Effect of CPAP on blood pressure in patients with OSA/hypopnea a systematic review and meta-analysis.
BACKGROUND
CPAP is considered the therapy of choice for OSA, but the extent to which it can reduce BP is still under debate. We undertook a systematic review and meta-analysis of randomized controlled trials (RCTs) to quantify the effect size of the reduction of BP by CPAP therapy compared with other passive (sham CPAP, tablets of placebo drug, conservative measures) or active (oral appliance, antihypertensive drugs) treatments.


METHODS
We searched four different databases (MEDLINE, EMBASE, Web of Science, and the Cochrane Library) with specific search terms and selection criteria.


RESULTS
From 1,599 articles, we included 31 RCTs that compared CPAP with either passive or active treatment. In a random-effects meta-analysis vs passive treatment (29 RCTs, 1,820 subjects), we observed a mean±SEM net difference in systolic BP of 2.6±0.6 mm Hg and in diastolic BP of 2.0±0.4 mm Hg, favoring treatment with CPAP (P<.001). Among studies using 24-h ambulatory BP monitoring that presented data on daytime and nighttime periods, the mean difference in systolic and diastolic BP was, respectively, 2.2±0.7 and 1.9±0.6 mm Hg during daytime and 3.8±0.8 and 1.8±0.6 mm Hg during nighttime. In meta-regression analysis, a higher baseline apnea/hypopnea index was associated with a greater mean net decrease in systolic BP (beta±SE, 0.08±0.04). There was no evidence of publication bias, and heterogeneity was mild ( I2, 34%-36%).


CONCLUSIONS
Therapy with CPAP significantly reduces BP in patients with OSA but with a low effect size. Patients with frequent apneic episodes may benefit the most from CPAP.
Department of Medicine, Clinical Biochemistry Section, University Hospital of Verona, Verona, Italy. Electronic address: cristiano.fava@med.lu.se.
Cristiano
C
Fava
Department of Medicine, Clinical Biochemistry Section, University Hospital of Verona, Verona, Italy.
Stefania
S
Dorigoni
Department of Medicine, Clinical Biochemistry Section, University Hospital of Verona, Verona, Italy.
Francesco
F
Dalle Vedove
Department of Medicine, Clinical Biochemistry Section, University Hospital of Verona, Verona, Italy; Division of Internal Medicine C, and Department of Life and Reproduction Sciences, Clinical Biochemistry Section, University Hospital of Verona, Verona, Italy.
Elisa
E
Danese
Division of Internal Medicine C, and Department of Life and Reproduction Sciences, Clinical Biochemistry Section, University Hospital of Verona, Verona, Italy.
Martina
M
Montagnana
Division of Internal Medicine C, and Department of Life and Reproduction Sciences, Clinical Biochemistry Section, University Hospital of Verona, Verona, Italy.
Gian Cesare
GC
Guidi
Department of Hypertension and Diabetology, Medical University of Gdańsk, Gdańsk, Poland.
Krzysztof
K
Narkiewicz
Department of Medicine, Clinical Biochemistry Section, University Hospital of Verona, Verona, Italy.
Pietro
P
Minuz
D001794:Blood Pressure; D045422:Continuous Positive Airway Pressure; D006801:Humans; D020181:Sleep Apnea, Obstructive / Q000503:physiopathology* / Q000628:therapy*