Exercise and incidence of myocardial infarction, stroke, hypertension, type 2 diabetes and site-specific cancers: prospective cohort study of 257 854 adults in South Korea

Impact of Hypertension on the Dose-Response Association Between Physical Activity and Stroke: A Cohort Study

BACKGROUND

Regular physical activity is associated with a reduced stroke risk. However, this relationship might be attenuated in the presence of hypertension and antihypertensive medication use. We examined the dose-response relationship between physical activity and stroke in normotensive and hypertensive individuals.

METHODS

A Dutch population-based cohort including 139 930 individuals (41% men; mean age, 44±13) was performed (median follow-up, 6.75 years). Participants were stratified at baseline as hypertensive (44%) or normotensive (56%) and categorized into quartiles of the lowest (Q1) to the highest (Q4) moderate-to-vigorous, self-reported physical activity. The primary outcome was incident stroke (fatal and nonfatal). Cox regression estimated hazard ratios and 95% CIs. The main analyses were stratified on baseline blood pressure and adjusted for confounders. Hypertensives were stratified into medicated (21%) or non-medicated (79%).

RESULTS

Compared with Q1, adjusted hazard ratios were 0.87 (0.69-1.10; P=0.23), 0.75 (0.59-0.95; P=0.02), and 0.94 (0.74-1.20; P=0.64) for Q2 to Q4, respectively in the total population. Hazard ratios for normotensives were 0.79 (0.50-1.25; P=0.32), 0.75 (0.48-1.18; P=0.22), 0.97 (0.62-1.51; P=0.90) for Q2 to Q4, respectively. In hypertensives, hazard ratios were 0.89 (0.68-1.17; P=0.41), 0.74 (0.56-0.98; P=0.03), 0.92 (0.69-1.23; P=0.56) for Q2 to Q4, respectively. There was no significant interaction between hypertension status for the relation between physical activity and stroke risk. The stratified analysis revealed a smaller benefit of moderate-to-vigorous physical activity in medicated hypertensives compared with nonmedicated hypertensives, but no significant interaction effect was found.

CONCLUSIONS

Regular moderate-to-vigorous physical activity is beneficial for stroke risk reduction (Q3 compared with Q1), which is not affected by hypertension. Antihypertensive medication may be associated with a smaller benefit of moderate-to-vigorous physical activity on the risk of stroke, but further research is warranted.

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.

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.

Physical activity and risk of lung cancer: A systematic review and dose-response meta-analysis of cohort studies

Objective

To synthesize the knowledge about the association of total physical activity (TPA), leisure-time physical activity (LTPA), occupational physical activity (OPA) and lung cancer risk and explore the dose-response relationship between LTPA level and lung cancer.

Methods

PubMed and Web of Science were searched up to 17 November 2021. The summary relative risks (RRs) and 95% confidence intervals (CIs) were calculated by random-effects or fixed-effects model. The dose-response analysis was conducted with restricted cubic splines.

Results

We identified 25 articles (42 cohort studies) that assessed the physical activity-lung cancer association, including 9,983,295 study participants and 85,988 incident cases of lung cancer. When comparing the highest to the lowest level of TPA and LTPA, lung cancer risk reduced 22% (RR, 0.78; 95% CI: 0.70, 0.86) and 12% (RR, 0.88; 95% CI: 0.83, 0.93), respectively. We found an approximately U-shaped association between LTPA and lung cancer (P non-linearity < 0.001), with the lowest risk at 15 metabolic equivalent of task hours per week (h/wk) of LTPA. Compared to participants with sitting occupations, lung cancer risk significantly increased among those being unemployed (RR, 1.33; 95% CI: 1.17, 1.51) or with standing occupations (RR, 1.37; 95% CI: 1.15, 1.63), but not among those with light or high OPA.

Conclusions

Our meta-analysis supported a protective effect of TPA and LTPA, but not OPA, on lung cancer risk. The novel finding of a U-shaped association between LTPA and lung cancer risk warrants further investigation.

Sex Differences in Physical Activity and Incident Stroke: A Systematic Review

PURPOSE

Physical inactivity, a modifiable risk factor for cardiovascular disease, is independently associated with stroke. Though some prior data have suggested sex differences in levels of physical activity, whether there are sex differences in the role of physical activity in primary stroke prevention is largely unknown. This systematic review identifies and describes recent findings on sex differences in the association between physical activity and incident (first-ever) stroke. This review also describes the current evidence on the strength of the association between physical activity and a reduced stroke risk in women in particular.

METHODS

Using a prespecified strategy, PubMed/MEDLINE and Cochrane Central were searched to identify observational studies or trials published from 2000 to 2020 and reporting sex differences in physical activity and incident stroke. To be included, among other criteria, studies had to include sex-specific effect estimates from women, men, or both. Titles, abstracts, and full-text articles were screened to identify studies meeting the inclusion criteria, and adjusted sex-specific estimates of the association between physical activity and incident stroke for total stroke (ischemic plus hemorrhagic) or ischemic stroke were abstracted.

FINDINGS

Thirty-seven studies met the inclusion criteria. Of 17 studies that included data on total incident stroke (ischemic and hemorrhagic combined) in both women and men, 7 (41%) showed similar associations between physical activity and incident stroke between women and men, 6 (35%) suggested a significant effect in women but not in men, and 3 (18%) showed a significant effect in men but not in women. Of 10 studies that included data on ischemic stroke in women and men, 5 (50%) suggested similar effects in women and men, 4 (40%) suggested a significant effect in women but not in men, and 1 (10%) showed an effect in men but not women. In women specifically, the majority of included studies demonstrated a reduced risk for incident stroke with physical activity, with relative risk reductions ranging from 11% to 72%, though most estimates fell between 20% and 40%.

IMPLICATIONS

The majority of studies indicated a clear association between physical activity and a reduction in stroke risk. Studies were split as to the potential for sex differences in this association. Future prospective investigations should identify strategies for the use of increased physical activity for primary stroke prevention, with sex-specific considerations as warranted. The data on sex-specific dose-response relationship between physical activity and stroke risk are inconclusive and warrant more research.

Association of physical activity with risk of hepatobiliary diseases in China: a prospective cohort study of 0.5 million people

OBJECTIVE

There is limited prospective evidence on the association of physical activity with hepatobiliary cancer subtypes and other major hepatobiliary diseases, especially in China. We aimed to quantify the associations with risk of these diseases.

METHODS

The study population involved 460 937 participants of the prospective China Kadoorie Biobank aged 30-79 years from 10 diverse areas in China without history of cancer or hepatobiliary disease at baseline. Cox regression was used to estimate adjusted hazard ratios (HRs) for each disease associated with self-reported total and domain-specific physical activity (occupational and non-occupational, ie, leisure time, household and commuting).

RESULTS

During ~10 years of follow-up, 22 012 incident cases of hepatobiliary diseases were recorded. The overall mean (SD) total physical activity was 21.2 (13.9) metabolic equivalent of task (MET)-hours/day, with 62% from occupational activity. Total physical activity was inversely associated with hospitalised non-alcoholic fatty liver disease (HR comparing top vs bottom quintile: 0.62, 95% confidence interval (CI) 0.53 to 0.72), viral hepatitis (0.73, 95% CI 0.62 to 0.87), cirrhosis (0.76, 95% CI 0.66 to 0.88) and liver cancer (0.81, 95% CI 0.71 to 0.93), as well as gallstone disease (0.86, 95% CI 0.81 to 0.90), gallbladder cancer (0.51, 95% CI 0.32 to 0.80) and biliary tract cancer (0.55, 95% CI 0.38 to 0.78). The associations for occupational physical activity were similar to those for total physical activity, but for non-occupational physical activity they differed by disease subtype. For leisure-time physical activity, there was an inverse association with liver cancer and an inverse trend for gallstone disease (HR comparing ≥7.5 MET-hours/day with none: 0.83, 95% CI 0.75 to 0.91 and 0.82, 95% CI 0.66 to 1.01).

CONCLUSION

Among Chinese adults, high total physical activity, particularly occupational physical activity, was inversely associated with risk of major hepatobiliary cancers and diseases, including non-alcoholic fatty liver disease, cirrhosis and certain types of cancer.

Long-term trends and regional variations of hypertension incidence in China: a prospective cohort study from the China Health and Nutrition Survey, 1991-2015

OBJECTIVE

The aim is to explore the trends of hypertension incidence and regional variations in China from 1991 to 2015.

DESIGN

A dynamic prospective cohort study.

SETTING

China Health and Nutrition Survey 1991-2015.

PARTICIPANTS

12 952 Chinese adults aged 18+ years.

PRIMARY OUTCOME MEASURES

Incident hypertension from 1993 to 2015.

RESULTS

Age-standardised hypertension incidence increased from 40.8 per 1000 person-years (95% CI 38.3 to 43.4) between 1993 and 1997 to 48.6 (95% CI 46.1 to 51.0) between 2011 and 2015. The increasing trends were further supported by results from subsequent extended Cox proportional hazard model. In addition, results from the modelling analysis showed that individuals in eastern, central and northeastern China had greater risks of hypertension occurrence in comparison with their counterparts in western China.

CONCLUSION

Hypertension incidence increased during the study period. The growth called for more attention on the health education and health promotion of individuals with great risks.

Genetic correlations and causal inferences in ischemic stroke

BACKGROUND AND PURPOSE

Considerable studies have reported inconsistent relationships between ischemic stroke and a large number of factors. These uncertainties may reflect the susceptibility to confounding in observational studies. We aimed to assess genetic correlations and causal relationships between ischemic stroke and diverse phenotypes.

METHODS

Summary-level data for ischemic stroke (34,217 cases and 406,111 controls) from the MEGASTROKE consortium were used as the outcome. Exposures were derived from two GWAS statistics curated databases. We explored the genetic correlations and causalities between hundreds of traits and ischemic stroke, using linkage disequilibrium score regression and Mendelian randomization (MR), respectively. Multiple sensitivity analyses were also performed.

RESULTS

Genetic correlation analyses reflected genetic overlaps between ischemic stroke and physical activity, cardiometabolic factors, smoking, and lung function. Applying MR, we found suggestive evidence that genetic predisposition to higher concentration of low-density lipoprotein particles (LDL.P) and cholesterol carried in different sizes of LDL.P (LDL.C) were associated with higher risk of ischemic stroke, particular large artery stroke. The strongest effect was observed for small LDL.P in large artery stroke (OR 1.31, 95% CI 1.09-1.56, p = 0.003). The results were overall robust for sensitivity analyses. We further observed significant positive associations of genetically predicted LDL.P and LDL.C with coronary artery disease and myocardial infarction.

CONCLUSIONS

Shared genetic overlaps might exist between ischemic stroke and physical activity, cardiometabolic factors, smoking, and lung function. We provided suggestive evidence for a potential causal role of LDL.P and LDL.C in ischemic stroke, particularly in large artery stroke. Future researches are required to confirm these findings.

Precision Medicine and Cardiovascular Health: Insights from Mendelian Randomization Analyses

Cardiovascular disease (CVD) is considered a primary driver of global mortality and is estimated to be responsible for approximately 17.9 million deaths annually. Consequently, a substantial body of research related to CVD has developed, with an emphasis on identifying strategies for the prevention and effective treatment of CVD. In this review, we critically examine the existing CVD literature, and specifically highlight the contribution of Mendelian randomization analyses in CVD research. Throughout this review, we assess the extent to which research findings agree across a range of studies of differing design within a triangulation framework. If differing study designs are subject to non-overlapping sources of bias, consistent findings limit the extent to which results are merely an artefact of study design. Consequently, broad agreement across differing studies can be viewed as providing more robust causal evidence in contrast to limiting the scope of the review to a single specific study design. Utilising the triangulation approach, we highlight emerging patterns in research findings, and explore the potential of identified risk factors as targets for precision medicine and novel interventions.