Alcohol use disorders and related morbidity and mortality after sleeve gastrectomy and Roux-en-Y gastric bypass: a nation-wide registry study (the BAR-REGISTER)

BACKGROUND: Bariatric surgery provides notable weight loss and metabolic benefits but may also increase the risk of alcohol use disorder (AUD). We investigated whether Roux-en-Y gastric bypass (RYGB) confers higher rates of AUD and related disorders than sleeve gastrectomy (SG) and examined associated morbidity and mortality. METHODS: We conducted a retrospective, population-based cohort study using data from the Norwegian Patient Registry and the Norwegian Prescription Database. A total of 17,800 patients underwent RYGB (n = 12,244) or SG (n = 5556) between 2008 and 2018. Patients with prior diagnoses related to alcohol or use of medications for AUD were excluded. Incidence rates (IR) for alcohol-related diagnoses were calculated per 1000 person-years; hazard ratios (HR) were derived comparing RYGB to SG. Morbidity was measured as number of specialized healthcare contacts, but also as number of prescriptions/defined daily doses in an exploratory model. RESULTS: Mean postoperative follow-up was 5.7 years (RYGB) and 3.8 years (SG). By 31 December 2018, 576 patients (3.2%) had developed a new alcohol-related diagnosis - an incidence rate of 6.34 per 1000 person-years. The adjusted HR for such diagnoses was 1.69 (95% CI 1.33-2.13, p < 0.001) for patients undergoing RYGB compared to SG. Because mortality did not differ significantly between RYGB and SG, mortality was assessed for the cohort as a whole: patients with alcohol-related diagnoses had an adjusted HR for death of 2.08 (95% CI 1.40-3.08) relative to those without. They also recorded, on average, 5.5 additional contacts in specialist care. CONCLUSIONS: Compared with SG, RYGB was associated with a 69% higher risk of alcohol-related diagnoses. Further, given the elevated morbidity and mortality linked to these disorders, enhanced preoperative screening and long-term postoperative monitoring are warranted in modern bariatric practice.