In the United States, more than 90% of 25.8 million adults with diabetes have type 2 disease, according to the CDC. More than 1.9 million cases were diagnosed in 2010 alone among adults aged 20 and older. Approximately 90% of type 2 diabetes has been attributable to excess weight and obesity. “The results of noninvasive interventions for type 2 diabetes and obesity, such as lifestyle changes and pharmacotherapy, have been disappointing,” says Jon C. Gould, MD. “Bariatric surgery appears to be one of the most effective, long-lasting treatments for obesity. In many clinical trials, these procedures have been quite effective for individuals who are obese and have type 2 diabetes.”

Riveting New Data on Bariatric Surgery Results

In the June 2011 Archives of Surgery, a systematic review was published demonstrating that bariatric surgery leads to marked and long-lasting weight reduction, and may be capable of improving or even curing type 2 diabetes. The analysis reviewed findings from nine studies that followed obese patients with diabetes who underwent either gastric bypass or gastric banding for 1 year. Rick Meijer, MD, and colleagues from Amsterdam found that Roux-en-Y gastric bypass led to a reversal rate of type 2 diabetes of 83%. Adjustable gastric banding led to a reversal rate of 62%, and this effect was achieved later after surgery (Figure 1).

“The presence of diabetes is a compelling argument to perform bariatric surgery in eligible patients according to nationally recognized criteria for the procedure,” says Dr. Gould. “Dr. Meijer’s study showed that glycemic control improved in the months after laparoscopic adjustable gastric banding, but it improved more rapidly and completely after laparoscopic Roux-en-Y gastric bypass surgery. In the end, both types of surgery were capable of improving or even curing type 2 diabetes, but the mechanisms may be different. It appears that surgeons should consider bariatric surgery earlier in the treatment of obese patients with diabetes to improve long-term outcomes.”

“Surgeons should consider bariatric surgery earlier in the treatment of obese patients with diabetes to improve long-term outcomes.”

—Jon C. Gould, MD

According to the study by Dr. Meijer and colleagues, the underlying mechanisms leading to improved glycemic control after bariatric surgery only have been partly elucidated. There are several mechanisms that should be considered responsible for the resolution of diabetes after bariatric surgery (Figure 2). “Hopefully, more data will emerge on the mechanisms of the resolution of diabetes related to which bariatric procedures are performed in obese patients with diabetes,” adds Dr. Gould. In addition to the beneficial effects on type 2 diabetes, improvements in other important risk factors partly explain the reduced mortality rates that have been observed after bariatric surgery. For example, hypertension improves in about 80% of patients after they receive their operation (see also, Helpful Guidelines for Heart Health in Diabetes. Other studies have shown that hypercholesterolemia and hypertriglyceridemia improve after surgery. Furthermore, cardiac function appears to improve, and obstructive sleep apnea appears to lessen postoperatively.

Weigh the Pros & Cons of Bariatric Surgery

Dr. Gould believes that the high upfront costs of bariatric surgery can be recouped within 18 months to 2 years when compared with the extended costs of managing diabetes and other obesity-related health issues. The study by Meijer et al found that the average medical expenditures among those with diabetes were 2.3 times higher than those among non-diabetic patients. “Eventually, people with diabetes develop serious complications that are very costly to manage,” says Dr. Gould. “Early intervention with bariatric surgery may help alleviate these costs.” (see also, Is Bariatric Surgery in Diabetics Cost-Effective?)

Like any operation, bariatric surgery has potential complications that should be considered. “That said,” Dr. Gould says, “bariatric surgery is continually becoming safer, with fewer complications following these procedures. Weight regain is another possibility for patients who undergo bariatric surgery, and there may be several reasons as to why this occurs. In order to avoid these problems, physicians must spend time up front with patients to ensure that they overcome any issues that may impact their ability to keep the weight off.”

Dr. Gould also stresses the importance of postoperative care. Follow-up programs should go beyond simply ensuring that incisions have healed appropriately to achieve positive long-term results by addressing dietary, psychologic, and other ongoing issues. “The benefits of bariatric surgery can wear off if the proper postoperative care isn’t addressed,” he says. “Fortunately, the establishment of Centers of Excellence programs can enhance outcomes so that bariatric surgery is safer than ever before.”

Gaining Acceptance: A Metabolic Procedure

According to Dr. Gould, bariatric terminology puts the focus on weight, which is why he prefers the term metabolic surgery. He says “bariatric surgeons have battled biases about these operations and about obesity in particular. The perception in the community is that bariatric surgery is an elective, cosmetic procedure. Referring to this surgery as a metabolic procedure may improve the perception of these procedures in the future.”

References

Meijer R, van Wagensveld B, Siegert C, et al. Bariatric surgery as a novel treatment for type 2 diabetes mellitus. Arch Surg. 2011;146:744-750.

Gould J. What’s in a name? Comment on “Bariatric surgery as a novel treatment for type 2 diabetes mellitus.” Arch Surg. 2011;146:750-751.

Zhang H, Wang Y, Zhang J, et al. Bariatric surgery reduces visceral adipose inflammation and improves endothelial function in type 2 diabetic mice. Arteriosclerosis, Thrombosis, Vasc Biol.  2011. Jun 16 [Epub ahead of print]. Available at http://atvb.ahajournals.org/cgi/content/short/ATVBAHA.111.225870v1?rss=1.

Cui Y, Elahi D, Andersen D. Advances in the etiology and management of hyperinsulinemic hypoglycemia after Roux-en-Y gastric bypass. J Gastroint Surg. 2011. Jun 14 [Epub ahead of print]. Available at www.springerlink.com/content/t370770117r26556.

Camastra S, Gastaldelli A, Mari A, et al. Early and longer term effects of gastric bypass surgery on tissue-specific insulin sensitivity and beta cell function in morbidly obese patients with and without type 2 diabetes. Diabetologia. 2011. May 26 [Epub ahead of print]. Available at www.springerlink.com/content/j64j449g42507207.

Eckel R, Kahn S, Ferrannini E, et al. Obesity and type 2 diabetes: what can be unified and what needs to be individualized? J Clin Endocrinol Metabolism. 2011;96:1654-1663.