Predictors and weight impact of postbariatric hypoglycemia after Roux-en-Y gastric bypass surgery: a prospective observational cohort study

Postbariatric hypoglycemia (PBH) is a challenging condition affecting quality of life of patients after bariatric surgery. However, its incidence and predictive factors remain debated. To determine the incidence of PBH, identify predictors of PBH and assess its association with weight trajectory after bariatric surgery. University Hospital. Prospective observational cohort study including 222 nondiabetic patients who underwent Roux-en-Y gastric bypass between 2014 and 2021, had an oral glucose tolerance test (OGTT) and/or A1C (glycated hemoglobin) measurement prior to surgery and were followed for at least 12 months. Diagnosis of PBH was made when symptoms of hypoglycemia were accompanied by a postprandial plasma glucose level < 3.9 mmol/l or a glycemia < 3.9 mmol/l during continuous glucose monitoring, with resolution of symptomatology after carbohydrate consumption. Univariable and multivariable logistic regression analyses were performed to identify factors associated with PBH. Out of 222 patients, 71 (32%) were diagnosed with PBH. The highest incidence rate was observed at 2 years postbariatric surgery with a cumulative incidence of 26.5%. Predictive factors for higher risk of PBH were younger age at surgery (OR = .97; 95% CI: .94–.99; P = .049) and early dumping syndrome (OR = 3.05; 95% CI: 1.62–6.04; P = .0008). In multivariable logistic regression, higher glycemia at 2 hours during preoperative OGTT was associated with lower risk of PBH (OR = .8; 95% CI: .63–.98; P = .04). PBH was not associated with weight trajectory after surgery in our cohort. Younger age at time of surgery and lower blood glucose at 120 minute during preoperative OGTT are risk factors for PBH. Early dumping syndrome is significantly associated with PBH and could be used as a red flag to help identify patients at risk of PBH.