Evolución de las alteraciones metabólicas y hormonales de la obesidad grave tras la disminución de la adiposidad mediante cirugía bariátrica

Résumé

Obesity is a complex disease that has acquired epidemic proportions, becoming a health problem of the first order. Bariatric surgery, as a treatment for obesity and associated comorbidities, obtains commendable results; however, the etiopathogenic bases of its effect remain unclear. The characterization of the metabolic alterations in obesity, and their evolution after bariatric surgery, will allow a better understanding of the physiological mechanisms involved. Therefore, in this doctoral thesis we analyse severe obesity and its evolution after bariatric surgery, specifically: 1. Anthropometry. 2. The most prevalent comorbidities. 3. The carbohydrate, lipid and liver profile, inflammation markers and the thyroid, somatotropic and gonadal axes. 4. Blood levels of fibroblast growth factor 21 (FGF21), acylated ghrelin, peptide tyrosine-tyrosine 3-36 (PYY3-36) and leptin. Likewise, the data are analysed from a gender perspective and according to the type of bariatric surgery. Obtaining that: 1. Weight and body mass index (IMC) improve regardless of gender and type of bariatric surgery. Whereas, the fat mass and the excess weight lost (EPP) are dependent on both factors and the excess body mass index (EIMCP) is dependent on the type of surgery. 2. In the cohort of morbidly obese patients who decided to undergo bariatric surgery and participate in this thesis, type 2 diabetes mellitus (DM2) and dyslipidaemia are more prevalent in men and anxiety-depressive syndrome in women. Improving all comorbidities regardless of the type of surgery during the first three months after the operation, however, men show a more marked improvement in DM2. 3. Bariatric surgery improves carbohydrate metabolism, lipid and liver profile, somatotropic, thyroid and gonadal axes, as well as markers of inflammation. Furthermore, we find that the somatotropic axis and the lipid profile are dependent on sex and the type of surgery, respectively. 4. FGF21, acylated ghrelin, PYY3-36, and leptin are altered during obesity; however, only leptin and PYY3-36 improve one year after surgery. Acylated ghrelin, PYY3-36, and leptin are sex-dependent; while the evolution of acylated ghrelin and leptin are of the type of surgery. In conclusion, bariatric surgery obtains important beneficial effects on the health status of operated patients, with Roux-en-Y gastric bypass (RYGB) being the surgery with the greatest impact.