Thyroid function tests during substantial weight change posts 61–90
This is a continuation of a long topic, addressed by post number rather than by page. Start at post 1.
Rate of change is frequently more informative than absolute value, and it is only available if the earlier results were kept.
This is the version I would want a new member to read first.
Lipid changes during substantial weight loss are expected and their trajectory is not always monotonic. A single mid-course panel can be misleading.
I would treat the number as indicative rather than as a measurement.
Liver enzyme changes during rapid weight loss are commonly reported and have several possible explanations, which is exactly why they need clinical interpretation rather than forum interpretation.
The rule of thumb is fine; the edge cases are where it earns its keep.
I read post #64 twice before replying, because I had assumed the opposite.
Two claims get bundled together under thyroid function tests during substantial and they need separating. The descriptive one — this is what was observed — is usually well supported. The causal one — this is why — usually is not.
Almost every disagreement in threads like this one dissolves once you say which of the two you are making.
Taking post #66 at face value and following it one step further.
I changed my mind about thyroid function tests during substantial 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.
Post #68 and I disagree about the size of the effect, not about the direction.
Glycaemic markers integrate over different periods. A point glucose and a longer-term marker disagreeing is not a contradiction; it is two different questions.
Speaking for myself and not for anyone else who has posted here.
Post #72 answers the question as asked. The question underneath it is different.
Reference intervals: constructed to contain the central 95% of a reference population, which means one in twenty healthy people falls outside one by definition. Add biological variation and analytical imprecision and the base rate of a meaningless flag is substantial.
Posting it because the silence on this was starting to look like agreement.
The number people quote for thyroid function tests during substantial is a central estimate presented without its interval, and the interval is wide enough that the estimate is nearly uninformative on its own.
Everything in post #75 holds. The case it does not cover is the one I have.
TSH and free hormones: TSH is a reasonable screening test but does not tell you about actual free hormone levels. If TSH is abnormal, free thyroid hormones confirm whether there is a real thyroid problem.
Reading it back, the second half matters more than the first.
Narrowing post #75, because the general version has more than one answer.
Filing a mild objection to the consensus on thyroid function tests during substantial. Mild because I might be wrong; an objection because nobody has addressed the case that does not fit.
Where I part company with post #75, and it is a narrow parting.
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.
I am describing what is, rather than arguing for what should be.
Post #79 is the version of this I will quote in future. One addition.
Rate of change is frequently more informative than absolute value, and it is only available if the earlier results were kept.
I would hold that lightly until someone with a larger sample weighs in.
Where I part company with post #78, and it is a narrow parting.
Practical experience of thyroid function tests during substantial, offered as one case with the conditions stated, not as a general finding. Conditions first, because they are what make it interpretable.
Thyroid function tests during substantial: I would want to see the raw numbers rather than the summary before agreeing. Summaries lose exactly the information that would settle this.
Confirming post #84 from a second method, which matters more than confirming it from a second person.
What I would check first on thyroid function tests during substantial is whether the thing being measured moved or whether the way of measuring it moved. Those look identical in a graph.
Renal function markers: eGFR is estimated, not measured. It depends on creatinine, age, and weight. A small change in creatinine might not mean a real change in kidney function.
Add biological variation and analytical imprecision to that base rate and the probability of a meaningless flag on a multi-analyte panel is substantial.
I would want to see it done twice before believing it once.
Thyroid function tests during substantial has a well-known answer and a correct answer, and the interesting work is establishing that they are the same. Nobody has done that here yet.
Adding what did not work for me on thyroid function tests during substantial, since the failures never get written up and they are half the useful information.