Bariatric Surgery Causes Most Cases of Type 2 to Remit Long-Term

In morbidly obese patients with Type 2 diabetes, bariatric surgery leads to resolution or improvement of the disease in close to 90% of cases, with benefits usually maintained for at least 2 years, according to a meta-analysis.

Dr. Henry Buchwald at the University of Minnesota in Minneapolis and fellow researchers analyzed data from 621 primary studies published between 1990 and 2006, involving 135,246 patients. Mean BMI at baseline was 47.9 and 22.3% of patients had Type 2 diabetes.

Among diabetic patients, postoperative insulin levels, HbA1c, and fasting blood glucose values all decreased significantly, with 87% of patients having improvement or resolution of the clinical signs of diabetes. They lost 64% of their excess body weight.

"These responses are more pronounced in procedures associated with a greater percentage of excess body weight loss and is maintained for 2 years or more," Dr. Buchwald and associates report.

Specifically, 78% of diabetes was totally resolved, with the effect greatest among those who underwent biliopancreatic diversion/duodenal switch (95%), followed by gastric bypass (80%), gastroplasty (80%), and laparoscopic adjustable gastric banding (57%).

The investigators note that mortality following bariatric operations is among the lowest of any surgical procedure in the US.
"Randomized clinical trials comparing surgery and medical therapies for Type 2 diabetes are urgently needed," which they believe should include less obese patients as well as those who are morbidly obese.

Am J Med  March 2009;122:248-256.