What is the best course of action for a non-diabetic patient with a history of coronary artery bypass grafting (CABG) experiencing episodes of hypoglycemia?

From the Guidelines

For a non-diabetic patient with a history of coronary artery bypass grafting (CABG) experiencing episodes of hypoglycemia, the best course of action is prompt medical evaluation to identify the underlying cause, followed by consumption of 15-20 grams of fast-acting carbohydrates to quickly raise blood glucose levels, as recommended by the most recent guidelines 1. The patient should first consume 15-20 grams of fast-acting carbohydrates (such as 4 ounces of fruit juice, 1 tablespoon of honey, or 3-4 glucose tablets) to quickly raise blood glucose levels, followed by a more substantial snack containing protein once symptoms improve.

• They should carry glucose tablets or a similar quick-acting carbohydrate source at all times.
• The patient should monitor blood glucose levels regularly using a home glucometer, keeping a log of readings and associated symptoms, meals, and activities.
• Urgent medical attention is necessary if hypoglycemia is severe or recurrent, as hypoglycemia in non-diabetic patients with cardiovascular disease history may indicate serious underlying conditions such as insulinoma, adrenal insufficiency, liver disease, or medication effects, as suggested by the guidelines 1. Some cardiac medications like beta-blockers can mask hypoglycemic symptoms or contribute to low blood sugar, and the combination of hypoglycemia and coronary artery disease is particularly concerning as low blood glucose can increase cardiac workload and potentially trigger cardiac events in patients with compromised coronary circulation.
• The patient's treatment plan should be reevaluated to decrease the risk of future hypoglycemic episodes, and glucagon should be prescribed if the patient is at increased risk of level 2 or 3 hypoglycemia, as recommended by the guidelines 1. The most recent study 1 provides the best evidence for the management of hypoglycemia in non-diabetic patients, and its recommendations should be followed to prioritize the patient's morbidity, mortality, and quality of life.

From the Research

Hypoglycemia in Non-Diabetic Patients with a History of Bypass Surgery

• Hypoglycemia after gastric bypass surgery is a challenging condition for patients and physicians alike, as seen in studies 2, 3, 4, 5, 6.
• The pathogenesis of postprandial hypoglycemia after gastric bypass surgery is not fully understood, but it is thought to be related to rapid and exaggerated increases of circulating incretins and insulin 3, 4, 6.
• Hyperinsulinism, which is either generated by pancreas anomalies or caused by an overstimulation of β cells by incretins, mainly glucagon-like peptide-1 (GLP-1), is a key factor in the development of hypoglycemia after gastric bypass surgery 4, 5, 6.

Diagnosis and Treatment

• The diagnosis of hypoglycemia after gastric bypass surgery can be challenging, and the Whipple triad with a glycaemia threshold of 55 mg/dl is recommended as the diagnostic reference 4.
• Treatment options for hypoglycemia after gastric bypass surgery include changes in eating habits, such as splitting food intake into five to six daily meals, slowing gastric emptying, reducing the glycaemic load and glycaemic index of foods, using fructose, and avoiding stress at meals 4.
• Pharmacological treatment with acarbose is efficient, but other drugs, such as GLP-1 analogs, still need to be validated in a greater number of subjects 3, 4.
• In severe cases, gastrostomy tube (GT) insertion into the remnant stomach may be an effective treatment option, as it can reverse neuroglycopenic symptoms by altering nutrient delivery 5.

Specific Considerations for Non-Diabetic Patients with a History of CABG

• While the studies primarily focus on patients who have undergone gastric bypass surgery, the principles of diagnosis and treatment may be applicable to non-diabetic patients with a history of coronary artery bypass grafting (CABG) who experience episodes of hypoglycemia.
• However, it is essential to note that the pathophysiology of hypoglycemia in non-diabetic patients with a history of CABG may differ from that of patients who have undergone gastric bypass surgery, and further research is needed to fully understand this condition.