incidence and mortality among patients with hypertension (Collins et al., 1990; Ezzati et al., 2002; Hebert et al., 1993; Staessen et al., 2001).
This section provides a discussion of the burden of hypertension by age, gender, and race or ethnicity and reviews data on levels of awareness, treatment, and control of hypertension. The relationship between behavioral risk factors and hypertension is addressed in Chapter 4, but trends in select risk factors are provided here.
The prevalence of hypertension in the U.S. general population is high and increasing in recent years (Cutler et al., 2008; Fields et al., 2004). The National Health and Nutrition Examination Survey (NHANES) conducted by the National Center for Health Statistics has been the principal means of tracking the burden of hypertension in the U.S. general population. Hypertension prevalence estimates derived from the NHANES are defined as systolic blood pressure ≥140 mm Hg and/or diastolic blood pressure ≥90 mm Hg and/or receiving antihypertensive medication.
The estimated prevalence of hypertension derived from the NHANES 1999-2004 was 28.9 percent of the U.S. adult population (Cutler et al., 2008). The prevalence of hypertension varies by age, gender, and race or ethnicity. The prevalence of hypertension is also affected by behavior such as the intake of dietary sodium and potassium, weight management, alcohol consumption, and physical activity. Overall, the prevalence of hypertension is similar in men and women in the United States. In the NHANES 1999-2004, the age-adjusted prevalence of hypertension for all races was 28.5 percent in men and 28.8 percent in women (Cutler et al., 2008). The relationship between gender and hypertension is modified by age. In young adults, the prevalence of hypertension is higher in men than in women. However, by their fifties, women tend to have blood pressure levels that equal or exceed those of men. The prevalence of hypertension is higher in women than in men later in life. The increase in the prevalence of hypertension by race and sex between the age groups of 18-29 years of age and >70 years of age was from 9.8 to 83.4 percent in black men, from 3.7 to 83.1 percent in black women, from 3.5 to 69.1 percent in Mexican-American men, from 1.5 to 78.8 percent in Mexican-American women, from 5.5 to 63.3 percent in non-Hispanic white men, and from 0.8 to 78.8 in non-Hispanic white women (Table 2-1). Isolated systolic hypertension (defined as systolic blood pressure ≥140 mm Hg and diastolic blood pressure <90 mm Hg) is common in older persons because systolic blood pressure tends to rise until the eighth or ninth decade, whereas diastolic blood pressure tends to remain constant or decline after the fifth decade (Whelton, 1994).