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From Honolulu, Hawaii, USA:

I had gestational diabetes with my previous pregnancy and almost had to go on insulin. My level after a one hour Glucola test was 214 mg/dl [11.9 mmol/L]. Luckily, since I work out almost every day and am knowledgeable about what foods to eat, I was able to control it through diet.

That said, I am now 33 weeks pregnant with my second baby and have been watching my diet from the start. At 28 weeks, my first Glucola test came out a little high 50 ml, 168mg/dl [9.3 mmol/L]. They gave me a glucometer to use since I was going on a two week trip and wasn't able to do a three hour test before that time. Ever since then, I have been testing myself four times a day. My fasting levels are always too high, anywhere around 110 mg/dl [6.1 mmol/L]. The other levels I am usually able to control by diet and exercise. My OB doctor told me to get my fasting levels down, otherwise, I would have to go on insulin, but still wanted me to do the three hour test, so I did.

That morning, according to my glucometer, my levels where: fasting -- 116 mg/dl [6.4 mmol/L]; after 1 hour 100 ml Glucola -- 224/mg/dl [12.4 mmol/L]; two hours -- 168 mg/dl [9.3 mmol/L]; and, at the three hour point, 71 mg/dl [3.9 mmol/L]. The gentleman at the laboratory also took my fasting test and told me his reading also came out to 116 mg/dl [6.4 mmol/L](from the vein in my arm).

Two days later, I got a call from my doctor telling me that my test came out fine. One hour -- 168 mg/dl [9.3 mmol/L]; two hours -- 135mg/dl [7.5 mmol/L]; and three hours 61 mg/dl [3.4 mmol/L]. When he read me my readings, and knowing my body very well, I seriously thought that he had the wrong results in front of him. My fasting levels continue to be too high and, if I don't stick to my diet, my sugar levels are above the normal range.

Is there that much difference in a glucometer reading and a venipuncture laboratory reading? I'm confused because, according to my glucometer, I would have to go on insulin. Should I get an second opinion?


The results of the glucose test you report are confusing. There is quite a discrepancy between the laboratory readings and your glucometer. I would tend to trust the laboratory and would recommend having your glucometer checked for proper calibration. The laboratory has strict quality controls and probably calibrates its glucometer daily (if not several times a day). I assume that the fasting was 116 mg/dl [6.4 mmol/L] from the laboratory test. This is elevated, but should be manageable with diet. If your glucometer is adjusted and you are still having slightly high readings, you may be a candidate for an oral hypoglycemic medication called glyburide. This may work before having to try insulin. Speak with your doctor further about your results and the need for any further testing.


Original posting 18 Oct 2005
Posted to Blood Tests and Insulin Injections and Other


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