Table 2.
Baseline characteristics for African-American and white treatment resistant hypertension cases and controls.
| Characteristic | African-American participants | White participants | ||||
|---|---|---|---|---|---|---|
| TRH cases | Controls | P value* | TRH cases | Controls | P value* | |
| Sample size, n | 929 | 719 | — | 1274 | 1635 | — |
| Age (y), mean (SD) | 65.8 (7.1) | 65.7 (7.4) | 0.92 | 67.4 (7.2) | 66.6 (7.5) | 0.003 |
| Women, n (%) | 440 (47.4) | 391 (54.4) | 0.005 | 440 (34.5) | 712 (43.6) | <0.001 |
| On antihypertensive treatment at baseline, n (%) | 892 (96.0) | 618 (86.0) | <0.001 | 1221 (95.8) | 1448 (88.6) | <0.001 |
| Randomized treatment group: | ||||||
| Chlorthalidone**, n (col%) | 253 (27.2) | 366 (50.9) | <0.001 | 420 (33.0) | 695 (42.5) | <0.001 |
| Amlodipine, n (col%) | 166 (17.9) | 161 (22.4) | 236 (18.5) | 349 (21.4) | ||
| Lisinopril, n (col%) | 301 (32.4) | 118 (16.4) | 383 (30.1) | 429 (26.2) | ||
| Doxazosin, n (col%) | 209 (22.5) | 74 (10.3) | 235 (18.5) | 162 (9.9) | ||
| Baseline blood pressure: | ||||||
| All participants, mm Hg: | ||||||
| SBP, mean (SD) | 151.9 (15.6) | 138.9 (15.5) | <0.001 | 152.3 (14.9) | 139.2 (15.4) | <0.001 |
| DBP, mean (SD) | 85.2 (11.1) | 83.2 (9.3) | <0.001 | 83.1 (10.5) | 82.5 (9.5) | 0.09 |
| Treated at baseline, mm Hg: | ||||||
| SBP, mean (SD) | 151.5 (15.6) | 136.6 (14.9) | <0.001 | 151.9 (14.8) | 137.6 (15.0) | <0.001 |
| DBP, mean (SD) | 85.0 (11.1) | 82.2 (9.2) | <0.001 | 83.0 (10.4) | 81.8 (9.5) | 0.002 |
| Untreated at baseline, mm Hg: | ||||||
| SBP, mean (SD) | 162.7 (13.3) | 153.4 (10.9) | <0.001 | 162.3 (12.7) | 152.1 (11.1) | <0.001 |
| DBP, mean (SD) | 89.6 (11.1) | 88.9 (8.3) | 0.69 | 85.6 (11.5) | 87.6 (7.9) | 0.14 |
| Current cigarette smoker, n (%) | 185 (19.9) | 200 (27.8) | <0.001 | 243 (19.1) | 336 (20.6) | 0.32 |
| Type 2 diabetes, n (%) | 435 (46.8) | 227 (31.6) | <0.001 | 531 (41.7) | 458 (28.0) | <0.001 |
| LVH by electrocardiogram, n (%) | 273 (29.4) | 149 (20.7) | <0.001 | 178 (14.0) | 212 (13.0) | 0.43 |
| Body mass index, mean (SD), kg/m2 | 31.3 (8.3) | 29.5 (6.4) | <0.001 | 29.9 (5.7) | 28.9 (5.3) | <0.001 |
| Fasting glucose, mean (SD), mg/dL | 132.8 (62.5) | 120.4 (60.8) | <0.001 | 124.8 (50.8) | 114.8 (48.1) | <0.001 |
| Total cholesterol, mean (SD), mg/dL | 217.1 (45.4) | 216.0 (44.7) | 0.64 | 213.6 (43.9) | 215.0 (41.7) | 0.38 |
| HDL cholesterol, mean (SD), mg/dL | 50.6 (15.9) | 52.8 (15.8) | 0.008 | 42.9 (13.7) | 45.1 (14.0) | <0.001 |
| Fasting triglycerides, mean (SD), mg/dL | 130.0 (75.9) | 125.4 (91.9) | 0.33 | 196.8 (142.9) | 177.7 (126.0) | <0.001 |
| Estimated glomerular filtration rate (eGFR) | 80.3 (21.3) | 86.2 (19.6) | <0.001 | 73.9 (18.3) | 75.8 (16.5) | 0.004 |
| Follow-up blood pressure, mm Hg: | ||||||
| SBP at 1 year, mean (SD) | 151.4 (18.4) | 129.1 (13.5) | <0.001 | 147.2 (17.7) | 128.1 (12.2) | <0.001 |
| DBP at 1 year, mean (SD) | 83.8 (11.3) | 78.1 (8.5) | <0.001 | 79.0 (10.4) | 76.5 (8.6) | <0.001 |
| SBP at 2 years, mean (SD) | 149.6 (18.8) | 127.9 (13.0) | <0.001 | 146.4 (17.2) | 126.3 (11.9) | <0.001 |
| DBP at 2 years, mean (SD) | 81.4 (12.5) | 77.1 (8.6) | <0.001 | 78.0 (10.8) | 75.5 (7.9) | <0.001 |
| SBP at 3 years, mean (SD) | 152.3 (18.3) | 117.2 (6.5) | <0.001 | 149.2 (16.9) | 117.9 (6.3) | <0.001 |
| DBP at 3 years, mean (SD) | 81.1 (12.3) | 73.1 (6.9) | <0.001 | 77.2 (11.6) | 72.0 (7.2) | <0.001 |
| Number of HT meds at 3 years, mean (SD) | 3.6 (0.72) | 1 (per def.) | — | 3.6 (0.69) | 1 (per def.) | — |
| Number on diuretic at 3 years, n (%) | 493 (53%) | 366 (51%) | 0.38 | 769 (60%) | 695 (43%) | <0.001 |
SBP: systolic blood pressure, DBP: diastolic blood pressure, HDL-C: HDL cholesterol, and LVH: left ventricular hypertrophy.
*Test of differences between case/control groups: ANOVA for continuous variables and chi-square for categorical variables.
**Participants were randomized to treatment in a ratio of 1 : 1 : 1 : 1.7 for amlodipine, lisinopril, doxazosin, and chlorthalidone, respectively.