Surgical Endoscopy

, Volume 28, Issue 5, pp 1489–1493

Improved insulin sensitivity after gastric bypass correlates with decreased total body fat, but not with changes in free fatty acids

  • Alessandro Mor
  • Lawrence Tabone
  • Philip Omotosho
  • Alfonso Torquati



Increased plasma free fatty acids (FFAs) are considered one of the key elements in the pathogenesis of insulin resistance (IR) and type 2 diabetes (T2DM). We hypothesize that, in diabetic patients undergoing laparoscopic Roux-en-Y gastric bypass (LRYGB), a postoperative decrease in FFA will correlate with improved insulin sensitivity (Si).


A total of 30 obese [body mass index ((BMI) >35 kg/m2] patients with a diagnosis of T2DM were studied preoperatively and 12 months after LRYGB in a prospective cohort study. Collected data included intravenous glucose tolerance test (IVGTT), total body composition by dual-energy X-ray absorptiometry and plasma levels of FFA. Si analysis from the IVGTT was estimated from minimal model analysis. Pre- and postoperative variables were compared using a paired sample t test. Relationships between changes in variables were determined with Pearson’s correlation test.


Twelve months after LRYGB the study population showed a significant decrease in BMI (p = 0.001), FFA (p = 0.03), and total body fat (p = 0.03), with an increase in Si (p = 0.001). Postoperative changes in Si significantly correlated (Pearson’s r = –0.53, p = 0.01) with change in total body fat, but not with changes in plasma FFA (Pearson’s r = –0.22, p = 0.31).


Our study challenges the notion that IR is mediated to a significant degree by changes in plasma FFA concentration. Instead, changes in adiposity and consequently changes in adipokine release can be the key players in determining remission of T2DM after LRYGB.


Bariatric surgery Laparoscopic Roux-en-Y gastric bypass Free fatty acid Insulin sensitivity Insulin resistance Total body fat Adiposity 


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Copyright information

© Springer Science+Business Media New York 2013

Authors and Affiliations

  • Alessandro Mor
    • 1
  • Lawrence Tabone
    • 1
  • Philip Omotosho
    • 1
  • Alfonso Torquati
    • 1
  1. 1.Department of Surgery, Duke Centre for Metabolic and Bariatric SurgeryDuke UniversityDurhamUSA

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