Race-Specific Comparisons of Antihypertensive and Metabolic Effects of Hydrochlorothiazide and Chlorthalidone

Pairwise comparison of hydrochlorothiazide and chlorthalidone responses among hypertensive patients

This study conducted a pairwise comparison of antihypertensive and metabolic effects of hydrochlorothiazide (HCTZ) and chlorthalidone (CTD) at 25 mg/day in the same individuals to address the clinical dilemma on preferred thiazide for hypertension (HTN) management. We included 15 African American (AA) and 35 European American (EA) patients with HTN treated with HCTZ and CTD as part of the Pharmacogenomic Evaluation of Antihypertensive Responses (PEAR) and PEAR-2 trials, respectively. Mean reduction in systolic/diastolic blood pressure (SBP/DBP) with HCTZ versus CTD was 8/5 versus 16/8 mmHg among EA patients (p < 1.0e^-5 SBP, p = 0.002 DBP) and 11/8 versus 20/11 mmHg among AA patients (p = 0.03 SBP, p = 0.22 DBP). While CTD showed clinically meaningful benefit over HCTZ in two-thirds of participants with respect to SBP reduction and half of EA patients with respect to DBP reduction, a majority of AA patients (53%) showed similar DBP reduction with both thiazides. Sixty percent of AA patients and 29% of EA patients attained blood pressure (BP) <140/90 mmHg with both thiazides. Mean potassium (K+) reduction was greater with CTD compared to HCTZ both in EA patients (mean difference = 0.35, p = 0.0002) and AA patients (0.49, p = 0.043). While 31% of AA patients developed severe hypokalemia on CTD, <5% of others developed severe hypokalemia. Although 46% of AA patients on CTD required K+ supplementation, only 6%-11% of others required supplementation. Overall, in the majority of EA patients, CTD was superior to HCTZ, whereas among AA patients, it was superior in a minority, and was associated with significant potassium-related risk, suggesting that guideline preferences for CTD over HCTZ are reasonable in EA patients but may be less reasonable in AA patients, particularly if the target is <140/90 mmHg.

Initial combination therapy for hypertension in patients of African ancestry: a systematic review and meta-analysis

We systematically reviewed randomized controlled trials (RCTs) that consider the effect of initial dual antihypertensive combination treatment on blood pressure (BP), morbidity, or mortality in hypertensive African ancestry adults, using the methodology of the Cochrane Collaboration. Main outcomes were difference in means (continuous data) and risk ratio (dichotomous data).We retrieved 1728 reports yielding 13 RCTs of 4 weeks to 3 years duration (median 8 weeks) in 3843 patients. Systolic BP was significantly higher on β-adrenergic blocker vs. other combinations, 3.80 [0.82;6.78] mmHg, but comparable for other combinations. Hypokalemia and hyperglycemia occurred with calcium channel blocker (CCB) + diuretics > diuretics + angiotensin converting enzyme inhibitor (ACEI)/angiotensin-II-type-1-receptor antagonist (ARB) > CCB + ACEI/ARB. An RCT including high-risk patients reported combined morbidity/mortality for hydrochlorothiazide (mg) 25 + benazepril 40 vs. amlodipine 10 + benazepril 40 of respectively 8.9% vs. 6.6% (n = 1414, risk ratio 1.35 [0.94;1.94]; all patients, N = 11 506, 1.23 [1.11;1.37]).We conclude that limited evidence supports CCB + ACEI rather than HCT + ACEI as first-line initial combination therapy in African ancestry patients with hypertension.

PROSPERO

CRD42021238529.