August 8, 2001
Diagnosis and Symptoms
Question from Coos Bay, Oregon, USA:
I am a 52 year old nurse who began having elevated blood glucose levels (on a meter) about two weeks ago. My fasting glucose ranges from 156 to 199 mg/dl [8.7 to 11.1 mmol/L], and my two-hour postprandial readings are 128-177 mg/dl [7.1-9.8 mmol/L]. Needless to say, this has caught my attention, and I am sending my HbA1c to a mail-in lab to check if perhaps this has been going on longer than I would expect.
Immediately I started to decrease my carbohydrate intake to approximately 20 to 35 grams per meal (or less), and I have started walking (I have been very sedentary for the last year due to two strained Achilles tendons, they have just started to stop stinging in the last month).
I am curious the fact that my elevated fasting blood sugars do not seem to come from hypoglycemia, the suddenness of elevated blood sugars, and how resistant I seem to be in lowering them even with a low carb intake. I have several questions:
I am not experiencing hypoglycemia during the night (140 to 160 mg/dl [7.8 -8.9 mmol/L] so why would my blood sugars be higher after eight of fasting?
Exactly what is cortisol’s involvement?
For at least 10 years, I frequently will get very hot as soon as I awaken, to where I have to throw my covers off and cool down first thing when I wake up — is this related?
Is it common see diabetes manifest this way?
Is there something else that could be causing this other than diabetes?
I have an appointment with my doctor in a month, and hopefully by then I will see how well diet and exercise can control it, I’ll know my HbA1c and I’ll be ready to follow whatever course he suggests.
You raise several questions that I will try and answer. First, I would not beat around the bush. Do a fasting glucose in the laboratory. Glucose meters have some degree of inaccuracy which should not be used to try and diagnose diabetes. The hemoglobin A1c is not sensitive enough for the diagnosis of diabetes, especially if there are few symptoms.
Cortisol does rise in the early morning hours and antagonizes insulin’s effects during that time. Therefore, with uncontrolled glucose output from the liver, the cortisol spike only serves to increase glucose intolerance in people who have diabetes.
I applaud you for getting out and modifying your lifestyle. However, you need to solid information to know if you have diabetes. The fasting blood sugar may be elevated after fasting because the liver puts out glucose over the night to provide for a glucose supply to brain, an obligate user of glucose.
I do not know why you have the hot spells.
[Editor’s comment: I too applaud your lifestyle changes, but I don’t believe it’s wise to wait a month to see your physician, especially in light of the fact that the meal plan changes and exercise don’t seem to be working. I think you be seen as possible to establish a diagnosis and get started on a prescribed treatment plan.
The spells at night may be the beginning of hot flashes, a sign of menopause.