why does nobody talk about baseline labs
Trying to get a straight answer on this: why does nobody talk about baseline labs.
Why so many single values look alarming and turn out to be nothing.
A reference interval is built to contain about 95% of a healthy reference population, so one test in twenty falls outside one by construction. Add biological variation, assay imprecision, fasting state and time of day, and a genuinely stable person will produce occasional out-of-range results.
That is why repeat testing before acting is standard. Regression to the mean handles most of it. None of which means an out-of-range value should be ignored — it means it should be repeated and taken to somebody who can put it in context, which is emphatically not a ranked feed.
How to make a panel worth comparing, which is most of the value people leave on the table.
Standardise the conditions: same lab, same fasting state, same rough time of day, same point in the week, similar hydration. Take a baseline before you change anything. Repeat any surprising value before acting on it. Change one thing at a time if you want to attribute anything to it.
Do that and a year of panels is a trend. Skip it and a year of panels is a collection of unrelated mornings, which is what most of the alarmed posts here are actually describing.
Panicked about a single result, posted here, got told to repeat it, repeated it, and it was fine.
Would rather be corrected in public than confident in private.
best — the order this archive was captured in
Reference intervals are typically the central 95% of a reference population. By construction one person in twenty falls outside one on any given test without anything being wrong.
Tracked ApoB against the weight trend for a year. The correlation was much weaker than I expected and that was worth knowing.
Correction: that marker is reported in different units by different labs, which explains the tenfold difference you are seeing.
Yes — same lab, same fasting state, same rough time of day, or the comparison is doing nothing.
Yes. Repeat before you react. Almost every alarming single value I have posted here regressed on the repeat.
Same view — ApoB if you add one thing. It answers a question the standard panel only gestures at.
Yes.
Disagreeing with this bit: that change is confounded by the weight loss itself and cannot be attributed.
That is a non-fasting value and the interval you are comparing it against is a fasting one.
The confounding problem, stated plainly, because this board keeps stepping on it.
Substantial weight loss moves lipids, liver enzymes, insulin sensitivity markers and several others in its own right. If you are losing weight while taking something, any change in those markers has at least two candidate explanations and you cannot separate them from your own panel.
What you can do is standardise, take a baseline, keep the series long, and be honest in your posts about what is and is not attributable. The threads that say "this compound did X to my ApoB" almost never have the design to support the claim, mine included.
The confounding problem, stated plainly, because this board keeps stepping on it.
Adding the obvious one — take it to whoever ordered the panel. This board cannot read it for you.
My ferritin moved and I spent a fortnight convinced I knew why. The repeat six weeks later was back in range and I had changed nothing.
I would not draw a line through two points, especially when the second was taken at a different time of day.
I would not draw a line through two points, especially when the second was taken at a different time of day.
valeria_karlsen is right that a reference interval is not a target. It is a description of a population.
Standing reminder: nobody here interprets your results, and posts asking us to get a pointer to somebody who can.
Have you taken this to whoever ordered it?
Agreed. The trend is the signal. A single value is a snapshot of one morning.
Time of day, fasting state, hydration and recent exercise all move common markers. Standardising the draw conditions is free and it removes most of the apparent variability.
Substantial weight loss independently moves lipids, liver enzymes and several other markers. Attributing a change to a compound while losing weight is confounded by design.
draw at the same point in the week if you want comparability
draw at the same point in the week if you want comparability
Agreed — and standardising the draw conditions is the cheapest improvement available.
Small fix — a reference interval is not a treatment target, and the post above uses them interchangeably.
the trend line matters more than any single value
Agreed on assay changes. A lab switching platforms between your draws is invisible unless you ask.
lab reference ranges are not treatment targets
- 1Agreed. The trend is the signal. A single value is a snapshot of one morning.7 comments in this branch · started by u/chidi_abubakar