Topic summary

Second pass at: Fasting versus non-fasting and which tests care

Clinical › Bloodwork lipase & amylase liver enzymes lipid panel HbA1c eGFR & renal function

This is a generated summary. It shows the 5 most-liked posts from a topic of 26, in their original order, with the accepted answer included where one exists. It is a reading aid and it will miss nuance — the full topic is the record.

blank_injectionTL2Analytical chemist16 Dec 2025#3

s.antonsen, post #2: The opening post put the caveat in the right place and I want to underline it. 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. Go to post

I would put moderate confidence on the mainstream reading of Fasting versus non-fasting and no more. That is not scepticism for its own sake; it is where the sourcing actually stops.

27 likes in reply to #2 7mo

z.cardosoTL25 Jan 2026#6

n.villalobos, post #4: That reframing is the whole thing. The facts I already had. Go to post

Post #5 and I disagree about the size of the effect, not about the direction.

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.

19 likes in reply to #4 7mo

FFaulknerTL3Regular28 Jan 2026#10

d.moreau, post #5: Adding the boring version of Fasting versus non-fasting, because the interesting version keeps getting posted and the boring one is usually right. Check the ordinary explanations, in order, and stop when one of them accounts for what you are seeing. Most of the time the second one does. Go to post

Fasting state, time of day, recent exercise and hydration all move several common analytes. Standardising the conditions matters more than the interval between draws.

It is worth stating the boring hypothesis before the interesting one.

26 likes in reply to #5 6mo

d.szymanskiTL3Wiki editor13 Feb 2026#13

I had written a reply contradicting post #11 and deleted it. Here is what survived.

Repeat before acting is standard practice for an isolated abnormal result on most analytes, and it is standard for a reason.

Worth reading the earlier posts in this thread before acting on mine.

23 likes 5mo

g.tanakaTL3Regular7 Apr 2026#24

I had read the opposite somewhere and cannot now find where, which tells me something.

30 likes 4mo

Read the full topic (26 posts)

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