Nerves orchestrate the flow of food through the digestive tract. Damage to the vagus nerve, which controls the passage of food through the stomach, can lead to a diabetes complication called gastroparesis.

Wildly fluctuating blood glucose levels may be one sign of gastroparesis. For example, if food remains in the stomach for longer than is typical, the insulin taken before a meal will hit the bloodstream before the glucose from the food does, leading blood glucose levels to go low. Then later, once the food is finally digested, the insulin has left the body, so the glucose from the meal remains in the circulation, leading to blood glucose highs. Other symptoms of gastroparesis include nausea, vomiting, reflux, feelings of fullness, bloating, and abdominal pain or discomfort.