my TSH moved and I cannot work out whether ferritin is why
my TSH moved and I cannot work out whether ferritin is why. I have gone back and forth on this for months.
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.
Brought the whole set to my clinician rather than one flagged value. Completely different conversation.
Tracked ferritin against the weight trend for a year. The correlation was much weaker than I expected and that was worth knowing.
Corrections welcome, especially the pedantic ones. Pedantry is how this board earns its reputation.
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.
fasting state and time of day change more than people expect
That comparison crosses two labs with different assays. The difference you are describing may be the method.
Repeat testing before acting is standard practice for a reason: regression to the mean does a lot of work on single outlying values.
the trend line matters more than any single value
Careful — that is a question for whoever ordered the panel, and nobody in this thread can answer it responsibly.
weight loss itself moves several of these independently
Draw at the same point in the week now, fasting, same lab. The noise dropped enormously once I standardised.
How many weeks between the two measurements?
one measurement is a point, two is a line, three is a trend
assay method matters, especially between different labs
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.
edit_for_clarity is right that a reference interval is not a target. It is a description of a population.
That is a non-fasting value and the interval you are comparing it against is a fasting one.
Disagree with reading anything into that. One value, one morning, and you changed two other things in the same window.
ApoB is the one worth adding if you only add one
Left up. It is a question about how to compare panels, not a request for interpretation.
bring the numbers to someone qualified to read them
Added ApoB to the panel after a thread here. It told me something the standard lipid panel had been hiding.
My triglycerides moved and I spent a fortnight convinced I knew why. The repeat six weeks later was back in range and I had changed nothing.
do not change three things and then read the panel
Different laboratories use different assay platforms with different calibration. Comparing across labs adds a systematic offset that is invisible on the report.
Push back: a value just outside a reference interval is a common finding in healthy people. It is a reason to repeat.
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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.
draw at the same point in the week if you want comparability
lab reference ranges are not treatment targets
- 1assay method matters, especially between different labs9 comments in this branch · started by u/liv_okafor
- 2Repeat testing before acting is standard practice for a reason: regression…7 comments in this branch · started by u/elin_trevino