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Section 2.1

Lifestyle And Risk Factor Management

Persons at risk of stroke and patients who have had a stroke should be assessed for vascular disease risk factors and lifestyle management issues (diet, sodium intake, exercise, weight, smoking and alcohol intake). They should receive information and counseling about possible strategies to modify their lifestyle and risk factors [Evidence Level B].

Lifestyle and risk factor interventions should include:

2.1.1 Healthy balanced diet: Eating a diet high in fresh fruits, vegetables, low-fat dairy products, dietary and soluble fibre, whole grains and protein from plant sources and low in saturated fat, cholesterol and sodium, in accordance with Canada’s Food Guide to Healthy Eating [Evidence Level B].

2.1.2 Sodium: Following the recommended daily sodium intake from all sources, known as the Adequate Intake. For persons 9 to 50 years, the Adequate Intake is 1500 mg. Adequate Intake decreases to 1300 mg for persons 50 to 70 years and to 1200 mg for persons over 70 years. A daily upper consumption limit of 2300 mg should not be exceeded by any age group [Evidence Level B].78

2.1.3 Exercise: Participating in moderate exercise (an accumulation of 30 to 60 minutes) such as walking (ideally brisk walking), jogging, cycling, swimming or other dynamic exercise four to seven days each week in addition to routine activities of daily living. High-risk patients (e.g., those with cardiac disease) should engage in medically supervised exercise programs [Evidence Level A].

2.1.4 Weight: Maintaining a body mass index (BMI) of 18.5 to 24.9 kg/m2 or a waist circumference of <80 centimetres for women and <94 centimetres for men [Evidence Level B].49

2.1.5 Smoking: Addressing smoking cessation and a smoke-free environment every healthcare encounter for active smokers.48

  1. In all healthcare settings along the stroke continuum, patient smoking status should be assessed and documented [Evidence Level A].
  2. Provide unambiguous, non-judgmental, and personally relevant advice regarding the importance of cessation to all smokers, and offer assistance with the initiation of a smoking cessation attempt–either directly or through referral to appropriate resources [Evidence Level A].
  3. A combination of pharmacological therapy and behavioural therapy should be considered [Evidence Level A].
  4. The three classes of pharmacological agents that should be considered as first-line therapy for smoking cessation are nicotine replacement therapy, bupropion, and varenicline [Evidence Level A].

2.1.6 Alcohol consumption: Limiting consumption to two or fewer standard drinks per day; fewer than 14 drinks per week for men; and fewer than nine drinks per week for women [Evidence Level C].

    Rationale

    A healthy lifestyle reduces the risk of an initial stroke and the risk of a subsequent stroke for patients with a prior stroke. Hypertension is the single most important modifiable risk factor for stroke. A recent research report estimated that reducing sodium in foods would abolish high blood pressure for almost one in three Canadians. Furthermore, this evidence suggests that lowering sodium consumption to adequate intake levels could reduce the incidence of stroke and heart disease by as much as 30 percent. Regular exercise also reduces the risk of stroke.

    Smoking is also a significant risk factor, as smokers have up to four times the risk of stroke of nonsmokers.

    Although causes of stroke are generally different for children, lifestyle management issues as described above are equally as important for the paediatric population, particularly as the long-term risk of recurrence for children is much higher.

    System Implications
    • Health promotion efforts that contribute to the prevention of stroke in all communities (integrated with existing chronic disease prevention initiatives).
    • Stroke prevention offered by primary care providers, and mechanisms to ensure that stroke is addressed during encounters with healthcare professionals throughout the continuum of care.
    • A focus on arterial health for paediatric cases–such as diet, exercise, non-smoking, avoidance of drugs.
    • National and international efforts to reduce sodium intake and increase public knowledge about the risks of sodium, directly targeting the food industry.
    • Access to risk factor management programs (such as hypertension and smoking cessation programs) in all communities, primary healthcare settings and workplaces.
    • Government actions to restrict smoking in public areas and discourage smoking through legislation and taxation initiatives.
    • Coordinated efforts among stakeholders such as Heart and Stroke Foundations (national and provincial), the Canadian Stroke Network, public health agencies, ministries of health and care providers across the continuum to produce patient, family and caregiver education materials with consistent information and messages on risk factor management.
    • Coordinated process for ensuring access to and awareness of educational materials, programs, activities and other media related to risk factor management by healthcare professionals, patients and caregivers, including advertising the availability of educational material, effective dissemination mechanisms and follow-up.
    • Educational resources, that are culturally and ethnically appropriate, are available in multiple languages and that address the needs of patients with aphasia.
    • Access to healthy living programs, educational materials and healthcare professionals for persons living in rural and remote locations.
    Performance Measures
    1. Proportion of the population with major risk factors for stroke, including hypertension, obesity, history of smoking, low physical activity, hyperlipidemia, diabetes, and atrial fibrillation (core).
    2. Annual occurrence of stroke in each province and territory by stroke type (core).
    3. Stroke mortality rates across provinces and territories, including in-hospital or 30-day rate and one-year rate (core).
    4. Percentage of the population who can identify the major risk factors for stroke, including hypertension, sodium intake, diet, weight, exercise, smoking and alcohol intake.
    5. Percentage of people who are aware of the healthy targets for each stroke risk factor.
    6. The annual readmission rate for a recurrent stroke event in patients with previous stroke or transient ischemic attack.

    Measurement notes

    • For performance measures 1, 2 and 3: self-reported data can be extracted from provincial and national health surveys.
    • Performance measures 4 and 5: administrative data are available at the local, provincial and national levels.
    • Mortality rates need to be risk adjusted for age, sex, stroke severity and comorbidities.
    Implementation Resources and Knowledge Transfer Tools
    Summary of the Evidence

    Diet and sodium

    Gillman and associates79 reported that, based on data collected as part of the Framingham Study, age-adjusted risk for stroke decreased as consumption of fruits and vegetables increased such that relative risk (RR) = 0.78 for each increase of three servings per day. This effect was independent of BMI, smoking, glucose intolerance, physical activity, blood pressure, serum cholesterol and intake of energy, ethanol and fat. A meta-analysis of fruit and vegetable consumption and stroke, which included eight studies and 257,551 individuals over a 13-year follow- up period, showed that consumption of five or more servings of fruits and vegetables per day is associated with a lower risk of stroke.80 Compared with individuals who had fewer than three servings of fruit and vegetables per day, the pooled relative risk of stroke was 0.89 (95% confidence interval [CI] 0.83–0.97) for those with three to five servings per day, and 0.74 (95% CI 0.69–0.79) for those with more than five servings per day.80

    Analyses of data from the Nurses’ Health Study, the Health Professionals Follow-up Study and the Women’s Health Study supported the association between consumption of fruit and vegetables and reduction of stroke risk in men and women.81,82 In an analysis of combined data from the Nurses’ Health Study and the Health Professionals Follow-up Study, Joshipura and associates found that an increase of 1 serving per day of fruits or vegetables was associated with a reduction of risk of six percent and that cruciferous vegetables, leafy green vegetables and citrus fruit (including juice) contributed most to this effect.81 Liu and colleagues reported a significant inverse relationship between consumption of fruits and vegetables and risk for cardiovascular disease including stroke.82 When individuals consuming the most fruits and vegetables were compared with those consuming the least, a relative risk reduction of 0.68 was demonstrated in favour of those with higher consumption levels.82

    Blood Pressure Canada has asserted that the average Canadian diet contains about 3500 mg of sodium a day, with an estimated 1 million Canadians experiencing hypertension due to excess intake of sodium.78 Blood Pressure Canada has released the following policy goal addressing a daily sodium intake conducive to health: “Given that the Institute of Medicine of the National Academies has established a daily Adequate Intake for sodium of 1200 mg and a daily Tolerable Upper Intake Level of 2300 mg for healthy adults, and that these values have been adopted by the Canadian and American governments for setting public health policy, the goal is to have Canadian adults reduce their sodium intake to within this range.”78

    Physical activity

    Lee and collaborators published a meta-analysis of 23 studies published between 1983 and 2002 examining the association between physical activity and stroke incidence or mortality.83 Eighteen cohort studies and 5 case–control studies were included for analysis. When both types of study were examined together, highly active individuals were reported as having a 27 percent lower risk of stroke than individuals who were

    designated as “low active.” Individuals who were designated as moderately active also had a significantly reduced risk of stroke when compared with low active individuals (RR = 0.80, p < 0.001). The benefits of high and moderate levels of activity were reported for both ischemic and hemorrhagic strokes. In that the meta-analysis showed increasing benefit with increasing activity, a dose–response relationship was also established. However, as Lee and collaborators pointed out, given the range of definitions of “level of physical activity” in the studies included for assessment, their analysis suffered from the lack of a single, cohesive definition of what constitutes low, moderate and high levels of activity.83 The question of what type or quantity of activity is required to reach a moderate level and so to benefit from a 20 percent reduction in the risk of stroke is one that needs to be investigated by means of a randomized controlled trial.

    Smoking

    Tobacco smoking remains a significant risk factor for many chronic diseases including cardiovascular disease. The United States Department of Health and Human Services have stated that tobacco “presents a rare confluence of circumstances: (1) a highly significant health threat; (2) a disinclination among clinicians to intervene consistently; and (3) the presence of effective interventions”. The World Health Organization “M-Power” report describes smoking as a global tobacco epidemic.84 In that report, 6 policies were recommended to reverse the tobacco epidemic, all of which are targeted at the national level. These policies are tobacco use and prevention policies; protection of people from tobacco smoke; assistance in quitting tobacco use; warnings about the dangers of tobacco; enforcement of bans on tobacco advertising, promotion and sponsorship; and raising taxes on tobacco. In Canada, the Public Health Agency of Canada report on cardiovascular disease found that 15.3 percent of the population over the age of twelve self-report being active smokers in 2007; this is an improvement from 19.9 percent reported in 2000.85 Smoking policies and regulations have made notable progression over that same timeframe.

    Research has demonstrated that current smokers who smoke 20 or more cigarettes per day have an associated increase of stroke risk approximately 2 to 4 times that of nonsmokers. 86-89 Overall, given that an estimated 25 percent of adults are active smokers, approximately 18 percent of strokes may be attributed to active smoking.90

    Smoking acts as a risk factor in a dose-dependent fashion, such that heavy smokers have more risk than light smokers, who in turn have more risk than nonsmokers.86,89,91,92 Results of a recent study demonstrated that the relative risk for ischemic stroke associated with smoking fewer than 20 cigarettes per day was 1.56 when compared with nonsmokers and 2.25 when 20 or more cigarettes were smoked per day.93,94

    Reported relative risks for hemorrhagic stroke among smokers followed a similar pattern. Within a male population, smoking fewer than 20 cigarettes was associated with a 1.6- fold increase for intracerebral hemorrhage and a 1.8-fold increase for subarachnoid hemorrhage compared with nonsmokers. 93,94 When the rate of smoking increased to 20 cigarettes or more, the associated risk increased to 2.1 and 3.2 for intracerebral hemorrhage and subarachnoid hemorrhage, respectively. A study conducted within a female subject population yielded a similar pattern of risk.93

    Risk associated with current cigarette smoking is greatest in the middle years and declines with age.91 The Cardiovascular STudy in the ELderly (CASTEL) reported that the relative risk associated with current smoking compared with current nonsmokers was 1.60 for fatal stroke.95 Mortality was particularly high among current smokers who had been smoking for 40 or more years (7.2% v. 1.8% for nonsmokers, p < 0.01).95

    A systematic review and meta-analysis of smoking cessation therapies found that Bupropion trials were superior to controls at one year (12 RCTs, OR1.56, 95% CI, 1.10–2.21, P = 0.01) and at three months (OR 2.13, 95% CI, 1.72–2.64).96 Two RCTs evaluated the superiority of bupropion versus NRT at one year (OR 1.14, 95% CI, 0.20–6.42). P =< 0.0001) and also at approximately 3 months (OR 3.75, 95% CI, 2.65–5.30). Three RCTs evaluated the effectiveness of varenicline versus bupropion at 1 year (OR 1.58, 95% CI, 1.22–2.05) and at approximately three months (OR 1.61, 95% CI, 1.16–2.21). Using indirect comparisons, varenicline was superior to NRT when compared to placebo controls (OR 1.66, 95% CI 1.17–2.36, P = 0.004) or to all controls at one year (OR 1.73, 95% CI 1.22–2.45, P = 0.001). This was also the case for three-month data. Adverse events were not systematically different across studies. A study that examined the effects of bupropion for relapse prevention found that it was associated with a higher point-prevalence for smoking abstinence

    compared to placebo (p=.007), and this was independent of past history of depression.97

    Alcohol

    A meta-analysis of 35 observational studies examining the effects of alcohol consumption on stroke risk revealed a significant (p = 0.004) J-shaped relationship between the amounts of alcohol consumed per day and the risk of ischemic stroke.98 In that analysis, individuals who consumed 1 to 2 drinks per day had the least risk for ischemic stroke (RR = 0.72), while those having more than 5 drinks per day had the most risk (RR = 1.69) when compared with a group of abstainers.99 The analysis also confirmed that alcohol consumption has a linear, dose-dependent effect on risk of hemorrhagic stroke. Heavy drinking (more than 5 drinks per day) was associated with a relative risk of hemorrhagic stroke of 2.18. Irregular and binge drinking (more than 5 drinks at one sitting) have also been associated with an increase in risk for hemorrhagic stroke.99

    Data from the Copenhagen City Heart Study were used to examine whether the type of alcohol consumed was related to the apparent decreased risk of ischemic stroke with moderate alcohol consumption.100 The overall beneficial effect of moderate alcohol consumption was confirmed; however, the benefit was seen mostly among those individuals who consumed wine. Wine drinking on a daily, weekly or monthly basis was associated with reduced risk of ischemic stroke (RR = 0.68, 0.66 and 0.88, respectively, after adjustments for age, sex, smoking, BMI, physical activity, systolic blood pressure, cholesterol, antihypertensive treatment, triglycerides, education, and diabetes). No similar effect was demonstrated among drinkers of beer or spirits. Both Kiechl and associates101 and Sacco102 reported the greatest risk reduction (RR = 0.41 and 0.40, respectively) among wine drinkers; however, this was not significantly lower than among drinkers of beer, liquor or a combination of types of alcohol.