unpopular opinion: most of what gets said here about bloodwork is guesswork
unpopular opinion: most of what gets said here about bloodwork is guesswork. I have gone back and forth on this for months.
Different laboratories use different assay platforms with different calibration. Comparing across labs adds a systematic offset that is invisible on the report.
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.
ApoB counts atherogenic particles rather than the cholesterol they carry, which is why it can diverge from LDL-C and why it is the addition most worth making.
I will update this if the picture changes rather than quietly leaving it up.
best — the order this archive was captured in
Standing reminder: nobody here interprets your results, and posts asking us to get a pointer to somebody who can.
Standing reminder: nobody here interprets your results, and posts asking us to get a pointer to somebody who can.
This is the sentence to read before anybody panics about a single value.
Agreed. The trend is the signal. A single value is a snapshot of one morning.
Nobody here can interpret your panel and this comment is not doing so. What a board can usefully do is help you ask better questions of somebody who can.
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.
Cosigning on baseline. The panel I regret most is the one I did not take before starting.
How many weeks between the two measurements?
That is a non-fasting value and the interval you are comparing it against is a fasting one.
Correction: that marker is reported in different units by different labs, which explains the tenfold difference you are seeing.
Small fix — a reference interval is not a treatment target, and the post above uses them interchangeably.
one measurement is a point, two is a line, three is a trend
Right, and weight loss itself moves several markers, so attribution is harder than these threads assume.
Yes — same lab, same fasting state, same rough time of day, or the comparison is doing nothing.
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.
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 hs-CRP" almost never have the design to support the claim, mine included.
The confounding problem, stated plainly, because this board keeps stepping on it.
flair_enthusiast is right that a reference interval is not a target. It is a description of a population.
Do you have a baseline from before you started?
Draw at the same point in the week now, fasting, same lab. The noise dropped enormously once I standardised.
same lab, same conditions, or you are comparing noise
same lab, same conditions, or you are comparing noise
Disagreeing with this bit: that change is confounded by the weight loss itself and cannot be attributed.
- 1Cosigning on baseline. The panel I regret most is the one I did not take…10 comments in this branch · started by u/whois_wanda