TABLE VIII.B. 4.a.
Evidence for PAP therapy and blood pressure control
| Study | Year | LOE | Study design | Study groups | Clinical end-point | Conclusion |
|---|---|---|---|---|---|---|
| Bazzano et al.1207 | 2007 | 1a | Meta-analysis of 16 RCTs (n = 818) – low heterogeneity | 1) OSA, treated with CPAP for at least 2 weeks (and up to 24 weeks, with good adherence in most studies). 2) OSA controls (sham-CPAP, pill, or usual care). OSA was mostly moderate-severe. All but 5 studies used ambulatory BP monitoring. |
1) SBP 2) DBP 3) MAP |
Mean SBP decreased by 2.46 mmHg (95% CI: −4.31 to −0.62), mean DBP by 1.83 mmHg (95% CI: −3.05 to −0.61) and MAP by 2.22 mmHg (95% CI: −4.38 to −0.05) with CPAP. Decreases in nocturnal and daytime BP were not statistically different. Dose–response relationship between mean hourly usage of CPAP and reduction in SBP was noted. |
| Fava et al.1209 | 2014 | 1a | Meta-analysis of 29 RCTs (n = 1820) – moderate heterogeneity | 1) OSA, treated with CPAP (good adherence in most studies) for 2–52 weeks. 2) OSA controls (sham-CPAP, pill, or usual care). OSA was mostly moderate–severe. Most studies used ambulatory BP monitoring, some included subjects with HTN. |
1) SBP 2) DBP |
Mean SBP decreased by 2.6 ± 0.6 mmHg and DBP by 2.0 ± 0.4 mmHg; p < 0.001) with CPAP. Daytime SBP and DBP fell by 2.2 ± 0.7 and 1.9 ± 0.6 mmHg respectively and nighttime SBP and DBP by 3.8 ± 0.8 and 1.8 ± 0.6 mmHg, respectively. Higher severity of OSA was associated with a greater decline in mean SBP. |
| Yu et al.654 | 2017 | 1a | Meta-analysis of 10 RCTs evaluating the primary outcome; two of these and two others, i.e., a total of four studies (n = 3017) measured BP before and after CPAP) – low to moderate heterogeneity | 1) OSA, treated with CPAP (most with suboptimal adherence). 2) OSA, receiving sham-CPAP or usual care. |
Major adverse cardiovascular events. BP (SBP, DBP) was an “inter-mediate” outcome | Pooled mean difference in SBP was 0.20 mmHg (95%CI: −2.29 to −1.89, p = 0.05 and DBP was 0.21 mmHg (95%CI: −1.06 to −0.65, p = 0.80) in CPAP vs. control groups. |
| Patil et al.39 | 2019 | 1a | Meta-analysis of 26 RCTs (n = 2444 had 24-h BP measured before and after) – moderate heterogeneity | 1) OSA, treated with CPAP (many with suboptimal adherence). 2) OSA, various control conditions (sham-CPAP, pill, or usual care). OSA was mostly moderate-severe. Five studies included subjects with HTN, five with RHTN. |
1) Multiple outcomes assessed, one of which was BP (SBP, DBP, and mean BP) | Mean nighttime SBP and DBP fell by 4.2 mmHg (95%CI: −6.0 to −2.5) and 2.3 mmHg (95%CI: −3.7 to −0.9) respectively with CPAP. Mean daytime SBP and DBP fell by −2.8 mmHg (95%CI: −4.3 to −1.2) and −2.0 mmHg (95%CI: −3.0 to −0.9), respectively; 24-h SBP, DBP, and mean BP all decreased significantly. In those with HTN, nighttime SBP and DBP, daytime SBP and DBP, and 24-h SBP and mean BP all decreased. In those with RHTN, significant reductions in nighttime SBP and DBP, daytime DBP, 24-h SBP and DBP, but no clinically significant reduction in daytime SBP was noted. |
| Bratton et al.1208 | 2015 | 1a | Meta-analysis of 51 studies (n = 4888) – moderate heterogeneity | 1) OSA, on CPAP. 2) OSA, on OA. 3) OSA, inactive control. follow-up ranged between 4 and 157 weeks, with variable adherence to CPAP. Many studies had subjects with HTN, including RHTN. Forty-four studies compared CPAP to inactive control, three compared OA to inactive control, one compared CPAP to OA, and three compared those on CPAP, OA, and inactive control. |
1) SBP 2) DBP |
CPAP reduced SBP by 2.5 mmHg (95%CI: −1.5 to −3.5; p < 0.001) and DBP by 2.0 mmHg (95%CI: −1.3 to −2.7; p < 0.001) vs. inactive control; a dose–response relationship between hours of usage of CPAP and reduction in SBP/DBP was noted. OA reduced SBP by 2.1 mmHg (95%CI: −0.8 to −3.4; p = 0.002) and DBP by 1.9 mmHg (95%CI: −0.5 to −3.2; p = 0.008). There were no significant differences in reduction in SBP/DBP between CPAP and OA in the network meta-analysis. |
| Iftikhar et al.1210 | 2014 | 1a | Meta-analysis (two observational studies, n = 44; four RCTs, n = 320) – moderate heterogeneity | 1) OSA and RHTN, treated with CPAP for 2–6 months. 2) OSA and RHTN, not treated. OSA was mostly severe. CPAP adherence was good. All but one study used ambulatory BP monitoring. |
1) 24-h SBP 2) 24-h DBP |
24-h SBP decreased by 7.21 mmHg (95%CI: −9.04 to −5.38; p < 0.001) and DBP by 4.99 mmHg (95%CI: −6.01 to −3.96; p < 0.001) with CPAP. Ambulatory SBP and DBP from four RCTs showed a decrease of 6.74 mmHg (95% CI: −9.98 to −3.49; p < 0.001) and 5.94 mmHg (95% CI: −9.40 to −2.47; p = 0.001), respectively. |
| Liu et al.1211 | 2016 | 1a | Meta-analysis of five RCTs (n = 216), moderate heterogeneity | 1) OSA and RHTN, treated with CPAP for 8 weeks to 6 months. 2) OSA and RHTN, not treated or on sham CPAP. OSA was moderate-severe. CPAP adherence was good and subjects reported no or mild sleepiness at baseline. |
1) 24-h SBP and DBP 2) Daytime SBP and DBP 3) Nocturnal SBP and DBP |
24-h SBP fell by 4.78 mmHg (95%CI: −7.95 to −1.61) and 24-h DBP by 2.95 mmHg (95%CI: −5.37 to −0.53) with CPAP. Nocturnal DBP decreased by 1.53 mmHg (95%CI: −3.07–0) with CPAP. |
Abbreviations: BP, blood pressure; CI, confidence intervals; CPAP, continuous positive airway pressure; CSA, central sleep apnea; CV, cardiovascular; DBP, diastolic blood pressure; MAP, mean arterial pressure; OA, oral appliance; OSA, obstructive sleep apnea; RCT, randomized controlled trial; RHTN, resistant hypertension; SBP, systolic blood pressure.