Bariatric surgery appears to prevent microvascular complications, too

Last Updated: 2018-08-08

By Megan Brooks

NEW YORK (Reuters Health) - For obese patients with type 2 diabetes mellitus (T2DM), bariatric surgery is not only associated with improved blood sugar control but also appears to help prevent microvascular complications, according to a new study.

"Not all patients will be interested in bariatric surgery to treat their T2DM, but providers should engage all patients with T2DM and a BMI of 35 kg/m2 or higher in a shared decision-making conversation about the benefits and risks of bariatric procedures," write the researchers, led by Dr. David Arterburn of Kaiser Permanente Washington Health Research Institute in Seattle.

Prior studies have shown that most patients experience remission of their T2DM after bariatric procedures. However, less is known about whether bariatric surgery reduces the risk of incident microvascular disease, Dr. Arterburn and colleagues note in Annals of Internal Medicine, online August 7.

They investigated the relationship between bariatric surgery and the development of microvascular complications of T2DM in a retrospective matched cohort study based in four integrated U.S. health systems. They selected 4,024 patients with T2DM who had bariatric surgery and matched them on relevant factors with up to three nonsurgical patients (n=11,059).

In adjusted Cox regression analysis, bariatric surgery was associated with a 59% reduction in incident microvascular disease at five years. Rates of microvascular disease were 17% for surgical versus 35% for nonsurgical patients (adjusted hazard ratio, 0.41; 95% confidence interval, 0.34 to 0.48).

Bariatric surgery was associated with significantly lower cumulative incidence of diabetic neuropathy (7% for surgical vs. 21% for nonsurgical patients), nephropathy (5% vs. 10%) and retinopathy (7% vs. 11%).

"What this study shows is that people with type 2 diabetes who undergo bariatric surgery have less than half the rate of long-term microvascular complications than patients who get usual medical care for their diabetes," Dr. Arterburn told Reuters Health by email.

"Such a remarkable decrease in microvascular complications has rarely been shown by any form of diabetes therapy," Dr. Carel le Roux from University College Dublin, in Ireland, and Dr. Philip Schauer from Cleveland Clinic Lerner College of Medicine, in Ohio, write in a linked editorial.

"For health care policy, these findings imply that bariatric surgery should now be considered an effective T2DM treatment not only to alleviate hyperglycemia but also to prevent the complications that account for the morbidity and mortality of the disease," they add. "With this new data . . . we can now consider surgery a treatment of diabetes beyond glycemia. Bariatric surgery can now be intended to prevent complications of T2DM."

"Bariatric surgery," they add, "is safe and is, at present, our most evidence-based treatment to put hyperglycemia from T2DM into remission. We are on the verge of having the data to tell our patients with T2DM in the clinic that we can offer them a treatment that significantly reduces the feared complications of this dreadful disease. Surgery should not be a last resort but instead should be used earlier, because prevention is definitely better than cure."

Dr. Arterburn said this is the first long-term study of all forms of microvascular disease in a U.S.-based cohort of patients undergoing contemporary bariatric procedures, including 76% gastric bypass, 17% sleeve gastrectomy and 7% adjustable gastric banding patients, which are the most common bariatric procedures performed today.

"Clinicians should make sure that all of their patients with severe obesity and diabetes are aware of this and other studies of diabetes outcomes after bariatric surgery, so that patients can make an informed decision about whether bariatric surgery is a reasonable treatment for their diabetes," he told Reuters Health.

The study was funded by the National Institute of Diabetes and Digestive and Kidney Diseases.

SOURCE: https://bit.ly/2M7HpCd and https://bit.ly/2AOdLgQ

Ann Intern Med. 2018.