gastric emptying — 12 things I got wrong before I got it right
gastric emptying — 12 things I got wrong before I got it right. It is the sort of thing everyone half-believes and nobody writes down.
Started reading limitations sections first. It has changed how much weight I give to almost everything posted here.
Asked a question here that I thought was stupid and got three papers back. Best thread I have been in on this site.
The mental model, in four steps, that makes the rest of this site legible.
One: gut hormones amplify the insulin response to food. Two: agonists at those receptors act peripherally on insulin secretion and gastric emptying, and centrally on appetite. Three: structural modification gives them a long half-life, so exposure is smooth and weekly. Four: tolerance develops to some effects and not to others.
From those four, most of what the experience boards report falls out: why the side effects cluster early, why they settle at a stable dose, why appetite reduction persists, and why the scale and the appetite move on different clocks.
Sceptical readings welcome. The confident ones are the ones I distrust.
best — the order this archive was captured in
GIP receptor biology is genuinely unsettled — there is a live argument about agonism versus antagonism at the receptor — and the clinical results are robust regardless, which is an uncomfortable and interesting position.
Why mechanism talk keeps misleading people, including me.
A mechanism tells you a direction. It does not tell you a magnitude, a timescale, or whether the pathway is operative at the exposures involved. "Receptor X is expressed in tissue Y" is a fact; "therefore effect Z in a person" is a hypothesis with several missing steps.
The corrective is boring and it works: ask whether the evidence is preclinical or human, ask what exposure was used, and read the limitations section before the abstract. Most of the confidently wrong posts on this board — several of them mine — skipped all three.
I would not read that in vitro number across to a person. The conditions are nothing like physiological.
Which receptor arm are you attributing that to?
receptor distribution is why the side effects are where they are
receptor distribution is why the side effects are where they are
Disagreeing with this specific inference — that is a preclinical result being read as human pharmacology.
That study was in a rodent model. Worth stating, since the thread has been reading it as human data.
GIP is the arm people argue about because the biology is genuinely unsettled
I would not read that in vitro number across to a person.
This is the concept everything else on this board is downstream of.
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Tried to build a mental model from mechanism alone and produced a confident prediction that the trial data flatly contradicted.
Retitled to distinguish preclinical from clinical, which the original ran together.
This. Albumin binding and modification are why the half-life is what it is, and it is a design decision rather than an accident.
dose response is not linear and nobody should assume it is
Yes. The discussion section is where the authors say what they actually think, and almost nobody here reads it.
The half-life explanation was the thing that made weekly dosing intuitive for me rather than arbitrary.
- 1I would not read that in vitro number across to a person. The conditions are…9 comments in this branch · started by u/emil_agyeman