Obese patients who underwent bariatric surgery were more like to achieve a BMI of <30 one year after surgery if they had a BMI<40 before surgery, according to a study published by JAMA Surgery. The study authors from University of Michigan Health Systems, Ann Arbor, Wayne State University and Henry Ford Health System, Detroit, Michigan, report that significant predictors for success included a preoperative BMI<40 and undergoing a metabolic procedure such as sleeve gastrectomy, gastric bypass, or duodenal switch.
It is estimated that more than 34 percent of adults in the US are classified as obese, with a BMI>30 or greater. Achieving a BMI of less than 30 is an important goal of bariatric surgery, given the increased risk for weight-related health conditions and death with a BMI above this level.
“Policies and practice patterns that delay bariatric surgery until the BMI is 50 or greater can result in significantly inferior outcomes.”
Dr Oliver A Varban, from the University of Michigan Health Systems, Ann Arbor and colleagues conducted a study to identify predictors for achieving a BMI<30 one year after bariatric surgery. The researchers examined data for a total of 27,320 adults who underwent bariatric surgery in Michigan between June 2006 and May 2015. They used logistic regression to identify the predictors, as well as 30-day postoperative complications and one-year self-reported comorbidity remission.
They found that 9,713 patients (36%; mean [SD] age, 46.9 [11.3] years; 16.6% male) achieved a BMI<30 at one year after bariatric surgery and a significant predictor for achieving this goal was a preoperative BMI<40 (odds ratio [OR], 12.88; 95% CI, 11.71-14.16; p<0.001). In addition, patients who had a sleeve gastrectomy, gastric bypass or duodenal switch were more likely to achieve a BMI<30 compared with those who underwent adjustable gastric banding (OR, 8.37 [95% CI, 7.44-9.43]; OR, 21.43 [95% CI, 18.98-24.19]; and OR, 82.93 [95% CI, 59.78-115.03], respectively; p<0.001).
Interestingly, only 8.5 percent of patients with a BMI>50 achieved a BMI>30 after bariatric surgery. Patients who achieved a BMI<30 had significantly higher reported rates of medication discontinuation for high cholesterol, diabetes, and high blood pressure, as well as a significantly higher rate of sleep apnoea remission, compared with patients who did not (all p<0.001).
The authors acknowledged that a limitation of their study was that the bariatric procedures were performed in a single state.
“Patients should be counselled appropriately with respect to weight loss expectations after bariatric surgery. Furthermore, policies and practice patterns that delay or incentivize patients to pursue bariatric surgery only once the BMI is highly elevated can result in inferior outcomes,” the authors conclude. “Patients with a preoperative BMI of less than 40 are more likely to achieve a BMI of less than 30 after bariatric surgery and are more likely to experience comorbidity remission. Policies and practice patterns that delay bariatric surgery until the BMI is 50 or greater can result in significantly inferior outcomes.”