-1.05). Linear dose-response analyses showed a 10%, 12%, 9%, and 8% risk reduction in CVD, CHD, stroke, and AF incidence, respectively, for every 20 MET-hours/week increase in LTPA. In nonlinear dose-response analyses, there were inverse associations up to 20 MET-hours/week with 19% and 20% reduction in CVD and CHD risk, and up to 25 MET-hours/week with 22% reduction in stroke, with no further risk reduction at higher LTPA levels. For AF, there was a U-shaped nonlinear association with the maximum 8% risk reduction at 10 MET-hours/week of LTPA. Higher levels of OPA were not associated with risk of CVD, CHD, stroke, or AF.

CONCLUSIONS

Overall, results showed an inverse dose-response relationship between LTPA and risk of CVD, CHD, stroke, and AF. Running was the most beneficial LTPA but the risk was similar among various LTPA intensities. OPA showed no benefits in total or any type of CVD.

Association of Accelerometer-Measured Physical Activity and Sedentary Behavior With Incident Cardiovascular Disease, Myocardial Infarction, and Ischemic Stroke: The Women's Health Study

Background Few studies have investigated associations of acclerometer-based assessments of physical activity (PA) and sedentary behavior (SB) with incidence of cardiovascular disease (CVD) and its components. This prospective cohort study assessed the associations of accelerometer-measured PA and SB with total CVD, myocardial infarction, and ischemic stroke (IS). Methods and Results The authors included 16 031 women aged 62 years and older, free of CVD, with adherent accelerometer wear (≥10 hours/day for ≥4 days) from the Women's Health Study (mean age, 71.4 years [SD, 5.6 years]). Hip-worn ActiGraph GT3X+ accelerometers measured total volume of PA (total average daily vector magnitude), minutes per day of high-light PA and moderate to vigorous PA (MVPA), and SB. Women reported diagnoses of CVD, which were adjudicated using medical records and death certificates. Hazard ratios (HRs) were estimated for each exposure, and 95% CIs using Cox proportional hazards models were adjusted for accelerometer wear time, age, self-reported general health, postmenopausal hormone therapy, smoking status, and alcohol use. The hypothetical effect of replacing 10 minutes/day of SB or high-light PA with MVPA on CVD incidence was assessed using adjusted isotemporal substitution Cox models. Over a mean of 7.1 years (SD, 1.6 years) of follow-up, 482 total CVD cases, 107 myocardial infarction cases, and 181 IS cases were diagnosed. Compared with the lowest quartiles of total average daily vector magnitude and MVPA (≤60 minutes), women who were in the highest quartiles (>120 minutes of MVPA) had a 43% (95% CI, 24%-58%) and 38% (95% CI, 18%-54%) lower hazard of total CVD, respectively. Estimates were similar for total average daily vector magnitude and MVPA with IS, but PA was not associated with myocardial infarction overall. High-light PA was not associated with any CVD outcomes. Women who spent <7.4 hours sedentary per day had a 33% (95% CI, 11%-49%) lower hazard of total CVD compared with those who spent ≥9.5 hours sedentary. Replacing 10 minutes of SB with MVPA was associated with a 4% lower incidence of total CVD (HR, 0.96 [95% CI, 0.93-0.99]). Conclusions Accelerometer-assessed total PA and MVPA were inversely associated with total CVD and IS incidence, and SB was directly associated with total CVD; high-light PA was not related to CVD.

Understanding of the Single-Item Physical Activity Question for Population Surveillance

BACKGROUND

Sport New Zealand conducts continuous representative "Active NZ" surveys. Between 2019 and 2020 (n = 13,887), these surveys asked International Physical Activity Questionnaire (IPAQ)-long-form questions, the single-item days (SI-days) per week question, and 1 question on hours per week (single-item hours [SI-hours] per week). This study examines relationships between the established SI-days question and meeting physical activity (PA) guidelines (150 min moderate-to-vigorous physical activity per week from SI-hours question and IPAQ).

METHODS

Analyses were descriptive, and the best fit between SI-days and the PA thresholds was estimated using area under the receiver operator characteristic curves and Youden index.

RESULTS

Using SI-hours, 60.6% achieved 150+ minutes; 85.2% reported the IPAQ-total minimum threshold, and 40.8% met the IPAQ-leisure time PA-only threshold. Receiver operator characteristic analyses showed area under the curve values with IPAQ between 0.63 and 0.76, but the SI-days showed a very good area under the curve of 0.82 (0.81-0.83) with the SI-hours 150-minute threshold. Youden index suggested the best fit was at 3+ days per week for maximizing Sensitivity and Specificity to meet IPAQ or SI-hours-defined PA guidelines.

DISCUSSION

The SI-days per week question reflects achieving PA guidelines, and the best fit was with the SI-hours per week question. This provides surveillance-relevant concurrent validity for the SI-days measure, but the cut point for broadly meeting guidelines appears to be at least 3 days per week, not 5 days per week as previously thought.

Effect of Physical Activity/Exercise on Oxidative Stress and Inflammation in Muscle and Vascular Aging

Functional status is considered the main determinant of healthy aging. Impairment in skeletal muscle and the cardiovascular system, two interrelated systems, results in compromised functional status in aging. Increased oxidative stress and inflammation in older subjects constitute the background for skeletal muscle and cardiovascular system alterations. Aged skeletal muscle mass and strength impairment is related to anabolic resistance, mitochondrial dysfunction, increased oxidative stress and inflammation as well as a reduced antioxidant response and myokine profile. Arterial stiffness and endothelial function stand out as the main cardiovascular alterations related to aging, where increased systemic and vascular oxidative stress and inflammation play a key role. Physical activity and exercise training arise as modifiable determinants of functional outcomes in older persons. Exercise enhances antioxidant response, decreases age-related oxidative stress and pro-inflammatory signals, and promotes the activation of anabolic and mitochondrial biogenesis pathways in skeletal muscle. Additionally, exercise improves endothelial function and arterial stiffness by reducing inflammatory and oxidative damage signaling in vascular tissue together with an increase in antioxidant enzymes and nitric oxide availability, globally promoting functional performance and healthy aging. This review focuses on the role of oxidative stress and inflammation in aged musculoskeletal and vascular systems and how physical activity/exercise influences functional status in the elderly.

Traditional and Emerging Sex-Specific Risk Factors for Cardiovascular Disease in Women

Cardiovascular disease (CVD) remains a major health threat in women. While traditional CVD risk factors such as hypertension, hyperlipidemia, diabetes, and smoking have been recognized for over 50 years, optimal control of these risk factors remains a major challenge. Unique sex-specific risk factors such as adverse pregnancy outcomes, premature menopause and low estrogen states, and chronic autoimmune inflammatory disorders also contribute to increased CVD risk in women. In addition, psychological risk factors such as stress, depression, and social determinants of health may have a disproportionately adverse impact in women. An improved understanding of traditional and emerging sex-specific CVD risk factors and management of modifiable factors is critical for clinicians who provide care for women. Early recognition and treatment of risk factors may alter the trajectory of adverse CVD events. A multi-disciplinary approach with team-based care involving multiple specialists and improved, targeted educational efforts are needed to reduce CVD risk factors and its adverse consequences in women.