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Physical Activity Q&A with Dr. Sheri Colberg, Part 3

Apr 23, 2010


Q: Dr. Sheri, I am a 41-year-old female and have been a long distance runner for most of my life. I am quite thin (bordering on underweight for many years) and already eat as a diabetic would to control blood glucose. Recently, I had my HbA1c checked with readings of 5.5 and then 5.7, so it has gone up. My fasting insulin level was 2.

 Given my lifestyle, I was concerned at the high HbA1c levels. I would have expected them to be lower. My fasting glucose was 93, which, although normal, still seems high. Am I at risk for diabetes, and if so, given my insulin levels, would you suspect Type 1? I would like to cut back on running and put on some weight by eating more but am now very concerned to do so given my numbers. I would have thought I would have had more of a buffer between my blood glucose levels and the outer limit of normal (HbA1c of 6%). Any ideas as to why my numbers are not better if I am a non-diabetic or non-prediabetic?  K.


A: K, your fasting insulin levels are low, but that is expected in people who are athletic. When you say that you "already eat as a diabetic would to control blood glucose," does that mean that you have a low or moderate carb intake? If you cut back on running, try to keep your intake of refined carbs lower, and avoid drinking sugary drinks. You can always get a blood glucose meter and test your blood sugars before and after eating to see how it responds. If you were to develop diabetes, Type 1 is more likely, but I don’t think that is likely at this point. I have a good article I posted online on all the things that can affect insulin action: www.insulitelabs.com/articles/enhancing_insulin_action.html. You may have other factors in your life that are decreasing your insulin action at times, most of which are modifiable or controllable.

Q: Dr. Sheri, thank you so much for the prompt, helpful response. To answer your question, yes, I would consider my carb intake to be very restricted. Also, no juices, soda, or alcohol. Perhaps, I eat too little for my energy output, and this is causing endocrine problems/ elevated glucose. This low carb intake combined with my running is what makes me feel an Ha1c of 5.5% and 5.7% is unexpectedly high. Would you agree?  K.

A: K, I think you answered your own question with your statement that, "Perhaps, I eat too little for my energy output, and this is causing endocrine problems/elevated glucose." When you eat too little, especially carbs, and do the type of training you’re doing, your body has to rely a lot more on fats, and elevated blood fats can cause insulin resistance. Try adding about 50 grams or so of carbs a day to your diet, and I bet that your HbA1c will go down, not up. 

Q: Dr. Sheri, our son has Type 1 diabetes and is a competitive high school swimmer. At our section championships, he did great the first day but seemed sluggish the second. His exercise routine is rigorous as he disconnects from the pump for 2 hours a day during practice, 6 days a week. We told him to keep checking his blood sugars throughout his routine and during swim meets. We also told him to stay connected to the pump as much as possible during the meets. I am concerned that he’ll spike or drop too low during the championships and not perform well. He is currently ranked #3 in the state for the 100 freestyle and has potential for scholarship. He has been swimming for 12 years and has had diabetes since he was 4. He’s now 17. Any general suggestions?  T & A

A: T & A, there are all sorts of reasons that your son was sluggish the second day of competition and not all of them have to do with diabetes! You’re right that he should stay connected to the pump as much as possible when he’s not competing. He may also need to give some corrective insulin boluses if his races raise his blood glucose above 200 mg/dl. When he eats carbs, he needs to cover those with boluses as well to make sure the carbs get into his muscles. The problem with competitions is the stress factor, which often raises blood glucose levels, as do sprints. (Gary Hall, Jr., once told me he’ll start a 50M sprint at 100 and end up around 300 mg/dl from only 20 seconds of exercise and the stress of competition.) Blood glucose will not necessarily come back down on its own like it usually does during longer swim practices. It’s unlikely that he’ll go too low during competition, but too high could be an issue. If he keeps his control tight, he should do fine.

Q: Dr. Sheri, my son is nine years old. He’s been Type 1 since he was 22 months old. Two weeks ago, he had his first seizure at 5:00 in the morning. My wife used glucagon for the first time and took him to the small local hospital. He was there for about six hours before being moved to the larger hospital. He was in the hospital for two days before being sent home. After he got home, my wife kept giving him carbs but couldn’t get his blood sugar to stay up. She pretty much didn’t sleep all weekend. She drove him back to the hospital the following Monday and he stayed for a few more days. They consulted with his endo and they’ve drastically reduced his insulin. They switched his Lantus from the evening to morning and reduced him to 12 units. They also said to give him no more that 5 units of the Novolog at any meal regardless of the carb count.

This is what my wife told me last night @ 9:59pm. "Ok, I may very well lose my mind here. Andrew is yet again low … he’s gone from 49 up to 62 in the past hour and a half. Drinking another 69 grams of apple juice right now." Then at 10:25pm: "Finally up to 81, but that’s not good enough. Down goes another 54 grams of orange juice." Then: "Back down to 62 at 10:50pm…." Then: "Down to 49 @ 11:20pm…" and finally @ 11:59pm: "Almost 390 grams of carbs later and he’s at 127…off to bed finally." He was down in the 40s by this morning. The doctors we’ve seen don’t know what’s going on and I’m looking for anything from any source. I’ve searched the internet but can’t find anything regarding this type of problem.   I work overseas and am not home to help my wife. T

A: T, the only things I know that cause those types of blood sugar drops are 1) taking too much insulin, 2) drastically lowering overall carbohydrate intake, and 3) delayed effects of exercise. Has your son changed his insulin, dietary, or exercise patterns recently? For example, a lot of diabetic athletes I know need 1/3 to 1/2 of their daily total insulin when they’re "in season" as opposed to between competitive seasons. I know lots of people who have rules that they never take more than 4 or so units of rapid-acting insulin at one time because of how fast it can drop your sugars. That seems like an excessive amount of carbs that your son needed to raise his sugars — to me that seems like he either got too much Novolog or he exercised a lot yesterday. Has your wife read Diabetic Athlete’s Handbook? She can find info about it on my website at www.shericolberg.com, along with other useful articles and information. Without being there with your son, I really can’t guess more accurately what the problem is.


If you have any physical activity, fitness, exercise, or nutrition questions for Dr. Sheri Colberg that you would like to see answered in my next column, please e-mail them to sheri@shericolberg.com.

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