Hi all experts, I'm hoping you can give me some answers. I had my Thyroid blood test on 25 April, stopping my B complex with biotin seven days before and fasting to the recommendations on HU, taking my Levo after. When I was having my test, the nurse took two phials of blood and I asked her why (thinking I was just getting my TSH test) and she said the GP had asked for full blood and calcium profile. Anyway, on checking my results on line, found that he had also tested my plasma viscosity which came back at 1.89 mPa.s [1.5 - 1.72] with a note to repeat test. My TSH came back as 1.15 mlU/L [0.3 - 5.0]. When I spoke to him on the 'phone, he said that my TSH level proved that I was on the right dose of Levo (75 mcg). As I still have many symptoms of hypo, mainly manifesting themselves when he (my GP) took me off Levo for six weeks (I think to try and prove a point, which didn't work out the way he thought it was going to do) I argued that 75 mcg was not high enough. He has reluctantly allowed me to have enough Levo for 75 mcg x 3 days and 100 mcg x 4 days alternating. This morning I received a text message to book a non fasting blood test in four weeks time. My question is, will a fasting blood test make any difference to my plasma viscosity as I suspect he might add a TSH test to that when I get there and I don't want to give him any ammunition to reduce my levo if I take my meds before going for the blood test.
TIA Gingernut44
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Gingernut44
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I can't find any reference as to whether plasma viscosity test should be fasting or non-fasting, all I have found is
Test Preparation Needed?
No test preparation is needed.
If it was me I would fast anyway (I do all my tests fasting just in case they pop something else in I don't know about and it may need to be a fasting test). If they ask you if you have fasted, skirt the question - ask "Why, would it make a difference?". If pushed, you can always say that you don't always have breakfast and today you didn't feel like any.
Many thanks SS, that's just what I thought but I wasn't sure - I don't tend to have breakfast, more likely brunch, but I do love my morning coffee so will forego that and leave off my B complex for seven days and leave my levo until after the test, just in case. Gingernut44
Research published in the journal Aviation, Space, and Environmental Medicine demonstrated that dehydration increases systolic blood viscosity by 9.3% and diastolic blood viscosity by 12.5%.
The results are from a study of 12 healthy men who sat for 4 hours at a dry-bulb temperature of 23.0-23.5¡C and a relative humidity of 18-36%. The purpose of the study was to assess the effects of prehydration with water and an electrolyte-glucose beverage (EGB) in comparison with controls subjects, who did not ingest either fluid prior to the study. Blood viscosity and plasma volume were tested every hour (including baseline prior to hydration), and routine laboratory hematological tests, urine volume, and body weight were recorded at 2 and 4 hours.
Hi, many thanks Humanbean - no, I have to admit, I totally forgot to drink plenty of water the day before my blood test. I know I don't drink enough water at the best of times but I'm sure going to drink plenty the day before my next one. Thanks for the reminder and the link. Gingernut44
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