Association between preoperative serum albumin levels with risk of death and postoperative complications after bariatric surgery: a retrospective cohort study

Hypoalbuminemia is common among individuals with obesity who qualify for bariatric surgery, but its relevance to clinical outcomes after bariatric surgery remains to be established.To examine the association of preoperative serum albumin with 30-day postoperative outcomes.Data from the 2015-2019 Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program Participant Use Files were used.Preoperative serum albumin level was categorized as hypoalbuminemia (<3.5 g/dL), and normoalbuminemia (3.5-5.5 g/dL) among patients who underwent bariatric surgery. Multivariate logistic regression models were used to determine the association of preoperative hypoalbuminemia with 30-day postoperative mortality and other co-morbid outcomes.Among 633,011 adult patients, 85.1% were women and the mean (standard deviation) age was 44.8 (12.0) years. The prevalence of hypoalbuminemia was 6.13% (n = 38,792). After adjustment for procedure type and demographic, lifestyle, and co-morbidity covariates, the odds ratio (OR) (95% confidence interval [CI]) for mortality was 1.42 (1.10, 1.82) for hypoalbuminemia. For all other outcomes, the ORs (95% CIs) for hypoalbuminemia ranged from 1.03 (.67-1.60) for cardiac arrest requiring CPR to 2.32 (1.66-3.25) for failure to be discharged by day 30. The ORs for several associations were higher for severe hypoalbuminemia than marginal hypoalbuminemia.Preoperative hypoalbuminemia was associated with several negative 30-day postoperative bariatric surgery outcomes and tended to be worse for severe hypoalbuminemia compared with marginal hypoalbuminemia. These findings suggest that serum albumin may be a useful biomarker to screen for negative bariatric surgery outcomes.