title: Morbidly obese individuals with impaired fasting glucose have a specific pattern of insulin secretion and sensitivity: effect of weight loss after bariatric surgery.
abstract: BACKGROUND
  Obesity is often associated with hyper-secrection of insulin. Impaired fasting glucose (IFG) has recently been redefined as a fasting plasma glucose of 5.6-6.9 mmol/L. The aim of this study was to determine whether changes in insulin secretion in morbidly obese persons also commence with normal serum glucose levels.
  
  
  METHODS
  32 morbidly obese subjects were studied before and after bariatric surgery. Measurements were made of glucose tolerance (K(G)), insulin sensitivity (SI), first-phase insulin release and the disposition index (DI) from a frequently sampled intravenous glucose tolerance test.
  
  
  RESULTS
  In morbidly obese subjects, the SI (P<0.01), DI (P<0.01) and first-phase insulin release (P<0.02) started changing with serum glucose levels considered to be normal (5.00-5.28 mmol/L). K(G) showed a clear slope according to the baseline glycemia status (P<0.05), and it was significantly related with the DI, both before (r=0.76, P<0.001) and after (r=0.57, P=0.002) surgery. Following surgery, all the variables significantly associated with insulin secretion and insulin sensitivity recovered significantly. The most significant changes occurred in morbidly obese individuals with IFG.
  
  
  CONCLUSIONS
  Morbidly obese subjects show slopes of insulin sensitivity and insulin secretion in accordance with their baseline serum glucose levels. The fall in first-phase insulin release begins when serum glucose values are considered normal. Morbidly obese persons with the IFG phenotype have a specific pattern of insulin sensitivity and insulin secretion. K(G) clearly discriminates the clinical phenotypes, depending on baseline serum glucose levels.
authors.affiliation: Fundación IMABIS, Málaga, Spain. edugf1@eresmas.com
authors.forename: Eduardo
authors.initials: E
authors.lastname: García-Fuentes
authors.forename: Jose Manuel
authors.initials: JM
authors.lastname: García-Almeida
authors.forename: Juan
authors.initials: J
authors.lastname: García-Arnés
authors.forename: Jose
authors.initials: J
authors.lastname: Rivas-Marín
authors.forename: Jose Luis
authors.initials: JL
authors.lastname: Gallego-Perales
authors.forename: Belén
authors.initials: B
authors.lastname: González-Jiménez
authors.forename: Isabel
authors.initials: I
authors.lastname: Cardona
authors.forename: Sara
authors.initials: S
authors.lastname: García-Serrano
authors.forename: M José
authors.initials: MJ
authors.lastname: Garriga
authors.forename: Montserrat
authors.initials: M
authors.lastname: Gonzalo
authors.forename: M Sol Ruiz
authors.initials: MS
authors.lastname: de Adana
authors.forename: Federico
authors.initials: F
authors.lastname: Soriguer
mesh_terms: D000293:Adolescent; D000328:Adult; D050110:Bariatric Surgery; D001786:Blood Glucose / Q000378:metabolism*; D016022:Case-Control Studies; D005215:Fasting / Q000502:physiology; D005260:Female; D005500:Follow-Up Studies; D018149:Glucose Intolerance / Q000097:blood* / Q000150:complications* / Q000601:surgery; D005951:Glucose Tolerance Test; D006801:Humans; D007328:Insulin / Q000097:blood* / Q000378:metabolism; D000078790:Insulin Secretion; D008297:Male; D008875:Middle Aged; D009767:Obesity, Morbid / Q000097:blood* / Q000150:complications* / Q000601:surgery; D015431:Weight Loss / Q000502:physiology
chemical_list: D001786:Blood Glucose; D007328:Insulin