An exaggerated rise in blood sugar following a meal. In people who don’t have diabetes, the pancreas secretes some insulin all the time. It increases its output as blood glucose rises following meals. In people with Type 2 diabetes, the pancreas can be sluggish about secreting insulin in response to a meal. This leads to postprandial hyperglycemia.
Postmeal blood glucose elevations pose a challenge to people with diabetes striving to maintain near-normal blood sugar levels. Insulin regimens of one or two injections of slow-acting insulin each day handle this challenge clumsily: The person must eat when the insulin is peaking, both to avoid hypoglycemia (low blood sugar) and to avoid postprandial hyperglycemia. Multiple injection regimens and insulin pumps provide more flexibility. A person can take Regular insulin half an hour to one hour before eating so that the insulin peak and glucose rise coincide. Using one of the three rapid-acting insulins — insulin lispro (brand name Humalog), insulin aspart (NovoLog), or insulin glulisine (Apidra) — before meals allows for even more flexibility and fine-tuning. Because they peak faster than Regular insulin, they can be taken within 15 minutes of eating. They also leave the body more quickly, losing effectiveness at the same time as blood glucose levels decline.
For people with Type 2 diabetes, there are now several oral drugs specifically designed to address postprandial hyperglycemia. Acarbose (Precose) and miglitol (Glyset) block the action of an enzyme in the small intestine that normally breaks down carbohydrate into glucose. Therefore, glucose enters the bloodstream more slowly, giving the pancreas extra time to secrete enough insulin to handle it. Repaglinide (Prandin) and nateglinide (Starlix) stimulate the pancreas to release insulin in a glucose-dependent fashion. (That is, the more glucose there is in the blood, the more insulin the pancreas secretes.) These drugs also begin acting, peak, and break down quickly, so they are well-suited to handle the brief rise in blood glucose that follows meals.