Get Off the Blood Glucose Roller Coaster

Avoid the glucose highs and lows that affect your thinking and mood

By Richard R. Rubin, Ph.D., C.D.E.

Dramatic fluctuations in your blood glucose levels have significant physical symptoms and increase your risk of diabetes-related complications. Often, the first signs that your levels may be off-target are changes in your thinking and mood. Learning to spot and act on the warning signs of glucose highs and lows will help you get off the blood glucose roller coaster and keep your glucose levels and your moods as stable as possible.

Symptoms of low blood glucose (hypoglycemia)

It can be physically uncomfortable when your blood glucose level drops even a little below the normal range (70-120 mg/dL). Symptoms may include fatigue, jitteriness and nausea. If it goes much lower—and it will if you don't eat or drink something containing sugar—things can quickly get worse and you could become disoriented, lose consciousness or lapse into a hypoglycemic coma.

Alice, a patient of mine, made it to the kitchen during a recent middle-of-the-night bout of hypoglycemia. Knowing she needed a snack, she opened the refrigerator door, and stood there for almost 15 minutes trying to decide which juice she should drink to raise her blood glucose. (Her sudden inability to move forward in her thought processes and make this simple decision is typical of how hypoglycemia can affect a person in its early stages.) When her husband Ed came downstairs to urge her to drink something, she got angry and collapsed in tears.

These moments of confusion, conflict and collapse are rare. They always pass as soon as Alice's brain gets the glucose it needs. Ed gets through these moments by telling himself that he's dealing not with Alice but with her confused, evil, hypoglycemic twin. If he stays calm and does the right thing, his dear Alice is soon back on the scene.

Avoiding the lows

Alice usually avoids glucose lows because she's adopted these regular habits:

• She eats carefully, so that the timing of her meals and the size of her portions don't vary much, but she does get the nutrients she needs from all food groups.
• She stays active on a regular schedule. After a bout of unusually intense activity, she tests her glucose and, if the reading is low, has a snack right away.
• She takes her insulin and other medications on schedule and uses her blood glucose meter regularly to be sure she is within her target range all day long.

Exercising good control gives Alice more energy and a more positive outlook.
Alice's plan almost always works. When it doesn't, she and Ed are well prepared. Ed can often tell when Alice's blood glucose might be low: if she is suddenly listless and indecisive, or breaks into a light sweat, he's on guard and will ask her to check her glucose. Ed's attention helps because symptoms appear quickly and can be remedied quickly with the right actions, and because Alice, though she's the one with symptoms, may not be as quick to realize that they signal possible hypoglycemia. Alice always has some hard candy with her in case of low blood glucose. If she's without her meter, she errs on the side of caution and consumes 10-15 grams of the candy or another fast-acting carbohydrate.

Symptoms of high blood glucose (hyperglycemia)

Low blood glucose affects Alice in obvious ways. High glucose levels affect her less obviously and, in all but the severest cases, do not pose the same immediate threat of unconsciousness or seizures as hypoglycemia. But glucose highs have just as much impact on her life because, like most people with diabetes, Alice's levels are above her target much more often than they are below.

Studies have shown that when blood glucose rises rapidly, as it may after a meal, many people experience a milder form of the same problems they have when glucose levels are too low. When their blood glucose levels rise rapidly, many people don't think as quickly as they normally do and they make more mistakes. They are more anxious and report having less energy when their blood glucose is high. Chronically high glucose levels have also been shown to increase the risks of heart disease, stroke, kidney disease and other diabetes complications.

Avoiding glucose highs

When my sister started using an insulin pump, her glucose control improved, especially after meals. Avoiding after-dinner glucose spikes gave my sister more energy and a clearer mind. As a result, she stopped spending her evenings dozing in front of the television and started doing things she really wanted to do.

Anything you can do to minimize glucose spikes after eating can improve your health and boost your energy. Here are some steps to consider:

• Maintain good glucose control before meals. This way, even if your glucose level spikes, it will be from a starting point within in your target range and won't end up in the stratosphere.
• Take a blood glucose reading just before a meal and again two hours after. Doing this just a handful of times will give you valuable information about when and how much your glucose level spikes, which will help you and your health care team fine-tune your treatment plan.
• Adjust your medications and insulin based on what you learn from your pre- and post-meal glucose meter readings. Ask your doctor or diabetes educator whether you should consult them before making any changes to your insulin and medication dosages.
• Limit the amount of starches (bread, potatoes, pasta, rice) and sweets in your meals. These foods contribute the most to post-meal spikes.

Benefits of avoiding highs and lows

You'll see the benefits of good glucose control right away if you take the steps described. Better control throughout the day gives you everyday advantages like stamina and alertness. Talk to your health care provider about the easiest and most effective ways to do that.

Richard Rubin, Ph.D., C.D.E., professor of medicine and pediatrics at Johns Hopkins, is the co-author of "Psyching Out Diabetes: A Positive Approach to Your Negative Emotions," "Sweet Kids," and "The Johns Hopkins Guide to Diabetes." He also has written extensively on the effects of diabetes education, psychological problems associated with diabetes and techniques for counseling people with diabetes.

©(2005-2009), Johns Hopkins University and Johns Hopkins Health System Corporation. All rights reserved. All information presented here is intended for your general knowledge only and is not a substitute for medical advice or treatment for specific medical conditions. You should seek prompt medical care for any specific health issues and consult your physician before starting a new fitness regimen. Use of this information is subject to this disclaimer and the terms and conditions of this website. Johns Hopkins abides by the terms of the HONcode principles of the Health On the Net Foundation. The information presented here is compiled by Johns Hopkins University School of Medicine with editorial supervision by one or more members of the faculty of the School of Medicine pursuant to a license agreement with LifeScan under which the School of Medicine and faculty editors receive payment for services rendered within the scope of the license agreement.