Trends and predictors of nutritional deficiencies after bariatric surgeries: analysis of real-world data

Background: Bariatric surgery (BS) can lead to postoperative nutritional deficiencies (NDs) due to restrictive and malabsorptive mechanisms, but there is limited literature quantifying NDs’ prevalence over time and their predictors among patients undergoing BS. Objective: To characterize time trends and predictors of postoperative NDs. Setting: This retrospective cohort study used the U.S. IBM MarketScan commercial claims database (2005–2019) to include adults who underwent BS with continuous enrollment. Methods: BS included Roux-en-Y gastric bypass (RYGB), sleeve gastrectomy (SG), adjustable gastric band (AGB), and biliopancreatic diversion with duodenal switch. NDs included protein malnutrition, deficiencies in vitamins D and B12, and anemia that may be related to NDs. Logistic regression models were used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) of NDs across BS types after adjusting for other patient factors. Results: Within 83,635 patients (mean age [SD], 44.5 [9.5] yr; 78% female patients), 38.7%, 32.9%, and 28% underwent RYGB, SG, and AGB, respectively. Age-adjusted prevalence of any NDs within 1, 2, and 3 years after BS ranged from 23%, 34%, and 42%, respectively (in 2006) to 44%, 54%, and 61%, respectively (in 2016). Relative to the AGB group, the adjusted OR of any 3-year postoperative NDs was 3.00 (95% CI, 2.89–3.11) for the RYGB group and 2.42 (95% CI, 2.33–2.51) for the SG group. Conclusions: RYGB and SG were associated with 2.4- to 3.0-fold odds of developing 3-year postoperative NDs compared with AGB, independent of baseline ND status. Pre- and postoperative nutritional assessments are recommended for all patients undergoing BS to optimize postoperative outcomes.