This is a continuation of a long topic, addressed by post number rather than by page. Start at post 1 · go to the accepted answer.
Picking up post #30: that is the part I would want checked first.
Source for the fasting versus non-fasting figure, since it was asked for. It is in the discussion rather than the abstract, which is why the version circulating is stronger than the paper is.
Reading the surrounding paragraph is worth the two minutes. The authors are more careful than their summarisers.
On post #30 — agreed on the reasoning, with one qualification.
Practical note on fasting versus non-fasting: write down what you expect before you look. The number of times I have found what I went looking for is higher than chance would allow.
Fasting state, time of day, recent exercise and hydration all move several common analytes. Standardising the conditions matters more than the interval between draws.
A request rather than an answer: could whoever has the primary source for fasting versus non-fasting post it? I have seen the claim three times this month and each version had lost a qualifier.
Adding the measurement that post #32 says would settle it.
What would change my mind on fasting versus non-fasting is a second dataset collected by someone with no stake in the first. Until then I hold it loosely and I would rather say so than pretend to more.
Repeat before acting is standard practice for an isolated abnormal result on most analytes, and it is standard for a reason.
I changed my mind about fasting versus non-fasting after someone here asked me for the source and I could not produce one. That is worth saying out loud because it is the ordinary way it happens.
I would rather this thread reach "we do not know" about fasting versus non-fasting than reach a confident answer that nobody can support when asked.
Post #39 put the caveat in the right place and I want to underline it.
Where the fasting versus non-fasting discussion usually stalls is that nobody wants to say "I do not know" and everyone is willing to say "it varies". Those are the same sentence with different clothes on.
Fasting state: some lab tests require fasting; others do not. Lipids on a fasting draw differ from lipids on a fed draw. Always note whether the test was fasting when comparing results.
I am describing what is, rather than arguing for what should be.
The arithmetic in post #43 is right; the assumption feeding it is the part to check.
Worth stating the null on fasting versus non-fasting before we explain it: the observation may be nothing. That possibility deserves a sentence and usually does not get one.
Following, with nothing to contribute beyond having asked the same thing elsewhere.
Post #43 is the version of this I will quote in future. One addition.
Glycaemic markers integrate over different periods. A point glucose and a longer-term marker disagreeing is not a contradiction; it is two different questions.
The short answer was in the first line; everything after is the working.
The honest answer on fasting versus non-fasting is that it depends, and the useful part is the list of what it depends on. Four items, in rough order of how much they matter.
Most people get the first two right and then argue about the fourth.
Time of day: some biomarkers vary across the day. Cortisol in the morning differs from cortisol in the evening. Comparing results from different times of day is comparing things that are not the same.
Reframing fasting versus non-fasting slightly, because I think the disagreement is about the question rather than the answer. If the question is "does it happen", yes. If it is "how often", nobody here knows.
Fasting versus non-fasting: I have looked for the primary source twice and failed twice. Either it does not exist or it is somewhere I do not know to look, and I would like to know which.
Everything in post #48 holds. The case it does not cover is the one I have.
Repeat before acting is standard practice for an isolated abnormal result on most analytes, and it is standard for a reason.
The general case is well covered; this is the awkward specific one.
A trend needs at least three points to be a trend. Two points are a line and a line through noise is still a line.
Repeat before acting is standard practice for an isolated abnormal result on most analytes, and it is standard for a reason.
Sensible. I would want the same detail before I acted on it either.
Posting my fasting versus non-fasting numbers with the method attached so they can be discounted properly. Uncontrolled, unblinded, and collected by someone who wanted a particular answer.
Having read the whole fasting versus non-fasting thread before replying: the question in the first post has not actually been answered yet, and three of us have answered a nearby one instead.