Physical activity and ischemic stroke risk. The atherosclerosis risk in communities study

Occupational physical activity: the good, the bad, and the proinflammatory

Background

Physical activity (PA) is beneficial for preventing several conditions associated with underlying chronic inflammation, e. g., cardiovascular disease (CVD) and cancer. While an active lifestyle appears to have anti-inflammatory effects, high levels of occupational PA (OPA) were associated with inflammation and elevated mortality risks. We aimed to summarize the current knowledge (1) on the association between inflammation and OPA and (2) its implications for health and mortality.

Methods and results

This mini-review summarized relevant literature published before January 2023 using established scientific databases and sources. For the primary outcome, observational studies (S) reporting immunological effects (O) in subjects (P), with high (I) vs. low OPA (C), were included. For secondary outcomes, i.e., morbidity and mortality associated with inflammatory processes, (systematic) reviews were included. While "active" occupations and "moderate" OPA appear to have beneficial effects, low (particularly sedentary) and "high-intensity" OPA (particularly including heavy lifting tasks) were associated with inflammation and (CVD and cancer-related) mortality; higher leisure-time PA has been almost consistently associated with lower proinflammatory markers and all-cause mortality risks. Workplace interventions appear to counter some of the observed health effects of unfavorable work strain.

Conclusion

The few studies addressing OPA "intensity" and inflammatory markers are largely heterogeneous regarding OPA classification and confounder control. Sedentary and "heavy" OPA appear to promote proinflammatory effects. In addition to targeted management of work-related physical strain and hazardous environmental co-factors, occupational health providers should focus on employer-initiated exercise interventions and the promotion of leisure-time PA.

Associations of physical activity types and intensity with cardiovascular diseases by age and gender among 18,730 Chinese adults

The associations of physical activity (PA) intensity and types with CVD (cardiovascular diseases) in different population are inconsistent and remains not very clear. A total of 7854 males and 10,876 females over 15 years were selected by multistage random sampling methods. In males, moderate-intensity physical activity (MPA) had no effect, while vigorous-intensity physical activity (VPA) played a significant protective role (OR = 1.319 and 0.615). However, in females, both MPA and VPA had significant protective effects (OR = 0.593 and 0.537). VPA presented as a significant protective factor in stroke patients and combined CVDs for males in all age groups; however, in females, the results suggested that, for those aged over 60-74 years, MPA was a protective factor. Furthermore, for the middle-aged or younger participants, the area under the curves (AUCs) of work, housework, and leisure activity were generally higher than that of other types, while for patients aged over 60 years, the AUCs of sedentary time and sleep activity seemed much higher. VPA had a better protective effect for preventing cardiovascular events, while the young and female population could benefit from MPA as well. Regardless of the types of PA, leisure activities were strongly recommended, and young people were much more likely to benefit from exercise than older people.

Digital Health Behavioural Interventions to Support Physical Activity and Sedentary Behaviour in Adults after Stroke: A Systematic Literature Review with Meta-Analysis of Controlled Trials

Background: As the global prevalence of stroke continues to rise, it becomes increasingly pressing to investigate digital health behaviour change interventions that promote physical activity and reduce sedentary behaviour for stroke patients to support active lifestyles. Purpose: The primary aim of this study is to investigate the effectiveness of digital health interventions in promoting physical activity and reducing sedentary behaviour for stroke patients. The secondary aim is to investigate the intervention components that explain intervention effectiveness to further inform intervention development and policy making. Methods: A systematic search of the literature was conducted in four databases (Scopus, MEDLINE (PubMed), Web of Science, and PsychINFO) to identify the most robust evidence in the form of randomised controlled trials of digital interventions for patients with stroke. A random-effects meta-analysis were utilized to quantify the intervention effects on behaviour change, and subgroup analyses to characterise intervention effective components. Results: In total, 16 RCTs were deemed eligible and included in the systematic review. Meta-analyses suggested significant improvements in physical activity (SMD = 0.39, 95% CI 0.17, 0.61, N = 326, p < 0.001, I2 = 0%), and reductions in time of sedentary behaviour (SMD= −0.45, 95% CI −0.76, -0.14, N = 167, p = 0.00, I2 = 0%) after stroke. The 10 m walk test for physical activity, and the timed up and go test for sedentary behaviour, were the objective outcome measures in the most effective behavioural change interventions. Subgroup analyses found that most effective interventions were underpinned by theories of self-regulation and utilised interactive functions to engage patients with the processes of behaviour change. Conclusions: Digital self-monitoring behavioural interventions are effective in promoting physical activity for stroke patients in adjunct to usual care clinical practice and rehabilitation programmes. Rigorous studies are required to provide evidence to disentangle the most effective intervention components for preventative practices and rehabilitation programs and to inform policymaking for stroke treatment.

Physical Activity Knowledge, Attitude, and Behaviours Among Adolescents in the Kingdom of Saudi Arabia Prior to and during COVID-19 Restrictions

Background

The prevalence of childhood and adolescent obesity has increased dramatically and poses a major public health threat globally. In the Kingdom of Saudi Arabia (KSA), the main cause of adolescent obesity is an increase in physical inactivity and unhealthy eating habits due to lifestyle changes. This study reports on factors associated with physical activity (PA) prior to and during the coronavirus disease of 2019 (COVID-19) among middle school students in Jeddah, KSA.

Method

A cross-sectional online survey was conducted in Jeddah, KSA among 1500 middle school students aged 11 to 15 years. Sociodemographic characteristics; PA knowledge, attitude, and behaviours; and information about the impact of COVID-19 on PA were collected. Knowledge, attitude, and behaviours of PA before and during COVID-19 restrictions and between gender were compared. Regression analyses were conducted to assess the determinants of PA.

Results

Female students were significantly more likely to report better knowledge of PA compared to males (p < 0.001). However, males were significantly more likely to participate in PA compared to females (p < 0.001). Approximately 60% of students reported their PA decreased during COVID-19 isolations. Most students did not participate in the recommended levels of daily PA during COVID-19 lockdowns and school closures. After adjusting for demographics, knowledge, and attitude, students who did not usually participate in school sports (p=0.017) and as members of clubs (p=0.002) were less likely to be active during COVID-19 lockdown.

Conclusions

Efforts to enhance PA should be implemented through coordinated school and community-based programs to achieve the recommended PA among adolescents at home and in schools. Policy to ensure students receive PA opportunities at school is recommended.

Increased residual cardiovascular risk in patients with diabetes and high versus normal triglycerides despite statin-controlled LDL cholesterol

AIM

To determine whether high triglycerides (TG) in the presence of statin-controlled LDL-C influence the risk of cardiovascular disease (CVD) among patients with diabetes in real-world clinical practice.

MATERIALS AND METHODS

We identified adults with diabetes from the Southern California and Pacific Northwest regions of Kaiser Permanente. We included patients undergoing statin therapy with LDL-C from 40-100 mg/dL who were not undergoing other lipid-lowering therapies and had a prior diagnosis of atherosclerotic CVD or at least one other CVD risk factor. We grouped patients into high TG (200-499 mg/dL; n = 5542) or normal TG (<150 mg/dL, n = 22 411) from January 2010 through December 2016 to compare incidence rates and rate ratios of first non-fatal myocardial infarction (MI), non-fatal stroke, unstable angina and coronary revascularization. We adjusted multivariable analyses for age, sex, race/ethnicity, smoking status, blood pressure, HbA1c, serum creatinine, presence of ischaemic heart disease and study site.

RESULTS

Adjusted rate ratios for the four outcomes were all statistically significantly different. The incidence rate for non-fatal MI was 30% higher in the high TG group (rate ratio, 1.30; 95% CI, 1.08-1.58; P = 0.006). The rate was 23% higher for non-fatal stroke (1.23, 1.01-1.49, P = 0.037), 21% higher for coronary revascularization (rate ratio, 1.21; 95% CI, 1.02-1.43; P = 0.027) and was, non-significantly, 33% higher for unstable angina (rate ratio, 1.33; 95% CI, 0.87-2.03; P = 0.185).

CONCLUSIONS

Despite statin-controlled LDL-C levels, CV events were greater among patients with diabetes and high TG levels. Because we controlled for cardiometabolic risk factors, it is likely that the difference in TG levels contributed to the excess risk observed in patients with high TGs.

Occupational and leisure-time physical activity differentially predict 6-year incidence of stroke and transient ischemic attack in women

Objectives Recent meta-analyses suggest a physical activity health paradox: high levels of occupational physical activity (OPA) increase cardiovascular disease (CVD) risk, while leisure-time physical activity (LTPA) decreases risk. However, studies of women and cerebrovascular disease are limited. This report examines physical activity effects on stroke and transient ischemic attack (TIA) among working women in the United States. Methods OPA history, health status, and lifestyle were assessed by baseline interviews of 31 270 employed Sister Study participants aged 35-74 years. OPA was assessed at six intensity levels (lowest: "mostly sitting"); the highest three were combined as "high intensity work." Independent OPA and LTPA effects on 6-year cerebrovascular disease incidence were estimated in adjusted Cox proportional hazard models. Results Stroke (N=441) and TIA (N=274) risk increased with more standing and higher intensity work at current and longest held job. Compared with mostly sitting, high intensity work at the current job increased TIA risk by 57% [hazard ratio (HR) 1.57, 95% confidence interval (CI) 1.04-2.38]. High intensity OPA at the longest held job increased risk for stroke by 44% (HR 1.44; 95% CI 1.08-1.93). Among women with CVD, sitting and standing equally, especially at the current job, increased risks up to two-fold (TIA HR 1.98, 95% CI 1.10-3.55) compared with mostly sitting at work. LTPA showed inverse associations. Conclusions Higher intensity levels of OPA increased stroke and TIA risks, while LTPA decreased risks; results corroborate the physical activity health paradox for women and cerebrovascular disease. More standing at work increased cerebrovascular disease risks, especially for women with CVD.

Models and methods for conditioning the ischemic brain

BACKGROUND

In the last decades the need to find new neuroprotective targets has addressed the researchers to investigate the endogenous molecular mechanisms that brain activates when exposed to a conditioning stimulus. Indeed, conditioning is an adaptive biological process activated by those interventions able to confer resistance to a deleterious brain event through the exposure to a sub-threshold insult. Specifically, preconditioning and postconditioning are realized when the conditioning stimulus is applied before or after, respectively, the harmul ischemia.

AIMS AND RESULTS

The present review will describe the most common methods to induce brain conditioning, with particular regards to surgical, physical exercise, temperature-induced and pharmacological approaches. It has been well recognized that when the subliminal stimulus is delivered after the ischemic insult, the achieved neuroprotection is comparable to that observed in models of ischemic preconditioning. In addition, subjecting the brain to both preconditioning as well as postconditioning did not cause greater protection than each treatment alone.

CONCLUSIONS

The last decades have provided fascinating insights into the mechanisms and potential application of strategies to induce brain conditioning. Since the identification of intrinsic cell-survival pathways should provide more direct opportunities for translational neuroprotection trials, an accurate examination of the different models of preconditioning and postconditioning is mandatory before starting any new project.

Trajectories in Leisure-Time Physical Activity and Risk of Stroke in Women in the California Teachers Study

BACKGROUND AND PURPOSE

Whether changes in leisure-time physical activity (LTPA) over time are associated with lower risk of stroke is not well established. We examined the association between changes in self-reported LTPA 10 years apart, with risk of incident stroke in the CTS (California Teachers Study). We hypothesized that the risk of stroke would be lowest among those who remained active.

METHODS

Sixty-one thousand two hundred and fifty-six CTS participants reported LTPA at 2 intensity levels (moderate and strenuous activity) at 2 time points (baseline 1995-96; 10-year follow-up 2005-2006). LTPA at each intensity level was categorized based on American Heart Association (AHA) recommendations (moderate, >150 minutes/week; strenuous, >75 minutes/week). Changes in LTPA were summarized as follows: (1) not meeting recommendations at both time points; (2) meeting recommendations only at follow-up; (3) meeting recommendations only at baseline; and (4) meeting recommendations at both time points. Incident strokes were identified through California state hospitalization records. Using multivariable Cox models, we examined the associations between changes in LTPA with incident stroke.

RESULTS

Nine hundred and eighty-seven women were diagnosed with stroke who completed both questionnaires. Meeting AHA recommendations at both the time points was associated with a lower risk of all stroke (adjusted hazard ratio, 0.84; 95% confidence interval, 0.72-0.98). The protective effects for stroke were driven by meeting AHA recommendations for moderate activity and largely observed for ischemic strokes (adjusted hazard ratio, 0.70; 95% confidence interval, 0.55-0.88).

CONCLUSIONS

Meeting AHA recommendations for moderate activity had a protective effect for reducing ischemic stroke risk. Participants who met AHA recommendations at baseline but not at follow-up, however, were not afforded reduced stroke risk.

Physical Activity and Lifetime Risk of Cardiovascular Disease and Cancer

PURPOSE

Although the World Health Organization has recommended moderate- to vigorous-intensity physical activity (MVPA) to prevent cardiovascular disease (CVD) and some cancers, there are no estimates of lifetime risk of these noncommunicable diseases according to PA levels. We aimed to estimate the lifetime risk of CVD and cancers according to PA levels.

METHODS

We followed 5807 men and 7252 women in the United States, 45-64 yr old, initially free of CVD and cancer from 1987 through 2012, and used a life table approach to estimate lifetime risks of CVD (coronary heart disease, heart failure, and stroke) and total cancer according to PA levels: poor (0 min·wk of MVPA), intermediate (1-74 min·wk of VPA or 1-149 min·wk of MVPA), or recommended (≥75 min·wk of VPA or ≥150 min·wk of MVPA).

RESULTS

During the 246,886 person-years of follow-up, we documented 4065 CVD and 3509 cancer events and 2062 non-CVD and 2326 noncancer deaths. In men, the lifetime risks of CVD from 45 through 85 yr were 52.7% (95% confidence interval = 49.4-55.5) for poor PA and 45.7% (42.7-48.3) for recommended PA. In women, the respective lifetime risks of CVD were 42.4% (39.5-44.9) and 30.5% (27.5-33.1). Lifetime risks of total cancer were 40.1% (36.9-42.7) for poor PA and 42.6% (39.7-45.2) for recommended activity in men and 31.4% (28.7-33.8) and 30.4% (27.7-32.9), respectively, in women.

CONCLUSIONS

Compared with a poor PA level, the PA recommended by the World Health Organization was associated with lower lifetime risk of CVD, but not total cancer, in both men and women.

Accelerometer-Determined Physical Activity and All-Cause Mortality in a National Prospective Cohort Study of Adults Post-Acute Stroke

PURPOSE

No epidemiological study has examined the association of objectively measured physical activity with all-cause mortality among adults who have had a stroke, which was the purpose of this study.

DESIGN

Prospective.

SETTING

National Health and Nutrition Examination Survey 2003 to 2006.

PARTICIPANTS

One hundred eighty-four patients with stroke.

MEASURES

Physical activity assessed via accelerometry (ActiGraph 7164), with stroke assessed via self-report of physician diagnosis. Mortality was assessed via linkage with the National Death Index, with follow-up through 2011.

ANALYSIS

Cox proportional hazard model.

RESULTS

The median follow-up period was 71.96 months, with 13 241 person-months; 53 deaths occurred during this follow-up period. After adjustments, for every 60 min/d increase in total physical activity, adults who have had a stroke had a 28% (hazard ratio = 0.72; 95% confidence interval: 0.59-0.88) reduced risk of all-cause mortality.

CONCLUSION

Physical activity among stroke survivors is inversely associated with all-cause mortality.

The Impact of Physical Work Demands on Need for Recovery, Employment Status, Retirement Intentions, and Ability to Extend Working Careers: A Longitudinal Study Among Older Workers

OBJECTIVE

Prospectively investigating whether different approaches of physical work demands are associated with need for recovery (NFR), employment status, retirement intentions, and ability to prolong working life among older employees from the industry and health care sector.

METHODS

A subsample from the Maastricht Cohort Study was studied (n = 1126). Poisson, Cox, and logistic regression analyses were performed to investigate outcomes.

RESULTS

Perceiving physical work demands as strenuous was associated with higher NFR. Continuous physical strain was associated with being out of employment 4 years later. Employees with the highest amount of physical work demands perceived they were less able to prolong working life, although no significant associations between physical work demands and retirement intentions were found.

CONCLUSIONS

Overall, physical work demands were associated with adverse outcomes, with divergent insights for the different approaches of physical work demands.

Lifestyle Factors and Metabolic Syndrome among Workers: The Role of Interactions between Smoking and Alcohol to Nutrition and Exercise

This study aimed to investigate (1) relations of smoking and alcohol to metabolic syndrome (MetS) and its components, with nutrition and exercise controlled; and (2) interactions between smoking/alcohol and nutrition/exercise on MetS. This cross-sectional study enrolled 4025 workers. Self-reported lifestyles, anthropometric values, blood pressure (BP), and biochemical determinations were obtained. Among males, smoking significantly increased the risk of low high-density lipoprotein cholesterol (HDL-C), high triglyceride, abdominal obesity (AO), and MetS. Additionally, smoking showed significant interaction effects with nutrition on high BP, AO, and MetS; after further analysis, nutrition did not decrease above-mentioned risks for smokers. However, there was no significant interaction of smoking with exercise on any metabolic parameter. Alcohol increased the risk of AO, but decreased low HDL-C. It also showed an interaction effect with exercise on AO; after further analysis, exercise decreased AO risk for drinkers. Among females, alcohol significantly decreased the risk of high fasting blood glucose, but did not show significant interaction with nutrition/exercise on any metabolic parameter. In conclusion, in males, smoking retained significant associations with MetS and its components, even considering benefits of nutrition; exercise kept predominance on lipid parameters regardless of smoking status. Alcohol showed inconsistencies on metabolic parameters for both genders.

Physical exercise training and neurovascular unit in ischemic stroke

Physical exercise could exert a neuroprotective effect in both clinical studies and animal experiments. A series of related studies have indicated that physical exercise could reduce infarct volume, alleviate neurological deficits, decrease blood-brain barrier dysfunction, promote angiogenesis in cerebral vascular system and increase the survival rate after ischemic stroke. In this review, we summarized the protective effects of physical exercise on neurovascular unit (NVU), including neurons, astrocytes, pericytes and the extracellular matrix. Furthermore, it was demonstrated that exercise training could decrease the blood-brain barrier dysfunction and promote angiogenesis in cerebral vascular system. An awareness of the exercise intervention benefits pre- and post stroke may lead more stroke patients and people with high-risk factors to accept exercise therapy for the prevention and treatment of stroke.

Physical activity and cardiovascular disease in African Americans in Atherosclerosis Risk in Communities

PURPOSE

Although there is substantial evidence that physical activity reduces a person's risk of cardiovascular disease (CVD), few of these studies have included African Americans. The studies that have included African Americans offer inconclusive evidence on the association, and none studied heart failure separately. We used data from the Atherosclerosis Risk in Communities study cohort to examine, in African Americans, the association of physical activity with the incidence of CVD and its major components-stroke, heart failure, and CHD.

METHODS

Participants age 45-64 yr (3707 African Americans and, for comparison, 10,018 Caucasians) had physical activity assessed via questionnaire in 1987 and were followed for incident CVD (n = 1039) through 2008.

RESULTS

After adjustment for potential confounders, physical activity was inversely related to CVD, heart failure, and CHD incidence in both races (P values for trend <0.0001), and with stroke in African Americans. Hazard ratios (95% confidence intervals) for CVD for each higher physical activity category were similar by race: 1.0, 0.65 (0.56-0.75), and 0.59 (0.49-0.71) for African Americans and 1.0, 0.74 (0.66-0.83), and 0.67 (0.59-0.75) for Caucasians (P value for interaction = 0.38).

CONCLUSIONS

Our findings reinforce recommendations that regular physical activity is important for CVD risk reduction in African Americans as well as Caucasians and support the idea that some physical activity is better than none.

The association of plasma lactate with incident cardiovascular outcomes: the ARIC Study

We examined the association of plasma lactate at rest, a marker of oxidative capacity, with incident cardiovascular outcomes in 10,006 participants in the Atherosclerosis Risk in Communities (ARIC) Study visit 4 (1996-1998). We used Cox proportional-hazards models to estimate hazard ratios of incident coronary heart disease, stroke, heart failure, and all-cause mortality by quartiles of plasma lactate (Q1, ≤5.3 mg/dL; Q2, 5.4-6.6; Q3, 6.7-8.6; and Q4 ≥8.7). During a median follow-up time of 10.7 years, there were 1,105 coronary heart disease cases, 379 stroke cases, 820 heart failure cases, and 1,408 deaths. A significant graded relation between lactate level and cardiovascular events was observed in the demographically adjusted model (all P for trend < 0.001). After further adjustment for traditional and other potential confounders, the association remained significant for heart failure (Q4 vs. Q1: hazard ratio (HR) = 1.35, 95% confidence interval (CI): 1.07, 1.71) and all-cause mortality (HR = 1.27, 95% CI: 1.07, 1.51) (P for trend < 0.02 for these outcomes) but not for coronary heart disease (HR = 1.02, 95% CI: 0.84, 1.24) and stroke (HR = 1.26, 95% CI: 0.91, 1.75). The results for heart failure were robust across multiple subgroups, after further adjustment for N-terminal pro-B-type natriuretic peptide and after exclusion of participants with incident heart failure within 3 years. The independent associations of plasma lactate with heart failure and all-cause mortality suggest an important role for low resting oxidative capacity.

Neuroprotection against transient cerebral ischemia by exercise pre-conditioning in rats

There is increasing evidence that physical activity is associated with decreased stroke risk and incidence. The purpose of this study was to determine whether increased levels of physical activity could reduce brain damage in rats subjected to transient or permanent middle cerebral artery (MCA) occlusion. Adult male Sprague-Dawley rats (three months old, n=36) exercised on a treadmill, which required repetitive locomotor movement, for 30 min each day for three weeks. Then, using an intraluminal filament, stroke was induced by either 2-h MCA occlusion followed by two days of reperfusion or by MCA occlusion for two days without reperfusion. Brain damage was determined by evaluating neurologic deficits and brain infarction. In rat with transient MCA occlusion, pre-ischemic motor activity significantly (p<0.01) reduced neurologic deficits and infarct volume in the frontoparietal cortex and the dorsolateral striatum. In contrast, the same exercise procedure did not produce neuroprotection in the permanently MCA-occluded stroke. In addition to decreasing stroke risk and incidence, physical activity also reduces brain damage after stroke. Although we cannot completely rule out a neuroprotective effect on ischemic episode, our study suggests that a major neuroprotection is conferred during reperfusion for rats that have undergone exercise pre-conditioning. This exercise-induced endogenous neuroprotection may be an effective strategy to ameliorate ischemia/reperfusion brain injury from stroke.

Association of physical activity level and stroke outcomes in men and women: a meta-analysis

OBJECTIVE

The protective effect of physical activity (PA) on risk of stroke remains controversial as a result of lack of insight into the sources of heterogeneity between studies. We performed a comprehensive meta-analysis of studies to (1) quantify the association between PA level and risk of stroke outcomes and (2) test the hypothesis that the association of PA level with stroke outcomes will be similar between men and women. The outcome measures are stroke incidence, stroke mortality, or both.

METHODS

Cohort studies were identified by searching MEDLINE and EMBASE (from 1986 to 2005) and meta-analysis conducted according to meta-analysis of Observational Studies in Epidemiology (MOOSE) group recommendations. Data were reported as pooled relative risk (RR) and 95% confidence intervals (CI) using random-effects models to assess the association of stroke outcomes with PA level. Heterogeneity was investigated, and sensitivity analysis was performed. Stratified analysis by gender was performed.

RESULTS

Of 992 articles, 13 satisfied all eligibility criteria and were studied. Compared with low PA, moderate PA caused an 11% reduction in risk of stroke outcome (RR = 0.89, 95% CI 0.86-0.93, p < 0.01) and high PA a 19% reduction (RR = 0.81, CI 0.77-0.84, p < 0.01). Among the men, results showed a 12% reduction in risk associated with moderate PA (RR = 0.88, CI 0.82-0.94, p < 0.01) and 19% reduction for high PA (RR = 0.81, CI 0.75-0.87, p < 0.01). Among the women, results showed a 24% reduction in risk for high PA (RR = 0.76, CI 0.64-.89, p < 0.01). There was, however, no significant risk reduction associated with a moderate PA level in women.

CONCLUSIONS

Increased PA level appears beneficial in reduction of risk of stroke and related outcomes. However, higher levels of PA may be required in women to achieve as significant a risk reduction as in men. An exercise regimen tailored to women to improve related physiological mechanisms will likely be beneficial.

Physical activity in the prevention of ischemic stroke and improvement of outcomes: a narrative review

Physical activity is an integral component of stroke prevention. Although approximately 80% of strokes are due to cerebral ischemia, the mechanisms linking physical activity to the incidence of and recovery from ischemic stroke are not completely understood. This review summarizes evidence from human and animal studies regarding physical activity in the prevention of overt and covert ischemic stroke and associated injury. In cohort studies, people who are physically active have reduced rates of overt ischemic stroke and ischemic stroke mortality. However, few human studies have examined physical activity and the incidence of covert stroke. Evidence from animal models of ischemic stroke indicates that physical activity reduces injury after ischemic stroke by reducing infarct size and apoptotic cell death. Accordingly, physical activity may reduce the magnitude of injury from ischemic stroke so that there are fewer or less severe symptoms. Future research should investigate physical activity and incidence of covert stroke prospectively, ascertain the optimal dose and type of exercise to prevent ischemic injury, and identify the underlying neuroprotective mechanisms.

Association between physical activity and risk of stroke subtypes: the atherosclerosis risk in communities study

BACKGROUND

The relationship between stroke subtypes and physical activity is unclear.

METHODS

Using data from 13,069 men and women aged 45-64 years who participated in the Atherosclerosis Risk in Communities Study, physical activity was assessed by self-report using the Baecke questionnaire at baseline (1987-1989). The American Heart Association's ideal cardiovascular health guidelines served as a basis for the calculation of three physical activity categories: poor, intermediate, and ideal. Stroke and its subtypes were ascertained from physician review of medical records. Multivariable adjusted hazard ratios (HR) and 95% confidence intervals (CI) were calculated using Cox regression models.

RESULTS

During a median follow-up of 18.8 years, a total of 648 incident ischemic strokes occurred. Significant inverse associations were found between physical activity categories and total, total ischemic, and nonlacunar stroke in adjusted models (age, sex, race-center, education, cigarette-years). Compared with poor physical activity, the adjusted HR (95% CI) for ideal physical activity were 0.78 (0.62-0.97) for total, 0.76 (0.59-0.96) for total ischemic, 0.85 (0.51-1.40) for lacunar, 0.77 (0.47-1.27) for cardioembolic, and 0.71 (0.51-0.99) for nonlacunar stroke. Additional adjustments for waist-to-hip ratio, systolic blood pressure, antihypertensive medication, diabetes, left ventricular hypertrophy and laboratory parameters attenuated the HR. Further sex- and race-specific analyses revealed that the association was predominantly observed among males and among African-Americans.

CONCLUSION

These data suggest a tendency toward a reduced risk of total, total ischemic, and nonlacunar stroke with higher levels of physical activity.

Racial differences in association of elevated interleukin-18 levels with type 2 diabetes: the Atherosclerosis Risk in Communities study

OBJECTIVE

Elevated plasma interleukin-18 (IL-18) has been linked to onset of diabetes mellitus (DM) and its complications. However, so far this association has been shown only in predominantly white populations. We examined IL-18 levels and their association with incident DM in a racially heterogeneous population.

RESEARCH DESIGN AND METHODS

In a nested case-cohort design representing a 9-year follow-up of 9,740 middle-aged, initially healthy, nondiabetic white and African American participants of the Atherosclerosis Risk in Communities Study, we selected and measured analytes on race-stratified (50% white, 50% African American) random samples of both cases of incident diabetes (n = 548) and eligible members of the full cohort (n = 536). RESULTS Baseline IL-18 levels were significantly higher in white participants compared with African American participants (P < 0.001). Although white participants in the fourth (versus first) quartile of IL-18 levels had a significant hazard ratio (HR) for developing DM (HR: 2.1, 95% CI: 1.3-3.4), after adjustment for age, sex, and study center, no difference was seen among African Americans (HR: 1.0, 95% CI: 0.6-1.7). Unlike those in African Americans, IL-18 levels in whites had a significant correlation with age (P < 0.01); anthropometric characteristics such as waist circumference (P < 0.001), height (P = 0.04), waist-to-hip ratio (P < 0.001), and BMI (P < 0.01); and total (P < 0.001) and high-molecular-weight (P < 0.001) adiponectin.

CONCLUSIONS

There are racial differences in levels of IL-18 and the association of IL-18 with risk factors and incident type 2 DM. In addition, there seems to be a complex interplay of inflammation and adiposity in the development of DM.

Physical activity in the prevention and treatment of stroke

The role of physical activity in the prevention of stroke is of great interest due to the high mortality and significant impact of stroke-related morbidity on the individual and on healthcare resources. The use of physical activity as a therapeutic strategy to maximise functional recovery in the rehabilitation of stroke survivors has a growing evidence base. This narrative review examines the existing literature surrounding the use of exercise and physical therapy in the primary and secondary prevention of stroke. It explores the effect of gender, exercise intensities and the duration of observed benefit. It details the most recent evidence for physical activity in improving functional outcome in stroke patients. The review summaries the current guidelines and recommendations for exercise therapy and highlights areas in which further research and investigation would be useful to determine optimal exercise prescription for effective prevention and rehabilitation in stroke.

The effects of early exercise on brain damage and recovery after focal cerebral infarction in rats

Aim

Exercise can be used to enhance neuroplasticity and facilitate motor recovery after a stroke in rats. We investigated whether treadmill running could reduce brain damage and enhance the expression of midkine (MK) and nerve growth factor (NGF), increase angiogenesis and decrease the expression of caspase-3.

Methods

Seventy-seven Wistar rats were split into three experimental groups (ischaemia-control: 36, ischaemia-exercise: 36, sham-exercise: 5). Stroke was induced by 90-min left middle cerebral artery occlusion using an intraluminal filament. Beginning on the following day, the rats were made to run on a treadmill for 20 min once a day for a maximum of 28 consecutive days. Functional recovery after ischaemia was assessed using the beam-walking test and a neurological evaluation scale in all rats. Infarct volume, and the expression of MK, NGF, anti-platelet-endothelial cell adhesion molecule (PECAM-1), and caspase-3 were evaluated at 1, 3, 5, 7, 14 and 28 days after the induction of ischaemia.

Results

Over time motor coordination and neurological deficits improved more in the exercised group than in the non-exercised group. The infarct volume in the exercised group (12.4 ± 0.8%) subjected to treadmill running for 28 days was significantly decreased compared with that in the control group (19.8 ± 4.2%, P < 0.01). The cellular expression levels of MK, NGF and PECAM-1 were significantly increased while that of caspase-3 was decreased in the peri-infarct area of the exercised rats.

Conclusions

Our findings show that treadmill exercise improves motor behaviour and reduces neurological deficits and infarct volume, suggesting that it may aid recovery from central nervous system injury.

[Measure of fitness and physical activity related to cardiovascular diseases and death]

The quality of fitness (aerobic capacity, maximal endurance performance or highly related physiological parameters) or physical activity improving fitness show a tight, reverse correlation to the all-cause and to the cardiovascular mortality within. The most fit one third of the population expect a 30-40 percent smaller chance for cardiovascular events, compared to the less fit third quarter. Low fitness (that can be changed) is just as a threatening risk factor as the traditional ones, its detection calls out for simple interventions to improve fitness: proper physical exercise.

Health-related quality of life by the type of physical activity in Korea

This study examined if health-related quality of life is different based upon the type of physical activity performed by 1,266 community-dwelling adults in urban area of Korea. Physical activity was categorized into (a) work, (b) leisure (non-sport), and (c) sports activity. The results indicated that only leisure and sports activity were positively correlated with health-related quality of life. Therefore, it is recommended that leisure and sports activity must be encouraged, especially to people who do not think that they need any leisure or sports activity because they are very active physically at work.

The effects of early exercise on brain damage and recovery after focal cerebral infarction in rats

AIM

Exercise can be used to enhance neuroplasticity and facilitate motor recovery after a stroke in rats. We investigated whether treadmill running could reduce brain damage and enhance the expression of midkine (MK) and nerve growth factor (NGF), increase angiogenesis and decrease the expression of caspase-3.

METHODS

Seventy-seven Wistar rats were split into three experimental groups (ischaemia-control: 36, ischaemia-exercise: 36, sham-exercise: 5). Stroke was induced by 90-min left middle cerebral artery occlusion using an intraluminal filament. Beginning on the following day, the rats were made to run on a treadmill for 20 min once a day for a maximum of 28 consecutive days. Functional recovery after ischaemia was assessed using the beamwalking test and a neurological evaluation scale in all rats. Infarct volume, and the expression of MK, NGF, anti-platelet-endothelial cell adhesion molecule (PECAM-1), and caspase-3 were evaluated at 1, 3, 5, 7, 14 and 28 days after the induction of ischaemia.

RESULTS

Over time motor coordination and neurological deficits improved more in the exercised group than in the non-exercised group. The infarct volume in the exercised group (12.4 ± 0.8%) subjected to treadmill running for 28 days was significantly decreased compared with that in the control group (19.8 ± 4.2%, P < 0.01). The cellular expression levels of MK, NGF and PECAM-1 were significantly increased while that of caspase-3 was decreased in the peri-infarct area of the exercised rats.

CONCLUSIONS

Our findings show that treadmill exercise improves motor behaviour and reduces neurological deficits and infarct volume, suggesting that it may aid recovery from central nervous system injury.

Exercise preconditioning and brain ischemic tolerance

It is well established that physical exercise can exert neuroprotection both in clinical settings and animal experiments. A series of studies have demonstrated that physical exercise may be a promising preconditioning method to induce brain ischemic tolerance through the promotion of angiogenesis, mediation of the inflammatory response, inhibition of glutamate over-activation, protection of the blood brain barrier (BBB) and inhibition of apoptosis. Through these mechanisms, exercise preconditioning may reduce the neural deficits associated with ischemia and the development of brain infarction and thus provide brain ischemic tolerance. An awareness of the benefits of exercise preconditioning may lead more patients to accept exercise therapy in cases of ischemic stroke.

Association between physical activity and retinal microvascular signs: the Atherosclerosis Risk in Communities (ARIC) Study

OBJECTIVE

To examine the association between physical activity measured during leisure, sport, and work and retinal microvascular signs.

METHODS

Participants of the Atherosclerosis Risk in Communities (ARIC) Study, a population-based cross-sectional study, had retinal photographs taken at their third follow up visit (1993-1995). Retinal microvascular signs were assessed using a standardized protocol and retinal vascular caliber by a computer-assisted method. Leisure, sport, and work-related physical activity levels were determined through a modified Baecke physical activity questionnaire.

RESULTS

A higher level of physical activity during sport and work was significantly associated with a lower prevalence of arteriovenous (AV) nicking, wider venular caliber, and retinopathy. In multivariate models, persons with a level of sport-related physical activity above the median were less likely to have AV nicking (odds ratio [OR] = 0.87; 95% confidence interval [CI] 0.78-0.97) and wider retinal venules (OR = 0.91; 95% CI: 0.83-0.99). Persons with a level of work-related physical activity above the median were less likely to have diabetic retinopathy (OR = 0.66, 95% CI: 0.51-0.85).

CONCLUSIONS

In this cross-sectional analyzes, higher levels of physical activity was associated with a lower prevalence of retinal microvascular abnormalities.

Physical activity and risk of stroke in women

BACKGROUND AND PURPOSE

Physical activity has generally been inversely related to the risk of developing stroke, but details regarding the amount and kinds of activity required are unclear as are associations for specific stroke subtypes.

METHODS

Eligible subjects were 39 315 healthy US women, > or =45 years of age, from the Women's Health Study. Women reported physical activity at baseline (1992 to 1995) and at 36, 72, 96, 125, and 149 months' follow-up. During an average follow-up of 11.9 years, 579 women developed incident stroke (473 ischemic, 102 hemorrhagic, and 4 of unknown type). Proportional hazards models related physical activity, updated over time, to the risk of incident stroke.

RESULTS

The multivariable relative risks associated with <200, 200 to 599, 600 to 1499, and > or =1500 kcal/week of leisure-time physical activity were 1.00 (referent), 1.11 (95% CI, 0.87 to 1.41), 0.86 (95% CI, 0.67 to 1.10), and 0.83 (95% CI, 0.63 to 1.08), respectively (P trend=0.06). Similar results were observed for ischemic stroke, whereas no associations were observed for hemorrhagic stroke. Vigorous physical activity was not related to stroke risk (P trend=0.50); however, walking time and walking pace were inversely related, either significantly or with borderline significance, to total, ischemic, and hemorrhagic stroke risks (P trend between 0.002 and 0.07).

CONCLUSIONS

This study shows a tendency for leisure-time physical activity to be associated with lower stroke risk in women. In particular, walking was generally associated with lower risks of total, ischemic, and hemorrhagic stroke.

A systematic review of the evidence for Canada's Physical Activity Guidelines for Adults

This systematic review examines critically the scientific basis for Canada's Physical Activity Guide for Healthy Active Living for adults. Particular reference is given to the dose-response relationship between physical activity and premature all-cause mortality and seven chronic diseases (cardiovascular disease, stroke, hypertension, colon cancer, breast cancer, type 2 diabetes (diabetes mellitus) and osteoporosis). The strength of the relationship between physical activity and specific health outcomes is evaluated critically. Literature was obtained through searching electronic databases (e.g., MEDLINE, EMBASE), cross-referencing, and through the authors' knowledge of the area. For inclusion in our systematic review articles must have at least 3 levels of physical activity and the concomitant risk for each chronic disease. The quality of included studies was appraised using a modified Downs and Black tool. Through this search we identified a total of 254 articles that met the eligibility criteria related to premature all-cause mortality (N = 70), cardiovascular disease (N = 49), stroke (N = 25), hypertension (N = 12), colon cancer (N = 33), breast cancer (N = 43), type 2 diabetes (N = 20), and osteoporosis (N = 2). Overall, the current literature supports clearly the dose-response relationship between physical activity and the seven chronic conditions identified. Moreover, higher levels of physical activity reduce the risk for premature all-cause mortality. The current Canadian guidelines appear to be appropriate to reduce the risk for the seven chronic conditions identified above and all-cause mortality.

Does depression predict coronary heart disease and cerebrovascular disease equally well? The Health and Social Support Prospective Cohort Study

BACKGROUND

The relationship between depression and cerebrovascular disease (CBVD) continues to be debated although little research has compared the predictive power of depression for coronary heart disease (CHD) with that for CBVD within the same population. This study aimed to compare the importance of depression for CHD and CBVD within the same population of adults free of apparent cardiovascular disease.

METHODS

A random sample of 23,282 adults (9507 men, 13,775 women) aged 20-54 years were followed up for 7 years. Fatal and first non-fatal CHD and CBVD events were documented by linkage to the National-hospital-discharge and mortality registers.

RESULTS

Sex-age-education-adjusted hazard ratio (HR) for CHD was 1.66 [95% confidence interval (CI) 1.24-2.24] for participants with mild to severe depressive symptoms, i.e. those scoring > or =10 on the 21-item Beck Depression Inventory, and 2.04 (1.27-3.27) for those who filled antidepressant prescriptions compared with those without depression markers in 1998, i.e. at study baseline. For CBVD, the corresponding HRs were 1.01 (0.67-1.53) and 1.77 (0.95-3.29). After adjustment for behavioural and biological risk factors these associations were reduced but remained evident for CHD, the adjusted HRs being 1.47 (1.08-1.99) and 1.72 (1.06-2.77). For CBVD, the corresponding multivariable adjusted HRs were 0.87 (0.57-1.32) and 1.52 (0.81-2.84).

CONCLUSIONS

Self-reported depression using a standardized questionnaire and clinical markers of mild to severe depression were associated with an increased risk for CHD. There was no clear evidence that depression is a risk factor for CBVD, but this needs further confirmation.

Physical activity and cardiovascular disease in Japan: the Jichi Medical School Cohort Study

Background

Many studies have reported an association between physical activity and cardiovascular disease (CVD); however, the effect of physical activity remains controversial. Few such studies have been conducted in Japan. Therefore, we examined the relationship between physical activity and death from CVD using prospective data from a Japanese population.

Methods

From a prospective cohort study that comprised 12 490 participants, data from 9810 were analyzed. From April 1992 through July 1995, a baseline survey was conducted in 12 communities in Japan. The participants were followed up until December 2005. Physical activity was assessed using the physical activity index (PAI). PAI scores were grouped in quartiles: Q1 was the lowest PAI quartile and Q4 was the highest. Hazard ratios (HRs) for death from CVD, stroke, and myocardial infarction (MI) were calculated for all PAI quartiles.

Results

The mean follow-up period was 11.9 years, during which time 194 participants died of CVD. With Q1 as the reference, the HRs for death from CVD in Q2, Q3, and Q4, were 0.62 (95% confidence interval, 0.40–0.98), 0.53 (0.31–0.88), and 0.40 (0.22–0.73), respectively, in men, and 0.71 (0.38–1.32), 0.52 (0.26–1.04), and 0.48 (0.22–1.05), respectively, in women. The HRs for death from CVD subtypes were similar but not statistically significant.

Conclusions

Among a Japanese population, physical activity was associated with a decreased risk of death from CVD. However, more evidence is needed to elucidate the relationships between physical activity and CVD subtypes.

Physical activity and risk of ischemic stroke in the Northern Manhattan Study

BACKGROUND

It is controversial whether physical activity is protective against first stroke among older persons. We sought to examine whether physical activity, as measured by intensity of exercise and energy expended, is protective against ischemic stroke.

METHODS

The Northern Manhattan Study is a prospective cohort study in older, urban-dwelling, multiethnic, stroke-free individuals. Baseline measures of leisure-time physical activity were collected via in-person questionnaires. Cox proportional hazards models were constructed to examine whether energy expended and intensity of physical activity were associated with the risk of incident ischemic stroke.

RESULTS

Physical inactivity was present in 40.5% of the cohort. Over a median follow-up of 9.1 years, there were 238 incident ischemic strokes. Moderate- to heavy-intensity physical activity was associated with a lower risk of ischemic stroke (adjusted hazard ratio [HR] 0.65, 95% confidence interval [0.44-0.98]). Engaging in any physical activity vs none (adjusted HR 1.16, 95% CI 0.88-1.51) and energy expended in kcal/wk (adjusted HR per 500-unit increase 1.01, 95% CI 0.99-1.03) were not associated with ischemic stroke risk. There was an interaction of sex with intensity of physical activity (p = 0.04), such that moderate to heavy activity was protective against ischemic stroke in men (adjusted HR 0.37, 95% CI 0.18-0.78), but not in women (adjusted HR 0.92, 95% CI 0.57-1.50).

CONCLUSIONS

Moderate- to heavy-intensity physical activity, but not energy expended, is protective against risk of ischemic stroke independent of other stroke risk factors in men in our cohort. Engaging in moderate to heavy physical activities may be an important component of primary prevention strategies aimed at reducing stroke risk.

Exercise as stroke prophylaxis

BACKGROUND

Stroke is the third most common cause of death in industrialized countries, accounting for more than 10% of deaths over age 65. Most strokes are due to arteriosclerosis. Regular physical activity lowers arterial blood pressure and body weight and improves glucose and lipid metabolism, thereby slowing the development of arteriosclerosis and its cardiovascular complications, particularly myocardial infarction. This review focuses on the question whether physical activity might also have a preventive effect on cerebral infarction and hemorrhage.

METHODS

This analysis is based on 33 prospective cohort studies and 10 case-control studies that addressed the potential effect of physical activity on stroke-related morbidity and mortality.

RESULTS

Our meta-analysis shows that physical activity reduces the risk of all types of stroke (infarction, hemorrhage, and stroke of unspecified type). The relative risk (RR) of fatal or non-fatal cerebral infarction is 0.75, while the corresponding figures for cerebral hemorrhage and stroke of unspecified type are 0.67 and 0.71, respectively. The reduction of risk is only statistically significant for men. The case-control studies show an RR of 0.32 for men and women combined.

CONCLUSIONS

When a multivariate analysis is performed that takes other vascular risk factors into account, physical activity is found to have an independent protective effect against cerebrovascular events. The effect is statistically significant only for men, not for women.

Physical activity and subclinical MRI cerebral infarcts: the ARIC Study

BACKGROUND

We hypothesized that physical activity (PA), which is often associated with reduced risk of ischemic stroke, may also be associated with reduced risk of subclinical cerebral infarcts.

OBJECTIVES

We studied the cross-sectional association between PA and subclinical cerebral infarcts among African-Americans in the Atherosclerosis Risk in Communities (ARIC) Study.

METHODS

PA self-reported at baseline and images from cerebral MRI examination obtained 6 years later were evaluated for presence and location of subclinical infarcts > or = 3 mm in size. After exclusions, 944 participants were eligible for study.

RESULTS

The results suggested an inverse relationship between odds of having a subclinical cerebral infarct and level of PA on several measures, although the multivariable adjusted odds ratios (OR) were statistically significant only for the sport score. A 1-unit increase in the sport score, indicating more leisure PA, was associated with an adjusted OR for having a subclinical cerebral infarct of 0.62 (0.44-0.87), with a statistically significant monotonic trend across quartiles of the score (P = 0.01). There was no association of work scores with subclinical infarcts.

CONCLUSIONS

In African-Americans, sport PA was inversely related to subclinical MRI-detected cerebral infarcts assessed six years later.

Occupation as socioeconomic status or environmental exposure? A survey of practice among population-based cardiovascular studies in the United States

Decisions about how occupation is used in epidemiologic research can affect conclusions about the importance of socioeconomic and environmental factors in explaining disparities for outcomes such as cardiovascular disease. A review of practices in the collection and use of occupational data was conducted among population-based cardiovascular studies in the United States. Studies were identified for review from the National Heart, Lung, and Blood Institute website and the biomedical database, Computer Retrieval of Information on Scientific Projects, by use of selected criteria. Data collection instruments and study publications were retrieved and reviewed for 30 of 33 studies (91%). Most of the studies (83%) collected at least descriptive occupational data, and more than half (60%) collected data on workplace hazards. The reviewed studies produced 80 publications in which occupational data were used in analyses, most often as an indicator of socioeconomic status. Authors rarely acknowledged known conceptual and empirical links among socioeconomic status, employment stability, and working conditions. Underutilization of data on workplace conditions was found. Existing data could be used more effectively to examine the contribution of work-related social and environmental conditions to the development of modifiable cardiovascular disease through multiple pathways.

Walking for prevention of cardiovascular disease in men and women: a systematic review of observational studies

In this systematic review, walking (a generally accessible activity for a largely sedentary population) was assessed as a preventive risk factor for development of fatal and non-fatal cardiovascular disease (CVD). PubMed, CINHAL and reference list searches identified 21 peer-reviewed publications examining walking in relation to CVD; studies assessing active transportation were excluded. Generally, there were dose-dependent reductions in CVD risk with higher walking duration, distance, energy expenditure and pace. Associations appeared to be stronger for ischaemic stroke than other CVD outcomes such as coronary heart disease or haemorrhagic stroke. Adjustment for clinical CVD risk factors, obesity or other types of physical activity generally attenuated but did not eliminate associations. Because functional status may be an important determinant of walking behaviour in adults, potential bias due to pre-existing illness is of concern in all studies reviewed, particularly in case-control studies which ascertain walking retrospectively and yielded the strongest associations. Study findings were consistent with current physical activity recommendations, but there is a need for improvements in measurement of walking and other CVD risk factors, more thorough control for pre-existing illness, examination of mediating or moderating conditions such as obesity and other analytical issues.

Television, physical activity, diet, and body weight status: the ARIC cohort

Background

Television (TV) watching is the most common leisure activity in the United States. Few studies of adults have described the relationship between TV and health behaviors such as physical activity, diet, and body weight status.

Methods

Extant data from the Atherosclerosis Risk in Communities (ARIC) Study were analyzed to assess the association of TV with physical activity, diet, and body mass index (BMI) among 15,574 adults at baseline (1986–89) and 12,678 adults six years later. Television, physical activity, and diet were collected with questionnaires and BMI was measured at both time points. Based on baseline TV exposure, adults were categorized into high, medium, and low TV exposure. Linear and logistic regression models were adjusted for gender, age, race-center, smoking, education, and general health.

Results

Relative to participants who had low TV exposure, those with high TV exposure were more likely to be less physically active and have a poorer dietary profile at baseline and six-years later. Participants with high TV exposure at baseline had a 40% and 31% greater odds of being considered insufficiently active at baseline (1.40, 95% CI 1.26, 1.55), and six years later (1.31, 95% CI 1.18, 1.46). At baseline, high TV exposure was also associated with a 20% to 30% greater odds of being above the median for servings of salty snacks (1.37, 95% CI 1.24, 1.51), sweets (1.26, 95% CI 1.15, 1.38), and sweetened drinks (1.29, 95% CI 1.17, 1.42), and below the median for fruit and vegetable servings (1.36, 95% CI 1.24, 1.50). Higher TV exposure was also cross-sectionally associated with a greater odds for being overweight or obese (1.43, 95% CI 1.29, 1.58). Similar associations were observed between baseline TV exposure and six-year physical activity and diet, but were not observed with BMI after six years follow-up.

Conclusion

These results support the hypothesis that time spent watching TV is associated with deleterious effects on physical activity, diet, and BMI.

Older adults, chronic disease and leisure-time physical activity

BACKGROUND

Participating in regular physical activity is an important part of healthy aging. There is an increased risk for inactivity associated with aging and the risk becomes greater for adults who have a chronic disease. However, there is limited information on current physical activity levels for older adults and even less for those with chronic diseases.

OBJECTIVE

Our primary objective was to determine the proportion of older adults who achieved a recommended amount of weekly physical activity (>or=1,000 kcal/week). The secondary objectives were to identify variables associated with meeting guideline leisure-time physical activity (LTPA), and to describe the type of physical activities that respondents reported across different chronic diseases.

METHODS

In this study we used the Canadian Community Health Survey Cycle 1.1 (2000/2001) to report LTPA for adults aged 65 years and older. This was a population-based self-report telephone survey. We used univariate logistic regression to provide odds ratios to determine differences in activity and the likelihood of meeting guideline recommendations.

RESULTS

For adults over 65 years of age with no chronic diseases, 30% reported meeting guideline LTPA, while only 23% met the recommendations if they had one or more chronic diseases. Factors associated with achieving the guideline amount of physical activity included a higher level of education, higher income and moderate alcohol consumption. Likelihood for not achieving the recommended level of LTPA included low BMI, pain and the presence of mobility and dexterity problems. Walking, gardening and home exercises were the three most frequent types of reported physical activities.

CONCLUSION

This study provides the most recent evidence to suggest that older Canadians are not active enough and this is accentuated if a chronic disease is present. It is important to develop community-based programs to facilitate LTPA, in particular for older people with a chronic disease.

Physical activity and Alzheimer's disease: from prevention to therapeutic perspectives

A number of factors, including physical activity, may contribute to prevention of cognitive decline and delay the onset of dementia. In addition to its convincing multiple benefits, an increasing body of evidence suggests that an active life has a protective effect on brain functioning in elders. Physical activity may also slow down the course of Alzheimer's disease. These hypotheses have led to increasing research in this specific area during the past decade. This review systematically analyzes the current literature on Alzheimer's disease and the effect of physical activity. Epidemiological studies, short-term randomized controlled trials (RCTs) in nondemented participants, and biological research suggest that physical activity improves cognitive function in older subjects. The limitations of these works are discussed. No RCTs have yet demonstrated that regular physical activity prevents dementia. Additional challenging clinical interventional studies are needed to demonstrate this relationship, but accumulating evidence from biological research is available. Defining the optimal preventive and therapeutic strategies in terms of type, duration, and intensity of physical activity remain an open question. In the future, the prevention of Alzheimer's disease may be based on rules governing lifestyle habits such as diet, cognitive activity, and physical activity.

TCF7L2 single nucleotide polymorphisms, cardiovascular disease and all-cause mortality: the Atherosclerosis Risk in Communities (ARIC) study

AIMS/HYPOTHESIS

We hypothesised that TCF7L2 single nucleotide polymorphisms (SNPs) are associated with cardiovascular disease (CVD) and that the associations differ in diabetic and non-diabetic persons.

METHODS

Our analysis included black and white participants from the Atherosclerosis Risk in Communities study who were free of prevalent CVD at baseline and had been genotyped for rs7903146, rs12255372, rs7901695, rs11196205 and rs7895340 (n=13,369). Cox proportional hazard regression was used to estimate the associations between polymorphisms and incident events; logistic and linear regression were used for associations with baseline risk factor levels.

RESULTS

TCF7L2 SNPs were not significantly associated with incident coronary heart disease, ischaemic stroke, CVD, prevalent peripheral artery disease (PAD) or all-cause mortality in the full cohort or when stratified by race.

CONCLUSIONS/INTERPRETATION

In the whole cohort, TCF7L2 SNPs were not associated with incident CVD, all-cause mortality or prevalent PAD. This result suggests that the increased health risk associated with rs7903146 genotype is specific to diabetes.

B-mode ultrasound common carotid artery intima-media thickness and external diameter: cross-sectional and longitudinal associations with carotid atherosclerosis in a large population sample

Background

Arterial diameter and intima-media thickness (IMT) enlargement may each be related to the atherosclerotic process. Their separate or combined enlargement may indicate different arterial phenotypes with different atherosclerosis risk.

Methods

We investigated cross-sectional (baseline 1987–89: n = 7956) and prospective (median follow-up = 5.9 years: n = 4845) associations between baseline right common carotid artery (RCCA) external diameter and IMT with existing and incident carotid atherosclerotic lesions detected by B-mode ultrasound in any right or left carotid segments. Logistic regression models (unadjusted, adjusted for IMT, or adjusted for IMT and risk factors) were used to relate baseline diameter to existing carotid lesions while comparably adjusted parametric survival models assessed baseline diameter associations with carotid atherosclerosis progression (incident carotid lesions). Four baseline arterial phenotypes were categorized as having 1) neither IMT nor diameter enlarged (reference), 2) isolated IMT thickening, 3) isolated diameter enlargement, and 4) enlargement of both IMT and diameter. The association between these phenotypes and progression to definitive carotid atherosclerotic lesions was assessed over the follow-up period.

Results

Each standard deviation increment of baseline RCCA diameter was associated with increasing carotid lesion prevalence (unadjusted odds ratio [OR] = 1.54, 95% confidence interval [CI] = 1.47–1.62) and with progression of carotid atherosclerosis (unadjusted hazards ratio (HR) = 1.37, 95% CI = 1.28–1.46); and the associations remained significant even after adjustment for IMT and risk factors (prevalence OR = 1.11, 95% CI = 1.04–1.18; progression HR = 1.11, 95% CI = 1.03–1.19). Controlling for gender, age and race, persons with both RCCA IMT and diameter in the upper 50^th percentiles had the greatest risk of progressing to clearly defined carotid atherosclerotic lesions (all HR = 1.71, 95% CI = 1.47–2.0; men HR = 1.88, 95% CI = 1.48–2.39; women HR = 1.59, 95% CI = 1.31–1.95) while RCCA IMT or diameter alone in the upper 50^th percentile produced significantly lower estimated risks.

Conclusion

RCCA IMT and external diameter provide partially overlapping information relating to carotid atherosclerotic lesions. More importantly, the RCCA phenotype of coexistent wall thickening with external diameter enlargement indicates higher atherosclerotic risk than isolated wall thickening or diameter enlargement.