New research presented at this year's annual meeting of the European Association for the Study of Diabetes (EASD) in Berlin, Germany, reveals that while gastric bypass (GBP) surgery offers obvious benefits in obese individuals with type 2 diabetes (T2D), there are also a range of potential adverse events that require monitoring and potential treatment.
The research conducted by Vasileios Liakopoulos and colleagues from the Department of Molecular and Clinical Medicine, University of Gothenburg, Gothenburg, Sweden sought to evaluate the long-term effects of GBP in obese patients with T2DM, in particular regarding the risks of postoperative complications.
Previous studies have looked into the effects of GBP, but there is limited information about the long-term impact on obese individuals with T2D. Having this information should allow doctors to make more informed decisions when selecting candidates for surgery, and give them a better understanding of the kind of follow-up and support that needs to be made available to patients.
The authors investigated postoperative outcomes from GBP in a nationwide cohort obtained by merging data from the Scandinavian Obesity Surgery Registry, the National Diabetes Register, and national databases. They matched patients with T2D who had undergone GBP with those who had not been treated surgically for obesity, based on factors including sex, age, and body mass index (BMI). The cohort for the study consisted of 5321 T2DM patients who underwent a GBP operation, and 5321 control subjects who did not, with both groups being followed for up to 9 years to evaluate outcomes.
The study found that all-cause mortality risk was reduced by 49% after GBP, the risk of cardiovascular disease fell by 34%, and there were positive effects on severe kidney disease. A number of short-term complications were significantly more likely following the operation with rates being 2 to 9 times higher than in the control population (gallstone & gallbladder disease [2.5 times higher risk], gastrointestinal ulcer/reflux [5.4 times], bowel obstruction [9.5 times]). Abdominal pain (5.5 times more) and gastrointestinal conditions occurred more frequently in the surgery group and often required additional surgery (HR 3.3 times increased risk).
The authors found that GBP increased the risk of anaemia by 92% and made patients 3 times more likely to suffer from malnutrition. In addition, individuals who underwent the operation were 33% more likely to be given a psychiatric diagnosis, and abused alcohol at a rate three times higher than the control group.
The authors state that: "This nationwide study confirms the benefits but also describes the variety of adverse effects after bariatric surgery in obese persons with type 2 diabetes."
They conclude that: "In order to maximise the benefit and minimise the risk of unfavorable results after bariatric surgery, a thorough and long-term follow-up and support of these patients appears vital. Better selection of patients for such surgery could probably also improve results."