Efficacy of the Treatment With Nasal Positive Continuous Airway Pressure to Reduce the Arterial Blood Pressure in Patients With Apneas-Hypopneas During the Sleep and Systemic Hypertension

AIMS:To know the effects of the treatment with nasal positive continuous airway pressure (CPAP) on systemic blood pressure and the expression of biological mediators, in systemic hypertension of recent diagnostic, whose have an apnea-hypopnea index > 15.

METHODOLOGY: DESIGN: Prospective, multicenter, randomized study, of parallel groups and controlled with placebo, in patients diagnosed of systemic hypertension (SH) with an apnea-hypopnea index, by conventional polysomnography > 15. A total of 340 patients with recently diagnosed of SH and without any pharmacological treatment will be studied. All patients will be randomized to receive, alternatively, CPAP treatment with optimal pressure titled with a proved system, or Sham-CPAP for 12 weeks.

MEASUREMENTS: A) Conventional polysomnography at baseline: B) Clinic: sleepiness (ATS, Basic Nordic Sleep Questionnaire and Epworth), quality of life (EuroQol); C) 24 hour blood pressure monitoring; D) Expression of biological mediators in blood: general determinations, endothelial, inflammatory, lipid, renin-angiotensin-aldosterone and adrenergic mediators.

ANALYSIS. Baseline measurements of all the variables will be compared with the situation at six and twelve weeks. We will use the chi square test and the Fisher´s exact test (categorical variables), the t test for continous variables and repeated measures ANCOVA for the primary objective. The analyses will be done under the criterion of intention to treat and for protocol. The variables will be controlled by the compliance with the CPAP..