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GBS in T2DM patients: Study highlights pros and cons, need for better patient selection



Gastric bypass surgery lowers the risk of all-cause mortality and cardiovascular disease and also has beneficial effects on severe kidney disease in obese patients with type 2 diabetes mellitus (T2DM), but the risk for a number of short-term complications is high, according to a nationwide, matched, observational cohort study in Sweden.

After 9 years of follow-up, all-cause mortality was 49% lower among 5,321 patients with T2DM compared with 5,321 matched control (183 vs. 351 deaths; hazard ratio, 0.51), as has been reported in prior studies, Vasileios Liakopoulos, MD, of the University of Gothenburg (Sweden) reported at the annual scientific sessions of the American Diabetes Association.

Cardiovascular disease (CVD) risk was 34% lower (108 vs. 150 patients; HR, 0.66), fatal CVD risk was 66% lower (21 vs. 64 patients; HR, 0.34), acute myocardial infarction risk was 45% lower (51 vs. 85 events; HR, 0.55) congestive heart failure risk was 51% lower (109 vs. 225 events; HR, 0.49), and cancer risk was 22% lower (153 vs. 188 cases; HR, 0.78) in cases vs. controls, respectively.

“[As for] the diagnoses that related to diabetes, hyperglycemia was lower by 66%, admission to the hospital due to amputation was 49% lower, and we also found something relatively new – that renal disease was lower by 42%,” Dr. Liakopoulos said.

Renal disease occurred in 105 cases vs. 187 controls (HR, 0.58), with the difference between the groups intensifying after the third year of follow-up, he noted.

However, numerous adverse events occurred more often in case patients, he said.

For example, hospitalizations for psychiatric disorders were increased by 33% (317 vs. 268; HR, 1.33), alcohol-related diagnoses were nearly threefold higher (180 vs. 65; HR, 2.90), malnutrition occurred nearly three times more often (128 vs. 46 patients; HR, 2.81), and anemia occurred nearly twice as often (84 vs. 46 cases; HR, 1.92) in cases vs. controls.

Of course, all the surgery-related adverse events occurred more often in the case patients, but interestingly, those events – which included things like gastrointestinal surgery other than gastric bypass, abdominal pain, gallstones/pancreatitis, gastrointestinal ulcers and reflux, and bowel obstruction – did not occur more often in case patients than in gastric bypass patients without diabetes in other studies, he noted.

The findings were based on merged data from the Scandinavian Obesity Surgery Registry, the Swedish National Diabetes Register, and other national databases, and persons with T2DM who had undergone gastric bypass surgery between 2007 and 2013 were matched by propensity score (based on sex, age, body mass index, and calendar time from the beginning of the study) with obese individuals who were not surgically treated for obesity. The risks of postoperative outcomes were assessed using a Cox regression model adjusted for sex, age, body mass index, and socioeconomic status, Dr. Liakopoulos said.

This study, though limited by its observational nature, minor differences in patient characteristics between the cases and controls, and potential residual confounding, confirms the benefits of gastric bypass surgery in obese patients with T2DM but also characterizes an array of both short- and long-term adverse events after bariatric surgery in these patients, he said.

“The beneficial effects of gastric bypass have been presented in terms of weight reduction, improvements in risk factors and cardiovascular disease, and mortality reduction in people with or without diabetes,” he said, noting, however, that only a few reports have addressed long-term incidence of complications after gastric bypass – and type 2 diabetes has only been addressed in small randomized studies or in low proportions in large prospective studies.

“[Based on the findings] we suggest better selection of patients for bariatric surgery, and we think improved long-term postoperative monitoring might further improve the results of such treatment,” he concluded.

Dr. Liakopoulos reported having no disclosures.

SOURCE: Liakopoulos V et al. ADA 2018, Abstract 131-OR.

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