Prevalence of resistant hypertension in the United States, 2003-2008.

The prevalence of resistant hypertension is unknown. Much previous knowledge comes from referral populations or clinical trial participants. Using data from the National Health and Nutrition Examination Survey from 2003 through 2008, nonpregnant adults with hypertension were classified as resistant if their blood pressure was ≥140/90 mm Hg and they reported using antihypertensive medications from 3 different drug classes or drugs from ≥4 antihypertensive drug classes regardless of blood pressure. Among US adults with hypertension, 8.9% (SE: 0.6%) met criteria for resistant hypertension. This represented 12.8% (SE: 0.9%) of the antihypertensive drug-treated population. Of all drug-treated adults whose hypertension was uncontrolled, 72.4% (SE: 1.6%) were taking drugs from <3 classes. Compared with those with controlled hypertension using 1 to 3 medication classes, adults with resistant hypertension were more likely to be older, to be non-Hispanic black, and to have higher body mass index (all P<0.001). They were more likely to have albuminuria, reduced renal function, and self-reported medical histories of coronary heart disease, heart failure, stroke, and diabetes mellitus (P<0.001). Most (85.6% [SE: 2.4%]) individuals with resistant hypertension used a diuretic. Of this group, 64.4% (SE: 3.2%) used the relatively weak thiazide diuretic hydrochlorothiazide. Although not rare, resistant hypertension is currently found in only a modest proportion of the hypertensive population. Among those classified here as resistant, inadequate diuretic therapy may be a modifiable therapeutic target. Cardiovascular diseases, diabetes mellitus, obesity, and renal dysfunction were all common in this population.