Table 1.
Studies that have investigated the association between resistant or refractory hypertension and sleep apnoea. Only those studies which have used a sleep test (either respiratory polygraphy or conventional polysomnography) have been included. Studies that assessed sleep apnoea risk based on screening questionnaires have not been included.
| Studies | Patients (n) | Age (Years) | Type of BP Measure SBP/DBP (mmHg) | Type of Sleep Study (AHI Threshold to Define OSA) | OSA Prevalence/AHI |
|---|---|---|---|---|---|
| Logan 2001 [13] | 41 patients with resistant HT (24 men, 17 women) | 57.2 (1.6) Men 54.6 (1.8) Women 58.3 (3.0) |
24 h ABPM SBP: 149.0 (2.6) in Men, 150.6 (3.7) in women DBP: 86.3 (2.0) in Men, 83.7 (1.9) in women |
PSG (AHI ≥ 10) | 82.9% (96% in men, 65% in women) Mean AHI: 32.2 (4.5) in men, 14.0 (3.1) in women |
| Martinez-Garcia 2006 [29] | 49 pts with resistant HT (40.8% men) | 68.1 (9.1) | 24 h ABPM SBP: 152.5 (13) DBP: 89.2 (8.5) |
RP (AHI ≥ 10) | AHI ≥ 10: 71.4% AHI ≥ 30: 40.8% Mean AHI: 26.2 (19.5) |
| Gonçalves 2007 [35] | 63 pts with resistant HT (21 men, 42 women) and 63 pts with controlled HT (23 men, 40 women) | 59 (7) in both the resistant and controlled HT groups | 24 h ABPM SBP: 141 (17) in the resistant HT group vs. 121 (10) in the controlled HT group DBP: 84 (12) in the resistant HT group vs. 74 (7) in the controlled HT group |
RP (AHI ≥ 10) | 71% in the resistant HT group vs. 38% in the controlled HT group (p < 0.001) Men: 86% vs. 52% (p = 0.016) Women: 64% vs. 30% (p = 0.002) |
| Prat-Ubunama 2007 [34] | 71 pts with resistant HT | 56.0 (9.9) | Office BP measurement SBP: 155.8 (27) DBP: 88.3 (15) |
PSG (AHI ≥ 5) | 85% (90% in men, 77% in women) Mean AHI: 24.1 (24.7) (Men 20.8, Women 10.8) |
| Lloberes 2010 [33] | 62 pts with resistant HT (67.3% men) | 59 (10) | 24 h ABPM SBP: 139.1 (1.6) DBP: 80.9 (1.2) |
PSG (AHI ≥ 5) | AHI ≥ 5: 90.3% AHI ≥ 30: 70% Mean AHI: 47.8 (23.4) |
| Pedrosa 2011 [16] | 125 pts with resistant HT (43% men) |
52 (10) | 24 h ABPM SBP: 176 (31) DBP: 107 (19) |
PSG (AHI ≥ 15) | AHI ≥ 15: 64% AHI ≥ 30: 32% Median AHI: 18 (interquartile range, 10–40) |
| Florczak 2013 [32] | 204 pts with resistant HT (123 men, 81 women) |
48.4 (10.6) | 24 h ABPM Daytime SBP: 145 (19), DBP: 90 (13) Nightime SBP: 132 (19), DBP: 79 (12) |
PSG (AHI ≥ 5) | AHI ≥ 5: 72.1% AHI ≥ 30: 26.5% |
| Ruttanaumpawan 2009 [14] | 42 pts with resistant HT and 22 pts with controlled HT, matched for age, sex and BMI | 56.5 (1.6) in resistant HT group, 60.1 (1.8) in controlled HT group | 24 h ABPM in the resistant HT group SBP: 149 (2) DBP: 85 (1) |
PSG (AHI ≥ 10) | 81% in the resistant HT group vs. 55% in the controlled HT group (p = 0.03) Mean AHI: 24.9 (3.2) in the resistant HT group vs. 16.5 (2.7) in the controlled HT group (p = 0.13) |
| Johnson 2019 [37] | 664 black participants with HT (205 men), of whom 96 (14.5%) had resistant HT | 64.9 (10.6) | Office BP measurement | RP (AHI ≥ 15) | 25.7% of all HT patients. Patients with resistant HT were 1.92 times more likely (95%CI 1.15–3.20) to have OSA, compared to those with controlled HT |
| Abdel-Kader 2012 [38] | 407 patients (229 men, 178 women), distributed in: 224 from general population without chronic kidney disease, 88 non-dialysis-dependent chronic kidney disease, and 95 with end-stage renal disease | 60.0 (7.2) for the non-chronic kidney disease, 52.2 (14) for the non-dialysis-dependent chronic kidney disease, and 53.8 (14.9) for the end-stage renal disease group | Office BP measurement Resistant HT was present in 4.9% of patients in the non-chronic kidney disease, 35.2% of the non-dialysis-dependent chronic kidney disease, and 22.1% of the end-stage renal disease group |
PSG (AHI ≥ 30) | Resistant HT was associated with severe OSA in participants with end-stage renal disease (adjusted OR 7.1, 95%CI 2.2–23.2), but not in the non-chronic kidney disease (adjusted OR 3.5, 95%CI 0.8–15.4) or the non-dialysis-dependent chronic kidney disease groups (adjusted OR 1.2, 95%CI 0.4–3.7) |
| Bhandari 2016 [36] | Retrospective cohort study of 470,386 individuals from a health insurance database | 65 (11) | HT and Resistant HT were identified by ICD-9 specific diagnoses codes SBP: 139 (20) DBP: 75 (13) |
Sleep apnoea was identified by ICD-9 specific diagnoses codes or by dispensation of positive pressure therapy | 9.6% in the resistant HT group vs. 6.8 in the non-resistant HT group (p < 0.01). Sleep apnoea was significantly more common in the resistant HT group compared to the non-resistant HT group (adjusted OR 1.16, 95%CI 1.12–1.19) |
| Martinez-Garcia 2018 * [15] | 229 pts with resistant HT (63% men). Of these, 42 (18.3%) had refractory HT | 58.3 (9.6) for the resistant HT group and 58.4 (8.5) for the refractory HT group | 24 h ABPM Resistant HT SBP: 141.6 (11.2) DBP: 82.2 (10) Refractory HT SBP: 152.4 (13.9) DBP: 85.6 (11.8) |
RP (AHI ≥ 5) | AHI ≥ 5 Resistant HT: 89.3% Refractory HT: 100% (p = 0.027) AHI ≥ 30: Resistant HT: 48.6% Refractory HT: 64.3% (p = 0.044) |
* This study investigate the association between OSA and refractory hypertension. HT: Hypertension; BMI: Body Mass Index; OSA: Obstructive Sleep Apnoea; SBP: Systolic Blood Pressure; DBP: Diastolic Blood Pressure; AHI: Apnoea–Hypopnoea Index; ABPM: 24h-Ambulatory Blood Pressure Monitoring; RP: Respiratory Polygraphy; PSG: Polysomnography; ICD: International Classification of the disease.