You may go to bed with blood gluocse levels within your target range, but that doesn’t mean they’ll stay that way overnight. If the data shows you’re in range at bedtime, the culprit is likely too little medication. Adjusting your medication or what and when you eat may help. A large dinner or a snack at bedtime can cause elevated blood glucose levels that last all night, as can too low a dose of insulin with your evening meal. If you have high blood glucose before you go to sleep, the elevated level can persist until morning. If the data shows you’re high at bedtime, the culprits are likely food and medication. Your readings will tell you and your doctor when your highs and lows occur and that, in turn, will help narrow the cause of the problem. If you don’t use one, see if your doctor can provide a temporary loaner. If you use a continuous glucose monitor (CGM), you can sleep through the night and it’ll gather the data you need. If a pattern of frequent morning highs emerges during your routine glucose monitoring, check your blood glucose levels at bedtime, in the middle of the night and first thing when you wake up to develop a better understanding of your glucose patterns. Your body makes more glucose in order to compensate, and you wake up with high blood glucose. Your blood glucose may fall too low overnight.

Say you miss dinner or take too much insulin after your evening meal. Named after Michael Somogyi, PhD, a chemist who was the first to describe it in the 1930s, the Somogyi effect is the body’s response to low blood glucose ( hypoglycemia) during the night. If you inject your long-acting insulin early, it may not last into the morning. Insulin duration-how long the drug works in your body-also comes into play. The reasons for the drop in insulin vary from person to person, but it most commonly occurs when your insulin pump settings provide too little basal (background) insulin overnight or if your long-acting insulin dose is too low. If your insulin level falls too low overnight, your blood glucose rises. Approximately half of those with either type 1 or type 2 experience it. The dawn phenomenon does not discriminate between types of diabetes. As a result, your levels may be elevated when you wake up. But if you have diabetes, you may not make enough insulin or may be too insulin resistant to counter the increase in blood glucose. This triggers beta cells in the pancreas to release insulin in order to keep blood glucose levels in check. In the early hours of the morning, hormones, including cortisol and growth hormone, signal the liver to boost the production of glucose, which provides energy that helps you wake up. But if those highs become consistent, they could push your A1C up into dangerous territory.

The occasional morning high will have little impact on your A1C, a measure of your average blood glucose (blood sugar) levels over time that indicates how well managed your diabetes is.

Slow burn through highs lows