title: Decrease in circulating glucose, insulin and leptin levels and improvement in insulin resistance at 1 and 3 months after gastric bypass.
abstract: BACKGROUND
  Hyperglycemia, insulin resistance and hyperleptinemia are some of the consequences of obesity. Gastric bypass for morbid obesity provides gastric restriction with decreased energy absorption. To confirm and extend previous reports in the literature, we evaluated the plasma glucose, serum insulin and leptin and insulin resistance of patients preoperatively and 1 and 3 months after Roux-en-Y gastric bypass (RYGBP).
  
  
  METHODS
  We determined body mass index (BMI), plasma glucose (glucose-oxidase method), serum leptin (immunoassay) and insulin (chemiluminescent immunometric assay), and insulin resistance index (IRI) by Homeostasis Model Assessment (HOMA) of 20 patients with morbid obesity both preoperatively and 1 and 3 months after RYGBP.
  
  
  RESULTS
  Patients showed a mean decrease in weight of 8 kg/month. Glycemia was above reference levels in 65% of the preoperative patients but dropped significantly 1 month postoperatively, serum insulin and leptin levels and the HOMA index also decreasing significantly in the same period. The percentage of patients with preoperative elevated serum insulin and leptin relative to reference levels decreased significantly following RYGBP. We also observed a weak but significant correlation between BMI and glucose, BMI and insulin, and leptin and insulin.
  
  
  CONCLUSIONS
  The beneficial effects of bariatric surgery are already noticeable 1 month postoperatively, the reduction in insulin levels being more important for leptin reduction than decreased BMI. Leptin appeared to be subject to multifactorial control and showed a larger reduction than body weight.
authors.affiliation: Laboratório de Análises Clínicas do Curso de Ciências Farmacêuticas da Universidade de Ribeirão Preto (UNAERP), Ribeirão Preto-SP, Brazil.
authors.forename: Adriana Pelegrino Pinho
authors.initials: AP
authors.lastname: Ramos
authors.forename: Márcia Regina Azevedo
authors.initials: MR
authors.lastname: de Abreu
authors.forename: Regina Célia
authors.initials: RC
authors.lastname: Vendramini
authors.forename: Iguatemy Lourenço
authors.initials: IL
authors.lastname: Brunetti
authors.forename: Maria Teresa
authors.initials: MT
authors.lastname: Pepato
mesh_terms: D000328:Adult; D001786:Blood Glucose / Q000032:analysis*; D005260:Female; D015390:Gastric Bypass; D006801:Humans; D007328:Insulin / Q000097:blood*; D007333:Insulin Resistance; D020738:Leptin / Q000097:blood*; D008163:Luminescent Measurements; D008297:Male; D008875:Middle Aged; D009767:Obesity, Morbid / Q000097:blood* / Q000503:physiopathology* / Q000601:surgery; D011184:Postoperative Period; D013997:Time Factors
chemical_list: D001786:Blood Glucose; D007328:Insulin; D020738:Leptin