1. Methods and an overview of the Canadian recommendations

Objective: To provide updated, evidence-based recommendations for health ca re professionals on lifestyle changes to prevent and control hypertension i n otherwise healthy adults (except pregnant women). Options: For people at risk for hypertension, there are a number of lifesty le options that may avert the condition-maintaining a healthy body weight, moderating consumption of alcohol, exercising, reducing sodium intake, alte ring intake of calcium, magnesium and potassium, and reducing stress. Follo wing these options will maintain or reduce the risk of hypertension. For pe ople who already have hypertension, the options for controlling the conditi on are lifestyle modification, antihypertensive medications or a combinatio n of these options; with no treatment, these people remain at risk for the complications of hypertension. Outcomes: The health outcomes considered were changes in blood pressure and in morbidity and mortality rates. Because of insufficient evidence, no eco nomic outcomes were considered. Evidence: A MEDLINE search was conducted for the period January 1966 to Sep tember 1996 for each of the interventions studied. Reference lists were sca nned, experts were polled, and the personal files of the authors were used to identify other studies. All relevant articles were reviewed, classified according to study design and graded according to level of evidence. Values: A high value was placed on the avoidance of cardiovascular morbidit y and premature death caused by untreated hypertension. Benefits, harms and costs: Lifestyle modification by means of weight loss ( or maintenance of healthy body weight), regular exercise and low alcohol co nsumption will reduce the blood pressure of appropriately selected normoten sive and hypertensive people. Sodium restriction and stress management will reduce the blood pressure of appropriately selected hypertensive patients. The side effects of these therapies are few, and the indirect benefits are well known. There are certainly costs associated with lifestyle modificati on, but they were not measured in the studies reviewed. Supplementing the d iet with potassium, calcium and magnesium has not been associated with a cl inically important reduction in blood pressure in people consuming a health y diet. Recommendations: (1) It is recommended that health care professionals deter mine the body mass index (weight in kilograms/[height in metres](2)) and al cohol consumption of all adult patients and assess sodium consumption and s tress levels in all hypertensive patients. (2)To reduce blood pressure in t he population at large, it is recommended that Canadians attain and maintai n a healthy body mass index. For those who choose to drink, alcohol intake should be limited to 2 or fewer standard drinks per day (maximum of 14/week for men and 9/week for women). Adults should exercise regularly (3) To red uce blood pressure in hypertensive patients, individualized therapy is reco mmended. This therapy should emphasize weight loss for overweight patients, abstinence from or moderation in alcohol intake, regular exercise, restric tion of sodium intake and, in appropriate circumstances, individualized cog nitive behaviour modification to reduce the negative effects of stress. Validation: The recommendations were reviewed by all of the sponsoring orga nizations and by participants in a satellite symposium of the fourth Intern ational Conference on Preventive Cardiology. They are similar to those of t he World Hypertension League and the Joint National Committee, with the exc eption of the recommendations on stress management, which are based on new information. They have not been clinically tested. Sponsors: The Canadian Hypertension Society, the Canadian Coalition for Hig h Blood Pressure Prevention and Control, the Laboratory Centre for Disease Control at Health Canada, and the Heart and Stroke Foundation of Canada.