More than 1 billion individuals worldwide, including at least 70 million Americans, have high blood pressure (BP) warranting some form of treatment.1,2,3,4 Higher-than-optimal BP is the largest contributor to global mortality, and approximately 9.4 million deaths per year are attributed to uncontrolled hypertension.2,3,4 As life expectancy continues to increase, hypertension will become an even more important medical and public health issue because BP typically increases with aging in most industrialized countries. In the United States, 50% of people 60 to 69 years of age and approximately 75% of people 70 years or older have hypertension.3 In some nonindustrialized populations, however, BP does not rise with increasing age, and only a small fraction of the population develops hypertension. This suggests that predisposing environmental factors play a major role in causing hypertension and that an increase in BP with aging is not inevitable when these factors are absent.
A direct positive relationship between BP and cardiovascular disease (CVD) risk has been observed in men and women of all ages, races, ethnic groups, and countries, regardless of other risk factors for CVD.1 Observational studies indicate that death from CVD increases progressively and linearly as BP increases above 115 mm Hg systolic and 75 mm Hg diastolic.1 For every 20–mm Hg increase in systolic BP or 10–mm Hg increase in diastolic BP, there is a doubling of mortality from both ischemic heart disease and stroke in all age groups from 40 to 89 years of age.5
Despite major advances in our understanding of its pathophysiology and the availability of many drugs that can effectively reduce BP in most hypertensive subjects, hypertension continues to be the most important modifiable risk factor for CVD.
BP is a variable, quantitative trait with a nearly normal distribution. In industrialized societies, where there is typically higher dietary sodium and increasing body weight with age, the BP distribution is skewed slightly to the right.
BP classification is determined through analysis of observational and experimental data (clinical trials) regarding the relationship of BP and cardiovascular risk. Several organizations provide BP or hypertension classifications based largely on measurements obtained in a single encounter (“office” BPs). Classifications based on home BP monitoring and 24-hour ambulatory BP monitoring will likely be common in the future.6
The cutoff points for BP classification are generally driven by evidence from clinical trials and represent recommended levels for initiation of pharmacological therapy, goal BP, and recommended levels for initiation of nonpharmacological therapy. The levels for initiation of drug therapy and goal BP have traditionally been the same BP level.
The most commonly cited and used BP classifications are the 2003 Seventh Report of the United States Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure ...