Efeitos do uso do aparelhos intra-oral sobre parâmetros de estresse oxidativo em pacientes com síndrome da apneia obstrutiva do sono

• Ano de defesa: 2010
• Autor(a) principal: Garbuio, Silvério Aparecido [UNIFESP]
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de São Paulo (UNIFESP)
• Palavras-chave em Português: Aparelho Intra-Oral; Catalase; Estresse Oxidativo; Polissonografia; Sono; Apnéia Obstrutiva do Sono
• Link de acesso: http://repositorio.unifesp.br/handle/11600/9428

Introduction: Obstructive Sleep Apnea Syndrome (OSAS) is associated with increased cardiovascular morbidity and mortality. The exact nature of the underlying pathophysiology of cardiovascular morbidity in OSAS patients has not been fully elucidated. One of the underlying mechanisms is the formation of Reactive Oxygen Species (ROS), increasing oxidative stress (OS) due to the intermittent hypoxia. Studies with OSAS patients highlighted an increase in markers of OS associated to vascular risk. Authors have demonstrated a decrease of OS after Continuous Positive Airway Pressure (CPAP). OS reduction by means of the Oral Appliance (OA) is yet to be comprehended. Objective: The purpose of this study was to evaluate the effect of an OA compared with CPAP regarding OS parameters in moderate to severe OSAS patients with a randomized, double blind and placebo controlled trial. Methods: Subjects were patients with moderate to severe OSAS, of both genders, BMI under 35, 25-65 years of age, in good dental condition. All patients were submitted to 3 treatments: mandibular repositioning appliance (BRD) in maximal comfortable protrusion, placebo appliance (PA) and CPAP with one month of each treatment and one week washout between them. It was a randomized, cross-over, double blind and placebo controlled trial. Epworth Sleepiness Scale (ESS), polysomnographic and OS parameters (Thiobarbituric Acid Reactive Substances -TBARS, Superoxide Dismutase, Catalase, Vitamins C, E, B6, B12 and Folate, Homocysteine, and Uric Acid) were evaluated at each phase (baseline and after one month of each treatment). Results: 29 patients (24 men and 5 women) took part of the study, with a mean age of 47.3 ± 8.9 years, BMI of 28.4 ± 3.6 Kg/m and scoring on ESS of 11.4 ± 5.3. Both OA and CPAP treatments led to a decrease on the Apnea and Hypopnea Index (AHI). The last, however, demonstrated better efficacy (baseline: 42.3 ± 4.5; PA: 48.7 ± 6.5; OA: 26.7 ± 4.8; CPAP: 3.2 ± 0.4; p < 0.05), besides improving ESS (baseline: 11.3 ± 1.0 versus CPAP: 9.7±0.8; p < 0.05). Notwithstanding, compliance rate during OA period was higher than during CPAP (86.3 ± 3.0% versus 72.0 ± 4.2%; p < 0.05). For the OS parameters, a significant drop in the levels of catalase activity was observed after OA compared to the baseline period (baseline: 115.8 ± 5.2; PA: 102.7 ± 4.4; OA: 95.3 ± 4.6; CPAP: 107.1 ± 3.8 U/mg Hb; p<0.01). Moreover, there was an increase in vitamin C levels after PA and CPAP (baseline: 54.9 ± 2.5; PA: 65.9 ± 3.0; OA: 62.3 ± 2.6; CPAP: 64.3 ± 2.5 umol/L; p<0.05), and in vitamin B6 after all treatment periods compared to initial values in baseline period (baseline: 18.9 ± 1.2; PA: 22.7 ± 1.5; OA: 22.2 ± 1.3; CPAP: 24.6 ± 0.9 nmol/L; p<0.05). Conclusion: Even though CPAP proved to be more effective in attenuating OSAS and its subjective associated complaints, the better compliance to OA in this group of patients supported the reduction of one of the enzymes which participates in ROS removal.