Roux-en-Y gastric bypass corrects hyperinsulinemia implications for the remission of type 2 diabetes.

Abstract

CONTEXT:

Roux-en-Y gastric bypass (RYGB) has been shown to induce rapid and durable reversal of type 2 diabetes.

OBJECTIVE:

The aim of the study was to investigate a possible mechanism for the remission of type 2 diabetes after RYGB.

DESIGN:

A cross-sectional, nonrandomized, controlled study was conducted. Surgery patients were studied before RYGB and 1 wk and 3 months after surgery.

SETTING:

This study was conducted at East Carolina University.

SUBJECTS:

Subjects were recruited into three groups: 1) lean controls with no surgery [body mass index (BMI) < 25 kg/m²; n = 9], 2) severely obese type 2 diabetic patients (BMI > 35 kg/m²; n = 9), and 3) severely obese nondiabetic patients (BMI > 35 kg/m²; n = 9).

INTERVENTION:

Intervention was RYGB.

RESULTS:

One week after RYGB, diabetes was resolved despite continued insulin resistance (insulin sensitivity index was approximately 50% of lean controls) and reduced insulin secretion during an iv glucose tolerance test (acute insulin response to glucose was approximately 50% of lean controls). Fasting insulin decreased and was no different from lean control despite continued elevated glucose in the type 2 diabetic patients compared with lean.

CONCLUSIONS:

After RYGB, fasting insulin decreases to levels like those of lean control subjects and diabetes is reversed (fasting blood glucose < 125 mg/dl). This leads us to propose that 1) exclusion of food from the foregut corrects hyperinsulinemia and 2) fasting insulin is dissociated from the influence of fasting glucose, insulin resistance, and BMI. The mechanisms for reversal of diabetes in the face of reduced insulin remain a paradox.

• Authors: Melissa A Reed, Walter J Pories, William Chapman, John Pender, Rita Bowden, Hisham Barakat, Timothy P Gavin, Tom Green, Ed Tapscott, Donghai Zheng, Nigel Shankley, Lynn Yieh, David Polidori, Steven P Piccoli, Leona Brenner-Gati, G Lynis Dohm
• Journal: The Journal of clinical endocrinology and metabolism (J Clin Endocrinol Metab) Vol. 96 Issue 8 Pg. 2525-31 (Aug 2011) ISSN: 1945-7197 [Electronic] United States
• PMID: 21593117 (Publication Type: Comparative Study, Controlled Clinical Trial, Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Insulin

Topics

• Adult
• Body Mass Index
• Diabetes Mellitus, Type 2 (complications, surgery)
• Female
• Gastric Bypass
• Glucose Tolerance Test
• Humans
• Hyperinsulinism (complications, surgery)
• Insulin (blood, metabolism)
• Insulin Resistance
• Insulin Secretion
• Middle Aged
• Obesity, Morbid (complications, surgery)
• Remission Induction