Staats, RichardBarros, Maria Inês Marques da Silva Figueiredo de2017-01-102017-01-102015http://hdl.handle.net/10451/25822Trabalho Final do Curso de Mestrado Integrado em Medicina, Faculdade de Medicina, Universidade de Lisboa, 2015Introduction: Blood pressure, cardiac output, heart rate and stroke volume are influenced by the sleep-wake cycle. Healthy subjects have a decrease in blood pressure associated with sleep onset (SO). Patients with Obstructive Sleep Apnea (OSA) often lack this reduction. Obesity is a major risk factor for OSA, and it is not clear if obese patients without OSA demonstrate this dipping. The aim of this study is to investigate the hemodynamic changes during SO in an obese population with and without OSA. Methods: Hemodynamic parameters were recorded in 40 obese patients via Nexfin-HD® device. We divided the patients into obese without OSA (group A) and with OSA (group B) and the study period in two phases: (0) 5 min before SO and (1) 20 min after SO. A p<0.05 was considered statistically significant. Results: In both groups, SO wasn’t associated with a significant decrease in any variable. Group B had a significant higher variability in all variables in phase 1 than group A. SO was also associated with higher variability than in group A, however this result only reach statistical significance in systolic and mean arterial pressure. Discussion: The non-dipping pattern noticed in all variables in both groups indicates that obesity might be an independent risk factor for OSA related changes in physiological hemodynamic response to SO. Apneic and hypopneic episodes seem to play a major role in the oscillating hemodynamic parameters and higher variability seen in OSA. In conclusion, obesity and OSA might act as additive factors for hemodynamic instability during sleep.Introdução: A pressão arterial, o output cardíaco, a frequência cardíaca e o volume sistólico são influenciados pelo ciclo sono/vigília. Nos indivíduos saudáveis, com o início do sono (IS), verifica-se um decréscimo da pressão arterial. No entanto, frequentemente, este decréscimo não se verifica em doentes com apneia obstrutiva do sono (AOS). A obesidade é um fator de risco major para a AOS e, não é claro, se os obesos sem AOS têm este decréscimo fisiológico. O objetivo deste estudo é investigar as alterações hemodinâmicas associadas ao início do sono em doentes obesos com e sem AOS.engObesidadePolissonografiaPressão arterialFrequência cardíacaOutput cardíacoVolume sistólicomaster thesis201059282