Dealing with Overnight Lows

Alarming episodes of hypoglycemia–low blood sugar levels–are a source of real concern for people with type 1 diabetes. Because hypoglycemia can have serious consequences, it requires careful, ongoing vigilance and management not only throughout the day but also at night. It is not unusual to discover that, in the middle of the night, blood sugar levels might drop to very levels.

With the advent of new glucose monitoring systems, researchers have gained the necessary tools to allow them to understand what causes patients to “go low” overnight. Some of the factors that can result in nighttime low blood sugar episodes are: too much insulin in circulation; the normal release of growth hormones (in children/teens) overnight, which can reduce the need for insulin; intense exercise during the day; and erratic eating patterns such as skipping a meal or not eating enough.

What’s more, research like the Diabetes Control and Complications Trial (DCCT) has noted that tight glucose control, while helping to reduce the risk of diabetic complications, can increase the risk of hypoglycemic episodes. Patients who are in tight control can make adjustments to their regimen during the day, but during an eight-hour sleep cycle, say researchers, the body can be like an airplane without a pilot.

JDRF often gets questions about nighttime hypoglycemia, particularly from parents who monitor their children for overnight lows. Annette Flygare discovered through routine nighttime checks that her son Mitch, 13, typically runs low as many as two nights a week after days of particularly vigorous exercise. So she began to feed him during the night between 1 and 3 a.m. to correct his lows. “Even though Mitch is sleeping, his body doesn’t seem to slow down after games,” she explains. “Once I saw a trend, I started checking him every night. Now that we have a handle on his patterns and made some adjustments, I check him before I go to bed, and depending on his number or activity level, I may get up and check him again in the early morning hours. If he’s low, we treat him with yogurt, juice, or a sports drink.”

Doctors and diabetes educators can help patients and families like the Flygares plan meals, snacks, and insulin doses to get young patients through the night when they’ve been extra active during the day. An important key is consistent blood glucose monitoring–before meals and snacks, before and after exercise, at bedtime, and, occasionally, in the middle of the night. Doctors recommend that families record all pertinent data, including blood sugar levels, carbohydrate intake, and insulin dosage, and then with their diabetes health care practitioners, review the results and patterns over time, and make any necessary changes in the daily routine.

Progress on the Horizon

An important form of relief becoming more widely available on the market are glucose monitors that sound a warning when needed, allowing extra peace of mind. Several of these devices have been approved in recent years by the Food and Drug Administration (FDA). Devices that integrate insulin pumps with real-time continuous glucose monitors are also becoming more common. These developments are integral to the so-called artificial pancreas, which is one of JDRF’s research priorities. Ultimately, researchers envision a day when a sensor would take readings, calculate, and respond with the correct dosage instructions to a pump that would infuse the insulin automatically.

“In the meantime, we tell people to get the best possible diabetes control they can, and that we can do very well with what we have now,” says Yale University’s Dr. William Tamborlane, a pioneer in hypoglycemia studies in type 1 diabetes. “Many patients are achieving levels of control today that we never thought possible 30 years ago, when I first began to tackle this problem.”