Are there really any predictive factors for a successful weight loss after bariatric surgery?

Abstract

Background: Currently, bariatric surgery is the most effective treatment for severe obesity and its metabolic complications; however, 15-35% of the patients that undergo bariatric surgery do not reach their goal for weight loss. The aim of this study was to determine the proportion of patients that didn't reach the goal of an excess weight loss of 50% or more during the first 12 months and determine the factors associated to this failure. Methods: We obtained the demographic, anthropometric and biochemical information from 130 patients with severe obesity who underwent bariatric surgery in our institution between 2012 and 2017. We used self-reports of physical activity, caloric intake and diet composition. An unsuccessful weight loss was considered when the patient lost < 50% or more of the excess weight 12 months after surgery. We compared the characteristics between the successful and unsuccessful groups in order to find the factors associated with success. Results: We included 130 patients (mean age 48 ± 9 years, 81.5% were women). One year after surgery, 26 (20%) had loss < 50% EBW. Unsuccessful surgery was associated with an older age, previous history of hypertension, abdominal surgery or depression/anxiety, also the number of comorbidities and unemployment affected the results. These patients loss enough weight to improve some of their comorbidities, but they are more prone to regain weight 2 years after surgery. Conclusions: A fifth of the patients undergoing bariatric surgery may not lose enough weight to be considered successful by current standards. Some patients may benefit from the surgery in the short term, but they are more likely to regain weight after 2 years. The factors influencing this result are still controversial but may be populationspecific. Early detection of the patients that are more likely to fail is imperative to establish additional therapeutic strategies, without denying them the opportunity of surgery or waiting for weight regain to occur.

Weight Regain and Insufficient Weight Loss After Bariatric Surgery: Definitions, Prevalence, Mechanisms, Predictors, Prevention and Management Strategies, and Knowledge Gaps—a Scoping Review

“…Conversely, other research observed younger age to be more likely associated with WR [82]. As for IWL, older age predicted IWL one year after BS [36]. Likewise, research suggested that male gender was associated with suboptimal or worse WL after RYGB [34,78].…”

“…Interestingly, preoperative psychiatric disorder was a weaker predictor of WR than the postoperative psychiatric disorder, likely due to the impact of the latter on eating behavior after BS [85]. The association of depression and anxiety with IWL has been less examined; however, recent research found that both conditions significantly predicted IWL 1 year after BS [36].…”

“…For instance, T2D predicted WR and IWL [34,[79][80][81]86]; while hypertension and low HDL cholesterol were both associated with poor weight trajectory [34]. Similarly, the number of comorbidities and previous history of hypertension predicted IWL [36]. Likewise, patients with obstructive sleep apnea achieved significantly lower EWL% at 1 year after surgery than patients with no sleep apnea [86].…”

“…In comparison with WR, data on the prevalence of IWL is more limited [36], mostly assessed or stated as a "spin-off" when discussing the indication for revisional surgeries [17,39]. For instance, among 17 patients who underwent revision after LSG, 40% were indicated for conversion to biliopancreatic diversion/duodenal switch (BPD/DS) and RYGB because of IWL [17], and others found that 32% of patients underwent revisional RYGB because of IWL [35].…”

Response: Factors Predicting Weight Loss after “Sleeve Gastrectomy with Loop Duodenojejunal Bypass” Surgery for Obesity (J Obes Metab Syndr 2020;29:208-14)

“… 3 We maintain that calculation of %EWL is required to analyze weight-loss success rates. 4 %EWL ≥50 and %TWL ≥25 are commonly used to measure weight-loss success rate. Abandoning use of %EWL may lead to difficulty comparing results with the existing literature.…”