Avoiding the Rollercoaster of Highs and Lows
Your June 2008 issue contains an article about the dangers of erratic blood glucose levels ("The Downside of Ups and Downs," p. 24). I have type 2 diabetes, and I'm insulin-dependent. My A1C has been pretty reasonable, although it has drifted above 7 recently. I try to adjust my diet, exercise, and insulin to prevent the highs and lows, but very often my next reading is way different than what I might have expected. My extremely fluctuating blood glucose more often than not results in hyperglycemia. How can I, as your article urges, "avoid the rollercoaster"? Jesse Etelson, Rockville, Maryland
Christy Parkin, MSN, RN, CDE, responds: The article that you refer to suggests that blood glucose levels that fluctuate wildly up and down are more dangerous than high blood glucose (hyperglycemia) alone. It is believed that erratic hyperglycemia causes production of free radicals (highly reactive chemicals that can damage cellular molecules) that lead to damage of the cells known as oxidative stress. This damage is a predictor of cardiovascular disease in diabetes.
A1C is generally a good indicator of the risk of diabetic complications; however, it is important to understand that having an A1C that's less than 7 does not necessarily indicate good blood glucose control. A1C is simply an average, and does not provide the whole picture. That is why blood glucose monitoring is so valuable. As you have noticed, checking your blood glucose after meals can help you to determine if you took enough insulin, or if you ate too many carbohydrates.
It may be helpful for you to get back to basics with your diabetes management. I would suggest meeting with a certified diabetes educator for a review of your plan and getting a nutrition consult. Learning how to accurately count carbohydrates and adjust mealtime insulin can greatly improve the after-meal spikes that you are experiencing. If you are taking rapid-acting insulin before meals, you should take the injection within 15 minutes prior to eating. I would take a look at your physical activity as well as any recent weight loss or gain. Also, I would want to evaluate how often you have episodes of low blood glucose (hypoglycemia), because this can lead to hyperglycemia (related to over-treating the lows and hormonal responses).
As you can see, there are many possible reasons for the variability in your blood glucose, and each factor must be considered carefully. You may also want to consider wearing a continuous glucose monitor for several days to see how your blood glucose fluctuates throughout the day and night. Talk to your doctor at your next visit about your concerns.