1. The Dawn Phenomenon
This occurs during the night while you’re asleep and the body releases stress hormones. This phenomenon usually occurs between 3 a.m. and 8 a.m. and involves growth hormone, cortisol, and adrenaline, which trigger the production and release of glucose from your liver. The end result of this chemical cascade is an increase in blood sugar. “These hormones are designed to get us up and moving in the morning,” says endocrinologist Renee Amori, MD, assistant professor of medicine in the division of endocrinology at the Drexel University College of Medicine in Philadelphia. While everybody experiences these natural changes in hormone levels, in people with diabetes the body may not adjust appropriately. This can lead to higher-than-normal blood sugar at the start of the day. Testing for these elevated first morning blood sugars is one way to diagnose people with type 2 diabetes.
2. The Somogyi Effect
High morning readings can also be caused by the Somogyi effect, a rebound response that occurs when the body overcompensates for a low blood sugar reaction at night. If you take blood sugar–lowering medication — such as insulin — in the evening, this may cause you to have a hypoglycemic reaction while you’re asleep, and your body will then release these stress hormones, causing you to have high blood sugar in the morning. If this is contributing to your high morning blood sugar, Dr. Amori says, you may experience symptoms of hypoglycemia that can wake you from sleep in the middle of the night, including headache and excessive sweating. You may also experience difficulty waking in the morning. If your physician is increasing your evening diabetes medication to lower your morning blood sugar but your blood sugar keeps going up, you may be experiencing the Somogyi effect.
3. Waning Insulin
The third common cause of high morning blood sugar levels is waning amounts of insulin, which means your insulin levels are going down and no longer keeping your blood sugar in check. As a result, you wake up to an elevated reading.
Finding the Cause of Your Morning Blood Sugar High
Though the three most likely causes of high morning blood sugar can all be treated, first you have to know which one is the source of your condition. “If you’re not sure, you might have to take the somewhat inconvenient step of waking up to check your blood sugar levels in the middle of your sleep pattern (for example at 3 a.m. if you go to bed at 11 p.m.)” suggests Amori. Here’s why:
Consistent blood sugar from bedtime until about 3 a.m. and then a rise suggests the dawn phenomenon.Low blood sugar at 3 a.m. suggests the Somogyi effect.Blood sugar that increases from bedtime to 3 a.m. and then is even higher when you wake is probably due to waning insulin.
Using a continuous glucose monitor enables you to get this information without having to wake up for it. “These monitors potentially help identify patterns and severity of high and low blood sugars,” explains Amori.
Treating High Morning Blood Sugar
A blood sugar high in the morning “can be tough to treat,” acknowledges Amori, but with the help of your medical team, you can try different approaches. Talk with your doctor about these strategies: Adjust your pump. If you’re testing high regularly and you use an insulin pump, you might be able to program it to help manage your morning highs. Check blood sugar before bed. Granted, many people have morning high blood sugar after an acceptable blood sugar before bedtime. Even so, “don’t go to bed with high blood sugar,” cautions Amori. Take basal insulin. Taking basal insulin at bedtime could help, but be sure to clear any changes in dosing with your physician before you try it. Adjust medication. If in fact your high morning blood sugar is a rebound response to a low blood sugar level while you’re asleep, you might need to change the dose of any medication you take in the evening that could be causing low blood sugar. Talk with your doctor about whether your medication schedule should be adjusted to treat morning highs. Have a healthy pre-bed snack. For those experiencing the Somogyi effect, a healthy mixed snack of protein and carbohydrates could help prevent your blood sugar roller coaster at night. Amori advises working with a registered dietitian if you’re not sure how to fit a pre-bed snack into your daily diet. Increase physical activity. Being physically active during the day can help you manage blood sugar more effectively in general. If your diabetes is treated with insulin or you have a concern about low blood sugar, find out how to exercise safely before increasing your physical activity. High morning blood sugar levels are a concern, especially if they happen regularly and seem to make it hard to meet your blood sugar goals. But taking steps to address these morning highs can improve your overall diabetes management and stave off diabetes-related complications.
