CPAP Effect on Lipid Profile and Hyperuricemia in Patients With Dyslipidemia and Moderate-severe Obstructive Sleep Apnea

Clinical Trial Phase IV Indication: Moderate-severe obstructive sleep apnea and dyslipidemia. Objectives: Main objective: To test whether 12 months of CPAP treatment associated with conventional pharmacological treatment improves the lipid profile of patients with dyslipidemia and moderate to severe OSA. Secondary objectives: * To test whether 12 months of treatment with CPAP associated with conventional pharmacological treatment improves serum uric acid concentration in patients with dyslipidemia and moderate-severe OSA. * To determine the additional medium- and long-term effect of CPAP on insulin resistance in patients with dyslipidemia and moderate-severe OSA. * To evaluate the impact of CPAP treatment on cardiovascular risk reduction in patients with dyslipidemia and moderate-severe OSA. * To analyze the impact of supplemental CPAP treatment on glycemic control and C-reactive protein concentration in patients with dyslipidemia and moderate-severe OSA. * To establish the impact of supplemental CPAP therapy on health-related quality of life in patients with dyslipidemia and moderate-severe OSA. * To evaluate the effect of CPAP on inflammatory cytokines, oxidative stress biomarkers, sympathetic tone and intake-regulating hormones in patients with dyslipidemia and moderate-severe OSA. * To relate CPAP-induced changes in serum lipid and uric acid concentration to changes in basal inflammatory response, oxidative stress, sympathetic activity, and intake-regulating hormones. * To identify the subgroup of patients with dyslipidemia and moderate-severe OSA in whom 12 months of CPAP treatment achieves a more marked reduction in serum lipids and uric acid. Design Randomized, parallel-group, nonblinded, controlled clinical trial with conventional treatment. Study population Subjects aged 35 to 80 years with a diagnosis of dyslipidemia made at least six months ago and with moderate-severe obstructive sleep apnea (OSA) not requiring CPAP treatment according to conventional indications. Sample size: 110 patients in each treatment arm. Treatment Patients will be randomly assigned in a 1:1 ratio to one of the following treatment arms: 1. Conventional hygienic-dietary recommendations and promotion of daily physical activity. 2. Conventional hygienic-dietary recommendations and promotion of daily physical activity, plus treatment with positive airway pressure (CPAP). Efficiency variables * Main variables: LDL-cholesterol and uric acid. * Total cholesterol, HDL-cholesterol and triglycerides. * Basal blood glucose, glycosylated hemoglobin (HbA1c), creatinine and C-reactive protein. * Systemic biomarkers: inflammatory (IL-6, IL-8 and TNF-α), oxidative stress (8-isoprostane), endothelial damage (endothelin, VCAM-1 and ICAM-1), sympathetic activity (neuropeptide Y) and appetite-regulating hormones (leptin, orexin A/hypocretin 1 and ghrelin). * Clinical questionnaires: SF-12, EuroQoL, FOSQ and IPAQ. Safety variables * Clinical adverse event reporting. * CPAP compliance (average hours of use per day). * Epworth Sleepiness Questionnaire. * Development of cardiovascular events.