Table 1
Baseline characteristics of participants by resistant hypertension.
| TOTAL n = 1378 | Non-RH (n = 1164) | RH (n = 214) | P-VALUE | |
|---|---|---|---|---|
| Age (years) | 55.6 ± 12.9 | 55.6 ± 13.1 | 55.5 ± 11.8 | 0.990 |
| Sex | ||||
| Male | 606 (43.9%) | 496 (42.6%) | 110 (51.4%) | 0.017 |
| Female | 773 (56.1%) | 669 (57.4%) | 104 (48.6%) | |
| Duration of hypertension (months) | 98.6 ± 99.0 | 92.5 ± 95.9 | 129.1 ± 108.7 | <0.001 |
| Fasting blood glucose (mmol/l) | 6.0 ± 2.4 | 6.0 ± 2.2 | 6.5 ± 3.1 | 0.010 |
| Diabetes Mellitus | 284 (20.6%) | 227 (19.5%) | 57 (26.6%) | 0.018 |
| Family history of hypertension | 783 (56.7%) | 651 (55.9%) | 132 (61.7%) | 0.011 |
| Alcohol use | 415 (30.1%) | 341 (29.3%) | 74 (34.6%) | 0.198 |
| Tobacco use | 79 (5.7%) | 62 (5.3%) | 17 (7.9%) | 0.204 |
| First office SBP (mmHg) | 145 ± 23 | 143 ± 21 | 160 ± 23 | <0.001 |
| First office DBP (mmHg) | 88 ± 14 | 87 ± 14 | 93 ± 15 | <0.001 |
| Office SBP at control (mmHg) | 125 ± 14 | 123 ± 13 | 132 ± 17 | <0.001 |
| Office DBP at control (mmHg) | 77 ± 9 | 77 ± 9 | 79 ± 12 | <0.001 |
| Total cholesterol (mmol/l) | 5.1 ± 1.2 | 5.1 ± 1.2 | 5.1 ± 1.4 | 0.542 |
| High-density lipoprotein (mmol/l) | 1.6 ± 0.6 | 1.6 ± 0.6 | 1.6 ± 0.6 | 0.525 |
| Low-density lipoprotein (mmol/l) | 3.0 ± 1.1 | 3.0 ± 1.1 | 3.1 ± 1.2 | 0.616 |
| Triglyceride (mmol/l) | 1.2 ± 0.6 | 1.2 ± 0.6 | 1.3 ± 0.7 | 0.050 |
| Dyslipidemia | 917 (70.6%) | 770 (70.5%) | 147 (71.4%) | 0.807 |
| Obesity (BMI > 30 kg/m2) | 660 (47.9%) | 535 (45.9%) | 125 (59.0%) | <0.001 |
| Number of antihypertensives | 2.6 ± 1.1 | 2.4 ± 1.0 | 4.1 ± 0.7 | <0.001 |
| No of office visits before BP control | 2.87 ± 1.58 | 2.66 ± 1.20 | 3.96 ± 2.59 | <0.001 |
| BP Control | <0.001 | |||
| Controlled Non-RH | 1105 (80.1%) | 1105 (94.8%) | 0.0 (0%) | |
| Controlled RH | 169 (12.3%) | 0.0 (0%) | 169 (79.0%) | |
| Uncontrolled Non-RH | 60 (4.4%) | 60 (5.2%) | 0.0 (0%) | |
| Uncontrolled RH | 45 (3.3%) | 0.0 (0.0%) | 45 (21.0%) | |
| White coat hypertension | 23 (1.7%) | 16 (1.4%) | 7 (3.3%)* | 0.073 |
| Serum creatinine (µmol/l) | 98.0 ± 36.8 | 96.9 ± 37.4 | 103.6 ± 33.1 | 0.009 |
| eGFR (mls/min/1.73 m2) | 72.3 ± 19.8 | 72.9 ± 19.8 | 69.4 ± 19.5 | 0.018 |
| LVMI (g/m2) | 107.9 ± 36.2 | 107.4 ± 36.7 | 111.0 ± 33.1 | 0.177 |
| Ejection fraction (%) | 64 ± 14 | 64 ± 15 | 67 ± 12 | 0.004 |
| Heart Failure | 207 (15.0%) | 188 (16.1%) | 19 (8.9%) | 0.006 |
| HFrEF/HFmrEF | 145 (10.5%) | 137 (11.8%) | 8 (3.7%) | 0.002 |
| HFpEF | 62 (4.5%) | 51 (4.4%) | 11 (5.1%) | 0.002 |
| Cerebrovascular Disease | 86 (6.2%) | 63 (5.4%) | 23 (10.7%) | 0.003 |
| Chronic Kidney Disease | 35 (2.5%) | 25 (2.1%) | 10 (4.7%) | 0.031 |
| Coronary Artery Disease | 27 (2.0%) | 22 (1.9%) | 5 (2.3%) | 0.664 |
[i] BP- Blood pressure, BMI- Body mass index, DBP- Diastolic blood pressure, eGFR- Estimated glomerular filtration rate, HFpEF- Heart failure with preserved ejection fraction, HFmrEF- Heart failure with mildly reduced ejection fraction, HFrEF- Heart failure with reduced ejection fraction, LVMI- Left ventricular mass index, RH- Resistant hypertension, No- Number, SBP- Systolic blood pressure.
Table 2
Multivariable logistic regression analysis of risk factors and cardiovascular comorbidities associated with resistant hypertension.
| OUTCOME (RESISTANT HYPERTENSION) | ||
|---|---|---|
| CO-VARIATES | ADJUSTED ODDS RATIO (95% CI) | P-VALUE |
| Sex (male) | 1.62 (1.19–2.21) | 0.002 |
| Family history of hypertension | 1.40 (0.99–1.96) | 0.053 |
| Obesity | 1.81 (1.32–2.47) | <0.001 |
| Diabetes Mellitus | 1.46 (1.03–2.06) | 0.032 |
| HFpEF | 3.36 (1.25–9.07) | 0.017 |
| HF | 0.26 (0.12–0.55) | <0.001 |
| Cerebrovascular disease | 2.00 (1.17–3.41) | 0.011 |
| Chronic kidney disease | 3.01 (1.33–6.84) | 0.008 |
[i] HF- Heart failure, HFpEF- Heart failure with preserved ejection fraction, Model fit p < 0.001, Cox & Snell R Square of 0.044, Nagelkerke R Square of 0.076, Hosmer and Lemeshow Test of 0.935.
Table 3
Medications and their combinations used by the participants.
| PARAMETERS | TOTAL (n = 1378) | Non-RH (n = 1164) | RH (n = 214) | P-VALUE |
|---|---|---|---|---|
| Medications | ||||
| Calcium channel blockers | 927 (67.2%) | 713 (61.2%) | 214 (100%) | <0.001 |
| Diuretics (Thiazides, Thiazide-like and Loop) ** | 834 (60.5 | 620 (53.2%) | 214 (100%) | <0.001 |
| Mineralocorticoid antagonists (Spironolactone/Eplerenone) | 104 (7.5%) | 71 (6.1%) | 33 (15.4%) | <0.001 |
| ACE Inhibitors | 540 (39.2%) | 449 (38.5%) | 91 (42.5%) | 0.273 |
| Angiotensin Receptor Blockers | 562 (40.8%) | 439 (37.7%) | 123 (57.5%) | <0.001 |
| Beta-blockers | 502 (36.4%) | 360 (30.9%) | 142 (66.4%) | <0.001 |
| Alpha-blockers | 55 (4.0%) | 13 (1.1%) | 42 (19.6%) | <0.001 |
| Centrally acting (Alpha Methyl Dopa) | 50 (3.6%) | 44 (3.8%) | 6 (2.8%) | 0.484 |
| Hydralazine | 5 (0.4%) | 2 (0.2%) | 3 (1.4%) | 0.006* |
| Medication combinations | ||||
| Free | 791 (57.4%) | 696 (59.7%) | 95 (44.4%) | <0.001 |
| Single pill combination | 88 (6.4%) | 86 (7.4%) | 2 (0.9%) | <0.001 |
| Mixed | 279 (20.2%) | 162 (13.9%) | 117 (54.7%) | <0.001 |
[i] *Fisher’s exact test, **Loop diuretics not used in those with RH. ACE- Angiotensin-converting enzyme. Mixed- use of free and single pill combinations together, RH- Resistant hypertension.