Sodium-Restricted Diet and Diuretic in the Treatment of Severe Sleep Apnea

Inclusion Criteria: * Men in the age range from 18 to 60 years * Full-night in-laboratory polysomnography with apnea-hypopnea index \> 30/h in the last three months * Body mass index \< 35 kg/m2 * Informed consent Exclusion Criteria: * Already having started any treatment for sleep apnea, including use of continuous positive airway pressure * NYHA heart failure, any class * Predominantly central apnea * Peripheral venous or lymphatic insufficiency * Any chronic renal disease * Use of diuretics and substances with action in the central or peripheral nervous system such as benzodiazepines, hypnotics, anticonvulsants, antidepressants, appetite suppressants, amphetamines, antiparkinson agents, muscle relaxants, bronchodilators * Stroke within 6 months or with incapacitating sequelae * Any physical, mental or social condition impairing the ability to participate in the trial