Surgery for Obesity Helps Treat Diabetes

Summarized by Robert W. Griffith, MD
February 12, 2004

Introduction

More and more obese people are turning to surgery to help achieve a dramatic reduction in weight. It's called 'bariatric surgery' (bariatric means related to the treatment of obesity). Different surgical techniques are used, but they all have the same purpose - to reduce the amount of food breakdown products that can be absorbed. One of the more successful is the laparoscopic Roux-en-Y gastric bypass procedure, which has been shown to achieve long-term weight loss (60% to 80% of excess body weight) in severely obese people. It has an acceptable safety record, with good recovery time.

Type 2 diabetics are often strikingly overweight. It's therefore important to know what sort of effect such a surgical intervention might have on the diabetic condition. A group of Pittsburgh surgeons have studied this, and reported their findings in the Annals of Surgery.

What was done

The surgeons had extensive experience with this type of surgery. Over a 5-year period (1997 to 2002) 1,160 patients had a laparoscopic Roux-en-Y gastric bypass procedure, or LRYGBP.¹ To be accepted for this surgery, patients had to be between 14 and 75, and have a BMI of 35 or more with some additional illness (such as diabetes, sleep apnea, or arthritis), or a BMI of 40 or above without any other additional condition.

Out of the 1,160 patients, 240 had type 2 diabetes or an impaired fasting glucose (IFG) level (i.e. it was above 110 mg/dL, or 6.1 mmol/L). This means one in five had frank diabetes or were in a pre-diabetic state. These patients were classified as to whether their diabetes was mild, moderate, or severe, and for how long they had been diabetic or pre-diabetic.

The results of surgery in diabetics and pre-diabetics

Follow-up information was obtained for 191 of the 240 diabetic patients who had surgery. Three-quarters of them were women. The average age was 48, ranging from 26 to 67 years.

After surgery in these patients, body weights decreased from an average of 308 lbs (140 kg) to 211 lbs (96 kg), and the average BMI fell from 50.1 to 34.

Fasting blood glucose levels fell to normal in 83% of the patients, and were greatly improved in the rest. Glycosylated hemoglobin levels (HbAc1) were equally improved. And there were significant reductions in the need for oral antidiabetic drugs and insulin in 80% of these patients.

Complete reversal of diabetes was found to be more likely in patients with the shortest duration of the disease (less than 5 years), the mildest form (i.e. controlled by diet alone), and those who lost the most weight after surgery.

How safe is this surgery in diabetics?

Sixteen patients (8%) had early major complications - pneumonia, or a leak at the new intestinal junction - and 29 (15%) had early minor complications - a leak causing peritonitis or abscess, or wound infection. Nineteen patients (20%) had late complications - intestinal obstruction, deep vein thrombosis, prolonged vomiting, and gastric ulcer. One death occurred 28 days after surgery, but the cause was not known, as autopsy was refused.

The overall major complication rate was 14%, the minor complication rate was 25%, and mortality was 0.5%. Clearly this is not a surgery to be undertaken lightly.

Comment

Obesity and type 2 diabetes are two of the most common chronic diseases of Western society, and both are increasing at a rapid rate. In a small group of patients, lifestyle changes (diet, physical activity) aren't able to reverse the process. These are potential candidates for gastric bypass surgery.

To date, bariatric surgery has been considered as an option for 'morbid' obesity. Only rarely is it mentioned as a way of correcting diabetes. The results of this study show that it can produce excellent results in this condition, and its use should be considered more often. The risks of diabetes associated with severe obesity are so great that surgery may be a worthwhile choice for some people. The fact that short duration and milder forms of diabetes respond best to this treatment suggests it should be considered earlier than has been the case up to now - but only when diet and exercise have been given an extensive trial, and have failed.

Source

• Effect of laparoscopic roux-en Y gastric bypass on type 2 diabetes mellitus. PR. Schauer, B. Burguera, S. Ikramuddin,  et al., Ann Surg, 2003, vol. 234, pp. 467--485

Footnotes
1. You can read about the actual Roux-en-Y bypass procedure at: http://www.bariatric.com/roux.htm. Laparoscopic means the procedure is done through two or more small incisions only, rather than a long incision, resulting in shorter convalescence. For a graphic description, go to: http://www.laparoscopy.com/obesity/roux.html

Related Links
The Roux-En-Y Gastric Bypass
Combine Healthy Habits to Tackle Syndrome X
Twenty Long Minutes
Stricter Guidelines for Diagnosing 'Pre-diabetes'

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