Semaglutide lowers hsCRP in SELECT

A pre-specified biomarker analysis of the SELECT cardiovascular outcomes trial, published in Circulation on 18 August 2026, finds that semaglutide 2.4 mg weekly reduced high-sensitivity C-reactive protein (hsCRP) in adults with established cardiovascular disease and overweight or obesity who had no diabetes^[1]. The analysis, led by Jorge Plutzky and co-authored by Paul Ridker (who established the clinical hsCRP thresholds still in routine use), is the first to quantify the inflammatory-marker effect of semaglutide specifically in a secondary-prevention cardiovascular cohort at scale.

The SELECT trial: who was enrolled and what was already known

SELECT (Semaglutide Effects on Cardiovascular Outcomes in People With Overweight or Obesity) enrolled 17,604 adults across 41 countries^[3]. All participants had pre-existing cardiovascular disease: prior myocardial infarction, stroke, or symptomatic peripheral arterial disease. None had diabetes at baseline. All had a body-mass index of 27 or above. They were randomised to subcutaneous semaglutide 2.4 mg weekly or placebo on top of standard care, with a median follow-up of about 40 months.

The primary outcome was a composite of cardiovascular death, non-fatal myocardial infarction, and non-fatal stroke (3-point MACE). The 2023 primary results paper reported a 20% relative reduction in MACE for the semaglutide arm versus placebo (hazard ratio 0.80, 95% CI 0.72 to 0.90)^[2]. That result was the basis for the FDA's 2024 approval of Wegovy for cardiovascular risk reduction in eligible adults^[5]. The 2026 Circulation paper now asks: what happened to the inflammatory biomarker picture, and does hsCRP reduction explain any of the benefit?

What hsCRP measures and why it matters here

High-sensitivity CRP is a blood-based acute-phase protein that rises in the presence of systemic inflammation. In cardiovascular medicine, hsCRP values below 1 mg/L indicate lower-than-average vascular risk; values between 1 and 3 mg/L indicate average risk; values above 3 mg/L indicate higher-than-average risk^[4]. Ridker's work, including the JUPITER trial, established that hsCRP predicts incident cardiovascular events independently of LDL cholesterol. That is the reason a substudy measuring hsCRP in a secondary-prevention cohort on semaglutide is clinically relevant: it speaks to whether the drug is doing something on the inflammatory axis, beyond the weight and glucose effects.

Inflammation is now understood as a core mechanism in atherosclerosis progression and plaque instability, not merely a bystander marker. Anti-inflammatory therapies (colchicine, canakinumab) have demonstrated cardiovascular benefit in trials, which means a drug that lowers hsCRP in a cardiovascular population is doing something mechanistically interesting, even if the direction of causation between the hsCRP reduction and the clinical event reduction cannot be established from a single biomarker analysis.

What the new Circulation analysis found

The Plutzky et al. paper is a pre-specified secondary analysis using hsCRP measurements taken at baseline and at multiple follow-up visits across the SELECT cohort^[1]. The key findings, as reported by the authors: semaglutide reduced hsCRP from baseline relative to placebo, and the reduction was present early in treatment and sustained. The analysis also examined whether the baseline hsCRP level or the on-treatment hsCRP trajectory modified the MACE benefit. The co-authorship of Paul Ridker, whose career is built on hsCRP as a cardiovascular risk stratifier, signals that the framing around residual inflammatory risk is central to how the authors interpret the result.

The paper is published in Circulation, the flagship journal of the American Heart Association, which imposes peer review standards consistent with a Tier 1 cardiovascular publication. The PMID is 42610271. Full access to the quantitative findings requires journal access or a library login; the abstract is indexed on PubMed.

What the hsCRP reduction does and does not tell us

Three things this analysis can tell us: that semaglutide modulates a validated inflammatory marker in a secondary-prevention cardiovascular population; that the effect is detectable at the scale of a 17,604-person trial; and that the patients most likely to benefit from semaglutide on a cardiovascular basis may be those with elevated baseline inflammation, not only those with the most weight to lose.

Three things it cannot tell us: whether the hsCRP reduction causes the MACE reduction, rather than both being downstream of weight loss or some other shared pathway; what the optimal target hsCRP is for patients on semaglutide in this setting; and whether a patient with low baseline hsCRP (already low inflammatory burden) gets the same cardiovascular benefit. The SELECT trial was not stratified by baseline hsCRP at randomisation, which limits subgroup inference.

It is also worth holding the mechanism question carefully. Weight loss itself lowers hsCRP, as does improved glycaemia and reduced visceral fat. GLP-1 receptor agonists may also have direct anti-inflammatory effects on immune cells and vascular endothelium, separate from the metabolic pathway. Disentangling those mechanisms from a clinical trial biomarker dataset is not straightforward, and the Plutzky et al. paper does not claim to have done so.

How this fits the broader semaglutide cardiovascular picture

SELECT has been generating sub-analyses since the 2023 primary readout. Earlier work examined long-term weight loss trajectories (Ryan et al., Nature Medicine 2024, PMID 38740993) and kidney outcomes (Colhoun et al., Nature Medicine 2024, PMID 38796653). The hsCRP paper is another layer in the mechanistic unpacking of why a drug approved for weight management reduces cardiovascular events in people who don't have diabetes. The weight argument is the simplest (less adiposity, less inflammation, less atherosclerotic stress), but the SELECT cohort's cardiovascular benefit appeared early in treatment, before large weight differences had accumulated, which has raised the question of whether there is a weight-independent pathway. That question also matters for context around tirzepatide, whose cardiovascular outcomes trial (SURPASS-CVOT) has not yet read out, leaving semaglutide as the only approved incretin-class drug with a secondary-prevention MACE indication.

The hsCRP data adds to, but does not resolve, that question. It tells us the inflammatory axis is moving. It does not tell us whether that is the mechanistic cause of the MACE reduction or a parallel effect. That question matters because it has implications for which patients to prioritise for semaglutide on cardiovascular grounds and whether the drug's cardiovascular benefit will generalise to populations without significant adiposity. Those questions remain open.

What we don't yet know

The outstanding questions in this space: whether hsCRP trajectory on semaglutide predicts individual cardiovascular outcomes better than weight loss alone; whether the inflammatory benefit is preserved at the lower 1.7 mg maintenance dose (also approved for cardiovascular risk reduction); whether other GLP-1 receptor agonists, including liraglutide and tirzepatide, show comparable hsCRP effects in secondary-prevention cohorts; and whether combining semaglutide with anti-inflammatory agents (colchicine, for example) produces additive cardiovascular protection. None of those questions has a trial answer today.