Links to Studies about Post-Gastric Bypass Hypoglycemia or Hyperinsulinemia

Hypoglycemia or Hyperinsulinemia are getting more attention in post-gastric bypass patients. It is turning out to be more common than once thought. Below are the links to studies related to this issue. The link is followed by a snippet from the abstract (summary). 

Most of the links go directly to the abstract, rather than the full text. Often times, the full text of a more recent research study requires access to an academic library or to the journal itself. So, if you would like to read more than the abstract, ask your bariatric practitioner or maybe a friend who works at a college to if they would mind getting a copy of the full text for you.

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1) Hyperinsulinemic Hypoglycemia After Roux-en-Y Gastric Bypass: Unraveling the Role of Gut Hormonal and Pancreatic Endocrine Dysfunction

Profound hypoglycemia occurs rarely as a late complication after Roux-en-Y gastric bypass (RYGB). We investigated the role of glucagon-like-peptide-1 (GLP-1) in four subjects who developed recurrent neuro-glycopenia 2 to 3 y after RYGB.

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2) Abnormal glucose tolerance testing following gastric bypass demonstrates reactive hypoglycemia

Symptoms of reactive hypoglycemia have been reported by patients after Roux-en-Y gastric bypass (RYGB) surgery who experience maladaptive eating behavior and weight regain. A 4-h glucose tolerance test (GTT) was used to assess the incidence and extent of hypoglycemia.
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3) Glucagon Treatment for Post-Gastric Bypass Hypoglycemia
Hyperinsulinemic hypoglycemia is a rare complication of RYGB; its pathophysiology remains incompletely understood (1,3,4). These patients exhibit inappropriately high insulin and C-peptide concentrations during hypoglycemia (5,6). In addition, exaggerated insulin and incretin responses are observed during mixed meal tolerance test (5) and may contribute to hypoglycemia, potentially mediated in part by islet cell hyperplasia and/or altered function (1,4). Although most cases are mild and managed with dietary modification, symptoms can be profound and result in serious adverse consequences, and clinical management can be challenging. Treatment options include intensive dietary modification (6,7), α-glucosidase inhibitors, octreotide, and diazoxide (5,7). However, some patients remain refractory to treatment, and partial pancreatectomy has been undertaken, with varying success (4). Given the lack of efficacy of available interventions in some patients, and the goal of averting pancreatectomy, additional pharmacologic options are needed.

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4) Advances in the Etiology and Management of Hyperinsulinemic Hypoglycemia After Roux-en-Y Gastric Bypass      Treatment of hypoglycemia after RYGB should begin with strict dietary (low carbohydrate) alteration and may require a trial of diazoxide, octreotide, or calcium-channel antagonists, among other drugs. Surgical therapy should include consideration of a restrictive form of bariatric procedure, with or without reconstitution of gastrointestinal continuity. Partial or total pancreatic resection should be avoided.

Addiction Tip Sheet – Addiction and Weight Loss Surgery: A Social Worker’s Perspective « Helpstartshere.org

Here's an excellent article by Katie Jay about transfer addiction after bariatric surgeon. She does a very nice job of showing how this risk exists for WLS patients by telling one person's story. It's worth the read.

Addiction Tip Sheet – Addiction and Weight Loss Surgery: A Social Worker’s Perspective « Helpstartshere.org:

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Bariatric Surgery and Long-term Cardiovascular Events, January 4, 2012, Sjöström et al. 307 (1): 56 — JAMA

This is an excellent article from JAMA, related to the reduced risk of heart attacks and other cardiovascular events after WLS. Below is excerpt of the abstract, followed by the link to the study.

Results Bariatric surgery was associated with a reduced number of cardiovascular deaths (28 events among 2010 patients in the surgery group vs 49 events among 2037 patients in the control group; adjusted hazard ratio [HR], 0.47; 95% CI, 0.29-0.76; P = .002). The number of total first time (fatal or nonfatal) cardiovascular events (myocardial infarction or stroke, whichever came first) was lower in the surgery group (199 events among 2010 patients) than in the control group (234 events among 2037 patients; adjusted HR, 0.67; 95% CI, 0.54-0.83; P < .001).

Conclusion Compared with usual care, bariatric surgery was associated with reduced number of cardiovascular deaths and lower incidence of cardiovascular events in obese adults.

Here is the Link to the full story - -

Bariatric Surgery and Long-term Cardiovascular Events, January 4, 2012, Sjöström et al. 307 (1): 56 — JAMA:

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Why is it so Hard to Maintain a Reduced Body Weight? | Dr. Sharma's Obesity Notes

This is an excellent article explaining the role of leptin maintaining weight loss. As this article explains, formerly obese people burn about 20% fewer calories than people of the same weight who were never obese. This is not only because metabolism has been slowed by the obesity, but because the body perceives a drop in leptin and begins to hoard fuel (save calories) even while exercising. This is a very interesting read:

Why is it so Hard to Maintain a Reduced Body Weight? | Dr. Sharma's Obesity Notes:

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Links to Studies on Changes in Taste Perception after RNY

Bariatric surgery and taste: novel mechanisms of weight loss http://www.mendeley.com/research/bariatric-surgery-taste-novel-mechanisms-weight-loss/ Abstract PURPOSE OF REVIEW: The mechanisms by which obesity surgery and in particular gastric bypass cause weight loss are unclear. The review will focus on the concept of alterations in the sense of taste after obesity surgery. RECENT FINDINGS: Patients after obesity surgery and gastric bypass in particular change their eating behaviour and adopt healthier food preferences by avoiding high-calorie and high-fat foods. Patients find sweet and fatty meals less pleasant not due to postingestive side effects but through changes in the sense of taste. The acuity for sweet taste increases after gastric bypass potentially leading to increased intensity of perception. Obese patients experience higher activation of their brain taste reward and addiction centres in response to high calorie and fat tasting. Gastric bypass may reverse these taste hedonics, perhaps through the influence on gustatory pathways caused by enhanced gut hormone responses after surgery. SUMMARY: Elucidation of the metabolic mechanism behind the alterations in taste after obesity surgery could lead to the development of novel surgical and nonsurgical procedures for the treatment of obesity. ____________________________________________________________ Taste Acuity Of The Morbidly Obese Before and After Gastric Bypass Surgery http://scholar.google.com/scholar_url?hl=en&q=http://www.springerlink.com/index/v33hk5766341qn8j.pdf&sa=X&scisig=AAGBfm3MKIWbrYjkDlE3k-HC-IUp9DN-lw&oi=scholarr Abstract Obese individuals have an increased preference for high caloric foods, such as sweets and fats. However, following gastric bypass (GBP) surgery, morbidly obese patients tend to avoid these foods. We hypothesize that this aversion may occur, in part, from permutations in taste acuity. To test this hypothesis, taste detection and recognition thresholds for the four basic tastes (salt, sweet, sour, and bitter) were assessed using a modification of the Henkin forced choice three stimulus technique. Taste acuity measurements were obtained at baseline and at 30, 60, and 90 days post-operative for six morbidly obese GBP women and ten non-surgical, lean female controls. We found non-significant differences in taste detection and recognition thresholds between morbidly obese and lean control study subjects at baseline, and no significant correlation between taste acuity and body size. Furthermore, in our study population of lean and obese women, ages 26 to 52, there were no significant interrelationships between baseline taste thresholds and known effectors of taste acuity, i.e., zinc levels, glycemic status, liver and kidney function, or age. Following GBP surgery, a significant up-regulation in taste acuity for bitter and sour was observed along with a trend toward a reduction in salt and sweet detection and recognition thresholds. These findings would suggest the following: (1) taste acuity does not influence taste preferences of the obese individual who has not had bariatric surgery; (2) taste effectors such as zinc, when within the range of normal values, do not alter thresholds of the 4 basic tastes; and (3) weight loss following gastric bypass surgery is associated with an up-regulation in taste acuity in the morbidly obese. Studies are currently under investigation at our center to identify the specific etiology of taste acuity upregulation in the morbidly obese following GBP surgery. ___________________________________________________ Taste change after laparoscopic Roux-en-Y gastric bypass and laparoscopic adjustable gastric banding http://scholar.google.com/scholar_url?hl=en&q=http://www.sciencedirect.com/science/article/pii/S1550728906001377&sa=X&scisig=AAGBfm0E3me9DwpuL3hs5nS7RVc5i1-4AQ&oi=scholarr F Abstract Background Many patients have described changes in taste perception after weight loss surgery. Our hypothesis was that patients develop postoperative changes in taste that vary by bariatric procedure. Methods Patients who underwent laparoscopic Roux-en-Y gastric bypass (LRYGB) or laparoscopic adjustable gastric banding (LAGB) completed a 23-question institutional review board–approved survey postoperatively regarding their degree and type of taste changes and food aversion and how these influenced their eating habits. Results A total of 127 patients participated. After removing the inadequately completed surveys, 82 LRYGB and 28 LAGB patients were included. Of these, 87% of LRYGB and 69% of LAGB patients believed taste is important to the enjoyment of food. More LRYGB patients (82%) than LAGB patients (46%) reported a change in the taste of food or beverages after surgery (P <.001). In addition, 92% of LAGB versus 59% of LRYGB patients characterized the change as a decrease in the intensity of taste (P <.05). Additionally, 68% of LRYGB and 67% of LAGB patients found certain foods repulsive and had developed aversions. Also, 66% of LRYGB and 70% of LAGB patients believed the taste changes were greater than expected preoperatively. Most patients (83% of LRYGB and 69% of LAGB patients) agreed that the loss of taste led to better weight loss. Conclusion Although most LRYGB and many LAGB patients experienced taste changes and food repulsion postoperatively, procedural differences were found in these taste changes. Taste changes need to be investigated further as a possible mechanism of weight loss after bariatric surgery. MY APOLOGIES FOR THE LACK OF FORMATTING. THIS WAS DONE FROM MY iPad.

Article in October Bariatric Times on Hypoglycemia after RNY

Noninsulinoma Pancreatogenous Hypoglycemia after Roux-en-Y Gastric Bypass: A More Simple Operative Treatment

October 2011

Surgical Pearls: Techniques in Bariatric Surgery

This Month’s Featured Expert: Michael G. Sarr, MD

Dr. Sarr is Professor of Surgery, Division of Gastroenterologic and General Surgery, Gastrointestinal Research Unit (GU 10-01), Mayo Clinic, Rochester, Minnesota

Citation:  Bariatric Times. 2011;8(10):8–9

Introduction
The development of documented, severe hypoglycemic episodes after a Roux-en-Y gastric bypass (RYGB), albeit quite rare (<1%), has become a neuroglycopenic syndrome that is of considerable interest to bariatric surgeons, bariatricians, and endocrinologists alike. It is called the noninsulinoma pancreatogenous hypoglycemia syndrome (NIPHS).

 Please click on the link, above,                                       to read the entire article!

Link to research on hypoglycemia and glucose monitoring after gastric bypass

Here's the link to the research paper that my Endocrinologist gave me.   It is very interesting:
New research on Hypoglycemia post gastric bypass.