Fasting levels versus post eating - advice please!

[Kristenmcl]

Hello, I haven’t been diagnosed with diabetes but I’m high risk as my mum has it and I also had gestational diabetes last year. I’m trying to take control and have been wearing a Freestyle Libre. I’d really welcome some advice as my fasting blood glucose levels seem to be varying between 5-7 which is obviously going into pre diabetic territory but during the day after meals, everything seems to be well below the 7.8 limit. I have had very brief spikes to over 8 on eating a homemade banana pancake and a slice of banana cake but both times I’ve returned very quickly to under 7.8 well within 2 hours.
But - could someone tell me whether I should worry about these fasting levels? Does it imply that I already have a level of insulin resistance? Am I pre diabetic already?! I’d so appreciate any advice from anyone knowledgeable about these things as I don’t know what to take from this data!

(As context last night I ate meatballs in homemade tomato sauce with grilled courgettes, a plain Greek yoghurt and a glass of red wine and my blood sugar at 5.30am was 5.9, at 7.16am was 5.1, 7.28 was 5.7, 8.15 was 6 and 8.45 was 5 - this was all before eating or drinking anything)

 

[KennyA]

Hi Kristenmcl and welcome.

One of the things that happens to some of us in the early mornings (diabetics and non-diabetics alike) is that our livers decide to dump glucose into our bloodstreams. This is often called the "dawn phenomenon" or "foot on the floor". This glucose is manufactured by the liver, not glucose coming directly from digested food. The thinking behind why this happens is that it gives us a boost for waking up, so we have an energy supply. More here:

Dawn Phenomenon (Liver Dump)

Dawn phenomenon is the term given to an increase in blood sugar in the morning caused by the bodys release of certain hormones. It is a relatively common phenomenon amongst diabetics.

www.diabetes.co.uk

My experience was that my morning fasting readings were/are usually the highest of the day, and when I was reducing my BGs they were the very last readings to come down. It seems livers are slow learners. I did a week of first thing testing a while ago, and while the values are not high, clustering around low to mid 5s, they are still consistently a bit higher than the 4s I'd expect at other times.

The other thing is that there is enough acceptable error in the fingerprick test process to cover all four of your morning readings, if the true value for all four was 5.5. BG levels vary naturally frpom eating and a range of other stimuli and none of those four readings looks questionable to me. This paper below is a bit dated now but does go into some of the "acceptable error" issues with fingerprick tests. It gives values in mg/dl, which will need to be divided by 18 to give UK mmol/l.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2845057/