Bariatric Surgery- Unstable Blood Sugar After Gastric Bypass

Many would say the benefits of weight loss surgery are obvious.  You look better, you feel better, you’re healthier, and you live longer.  There are many common side effects of surgery, which clients obviously must decide for themselves if the potential benefits are worth the risks and inconveniences.  There is an emerging trend however of a much more serious complication of unstable blood sugar. 

Bariatric surgery is a general term referring to weight loss surgery. Approximately 160,000 Americans have gastric bypass weight loss surgery each year. Generally candidates must be at least 100 lbs overweight, and go through rigorous testing and counseling before surgery. The most common surgery is the Roux-en-Y. Of course there are risks with any surgery, and the decision to have bariatric surgery cannot be taken lightly. The benefits must outweigh the risks. What are the benefits and risks?

A significant proportion of prospective clients already have weight-related chronic health problems such as high blood pressure, sleep apnea and diabetes. Many bariatric candidates and their physicians consider the surgery a matter of life and death. Other candidates are surely at risk to develop these and other obesity-related problems that are known to negatively impact good health and quality of life.

There are risks of complications related directly to the surgery, such as bleeding and leakage around the surgical site. There is an array of side effects after surgery, many of which are permanent. Among these are multiple vitamin and nutritional deficiencies and something called dumping syndrome. Dumping occurs when undigested food passes too quickly from the now egg-sized stomach into the small intestine. Symptoms, which can include feeling faint or dizzy, tend to happen after a high carbohydrate meal.

A condition is emerging in a small percentage of clients, occurring 2 to 5 years after bariatric surgery. The condition, associated primarily with the Roux-en-Y procedure, is a potentially dangerous drop in blood sugar, called hypoglycemia. The symptoms occur after meals and include feeling confused or light headed, having a fast pulse, sweating, and shaking. Because these symptoms are similar to dumping symptoms, many clients are not given a proper workup for blood sugar regulation abnormalities. One factor that distinguishes hypoglycemia in these clients is blacking out, and in some cases causing car accidents. Clients may also report feeling ravenous, having bad morning headaches, or having nightmares.

In 2005, the president of the American Society for Bariatric Surgery, Dr. Neil Hutcher, stated he had not seen the severe low blood sugar complication, neuroglycopenia, in his 3000 bariatric operations. Other experts at that time proclaimed the problem was rare, corrected by surgical removal of all or part of the pancreas, and that patients had no further complications. They therefore concluded it was unnecessary to curtail bariatric procedures.

Also in this timeframe, by contrast major hospitals and universities were publishing studies of small numbers of clients with reactive hypoglycemia. Clients were experiencing these dramatic severe drops in blood sugar after meals. Episodes began several years after successful weight loss from bariatric surgery. Considered a delayed or latent effect of dumping syndrome, undigested food quickly passes from the stomach pouch to the small bowel. Excessive insulin is then released, resulting in the rapid and dramatic drop in blood sugar, and onset of symptoms including confusion or passing out.

Also in 2005, an important study was released in October by a collaborative group of researchers from Joslin Diabetes Center, Brigham and Women’s Hospital and Beth Isreal. The researchers noted that, while rare, the blood sugar should be evaluated expeditiously in clients exhibiting symptoms. The severe drop in blood sugar is potentially dangerous and the researchers were concerned that they would be attributed to dumping and essentially ignored. It is easy to imagine that many cases may go undiagnosed if they occur 5 years after gastric bypass surgery. By this time, the client may no longer be following up with the bariatric team. Clients and personal physicians may likely attribute symptoms to dumping.

The research team studied three clients who experienced severe hypoglycemic episodes after meals. Two clients caused auto accidents. These clients did not respond to dietary changes or medicines. Their symptoms got worse over time. They all subsequently had all or part of their pancreas removed, which was the emerging treatment for this condition. Examination of the removed tissue revealed an increase above normal in the number insulin producing cells.

Most studies concluded clients seemed to experience decreased severity of symptoms due to drops in blood sugar following removal of pancreatic tissue. For some clients however, the condition recurred.

In 2009 at the American Society for Metabolic & Bariatric Surgery Meeting, Dr. Mitchell Roslin of Lenox Hill Hospital, NY reported another tend of blood glucose issues. He noted common presentations by clients who regained weight after gastric bypass. Patients were understandably alarmed, and reported an uncontrollable drive to eat shortly after meals. Although less dramatic, again a reactive hypoglycemia was suspected. They theorized mildly decreased blood sugar levels due to increased insulin release would increase hunger.

Dr. Roslin and associates studied 67 clients, with an average of four years since gastric bypass surgery. The average age was 48, with 81% female. Average weight pre-surgery was 300 lbs, with an average body mass index (BMI) of 49. (Healthy BMI is 18.5 to 25.) Clients lost an average of 55% BMI of their excess weight. Clients had regained an average of 26 lbs. After glucose tolerance testing, 80% were determined to have glucose abnormalities.

The specialists found the most dramatic swings in blood glucose were associated with small stomach pouches with wide anastomoses. They concluded that alternatives to the standard gastric bypass procedure, such as incorporation of valves needed to be explored. Further, they suggested that gastric bypass be abandoned, and a completely different approach be explored. Bombshell!

This article is dedicated to Miss Betty, Peter and Amy.