An estimated 43 million American adults have hypertension, or high blood pressure. It is more common in African Americans and the elderly than in other groups. In the United States hypertension is responsible for 35 percent of all heart attacks and strokes, 49 percent of all episodes of heart failure, and 24 percent of all premature deaths. Additional complications of hypertension include kidney disease, eye disease, and aneurysms. In 1998, an estimated $109 billion was spent on health care of patients with hypertension and its complications; $22 billion of this total was spend on the treatment of hypertension alone.
Blood pressure measurement using an appropriate upper arm cuff is the standard screening test for hypertension. Office measurement of blood pressure is most commonly done with a blood pressure cuff, or sphygmomanometer. High blood pressure (hypertension) is usually defined in adults as a systolic blood pressure (SBP) of 140 mm HG or higher, or a diastolic blood pressure (DBP) of 90 mm HG or higher. When performed correctly, this measure of blood pressure is highly predictive of risk for heart disease. However, office blood pressure measurements exhibit great variability and may not represent the patient's usual blood pressure outside the clinical setting. Due to the limitations in the reliability of blood pressure measurement, experts commonly recommend that doctors diagnose hypertension only after obtaining two or more elevated readings at two or more office visits at intervals of one to several weeks.
Many clinical studies have demonstrated a beneficial effect of treating patients with elevated blood pressures detected during screening examinations. The risks associated with elevated blood pressure and the potential benefits of screening and subsequent treatment depend both on the degree of blood pressure elevation and on the presence of other heart disease risk factors, such as age, gender, lipid disorders, smoking, and diabetes. Although the benefits of treatment generally correlate with achieving a decrease in blood pressure, recent trails suggest the degree of blood pressure reduction is not necessarily the only way to predict the benefits of treatment. The benefit of treating high blood pressure depends on the level of cardiovascular risk as predicted by the presence of other risk factors for heart disease. Those at the highest risk also experience greater absolute benefit from blood pressure reduction. This benefit appears to hold true across all age groups and for reductions in both systolic and diastolic blood pressure.
The recommended goal of treatment is to achieve and maintain SBP below 140 mm Hg and DBP below 90 mm Hg, and lower if tolerated. Evidence indicates that reducing DBP to below 80 mm HG appears to be most beneficial for patients with hypertension and diabetes.
Nonphamacological therapies, such as reducing dietary sodium intake, potassium supplementation, increased physical activity, weight loss, stress management, and reducing alcohol intake, are associated with a reduction in blood pressure, but their impact on cardiovascular outcomes has not been studied. For those who consume large amounts of alcohol (more than 20 drinks in a week), studies have shown that reduced drinking decreases blood pressure.
Article written by Lloyd Klein, MD, FACP, FACC 675 W. North Avenue, Suite 406, Melrose Park, IL 60160 (708) 681-7862
LOYOLA UNIVERSITY HEALTH SYSTEM
