Obesity is a major public health problem in developed and developing countries, causing a range of respiratory and metabolic changes. There is a strong correlation between obesity and cardiorespiratory sleep disorders. The weight loss reduces the comorbidities and improves the quality of life, but clinical treatment it is not effective for a long period. In this context, currently bariatric surgery is an option for the real weight loss in the long term. Obstructive sleep apnea (OSA) is a common clinical condition observed in patients with obesity. Recent studies have found that more than 2/3 of obese patients also have OSA, and that these exhibit similar pathophysiological substrates for cardiovascular disease where increased blood pressure is a common consequence. This raises another discussion where obesity and OSA may have an additive effect on cardiovascular risk factors. Our main objective is to evaluate whether the systemic and adipose markers of inflammation alters after bariatric surgery through biochemical indexes in the visceral (omental, mesenteric) and subcutaneous adipose tissue depots and fasting blood samples, including the proinflammatory cytokines tumor necrosis factor α (TNFα), interleukin 6 (IL-6), interleukin 8 (IL-8), interleukin 18 (IL-18), soluble TNF receptor-2 (sTNFR2), soluble E-selectin, soluble intercellular adhesion molecule-1 (sICAM-1), soluble vascular cell adhesion molecule-1 (sVCAM-1), monocyte chemoattractant protein 1 (MCP 1), high sensitivity C-reactive protein (hsCRP), adiponectin (AdipoQ) genes, vascular endothelial growth factor A (VEGF-A), nuclear factor Kappa B (NF-kB) and adipose-derived hormone leptin. Moreover, identify the possible association of systemic and adipose inflammation before bariatric surgery with the magnitude of surgery-induced weight loss and to assess pulmonary function through spirometry and, maximal ventilatory pressures through vacuometry; to determine whether surgical procedure induced decrease in body weight, BMI, abdominal circumference and, improve quality of life; to study sleep patterns through full standard polysomnography and quality of life in obese patients undergone to bariatric surgery and verify a possible correlation between weight loss and physiological variables. Will participate in this study, patients with severe obesity (BMI > 40 or 35 to 39.9 kg/m2 associated comorbidities), with indication of bariatric surgery, screened Bariatric Surgery Service of Santa Casa de São Paulo in São Paulo. Inclusion criteria are severely obese, bariatric surgery indication and agreement to participate in the study. Are excluded patients with BMI > 55 kg/m2, clinical instability, mental instability or significant and unrealistic expectations of surgery. Patients will be assessed before and after bariatric surgery, 90, 180 and 360 days. The evaluation protocol will consist of clinical history, vital signs, neck and waist circumference, clinical analysis of blood inflammatory markers, lung function tests, maximal ventilatory pressures, full overnight standard polysomnography, excessive daytime sleepiness scale, cardiovascular risk, quality of life and personal satisfaction questionnaires.