Post-Bariatric Hypoglycemia

Post-bariatric hypoglycemia (PBH) is an increasingly recognized, complex, and sometimes severe complication of bariatric and other upper gastrointestinal surgical procedures. PBH usually begins at least 1 year postoperatively, and hypoglycemia is typically experienced in the postprandial state. While pathophysiology is incompletely understood, dominant factors include alterations in gastric emptying leading to rapid delivery of nutrients to absorptive intestinal mucosa. Increases in plasma glucose, together with increased incretin hormone secretion, contribute to increased plasma insulin levels, resulting in a rapid drop in glucose levels to overt hypoglycemia 1–3 h after meals. Additional contributors include reduced counterregulatory hormone responses to hypoglycemia and disrupted bile acid signaling. Clinically, evaluation is focused on verifying hypoglycemia and excluding other causes of hypoglycemia, including adrenal insufficiency, undernutrition, autonomous insulin secretion due to insulinoma, alcohol use, and side effects of concomitant medications. Identification of precipitating factors can be helpful in the development of an individualized management plan. Medical nutrition therapy remains the cornerstone of therapy and is focused on avoidance of simple carbohydrates, intake of complex carbohydrates in controlled portions, and adequate protein and micronutrient intake. Acarbose can be used pre-meals to slow carbohydrate absorption, reduce glycemic spikes, and reduce insulin secretion. If this is not sufficient, additional medications and surgical/endoscopic interventions to slow gastric emptying or reduce insulin and incretin secretion can be added. Unfortunately, responses are often incomplete, highlighting the need for new therapeutic approaches for this challenging condition.