I am 21 years old, and several years ago was diagnosed with reactive hypoglycemia. I have taken the GTT twice, the second time dropping into the 40’s [mg/dl, 2.2 mmol/L] by the second hour. I am a swimmer, and am having trouble understanding what exactly is going on in my body. Though I am trying to control the sugar fluctuations with diet, this is not always possible, and stress especially causes rapid changes and makes it hard to swim.

When I was at my final swim meet of the season, I checked my sugar in the morning before breakfast (I always do so at competitions), and it was 70 mg/dl [3.8 mmol/L], which is pretty normal. I then had breakfast, checked it once again because I felt sick to my stomach, and it was 174 mg/dl [9.7 mmol/L]. I am not sure why this would happen, because my sugar rarely goes above 90 mg/dl [5 mmol/L]. In addition, there were several times over the past year when my fasting sugar has been 130-160 mg/dl [7.2-8.9 mmol/L].

I have read that there is no correlation between hypoglycemia and type 2 diabetes, so I am having a hard time figuring out what is causing the problem in my body, or how to fix it. My endocrinologist said that there is nothing that can be done unless the numbers are caught in the lab, and my primary care doctor told me that the condition of hypoglycemia does not exist. I am not really sure where to go from here. Do you have any suggestions?

Under usual situations, after a meal, the blood glucose level begins to rise which prompts the pancreas to secrete insulin in direct relation to the amount of blood glucose in order to bring down and maintain the glucose level in a relatively fixed range of about 60-110 mg/dl [3.3-6.1 mmol/L], at which point the insulin secretion should decrease also. So-called reactive hypoglycemia is a process whereby after a meal, when the insulin should be lowering the blood glucose, instead of the insulin level decreasing also, it is maintained which then forces the glucose into the hypoglycemic ranges — often into the 40’s [mg/dl, 2.2 mmol/L]. There is no precise mechanism behind reactive hypoglycemia. Some clinicians believe that those with reactive hypoglycemia are more apt to develop diabetes later in life, but the literature does not really support that.

However, you have indicated that you have tested your sugar fasting blood sugars, and they has been greater than 126 mg/dl [7 mmol/L]. I presume that is on a glucose meter and not in a hospital lab. I also presume that the oral glucose tolerance test you have received have been properly done (prepare by eating at least 60% of your calories as carbs for the three days before the test; getting the correct glucose load during the test [1.75 grams of glucose per kilogram body weight to a maximum of 75 grams for the load] and that insulin levels were measured too. Was the GTT done since you’ve had high fasting glucoses?

I think I might be concerned about a smoldering type 1 diabetes situation in you that may be somewhat masked by what sounds like great exercise habits. I’d still talk to your doctor about this.

As for “reactive hypoglycemia”, see if it makes a difference if you lower your consumption of simple carbohydrates — which may be hard for you to do on race day. Complex carbs and increased protein are usually the dietary treatments for reactive hypoglycemia.

DS