Table 2

Randomised controlled studies of blood pressure and OSAHS

Study	No of subjects	Epworth Sleepiness Score	AHI	Placebo	Outcome	Comments
AHI, apnoea/hypopnoea index; BP, blood pressure; CPAP, continuous positive airway pressure; RDI, respiratory disturbance index; RCT, randomised controlled trial.
Faccenda¹⁷	68	Mean 15	Mean 35	Placebo tablet	1.5 mm Hg diastolic BP fall with CPAP	Subgroup analysis showed greatest BP fall in those with most severe disease (RDI >20)
Dimsdale²⁰	39	Not documented	Mean RDI 48.1	Sham CPAP	About 5 mm Hg mean nocturnal BP fall	One week treatment; fall in daytime BP in placebo group at 1 week
Barbe¹⁸	55	Mean 7	Mean 56	Sham CPAP	No change in BP	Patients with no hypersomnolence compared with other RCTs
Pepperell¹	95	Mean 16	Mean 4% >dip rate 37	Sham CPAP	Mean BP fall 3.3 mm Hg	Subgroup analysis showed greatest BP fall in those on antihypertensives
Monasterio²²	125	Mean 12.6	Mean 20	Conservative treatment	No change in BP at 3 and 6 months	No BP effect in patients with mild disease
Becker¹⁹	32	Mean 14	Mean 64	Partially therapeutic sham CPAP	Mean BP fall 9.9 mm Hg	9 weeks of treatment, more severe disease, two-thirds on antihypertensives