Conference Coverage

Score predicts bariatric surgery’s benefits for obesity, type 2 diabetes



Researchers have devised a risk calculator for patients with obesity and type 2 diabetes that can estimate their 10-year risk for death and cardiovascular disease events if their clinical status continues relatively unchanged, or if they opt to undergo bariatric surgery.

Dr. Ali Aminian, surgeon, Cleveland Clinic Mitchel L. Zoler/MDedge News

Dr. Ali Aminian

The Individualized Diabetes Complications risk score “can provide personalized, evidence-based risk information for patients with type 2 diabetes and obesity about their future cardiovascular disease outcomes and mortality with and without metabolic surgery,” Ali Aminian, MD, said at a meeting presented by the Obesity Society and the American Society for Metabolic and Bariatric Surgery.

Although the calculator needs validation in a prospective, randomized study to document its impact on practice, it is now available on two separate websites and as a downloadable app, said Dr. Aminian, a surgeon at the Cleveland Clinic.

The calculator inputs data for 26 distinct, “readily available” demographic and clinical entries, and based on that, estimates the patient’s 10-year risk for all-cause death, diabetic kidney disease, cerebrovascular disease, heart failure, and coronary artery disease if no surgery occurs or after some type of metabolic or bariatric surgery. The calculator does not currently have the ability to individualize predicted risks based on the specific type of metabolic surgery performed, but that is planned as a future refinement of the score.

“We validated the model in the nonsurgical patients, which showed it was very accurate. The next step is to run a randomized trial to see how useful the calculator is” for assisting in patients’ decision making, Dr. Aminian said.

The data for deriving the risk calculator, and for a preliminary validation of it, came from 13,722 patients with obesity (body mass index, 30 kg/m2 or greater) and type 2 diabetes, who were managed at the Cleveland Clinic during 1998-2017, drawn from more than 287,000 such patients in the clinic’s database. The study focused on 2,287 patients who underwent metabolic (bariatric) surgery and 11,435 patients from the same database who did not have surgery and matched by propensity scoring on a 5:1 basis with those who had surgery. The two cohorts this created matched well for age (about 54 years), sex (about two-thirds women), body mass index (about 44 kg/m2), and the prevalence of various comorbidities at baseline.

Dr. Aminian and associates then analyzed the incidence of all-cause mortality and various cardiovascular disease endpoints, as well as nephropathy during follow-up, through December 2018. Patients who had undergone metabolic surgery showed statistically significant reductions in the incidence of each of those events, compared with patients who did not have surgery (JAMA. 2019;322[13]:1271-82).

The investigators used these findings to create their model for calculating a patient’s risk score. For example, to calculate an estimate for the 10-year risk from all-cause mortality, the results showed that the most powerful risk factors were age; baseline body mass index, heart failure, and need for insulin; and smoking status. For the endpoint of nephropathy, the most important factors were estimated glomerular filtration rate at baseline and age. Identified risk factors could account for about 80% of the 10-year risk for all-cause death and for about 75% of the risk for developing nephropathy during 10 years, based on the area-under-the-curve values the model produced.

The risk score may help patients better understand the potential role that metabolic surgery can have in reducing their future event risk, thereby helping them better appreciate the benefit they stand to gain from undergoing surgery, Dr. Aminian said.

The calculator is available at a website maintained by the Cleveland Clinic, at a site of the American Society for Metabolic and Bariatric Surgery, and in app stores, he said.

The work was partially funded by Medtronic. Dr. Aminian has received grants from Medtronic.

SOURCE: Aminian A et al. Obesity Week 2019, Abstract A101.

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