December 20, 2007
Diagnosis and Symptoms
Question from New Jersey, USA:
I do not have diabetes. I am a 41 year old female, a nurse with a BMI of 21, a good lipid profile, great blood pressure (100/70), active, follow a very good diet, and am healthy.
About a month ago, I decided to check my blood glucose with a meter I have in my office because I had noticed I had to urinate more frequently (main symptom). To my surprise, it was 360 mg/dl [20.0 mmol/L] about an hour after oatmeal. An hour later, it was 198 mg/dl [11.0 mmol/L]. I thought the meter was wrong so I bought two more over the course of the next few weeks. I checked fasting and one to two post meal blood sugars (using good technique on a calibrated monitor) almost everyday. My fasting blood sugars ranged from 95 mg/dl [5.3 mmol/L] to 110 mg/dl [6.1 mmol/L]. My post meal blood sugar were very high, at times over 300 mg/dl [16.7 mmol/L], while some were over 200 mg/dl [11.1 mmol/L] and many 140 mg/dl [7.8 mmol/L] to 200 mg/dl [11.1 mmol/L]. BUT, many were under 140 mg/dl [7.8 mmol/L] post meal. So, I went to my nurse practitioner (NP) and told her of my findings. She was not impressed. She dipped my urine (not clean catch) for sugar and, I guess, bacteria because she told me I had an UTI, which I did not. A laboratory urinalysis confirmed that the next day and I did not have the usual symptoms I have with UTI. She did a fingerstick in the office to correlate my meter. They were both within three points of 180 mg/dl [10.0 mmol/L]. She sent me for a laboratory fasting test and an A1c the next day. My fasting blood sugar was 88 mg/dl [4.9 mmol/L] and my A1c was 5.4. These results were given to me by the office staff and I never received a follow-up call from the NP so I assumed she blew it all off, which doesn’t sit right with me.
Some days my blood sugars are good with only one “higher,” like 176 mg/dl [9.8 mmol/L], or none high. But, some days they have been high (over 250 mg/dl [13.9 mmol/L]) for hours, returning to normal later in the day.
My main question….can you have diabetes and still have days with good blood sugars? I am confused. I think I would need a glucose tolerance test. Should I see an endocrinologist? I think I am firing my NP!
Answer:
You raise a very interesting issue. It is good that your A1c is not elevated. The problem is that A1c is not used to diagnose diabetes. Previous studies have shown it is not sensitive enough to make the diagnosis. Fasting glucose values of 126 mg/dl [7.0 mmol/L] or higher on two occasions, as drawn from a venous blood sample and run in a clinical laboratory, are used for diagnosis. The 75 gram oral glucose tolerance test (OGTT) is also a valid test for the diagnosis of diabetes and is probably the most sensitive of all. We have more data about future risk of diabetes based on fasting glucose than we do on postprandial blood sugars. Your fasting glucose was good at 88 mg/dl [4.9 mmol/L]. The only other test you have not had would be the OGTT. If you really feel strongly, you can get the OGTT. However, I would not necessarily continue to monitor more glucose levels and don’t think you necessarily need an endocrinologist at this point.
JTL
