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HbA1c bloods and fasting.

JohnEGreen

Master
Messages
14,002
Location
Nottinghamshire
Type of diabetes
Other
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Diet only
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Tripe and Onions
I know this comes up time and time again, but I have blood tests booked for the morning for HbA1c and lipids and I can't decide if I should fast for them or not.

I also know it's not generally considered necessary these days but am unsure if not fasting will skew the results or not.
 
As your hba1c is based on approx 90 days and dietary cholesterol is supposed to have nothing to do with blood cholesterol then I can never understand the point of fasting for a blood test personally, plus if your GP wanted you to fast then surely he should have told you to.
 
When I get my hba1c and cholesterol and the other tests that get done together, it is always marked fasting on the pathology shop request form by my GP.

That's when I go and have breakfast and coffee at the private hospital cafe with my little baggy of pills.
 
HbA1c is irrelevant wrt to fasting @JohnEGreen.

However, lipid profiles can get interesting on fasting. If skipping breakfast, trigs can be a lot lower, which will have a big impact on your TC (I think).

Not going to pretend even further in that I know any more than I do, but I will guarantee that @Bluetit1802 does. She will give you the best answer here on the forum regarding lipid tests and breakdowns.
 
It is not really necessary for HbA1c test alone, but will be necessary if also having either an FBG test ot Lipid Panel where fat intake would skew the results significantly. There may be other tests that require fasting, but I am not aware of them. There may be some kidney function tests? or an OGTT test? But not HbA1c alone. Also may affcct any urine tests such as protein or glucose content?
 
@Oldvatr I was stating what is written on the pathology request form from my GP, when hba1c and cholesterol testing are both together it has "fasting" on the form.

So I do...
 
I always understood that TriGs were fasting sensitive so I've always fasted and made sure the bloods are taken fairly early on in the day. Keeps it the same as it's always been..... which is no good reason to stick with it.... but I do.
Wish you good numbers.
 
If you are getting a full lipid panel then you should fast otherwise the results will be meaningless. If they are just testing for total cholesterol ( a fairly pointless number IMHO then you don't). At my surgery they ask if I have fasted and always seem surprised when I say yes but then do the full panel.
 
Thanks for the replies when I asked I was told not to worry about fasting as if the lipids were high they would bring me back in for a fasting test but I want to know the range of lipids so I can work out ratios and such. and the idea of being called back in for another test seems a waste of time.

I think on reflection I will play it safe and fast any way.
 
hankjam said:
I always understood that TriGs were fasting sensitive so I've always fasted and made sure the bloods are taken fairly early on in the day.
Click to expand...
I get down to the pathologists around 7:30 am as the early rush has nearly finished.

I am normally home by 8:45 after having breakfast there at the private hospital.

JohnEGreen said:
I think on reflection I will play it safe and fast any way.
Click to expand...

That's the best bet for a win win.
 


Ha ha. I don't know any more than others on this forum, but thanks for the tag.

If you are having lipid tests that include triglycerides you must fast if you want an accurate result. If you eat beforehand, your triglycerides will be swimming about in your blood stream doing their job. Especially so if the meal contains any fat. Anything swimming about in your blood stream will get sucked into that vial and tested at the lab. Just stick to water, eat nothing for 10 hours beforehand, and no alcohol the night before. I don't know the reason for the no alcohol, but that is what I have read.

There are actually 2 standard ranges for triglycerides.
0 to 1.7 fasting
less than 2.3 non-fasting.
However, our labs haven't caught on to this yet and nor have our doctors, so they just stick to the 1.7.

https://heartuk.org.uk/health-and-high-cholesterol/cholesterol-tests---know-your-number
  • Triglyceride (TG) this represent your body's ability to clear fat from the blood after a meal. Ideally it should be less than 1.7 mmol/L* on a fasting sample or less than 2.3 mmol/L on a non fasting sample)
 
Tipetoo said:
@Oldvatr I was stating what is written on the pathology request form from my GP, when hba1c and cholesterol testing are both together it has "fasting" on the form.

So I do...
Click to expand...
As I said, lipid panel or cholesterol test is best done fasting. I did also point out that it is not the HbA1c that needs it,
 
Yes, I insist on a fasting blood lipids test, as I know that your triglycerides test is dependent on what you have eaten prior to the test, so the only way to really tell if your body is dealing well with the fat you are eating and producing, is by having a fasting trig level. (Ie your body has been 'dealing' and dealt with the fat you ate the day before).

It is the only way to have good comparative results for your triglycerides.

The reason why this is not prioritised is there has been a focus on cholesterol levels. There are many, like me, who keep a close eye on their trig/HDL ratio, instead of their cholesterol/HDL ratio.

Blood lipid tests are really important for diabetics because the main thing we die of too early is from strokes and CVDs. If you are watching your health as a diabetic it is probably very important to find out as much as you can about strokes and CVDs, their causes, treatments and absolutely - the blood tests and how to interpret the results yourself. IMO, at any rate.

Other than that - there is no reason to have a fasting HBA1c .

I, like Tipetoo, have a treat at a favourite cafe after having my regular blood lipid tests. (Chopped liver, boiled eggs and humus! A good LCHF treat.) (The coffee goes without saying.)

I should add that I have had my blood lipids tests done during longer term fasts, but I won't do that again, as I get a bit, ah, tetchy after some days without food, and I ended up feeling sorry for the blood-taking technicians, or at least those at reception. (Never be anything other than charming to someone approaching your arm with a needle). I think I may have been, ah, a bit strident explaining why I always have fasting tests, and I am sick of asking them to note it every time - something like that! (Great on the spot BG test though, of course, but that just confuses the lab...) (As far as I know they don't note "Client is a b**** when she goes without food for days on end" although they probably should! .)
 
Oldvatr said:
As I said, lipid panel or cholesterol test is best done fasting. I did also point out that it is not the HbA1c that needs it,
Click to expand...

I did say when hba1c and cholesterol are both requested together.
AloeSvea said:
I, like Tipetoo, have a treat at a favourite cafe after having my regular blood lipid tests. (Chopped liver, boiled eggs and humus! A good LCHF treat.) (The coffee goes without saying.)
Click to expand...
It's normally bacon and eggs and coffee, as they do not sell what you would like except for the boiled egg.
 
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