Chapter 7

NON PHARMACOLOGIC THERAPY OF HYPERTENSION

v      Lose weight if overweight.

v      Reduce salt intake to no more than 6 gm of sodium chloride/ day.

v      Maintain adequate intake of dietary potassium (approximately 90 mmol/d)

v      Maintain adequate intake of dietary calcium for general health

v      Encourage intake of diet rich in fresh fruits, vegetables, and in low-fat dairy products with a reduced content of saturated and total fat.

v      Stop alcohol or limit intake to no more than one-two drinks/ day.

v      Stop smoking.

v      Increase physical activity (30-45 minutes) of brisk walking most days of the week.

v      Limited evidence supports the role of calcium and magnesium, or stress management.

v      Management of other cardiovascular risk factors. 

·         Non pharmacological interventions (life style modification) are beneficial in reducing a variety of cardiovascular risk factors including high blood pressure. They may also reduce the dosage requirements of antihypertensive drugs.

·         Life style modification should be recommended in all hypertensive patients initially and as an adjunct to drug therapy.

 A reasonable generalized approach for all patients includes:

1.       Weight reduction for the overweight patient.

2.       Reduced dietary intake of sodium, fat and increased calcium, potassium, vitamins, fish oil and fibres from food sources.

3.       Regular physical activity.

4.       Smoking cessation.

5.       Moderation of alcohol consumption.

Weight Reduction

Rationale

·         Excess body weight (body mass index of 27 or greater) is correlated closely with increased blood pressure.

·         Excess fat in the upper parts of the body (visceral or abdominal), defined as waist circumference ≥85cm in women or ≥98cm in men, increases the risk of hypertension, dyslipidemia, diabetes and cardiovascular mortality.

·         One kilogram decrease in body weight is accompanied by an average reduction of 1.6 and 1.3 mmHg in systolic and diastolic blood pressure respectively.

·         Possible mechanisms of hypertension in obesity include: increased blood volume, hyperinsulinaemia, and increased sympathetic activity.

 Recommendations

·         All hypertensive patients should maintain normal body weight (body mass index: 18.5-24.9 kg/m²).

·         A reasonable goal is to decrease body weight by 5 kg over 4-6 month period. This reduction in body weight will decrease the blood pressure and improve the cardiovascular risk profile.

·         General guidelines to reduce calories:

-    Prepare all foods without addition of butter, margarine, fat, oil or sugar.

-    Limit servings to 3 meals a day and one small snack in the afternoon. Avoid continuous eating or snacking.

-    Limit portion sizes.

-    Avoid high caloric foods: Candy, cookies, pies, pastries, carbonated beverages (e.g., coca cola), nuts, chips, dried fruits.

-    Avoid appetizers.

Moderation of Dietary Sodium

Rationale

·         Increased sodium in diet has been associated with increased incidence of future cardiovascular events.

·         Sodium, in the form of sodium chloride or table salt, is linked to levels of blood pressure.

·         Moderate sodium restriction increases the efficacy of all classes of antihypertensive drugs (with the exception of calcium channel blockers).

·         Other favorable effects: protection from diuretic induced hypokalaemia, left ventricular hypertrophy regression, and improvement of renal function.

 Salt Sensitivity:

·         Hypertensive patients can be classified into salt sensitive and salt resistant individuals.

·         Salt sensitivity is present in 40% of patients with essential hypertension.

·         Salt sensitivity is more common in the following groups:

-          Elderly.

-          Blacks.

-          Insulin dependent diabetes.

-          Secondary hypertension: hyperaldesteronism .

Recommendations

Moderate sodium reduction to a daily level of no more than approximately 6 gm of sodium chloride is recommended (table 9).

Table 9. Guidelines for Moderate Salt Restriction (6gm Na chloride/day)

Potassium Intake

Rationale

·         Epidemiologic and clinical studies have implicated potassium depletion in the pathogenesis and maintenance of essential hypertension.

·         High dietary potassium intake may protect against developing hypertension and improve blood pressure control in patients with hypertension.

Recommendations

·         Maintenance of adequate potassium intake > 90 mmol/d, preferably from dietary sources, is recommended for hypertensive persons.

·         A diet rich in fruits and vegetables (DASH Diet) is superior to taking pills or other supplements as potassium sources (table 10).

·         Potassium supplements should be avoided in patients with renal insufficiency, or those taking potassium sparing diuretics, ACE inhibitors, or ARBs.

Table 10.  Foods Rich in Potassium

Calcium and Magnesium Intake

There is currently no rationale for recommending calcium or magnesium supplements to prevent or treat hypertension. However, calcium or magnesium deficiency should be avoided.

Other Dietary Factors

·         DASH Diet (table 11): the dietary approach to stop hypertension (DASH) trial showed a reduction in blood pressure of 11.4/5.5 mmHg in hypertensive persons maintained on a diet rich in fruits and vegetables and low fat dairy products compared with control subjects maintained on the so called usual American diet.

·         Encourage intake of diet rich in fibres, fish (omega -3 fatty acids), garlic, low fat dairy products (e.g., cottages cheese, skimmed milk), fresh fruits, vegetables (especially raw) and fruit juices.

·         Caffeine (consumed as coffee, tea, or cola drinks) raises blood pressure acutely. Tolerance to its pressor effect develops rapidly. There is no direct relationship between caffeine intake and persistent elevation of blood pressure.

Regular Physical Activity

Rationale

·         Regular aerobic exercise has been shown to reduce blood pressure by 6/7 mmHg in borderline hypertension and by 10/8 mmHg in hypertension.

·         Mechanisms of hypotensive action of physical activity include: weight reduction, attenuation of adrenergic activity and improved insulin sensitivity.

Recommendations

·         Moderate activity such as 30-45 minutes of brisk walking 3-5 times/week is beneficial.

·         Exercise intensity can be set at a heart rate of 190 beats/min minus age.

·         Training should be regular and progressive, avoiding exhaustion and sudden bursts of energy.

·         Cardiovascular status should be carefully evaluated in the elderly hypertensive (> 65 years) before initiating an exercise program.

Tobacco Avoidance

Rationale

·         A significant rise in blood pressure accompanies the smoking of each cigarette.

·         The cardiovascular benefits of discontinuing tobacco use can be seen within a year in all age groups.

·         Malignant hypertension is more common in smokers.

Recommendations

Avoidance of tobacco in any form is essential.

Moderation of Alcohol Intake

Rationale

·         Excessive alcohol intake is an important risk factor of high blood pressure and can cause resistance to antihypertensive therapy.

·         Reduction in alcohol intake in individuals who consume 3 or more drinks /day is effective in lowering the blood pressure to a degree comparable with or greater than that achieved by most other effective life style interventions.

Recommendations

·         All hypertensive patients should be advised to limit alcohol intake not exceeding 1-2 drinks /day in men and one drink/day in women.

Relaxation and Biofeedback

·         Emotional stress can raise the blood pressure acutely.

·         The available data does not support the use of relaxation therapies for treatment or prevention of hypertension.

Combined Therapies

·         When several life style modifications are combined, additional antihypertensive effects may occur.

   Table 11. DASH Diet