More than half of hypertensive black patients don't receive diuretics

More than half of black patients with uncontrolled hypertension don't receive diuretics, despite recommendations favoring their use as a first-line agent, a study found.

The study was conducted in the post-acute care division of a large, urban Medicare/Medicaid-certified home health organization. Prescribing clinicians came from a wide variety of service settings, the researchers noted.

Results appeared in the American Journal of Hypertension.

Of the 658 patients with uncontrolled hypertension (defined as home blood pressure readings of ≥140/90 mm Hg or ≥130/80 mm Hg in patients with diabetes), 300 (46%) took a diuretic, including 30 who were taking more than one. Among these 300 patients, 68% received a thiazide diuretic, 33.3% received a loop diuretic, and 4.3% received a potassium-sparing diuretic (including 3% who took an aldosterone receptor blocker).

Participants who were not taking a diuretic took fewer antihypertensive medications (1.7 vs. 2.9 medications; P<0.0001) compared with those who were. They had a higher mean diastolic blood pressure (89.2 vs. 85.5 mm Hg; P=0.0005) and were more likely to have a systolic blood pressure of 160 mm Hg or greater (57.6% vs. 49.0%; P=0.04).

Among the 94.5% of participants taking antihypertensive medication, 26.5% (n=165) took just one drug. In this group, only 12% (n=19) took a diuretic. The percentage taking a diuretic increased to 43% among those taking two drugs, 73% among those taking three drugs and 90% among those taking four or more medications.

Diuretics were associated with lower systolic and diastolic blood pressure. The mean systolic difference was −5 mm Hg (95% CI, −8.80 to −1.21; P=0.01) and the mean diastolic difference was −3.79 mm Hg (95% CI, −6.16 to −1.41; P=0.002) in patients taking a diuretic-containing regimen compared with those treated with other antihypertensive agents.

The authors also speculated that the dose in diuretic-treated patients may have been inadequate based on recent research evaluating the efficacy of different diuretic regimens. While 67.3% of patients who were taking a diuretic received hydrochlorothiazide, in 93.1% of cases the dose was less than or equal to 25 mg/d, a level associated with a lower antihypertensive effect than higher doses. The remaining patients received a higher dose or a combination with a potassium-sparing agent.

“These findings are particularly striking, because all of the patients assessed in this study were black and had uncontrolled hypertension, in whom a diuretic would almost always be recommended,” the researchers wrote. “The finding is even more disturbing given the socioeconomic status of most patients in this study and the low cost of diuretic therapy that could enhance patient adherence.”