Relevance of fasting blood glucose to diabetes control

I think it largely depends on what it is you want to know, really... For a diabetic, morning fasting blood glucose is likely to be higher than a non-diabetic due to dawn phenomenon. It's not so much the exact number, I think it's more that higher numbers are indicative of a insulin sensitivity problem. The HbA1c is useful if you want to know whether you're making progress or not with blood sugar control, it can let a surgeon know whether your body is capable of healing after scalpel-work, it'll explain why you might be having symptoms, or none at all. Testing before and 2 hours after a meal will tell you whether your body could deal with what you put in there, but it'll miss the spike. It's basically all relative, with little absolutes in there anywhere.... But it's something to work with, a bit of a guide. Not sure if that makes any sense? But that's what it means to me, by and large.

I rely on my morning fasting BG as it gives me an indication of my progress and whether I’ve had too many carbs the previous day. If my insulin levels are high I don’t lose weight which I think is typical of most T2 diabetics and I need to lose weight and get my blood pressure down!
As @JoKalsbeek said, surgeons won’t operate unless your hba1c is under 69mmol/l (I live in the UK), as a higher reading impedes recovery.
We’re all different (stating the obvious ) and I think we all can decide whether we rely on these numbers or not and luckily as a T2 most of us can request the test for free on the wonderful nhs!

KennyA said:

Personally I very rarely test my fasting BG. These days I do a week of testing once a year, that's all. The information isn't that useful to me. It does give you some indication of what your liver's up to, but what can you do with it?

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I do a fasting test every day. I use it as an indicator of how my overall sugar control is doing. But I also use it as a starting point for my food choices for the day ahead.

I measure my FBG, even though I don't currently have a specific use for it. I’ll record it anyway, as one day it might be useful. What was never recorded can never be analysed after all.

thanks for guidance.

This thread is a great reminder that no single number tells the full story. Fasting blood glucose can be useful for spotting trends or gauging liver output, but like @JoKalsbeek and others said, it’s only part of the picture. Time in range, post-meal spikes, and overall patterns often give more actionable insight, especially with CGMs.

I have not checked my fasting level for years - as I can't do anything about it.

Resurgam said:

I have not checked my fasting level for years - as I can't do anything about it.

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Me neither but it gives me a pointer as to how high my next HbA1c could potentially be if I take first (usually highest) reading of the day as "average" in the BG/HbA1c converter. That way I can be ready and armed when it gets close to 70, the level at which I will apparently be threatened with an SGLT2i drug I don't want to take.