Obesity is associated with several comorbidities, especially cardiovascular and metabolic diseases. Bariatric surgery is the most effective treatment for obesity, leading to long-term weight loss, reversal of the associated diseases and reduction in long-term mortality. The relative effectiveness of each type of surgery is not yet fully clear, but all the surgeries lead to a significant improvement in metabolic diseases. Resistance to insulin is associated to obesity and is an essential step in the pathophysiology of diabetes. The metabolic effects of surgery (most studied are the effects of gastric bypass) lead to an early improvement of insulin resistance even before significant weight loss has occurred. Metabolic syndrome clusters several cardiovascular risk factors and is increased in obese patients. Surgery leads to remission of metabolic syndrome in up to 80% of patients. The remission of type 2 diabetes after surgery is significantly greater after surgery than with the best medical management, varying between 50-80%. Severity and control of type 2 diabetes are related to the resolution rates after surgery. Coronary artery disease, atherosclerosis, gastro-esophageal reflux disease, obstructive sleep apnea, cardiac failure, renal failure, non-alcoholic hepatic steatosis and other obesity-associated diseases are significantly improved after bariatric surgery. Patients with higher body mass indexes and lower disease burden seem to be those that improve the most, achieving higher remission rates of obesity-associated diseases. Even in the most severe forms of uncontrolled metabolic disease, bariatric surgery leads to a significant improvement of comorbidities.
Keywords: Bariatric surgery, Body mass index, Cardiovascular risk factor, Chronic kidney disease, Dislypidemia, Gastro-esophageal reflux disease, Glycemic control, High blood pressure, Metabolic surgery, Metabolic syndrome, Mortality, Non-alcoholic fatty liver disease, Obstructive sleep apnea, Predictors, Quality of life, Remission, Resistance to insulin, Roux-en-Y gastric bypass, Sleeve gastrectomy, Type 2 diabetes mellitus, Weight loss.