Do you take your metformin the day of a glucose challenge?

stacicali

Just curious how other people's drs are advising the dosing of metformin on the day of a glucose challenge (the test where you drink the sugary awfulness and then have blood drawn.) I have one dr saying take the morning metformin dose as usual, one saying skip the morning dose, and one saying stop all metformin 5 days prior then resume after the test.

anubis609

The purpose of an oral glucose tolerance test (OGTT) is to see how well your body responds to incoming glucose. There's not really a protocol, however, know that metformin is going to skew the result and it will become a question of "is it the medication that made this result or was it my own body?"

Not sure if you're at keto low carb levels, but for you or anyone else that is keto, an OGTT is going to be a failed test if you don't activate the glycolytic pathways prior to the test.

If you're getting around 100-150g of carbs per day already, then it should be fine.

A better test would be to get a fasting insulin blood draw at the same time you get your other fasting labs.

KnitOrMiss

@anubis609 - @stacicali is having to do the glucose tolerance test because she is pregnant...they're using it to determine whether she has gestational diabetes.

anubis609

@KnitOrMiss - Gotcha. Low carbing through pregnancy is still practiced, so it's still applicable if her macros follow that. Outside of dieting and maintaining a healthy weight to support the baby, my assumption is if she's currently on metformin, she's already diabetic, no?

AutumnDraidean

So if the OB ordered the test then that's who's directions should be followed. I "thought" that one was started fasting, and they draw first, then have you drink the crap, but it's been 12 years so...

My nurse radar is ringing though, saying that if metformin is involved this might be a little more complicated and you'll want to be completely clear with directions so call the doctor who ordered the test and ask, no need to risk having to drink glucola twice! (eewww)

T1DCarnivoreRunner

Here's my view:

The dr. who says not to take it the morning of is definitely wrong. Metformin builds up in your system, so skipping a single dose on the morning of the test is going to make very little difference. That dr. clearly doesn't understand how metformin works.

As to the others either saying to stop 5 days before-hand or to continue taking as you normally would... neither is right or wrong, but the results must be interpreted based upon what you did. For this reason, you should follow the direction of whichever dr. is going to be interpreting the results.

Unless, of course, the dr. ordering /interpreting the test is the same dr. who said to just skip that morning's dose. If that is the case, run away!

KnitOrMiss

anubis609 wrote: »

@KnitOrMiss - Gotcha. Low carbing through pregnancy is still practiced, so it's still applicable if her macros follow that. Outside of dieting and maintaining a healthy weight to support the baby, my assumption is if she's currently on metformin, she's already diabetic, no?

@anubis609 - Pre-Diabetic, Insulin Resistant, but not fully diabetic. Following lower carb (not sure of how low currently) for glucose/health management during pregnancy. Reasonable glucose control in general, but a little more chaotic recently.

I know as someone who is also pre-diabetic and insulin resistant that a dump of glucose in my system like that would have me taking a full on nap - but my spikes and drops are short, quick, and regulated by my body...but my insulin charts probably look like an EKG...

I seem to recall that if you're low carb, you will fail a OGT test, period, without going higher carb for a week or whatever before the test, but I will never understand how that makes any sense to change if you are low for health reasons....there has to be a better test.

Personally, I like @midwesterner85 's suggestion - check with the doc, either be off the week 5 days before or on even that AM...skipping one dose when you're on higher and multiple a day seems...like a tiny drop in a huge bucket.

stacicali

Thanks for everyone's answers, and sorry I've been out of the loop. The perinatologist (an OB who specializes in maternal fetal medicine) wanted me to skip 5 days, and my regular OB said to skip the morning of. The perinatologist is very conservative and has stated that she would prefer that I not be on metformin during pregnancy. She would rather the metformin not "mask" gestational diabetes and treat me with insulin shots. I have my own glucose meter and have experimented with skipping metformin doses during this pregnancy, and some of the readings have been alarming. Since high blood sugar spikes are bad for the baby, I felt it was dangerous to go off the metformin for 5 days. Due to numerous studies showing no adverse affects to the fetus with metformin and multiple benefits to the mother, I insisted on staying on metformin with my last pregnancy and have insisted on staying on it with this one. My regular OB agrees with my position and is continuing to prescribe metformin throughout the pregnancy. So I took the OB's instructions of skipping the metformin the morning of (and also skipped the evening before) and passed the glucose tolerance test. Since I am staying on metformin regardless, I felt that was the best approach and at least complied with one set of drs. Thanks again to everyone who responded.

KnitOrMiss

@stacicali - This is fantastic news! You go. That's awesome, and I love how you gathered the data to do what's best for you and the baby...

And the metformin doesn't, in my opinion, MASK GD...it TREATS the precursors to it... Good call, Mama!