Obesity Surgery

, Volume 19, Issue 11, pp 1550–1556 | Cite as

Plasma Glucose and Insulin Regulation Is Abnormal Following Gastric Bypass Surgery with or Without Neuroglycopenia

  • Sun H. KimEmail author
  • Teresa C. Liu
  • Fahim Abbasi
  • Cindy Lamendola
  • John M. Morton
  • Gerald M. Reaven
  • Tracey L. McLaughlin
Research Clinical



Enhanced insulin sensitivity is commonly seen following Roux-en-Y gastric bypass surgery (RYGB) whereas symptomatic hypoglycemia post-RYGB seems to occur infrequently. It is unclear how different plasma glucose and insulin responses are in patients with symptomatic hypoglycemia (SX-RYGB) versus those who remain asymptomatic (ASX-RYGB), nor when compared with non-surgical controls with varying degrees of insulin sensitivity.


Plasma glucose and insulin concentrations were determined following a 75-g oral glucose challenge in five groups: symptomatic and asymptomatic patients following RYGB (n = 9 each) and overweight/obese controls, divided into three subgroups (n = 30 each) on the basis of degree of insulin sensitivity measured by the insulin suppression test.


SX-RYGB group had higher 30-min glucose after oral glucose compared with the ASX-RYGB group (p = 0.04). The two groups did not differ in peak glucose and insulin concentrations, nadir glucose concentration, or insulin-to-glucose ratio 30 min after oral glucose. These values were significantly different from the three control groups, and peak insulin concentrations post-RYGB were increased at every degree of insulin sensitivity as compared with the control groups.


Plasma glucose and insulin responses to oral glucose in patients with symptomatic hypoglycemia post-RYGB are minimally different when compared to individuals who remain asymptomatic, and both groups demonstrate hyperinsulinemia out of proportion to their degree of insulin sensitivity.


Gastric bypass Hypoglycemia Obesity Hyperinsulinism Insulin resistance 



This study was supported by NIH Research Grants RR-00070 and K23 MH079114 (SHK).


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Copyright information

© Springer Science + Business Media, LLC 2009

Authors and Affiliations

  • Sun H. Kim
    • 1
    Email author
  • Teresa C. Liu
    • 1
  • Fahim Abbasi
    • 1
  • Cindy Lamendola
    • 1
  • John M. Morton
    • 2
  • Gerald M. Reaven
    • 1
  • Tracey L. McLaughlin
    • 1
  1. 1.Department of MedicineStanford University Medical CenterStanfordUSA
  2. 2.Department of SurgeryStanford University Medical CenterStanfordUSA

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