question about lab work

[vetobob9]

Do you have to have fast for your lab tests? I have been on estrogen patch and spironolactone since the first week of April.

[Aprilrain]

Not for hormone labs

[donnalee]

Did your Dr. order a lipid panel along with your other tests? I know that is a fasting test and there are others, I think. If there were prior concerns about cholesterol, this would be monitored or they may be trying to find a baseline.

[LeaP]

Hormone tests related to HRT meds do not typically require fasting. There are some test types that do, but they are uncommon.

[Frances]

All of the above. It depends on the actual tests. Call the doctor's office.

[Lilo]

I have had to fast for lipid profiles before but last time I did not have to. Apparently the recommendations changed in between. Still Dr. Knows best

[Janelle_C]

I had to fast for the lipid test too. But I also had to have the blood drawn by 10:00am for the testosterone level I don't why.

[Starling]

Could it be that Mr. Testy takes a liquid brunch and is useless for the rest of the day?

:) Lallie

[sandra-leigh]

Lipid (cholesterol) tests need fasting, as do glucose (diabetes) tests. None of the other tests I have done have ever needed fasting (unless maybe it was for my detailed kidney test)

[Inna]

HRT related testing for hormone levels and presumably liver and kidney function do not require fasting.

[Frances]

She said lab tests. She did not mention what they were. All this is speculation, and not very useful. Whatever the case may be, the worst that can happen is being turned away for not having an empty stomach and losing half a day.

[LeaP]

Exactly, Frances.

Just about everyone on HRT is routinely tested for hormone levels using blood tests. The results measure the levels of the hormones in blood serum. This is more than adequate for the purpose in almost all cases. But there are limitations. Except for testosterone, blood serum tests cannot accurately measure the levels of bound versus free hormones. It is hard to accurately measure progestogens in serum. Some estrogens are not measurable using blood serum tests. Hormone metabolites are not measured with blood tests. Test results of sex hormones in serum levels are snapshots. In reality, the body releases endogenous hormones in pulses, and metabolizes hormones (from any source) over varying amounts of time, with varying interactions. Ignoring panels which contain tests like lipids which require fasting in their own right, if the need is to test for interactions with sex hormones, sometimes the related test requires fasting, like growth hormones. That can include things like cancers or other pathology-related tests that are sensitive to both hormone timing and fasting.

Hormones can also be measured by saliva and urine testing. A 24 hour urine collection might be ordered, for example, to get an accurate measure of levels for a full day as well as to measure metabolites and the amount of unmetabolized hormones you are excreting - which may require fasting. Is your doctor likely to order a test like this under normal circumstances? Nope.

Saliva tests are great. Fast and simple. Oh, as long as you don't eat, didn't just brush your teeth, have bleeding gums, chew gum, or even wear too much lipstick ...

Hormones are complicated. The testing can be too, depending on what's needed, the level of accuracy, timing, interactions, lab capabilities, and other considerations. Again, routine serum tests measuring total levels of the principal sex hormones are fine for the purpose, but be aware also that they require some care and knowledge in interpreting results. First, trends over time provide an important perspective. Second, absolute levels mean nothing, absent knowledge of the specific approach being taken by the prescriber.

[kimdl93]

you wouldn't for these, as noted above. However, if you're getting a metabolic panel for lipids, blood sugar, etc, then fasting is necessary.