Field Notes

Gastric Bypass Improves Long-Term Diabetes Remission

Adults who have obesity and type 2 diabetes are much more likely to see their diabetes stay in remission if they undergo gastric bypass surgery rather than sleeve gastrectomy, even after regaining weight, according to a study published in the Journal of the American College of Surgeons (JACS).

Some people who undergo weight loss surgery regain a significant amount of weight within a few years after the procedure. Specific types of bariatric surgery include gastric bypass, which bypasses a part of the small intestine, called the duodenum, and a more popular, minimally invasive procedure called sleeve gastrectomy, which works by making the stomach smaller, restricting the amount of food that can be consumed.1

“We showed that in patients who had bariatric surgery, bypassing the duodenum has a greater benefit for patients with diabetes. We saw that patients who had sleeve gastrectomy and weight recurrence had a much greater chance of having their diabetes return when compared to their gastric bypass counterparts, even after adjusting for all diabetes patient factors,” says lead study author Omar M. Ghanem, MD, FACS, DABS, a bariatric and metabolic surgeon at Mayo Clinic in Rochester, Minnesota.

“We know that the first portion of the intestine, the duodenum, plays a very important part of digestion, and helps regulate what we call the ‘gut metabolic pathway.’ Bypassing that axis contributes to many physiologic actions or changes in metabolism and one of them is the regulation of glycemia and eventually diabetes,” Ghanem says.

For the study, researchers investigated whether diabetes returned when patients regained their weight after bariatric surgery. The review was based on data from 224 patients who underwent gastric bypass surgery and 46 control subjects who underwent sleeve gastrectomy at Mayo Clinic between 2008 and 2017. All patients involved in the analysis had obesity and had been diagnosed with type 2 diabetes before they underwent weight loss surgery. Each patient was followed for at least five years after the operation. Diabetes remission rates were then grouped into four weight relapse categories and compared. The aim was to see if weight gain led to diabetes recurrence.

Among Key Findings of the Study

Overall, 75% of gastric bypass patients saw their diabetes stay in remission, compared with only 34.8% of patients in the sleeve gastrectomy group.
After adjusting for patient and weight-related factors, the odds of diabetes returning over the five-year follow-up period were 5.5 times greater in the sleeve gastrectomy group compared to the gastric bypass group.
In a subgroup analysis of gastric bypass patients, diabetes remission rates were stratified into four weight regain categories. Over half of the patients in all four categories (patients who lost weight after surgery and regained 25%, 25% to 50%, 50% to 75%, and more than 75% of the weight they initially lost from having surgery) kept their diabetes in remission.
Among patients who regained 100% or more of their weight after gastric bypass surgery, about 60% kept their diabetes in remission five years after the operation, compared to zero in the gastric sleeve group.
Insulin use, higher preoperative A1c (which measures average blood sugar levels), and longer preoperative duration of diabetes were associated with diabetes recurrence, whereas weight regain was not.

Obesity is a leading risk factor contributing to death in the US. Most of the mortality risk linked to obesity is due to the development of diabetes and CVDs.2 The researchers note they intend to conduct more in-depth studies to understand this connection on a cellular level, which will better explain these findings.

“These findings help us understand how the bypass works and how to keep diabetes in remission. Looking forward, we need to understand the mechanism behind this association so we can counsel patients on the best procedure for them when presenting to us with diabetes,” Ghanem says.

“A major determining fact when choosing the most appropriate surgery is if the patient wants to eliminate diabetes or wants to have the least chance of having diabetes come back in the long term. While both procedures are great, we know that gastric bypass is a better procedure for patients with diabetes at this point.”

“Diabetes remission is more durable after gastric bypass than after sleeve gastrectomy. The magnitude of the difference in this study is important,” says Anthony T. Petrick, MD, FACS, director of the division of bariatric and foregut surgery at Geisinger Health System, who was not involved with the study. “Although there was a small number of sleeve gastrectomy patients in this study, the long-term follow-up is a strength of these findings.”

References

1. Noria SF, Shelby RD, Atkins KD, Nguyen NT, Gadde KM. Weight regain after bariatric surgery: scope of the problem, causes, prevention, and treatment. Curr Diab Rep. 2023;23(3):31-42.

2. Abdelaal M, le Roux CW, Docherty NG. Morbidity and mortality associated with obesity. Ann Transl Med. 2017;5(7):161.

— Source: American College of Surgeons

Abdominal Fat Impacts Brain Health in High Alzheimer’s Risk Individuals

The impact of abdominal fat on brain health and cognition is generally more pronounced in middle-aged men at high risk of Alzheimer’s disease as opposed to women, according to researchers at Rutgers Health.

In middle-aged individuals with a family history of Alzheimer’s disease, the amount of fat in their abdominal organs (pancreas, liver, and belly fat) is related to their brain volumes and cognitive function, according to the study published in the journal Obesity. The study was written by Sapir Golan Shekhtman, a PhD student at the Joseph Sagol Neuroscience Center at the Sheba Medical Center in Israel, and led by Michal Schnaider Beeri, director of the Herbert and Jacqueline Krieger Klein Alzheimer’s Research Center at Rutgers Brain Health Institute.

The research, conducted on 204 healthy middle-aged Alzheimer’s-dementia offspring, investigated fat depots in the pancreas, liver, and abdomen measured with MRI.

“In middle-aged males at high Alzheimer's disease risk—but not females—higher pancreatic fat was associated with lower cognition and brain volumes, suggesting a potential sex-specific link between distinct abdominal fat with brain health,” Beeri says, who’s the Krieger Klein Endowed Chair in Neurodegeneration Research at BHI and a faculty member of the Rutgers Institute for Health, Health Care Policy and Aging Research.

Obesity is a risk factor for lower cognitive functioning and higher dementia risk, with different associations between sexes.

The research findings highlight the importance of investigating the interrelationships of fat depots, brain aging, and cognition in the context of sex differences.

In addition, the study challenges the conventional use of BMI as the primary measure for assessing obesity-related cognitive risks. The researchers say BMI poorly represents body fat distribution and doesn’t necessarily account for sex differences.

“Our findings indicate stronger correlations compared to the relationships between BMI and cognition, suggesting that abdominal fat depots, rather than BMI, is a risk factor for lower cognitive functioning and higher dementia risk,” Shekhtman says.

These research findings open new avenues for targeted interventions and further exploration of sex-specific approaches in understanding and mitigating the impact of abdominal fat on brain health, Shekhtman explains.

— Source: Rutgers University – New Brunswick