Thread by @ZdenekVrozina

A new warning study that deserves attention.
SARS-CoV-2 leaves a long-term endothelial and metabolic footprint in the blood months after infection - even in people without obvious Long COVID symptoms.
And that matters🧵

Researchers followed 262 adults in Germany and measured blood biomarkers about 37 weeks after infection - roughly 9 months later.

People who had previously had COVID showed higher markers of endothelial dysfunction and tissue stress, including soluble thrombomodulin and LDH, compared with never-infected controls.

In simple English.
Their blood still carried signs of vascular and metabolic disturbance long after the acute infection was over.

The most important part?
These changes were not limited to people diagnosed with post-COVID syndrome.

Similar signals were also seen in people recruited from a population cohort after infection - not just in patients who showed up at a Long COVID clinic.

It does show something deeply uncomfortable.
SARS-CoV-2 can leave a measurable biological mark even in people who think they have fully recovered.

The study also found changes in amino-acid pathways linked to nitric oxide metabolism - including L-arginine, citrulline, and taurine.
Nitric oxide is central to vascular tone, microcirculation, and normal endothelial function.

That makes this more than a random lab finding.
In people with more severe fatigue, the signal looked different. Higher levels of specific fatty acids, including linoleic, oleic, and palmitoleic acid.

It may reflect real metabolic and energy-regulation disruption.

This findings also fit into a broader hypothesis emerging across post-COVID research -
that SARS-CoV-2 may push part of the population toward a longer-term shift in lipid and metabolic health - potentially including triglycerides and broader cardiometabolic risk.

So here is the part we should not ignore.
We do not know whether this endothelial and metabolic footprint disappears.
We do not know when it disappears.
And we cannot rule out that, in some people, it persists for years.

That is why the population-level question matters.
Even a modest shift in vascular or metabolic biomarkers across millions of people could translate into a meaningful shift in long-term cardiovascular risk.

This study does not say that everyone after COVID is automatically a cardiovascular patient.
But it does say something serious.
SARS-CoV-2 can leave measurable biological traces even in people who look fine.

And if infections keep repeating, the question is no longer only
Did I get Long COVID?
It is also -
What are repeated infections doing to my blood vessels, my metabolism, and my long-term health?

Participants were recruited in Germany between July 2021 and January 2022 - not just a single wave or variant.

Oestreich at al., Endothelial dysfunction and metabolic biomarkers in post-COVID-19 syndrome. nature.com/articles/s4159…