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The goal of therapy is not just to bring the blood pressure lower than 140 mm Hg systolic and 90 mm Hg diastolic, but rather to prevent the morbidity and mortality associated with hypertension. As such, the decision to treat hypertension is based on documentation that the blood pressure has remained elevated and on assessment of the risk for that particular patient. In general, individuals with blood pressure ranges considered borderline high (i.e., systolic of 130 to 139 mm Hg or diastolic of 85 to 89 mm Hg) should have their blood pressures rechecked within 1 year.
Blood pressures in the stage 1 range should be confirmed within 2 months by repeated measurements; however, certain lifestyle approaches are appropriate even at this level. Blood pressures that are markedly elevated (e.g., systolic > 180 mm Hg or diastolic > 110 mm Hg) or those associated with evidence of existing end-organ damage may require immediate pharmacologic intervention. In general, whether pharmacologic intervention is initiated, a nonpharmacologic approach is the foundation of any management strategy.
Nonpharmacologic Therapeutic Approaches
Information concerning dietary modifications, exercise, weight reduction, the role of cations, and the possible role of relaxation and stress management techniques for reducing blood pressure have opened the door for greater acceptance of multiple nonpharmacologic approaches to the treatment of hypertension. The 1988 report of the Joint National Committee (JNC) on the Detection, Evaluation, and Treatment of High Blood Pressure recommended that “nonpharmacological approaches be used both as definitive intervention and as an adjunct for pharmacological therapy and should be considered for all antihypertensive therapy.”
Several studies have shown positive correlation of increased blood pressure with alcohol consumption of more than 2 ounces/day. Although smoking has not been shown to cause sustained hypertension, it is associated with increased cardiovascular, pulmonary, and hypertension risks, and therefore should be eliminated.
Weight reduction has a strong correlation with decreased blood pressure in obese individuals. Stamler et al5 reported that a 10-pound weight loss maintained over a 4-year period allowed 50% of participants previously on pharmacologic management to remain normotensive and free of medication.
Sodium restriction has been a mainstay of hypertension control, as a 100-mEq drop in daily intake can result in a 2- to 9-mm Hg decline in systolic blood pressure in salt-sensitive individuals. This goal is one of the easiest for a patient to accomplish, as moderate restriction can be accomplished by eliminating table salt for cooking, avoiding salty foods, and using a salt substitute.
Regular aerobic exercise not only assists with weight reduction but also appears to lower diastolic blood pressure. Cade and associates reported a decline from 117 to 97 mm Hg diastolic blood pressure after 3 months of daily walking or running for 2 miles. This effect appeared to be independent of weight loss, and some benefit persisted even if the patient became sedentary.
Vegetarian diets high in polyunsaturated fats, potassium, and fiber result in lower blood pressures than diets high in saturated fats. Dietary fat control also contributes to the reduction of cholesterol and coronary artery disease risk. The role of cations such as potassium, magnesium, and calcium in lowering blood pressure has now been investigated. High potassium intake (>80 mEq/day) may result in a modest decline in blood pressure while offering a natriuretic and cardioprotective effect. These effects are more pronounced in hypokalemic individuals.
Magnesium and calcium supplementation of more than 300 mg/day and 800 mg/day, respectively, have been shown to lower the relative risk of developing hypertension in a large cohort of women. The impact of individual supplementation is less clear, and the role of these substances is still controversial. Stress management and relaxation techniques over a 4-year period have been shown to reduce systolic blood pressure 10 to 15 mm Hg and diastolic blood pressure 5 to 10 mm Hg. However, these results are variable and are largely dependent on the instructor–patient relationship.
The effects of nonpharmacologic approaches can be additive and certainly are beneficial even if the patient requires drug therapy. Stamler and associates documented that reducing weight and lowering salt and alcohol intake allowed 39% of patients previously on therapy to remain normotensive without medication over a 4-year period. In the mildly hypertensive individual, these lifestyle modifications should be tried for at least 6 months before initiating pharmacologic therapy.
Pharmacologic Therapy
The decision to initiate drug therapy requires consideration of individual patient characteristics, such as age, race, sex, family history, cardiovascular risk factors, concomitant disease states, compliance, and ability to purchase the prescribed therapeutic agent. Pharmacologic therapy is recommended when the systolic blood pressure is higher than 160 mm Hg and the diastolic blood pressure remains higher than 100 mm Hg. Treatment of stage 2 and 3 hypertension (systolic pressure >160 and diastolic pressure >100 mm Hg) has reduced cardiovascular morbidity and mortality dramatically since the 1960s.
The incidence of stroke, congestive heart failure, and left ventricular hypertrophy has also decreased among treated stage 1 hypertensives, and therapy is recommended if patients have one or more cardiovascular risk factors and have not controlled their blood pressure after 6 months of lifestyle modification. The ideal antihypertensive agent would improve quality of life, reduce coronary heart disease risk factors, maintain normal hemodynamic profiles, reduce left ventricular hypertrophy, have a positive impact on concomitant disease states, and reduce end-organ damage while effectively lowering blood pressure on a convenient dosing regimen at minimal cost to the patient. This “magic bullet” has yet to be synthesized, although several of the newer antihypertensive classes offer the possibility of many of these positive outcomes.
The selection of an appropriate antihypertensive agent may be based on the current recommendations of the JNC on the Detection, Evaluation, and Treatment of High Blood Pressure or individualized to the specific medical, social, psychological, and economic situation of each patient. The previous stepped-care approach has been modified by the JNC into an algorithm that permits an individualized approach to the patient. Many clinicians have moved away from the stepped-care philosophy toward a monotherapy approach, which maximizes the dose of one drug before substituting or adding another. Combination therapy with lower doses of several agents may also be utilized to minimize adverse effects. Therapeutic choices must be based on a sound understanding of the mechanism of action, pharmacokinetics, adverse effect profile, and cost of available agents.
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