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What did the placebo arm of TRIUMPH-1 report for fatigue?

Asked 13 Sept 2025Modified 7 months agoViewed 26k times
26

Concretely: TRIUMPH-1 · fatigue.

The figures are clear enough; the question is what they mean and what they do not.

I can supply the numbers if the specifics change the answer.

How should I read this, and where are the traps?

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askedorla_ferriter47k3813 Sept 2025

5 Answers

Accepted answer first, then by votes
56

Accepted answer

In practice, this is a question about what the trial was designed to answer, and the honest response is that it was not designed to answer this.

The early fall in estimated glomerular filtration rate on treatment is haemodynamic rather than structural. Reduced intraglomerular pressure lowers the filtration rate acutely and preserves the glomerulus chronically — the same pattern seen with renin-angiotensin blockade and with SGLT2 inhibition. A dip of a few millilitres per minute in the first weeks, followed by a shallower long-term slope, is the desired trajectory, not a warning sign.

Headline results, principal programmes

TrialAgentnDurationPrimary result
STEP 1Semaglutide 2.4 mg1,96168 wk−14.9 % vs −2.4 % weight
STEP 2Semaglutide 2.4 mg, T2DM1,21068 wk−9.6 % vs −3.4 % weight
SURMOUNT-1Tirzepatide 5/10/15 mg2,53972 wk−15 / −19 / −21 % weight
SURMOUNT-4Tirzepatide, withdrawal67088 wkContinued loss vs substantial regain
SELECTSemaglutide 2.4 mg17,604~40 moMACE HR 0.80 (0.72–0.90)
FLOWSemaglutide 1.0 mg, CKD3,533~3.4 yrRenal composite reduced; stopped early
SURMOUNT-OSATirzepatide, OSA46952 wkAHI reduced with and without PAP

Creatinine is a muscle-derived metabolite, so a substantial loss of lean mass lowers serum creatinine and mathematically raises estimated GFR without anything happening to the kidney. If you have lost twenty kilograms, your creatinine-based eGFR is flattering you. Cystatin C is not muscle-dependent and is the measure to use when the two disagree.

The PIONEER programme established oral semaglutide’s efficacy and the constraints on its administration, and the bioavailability figure of roughly one per cent is what drives the fasting and water-volume requirements[1].

If the trend across three draws is flat, the difference between draws one and two was noise. Most of what people react to is noise.

edited 30 Dec 2025 by Dr_Idris_Coulibaly — added a caveat about sampling

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answered · acceptedDr_Idris_Coulibaly40k13815 Dec 2025
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21

It helps to be literal here: the confidence interval is the informative part. A point estimate with an interval spanning no effect is a different object from the same point estimate with a tight interval, and the abstract presents them identically.

The rodent thyroid C-cell findings that generated the labelled warning appear to be species-specific: rodent C-cells express GLP-1 receptors at high density, human C-cells at very low density, and human calcitonin data across large trial populations has not reproduced the signal. A family history of medullary thyroid carcinoma or MEN2 is nonetheless a genuine contraindication rather than a theoretical one.

The part that matters: liver enzymes are a poor surrogate for hepatic histology in both directions: substantial steatohepatitis with normal transaminases is common, and modest enzyme elevation with minimal fibrosis is common. If the question is fibrosis, the answer comes from a non-invasive score such as FIB-4 or a stiffness measurement, not from ALT.

Read the confidence interval, read the estimand, and compute the absolute effect yourself. It takes two minutes and it changes how the result feels.

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answeredDr_Priya_Raghunathan94k24826 Dec 2025
15

On the detail: start with the population. The inclusion criteria of the trial determine what its result can be extrapolated to, and the extrapolation people want is usually to a population the trial excluded.

ApoB and LDL-C disagree because they measure different things: LDL-C is the cholesterol mass carried in the LDL fraction, ApoB is a count of atherogenic particles. Small dense particles carry less cholesterol each, so a person with many small particles has a concordantly higher ApoB than their LDL-C suggests. When they disagree, ApoB is the better risk marker.

A fasting lipid panel drawn during rapid weight loss reads oddly for a mechanical reason: mobilised adipose tissue delivers free fatty acids to the liver, and hepatic triglyceride export rises. Triglycerides can transiently increase while the person is doing exactly the right thing. Draw the panel when weight has been stable for a few weeks if you want an interpretable number.

Worth being explicit that this is interpretation of published data and not medical advice. Laboratory results belong in a conversation with whoever ordered them.

None of this replaces a clinician who can see the whole picture, and the whole picture is usually where the answer is.

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answeredshear_at_the_front15k2823 Nov 2025
Thank you — the worked example is what makes this usable. – shear_at_the_front 3 months ago
2Related: the same reasoning applies to the counter-ion question. – p_mkhize 5 months ago
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A single laboratory value is a point on a noisy curve. What you want is a trend across at least three draws under comparable conditions, and "comparable" is doing a lot of work in that sentence.

A network meta-analysis can rank agents that were never compared directly, but only under a transitivity assumption — that the trials being linked are similar enough in population, duration and endpoint definition for the indirect comparison to hold. In this field that assumption is often visibly violated, which is why indirect rankings should be read as hypotheses.

SURMOUNT-1 reported mean weight reductions of approximately 15, 19 and 21 per cent at tirzepatide 5, 10 and 15 mg respectively at 72 weeks[1].

The papers are readable. Read the paper rather than the summary of the paper, especially where the summary is enthusiastic.

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answeredplate_count_9k95k1581 Nov 2025
12

The hazard ratio is the relative effect. What changes decisions is the absolute effect, and converting between them requires the event rate in the control arm, which is usually in the same table and rarely in the abstract.

Absolute risk reduction, worked: if the control-arm event rate is 8.0 per cent over the follow-up period and the hazard ratio is 0.80, the treated rate is approximately 6.4 per cent, the absolute risk reduction is 1.6 percentage points, and the number needed to treat is 1 ÷ 0.016 ≈ 63 over that period. A 20 per cent relative reduction and a number needed to treat of 63 are the same finding stated two ways, and only one of them sounds impressive.

The limitation is that surrogate endpoints and hard endpoints have come apart before in metabolic medicine, so a favourable biomarker is a reason for optimism rather than a conclusion.

Convert everything to an absolute effect before you compare two interventions. Relative effects are not comparable across different baseline risks.

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answeredp_mkhize41k1384 Dec 2025

Your answer

Ask PeptideStack is a static archive. Posting is closed, but the norms are worth stating: answer the question that was asked, show your working, cite the trial or the certificate, and say plainly where the evidence runs out.

Not medical advice. Research-use-only compounds are not approved for human use.