S1453 Weight Loss in Bariatric Surgery Patients Treated at a Novel Clinic Incorporating Obesity Medicine for Treatment of Nonalcoholic Fatty Liver Disease

Abstract

Introduction: The Yale Fatty Liver Disease Program (YFLDP) is a patient care model incorporating weight management with standard hepatology care for targeted treatment of nonalcoholic fatty liver disease (NAFLD). Weight management is the mainstay treatment for NAFLD, with 10% total body weight loss (TBWL) leading to disease improvement. Bariatric surgery is an effective treatment for obesity and associated metabolic diseases, though only an estimated 1% of eligible patients receive referral nationwide. We studied YFLDP patient referral rates to bariatric surgery, clinical and surgical characteristics, and weight loss outcomes. Methods: We retrospectively extracted demographic, surgical, and weight loss outcome data of adult YFLDP patients from 10/2015 to 5/2022. Standard eligibility criteria included body mass index (BMI) >40 kg/m2 or >35 kg/m2 with an obesity-associated comorbidity. Actual 1-year weight loss outcomes were compared to predicted weight-loss outcomes calculated using the MBSAQIP Bariatric Surgical Risk/Benefit Calculator and assessed with a 2-tailed t-test. Results: There were 1,166 patients, of whom 596 (51.1%) were eligible for bariatric surgery (Table). Of these, 150 (25.3%) received referral, 32 patients (21.3%) underwent surgery (22 received sleeve gastrectomy (SG) and 10 had a Roux-en-Y gastric bypass [RYGB]). Patients who received surgery were more likely female and upper class compared to those who continued with lifestyle/medication management. Patients receiving SG and RYGB had mean TBWL 21.5% and 20.0%, respectively, while patients who continued medication/lifestyle management had TBWL of 3%. There was no significant difference comparing actual vs predicted final BMI (P=0.12), actual vs predicted weight loss (P=0.13), and actual vs predicted TBWL (P=0.13) post-bariatric surgery for all procedures (Figure). Conclusion: Integration of weight management with hepatology medical care is an effective model for NAFLD weight loss treatment. Patients receive referral for bariatric surgical evaluation at a rate 25 times greater than the national average, and those that receive surgery have comparable weight loss to that predicted in all patients receiving these surgeries, and on average exceeded the treatment threshold expected to treat NAFLD. Further study to identify patients who would most benefit from bariatric surgery would help to inform better patient selection and proactive referral efforts.Figure 1.: Predicted vs actual bariatric surgical outcomes in patients referred for surgery. (A) Actual vs Predicted Final Body Mass Index (BMI) post Bariatric Surgery: Comparison between YFLDP (Yale Fatty Liver Disease Program) patients’ actual BMI post bariatric surgery vs predicted BMI post bariatric surgery using the MBSAQIP Bariatric Surgical Risk/Benefit Calculator. There was no statistically significant difference between actual and predicted BMI (P=0.12). (B) Total Body Weight Loss (TBWL) in Patients given Bariatric Surgery Referral: Comparison between YFDLP patients’ total body weight % reduction in patients given a bariatric surgery referral who either underwent a gastric bypass or sleeve gastrectomy or did not have surgery and continued with lifestyle/medication management. Patients who underwent surgery had a statistically significant percent reduction in TBWL compared to patients managed with only lifestyle/medications. Error bars represent standard error. ***P< 0.001 Table 1. - Demographic and surgical characteristics of Yale Fatty Liver Disease Program patients who were referred for bariatric surgery Patient Characteristics Referred, Underwent Bariatric Surgery (+)(n=32) Referred, Did Not Undergo Bariatric Surgery (-)(n=118) P Sex n (%) Male 6 (19) 35 (30) 0.22 Female 26 (81) 83 (70) Age years (SD) 49 (10.3) 51 (12.98) 0.60 Medicare Qualifying n (%) 2 (6) 19 (12.98) 0.15 Race n (%) White 22 (69) 86 (73) 0.29 Black 4 (13) 15 (13) Asian 1 (3) 0 (0) Other/Declined 5 (15) 17 (14) Ethnicity n (%) Hispanic 6 (19) 27 (23) 0.62 Non-Hispanic 26 (81) 91 (77) Insurance Status n (%) Uninsured 0 (0) 0 (0) 0.045 Medicaid 14 (44) 31 (26) Medicare 2 (6) 27 (23) Private 16 (50) 60 (51) Median House Income by Zip Code n (%) < $50k 7 (22) 29 (25) 0.48 $50k-100k 19 (59) 75 (63) >$100k 6 (19) 14 (12) Anti-Obesity Medications n (%) Lifetime 16 (47) 38 (32) 0.78 Since YFLDP 10 (31) 29 (25) BMI Reduction mean (SD) RYGB (n=10) 8.3 (5.4) Predicted 1.3 (3.9) < 0.001 SG (n=22) 9.4 (6.1) < 0.001 TBWL % (SE) RYGB (n=10) 20.5 (3.5) Predicted 3 (0.8) < 0.001 SG (n=22) 21 (2.73) < 0.001 (+) Surgery denotes patients who underwent bariatric surgery after referral. (-) Surgery denotes patients who did not undergo bariatric surgery after referral. Patients who underwent bariatric surgery had statistically significant greater reduction in mean BMI compared to patients who did not have surgery. SD is standard deviation, SE is standard error, BMI is body mass index (kg/m2), RYGB is Roux-en-Y gastric bypass, SG is sleeve gastrectomy, TBWL is total body weight loss.