Abstract
Introduction: Increased visit‐to‐visit blood pressure variability (BPV) is associated with serious cardiovascular (CV) events, but whether continuous positive airway pressure (CPAP) influences BPV in patients with obstructive sleep apnea (OSA) is uncertain. We aimed to determine the effects of CPAP treatment on visit‐to‐visit BPV in participants of the Sleep Apnea and cardioVascular Endpoints (SAVE) trial.
Methods: SAVE was an international, randomized, parallel group, open trial of CPAP plus usual care or Usual Care (UC) alone in participants with moderate‐severe OSA and established CV disease. Between‐group comparisons of BPV were made for participants with either 5 or 6 in‐office BP measurements during 24 months post‐randomization, with BPV defined as the standard deviation (SD) for each participant's BP across visits. Baseline‐adjusted mean BP at each time point was compared between groups using a mixed effects linear regression model. The effect of systolic BPV (SBPV) on the primary composite CV endpoint, stroke and myocardial infarction were also determined in multivariable Cox regression models.
Results: 2,381 SAVE participants met the inclusion criteria, 1,887 (˜80%) of whom were taking anti‐hypertensive therapy. Compared to the UC group, CPAP‐treated participants showed small, significant, decreases in mean SBP (baseline adjusted p = 0.015) and mean DBP (baseline adjusted p = 0.013) that were stable through months 1–12. There was no between‐group difference in the adjusted BPV across months 1–24 (SBPV difference 0.35 mmHg (95% CI −0.55 to 0.77 mmHg, p = 0.090; DBPV difference 0.00 mmHg (−0.01 to 0.02 mmHg, p = 0.712). There was a linear effect of SBPV on the risk of CV events (p = 0.010 for trend); after adjusting for mean BP and other known CV risk factors, participants in the highest quintile of SBPV had a 63% increased risk of having another CV event (p = 0.004).
Discussion: CPAP had no overall effect on BPV after the first month of treatment. Modest reductions in mean SBP and DBP occurred in the first year of treatment.
Methods: SAVE was an international, randomized, parallel group, open trial of CPAP plus usual care or Usual Care (UC) alone in participants with moderate‐severe OSA and established CV disease. Between‐group comparisons of BPV were made for participants with either 5 or 6 in‐office BP measurements during 24 months post‐randomization, with BPV defined as the standard deviation (SD) for each participant's BP across visits. Baseline‐adjusted mean BP at each time point was compared between groups using a mixed effects linear regression model. The effect of systolic BPV (SBPV) on the primary composite CV endpoint, stroke and myocardial infarction were also determined in multivariable Cox regression models.
Results: 2,381 SAVE participants met the inclusion criteria, 1,887 (˜80%) of whom were taking anti‐hypertensive therapy. Compared to the UC group, CPAP‐treated participants showed small, significant, decreases in mean SBP (baseline adjusted p = 0.015) and mean DBP (baseline adjusted p = 0.013) that were stable through months 1–12. There was no between‐group difference in the adjusted BPV across months 1–24 (SBPV difference 0.35 mmHg (95% CI −0.55 to 0.77 mmHg, p = 0.090; DBPV difference 0.00 mmHg (−0.01 to 0.02 mmHg, p = 0.712). There was a linear effect of SBPV on the risk of CV events (p = 0.010 for trend); after adjusting for mean BP and other known CV risk factors, participants in the highest quintile of SBPV had a 63% increased risk of having another CV event (p = 0.004).
Discussion: CPAP had no overall effect on BPV after the first month of treatment. Modest reductions in mean SBP and DBP occurred in the first year of treatment.
Original language | English |
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Article number | e33_12765 |
Number of pages | 2 |
Journal | Journal of Sleep Research |
Volume | 27 |
Issue number | S2 |
DOIs | |
Publication status | Published - Oct 2018 |
Event | Sleep Down Under 2018: 30th ASM of Australasian Sleep Association and the Australasian Sleep Technologists Association - Brisbane, Australia Duration: 17 Oct 2018 → 20 Oct 2018 |
Keywords
- CPAP
- blood pressure
- Obstructive sleep apnea
- Cardiovascular disease