title: Circulating Apolipoprotein A-IV presurgical levels are associated with improvement in insulin sensitivity after Roux-en-Y gastric bypass surgery.
abstract: BACKGROUND
  Apolipoprotein A-IV (ApoA-IV) has been shown to be involved in obesity and diabetes pathogenesis in animal studies, but its role in humans is uncertain.
  
  
  OBJECTIVE
  The objective of this study was to determine the relation of ApoA-IV with changes in glucose metabolism and weight after bariatric surgery.
  
  
  METHODS
  University Hospital.
  
  
  METHODS
  The patients (n = 49) included lean controls (n = 8) and patients before and after a mean of 7 months after laparoscopic adjustable gastric banding (LAGB, n = 12), laparoscopic Roux-en-Y gastric bypass (RYGB, n = 22), or laparoscopic sleeve gastrectomy (SG, n = 11). ApoA-IV and other hormone assays were performed in the fasting and the postprandial state. Pearson's correlation analyses controlled for baseline BMI and percent excess weight loss (EWL) were used to determine relationships between ApoA-IV levels and insulin resistance (HOMA-IR).
  
  
  RESULTS
  With all bariatric procedures combined, the change in ApoA-IV [533 versus 518 microg/L, P = .813] or ApoA-IV area under the curve (AUC - 1072 versus 1042, P = .939) was not significant. None of the surgeries individually affected levels of fasting or ApoA-IV AUC. Bariatric surgery resulted in a decrease in HOMA-IR (5.3 versus 2.0, P<.001). In the RYGB group, higher baseline ApoA-IV levels correlated with decrease in HOMA-IR [r = -.6, P = .008]. This relationship was independent of EWL and was not observed in the LAGB or SG group. There was no association of ApoA-IV levels with EWL, insulin secretion, Peptide-YY, or leptin levels.
  
  
  CONCLUSIONS
  Preoperative ApoA-IV levels, rather than changes in levels, positively correlate with improvements in insulin sensitivity independent of weight loss after RYGB.
authors.affiliation: Department of Surgery, Rutgers Robert Wood Johnson Medical School, New Brunswick, NJ.
authors.forename: Raghavendra
authors.initials: R
authors.lastname: Rao
authors.affiliation: Bowdoin College, Brunswick, ME.
authors.forename: Alexander
authors.initials: A
authors.lastname: Roche
authors.affiliation: Department of Medicine, Columbia University Medical Center, New York, NY.
authors.forename: Gerardo
authors.initials: G
authors.lastname: Febres
authors.affiliation: Department of Surgery , Columbia University Medical Center, New York, NY.
authors.forename: Marc
authors.initials: M
authors.lastname: Bessler
authors.affiliation: Department of Pathology and Laboratory Medicine, Metabolic Diseases Institute, University of Cincinnati, Cincinnati, OH.
authors.forename: Patrick
authors.initials: P
authors.lastname: Tso
authors.affiliation: Department of Medicine, Columbia University Medical Center, New York, NY. Electronic address: jk181@cumc.columbia.edu.
authors.forename: Judith
authors.initials: J
authors.lastname: Korner
mesh_terms: D000328:Adult; D001054:Apolipoproteins A / Q000378:metabolism*; D001786:Blood Glucose / Q000378:metabolism; D015992:Body Mass Index; D016022:Case-Control Studies; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000601:surgery; D005215:Fasting / Q000097:blood; D005260:Female; D005743:Gastrectomy; D015390:Gastric Bypass; D015391:Gastroplasty; D006801:Humans; D007333:Insulin Resistance / Q000502:physiology; D010535:Laparoscopy; D008297:Male; D009765:Obesity / Q000097:blood / Q000601:surgery; D019894:Peptide YY / Q000378:metabolism; D011182:Postoperative Care; D019518:Postprandial Period; D011300:Preoperative Care; D015431:Weight Loss / Q000502:physiology
chemical_list: D001054:Apolipoproteins A; D001786:Blood Glucose; C022205:apolipoprotein A-IV; D019894:Peptide YY
keywords: Laparascopic adjustable gastric banding; PYY; RYGB, LAGB, LSG, Apolipoprotein A4, insulin resistance, Roux-en-Y gastric bypass; Sleeve gastrectomy; apolipoprotein A-IV