A Covid infection, particularly in women, may lead to blood vessels aging around five years, according to research published today (August 18) in the European Heart Journal.

Blood vessels gradually become stiffer with age, but the new study suggests that Covid could accelerate this process. Researchers say this is important since people with stiffer blood vessels face a higher risk of cardiovascular disease, including stroke and heart attack.

The study was led by Professor Rosa Maria Bruno from Université Paris Cité, France. She said: "Since the pandemic, we have learned that many people who have had Covid are left with symptoms that can last for months or even years. However, we are still learning what's happening in the body to create these symptoms.

"We know that Covid can directly affect blood vessels. We believe that this may result in what we call early vascular aging, meaning that your blood vessels are older than your chronological age and you are more susceptible to heart disease. If that is happening, we need to identify who is at risk at an early stage to prevent heart attacks and strokes."

The study included 2,390 people from 16 different countries (Austria, Australia, Brazil, Canada, Cyprus, France, Greece, Italy, Mexico, Norway, Turkey, UK and US) who were recruited between September 2020 to February 2022. They were categorized according to whether they had never had Covid, had recent Covid but were not hospitalized, hospitalized for Covid on a general ward or hospitalized for Covid in an intensive care unit.

Researchers assessed each person's vascular age with a device that measures how quickly a wave of blood pressure travels between the carotid artery (in the neck) and femoral arteries (in the legs), a measure called carotid-femoral pulse wave velocity (PWV). The higher this measurement, the stiffer the blood vessels and the higher the vascular age of a person. Measurements were taken six months after Covid infection and again after 12 months.

Researchers also recorded demographic information such as patient's sex, age and other factors that can influence cardiovascular health.

After taking these factors into consideration, researchers found that all three groups of patients who had been infected with Covid, including those with mild Covid, had stiffer arteries, compared to those who had not been infected. The effect was greater in women than in men and in people who experienced the persistent symptoms of long Covid, such as shortness of breath and fatigue.

The average increase in PWV in women who had mild Covid was 0.55 meters per second, 0.60 in women hospitalized with Covid, and 1.09 for women treated in intensive care. Researchers say

an increase of around 0.5 meters per second is "clinically relevant" and equivalent to aging around five years, with a 3% increased risk of cardiovascular disease, in a 60-year-old woman.

People who had been vaccinated against Covid generally had arteries that were less stiff than people who were unvaccinated. Over the longer term, the vascular aging associated with Covid infection seemed to stabilize or improve slightly.

Professor Bruno said: "There are several possible explanations for the vascular effects of Covid. The Covid-19 virus acts on specific receptors in the body, called the angiotensin-converting enzyme 2 receptors, that are present on the lining of the blood vessels. The virus uses these receptors to enter and infect cells. This may result in vascular dysfunction and accelerated vascular aging. Our body's inflammation and immune responses, which defend against infections, may be also involved.

"One of the reasons for the difference between women and men could be differences in the function of the immune system. Women mount a more rapid and robust immune response, which can protect them from infection. However, this same response can also increase damage to blood vessels after the initial infection.

"Vascular aging is easy to measure and can be addressed with widely available treatments, such as lifestyle changes, blood pressure-lowering and cholesterol-lowering drugs. For people with accelerated vascular aging, it is important to do whatever possible to reduce the risk of heart attacks and strokes."

Professor Bruno and her colleagues will continue to follow the participants over the coming years to establish whether the accelerated vascular aging they have found leads to an increased risk of heart attacks and strokes in the future.

In an accompanying editorial Dr Behnood Bikdeli from Harvard Medical School, Boston, USA and colleagues said: "Although the acute threat of the COVID-19 pandemic has waned, a new challenge emerged in its aftermath: post-acute COVID-19 syndrome. Defined by the World Health Organization as symptoms appearing three months post-infection and lasting at least two months, studies suggest that up to 40% of initial COVID-19 survivors develop this syndrome.

"This large, multicentre, prospective cohort study enrolled 2390 participants from 34 centres to investigate whether arterial stiffness, as measured by PWV, persisted in individuals with recent COVID-19 infection. […] sex-stratified analyses revealed striking differences: females across all COVID-19-positive groups had significantly elevated PWV, with the highest increase (+1.09 m/s) observed in those requiring ICU admission.

"The CARTESIAN study makes the case that COVID-19 has aged our arteries, especially for female adults. The question is whether we can find modifiable targets to prevent this in future surges of infection, and mitigate adverse outcomes in those afflicted with COVID-19-induced vascular aging."

Read more …Even mild Covid may leave blood vessels five years older

Millions of Americans have altered vision, ranging from blurriness to blindness. But not everyone wants to wear prescription glasses or contact lenses. Accordingly, hundreds of thousands of people undergo corrective eye surgery each year, including LASIK -- a laser-assisted surgery that reshapes the cornea and corrects vision. The procedure can result in negative side effects, prompting researchers to take the laser out of LASIK by remodeling the cornea, rather than cutting it, in initial animal tissue tests.

Michael Hill, a professor of chemistry at Occidental College, will present his team's results at the fall meeting of the American Chemical Society (ACS). ACS Fall 2025 is being held Aug. 17-21; it features about 9,000 presentations on a range of science topics.

Human corneas are dome-shaped, clear structures that sit at the front of the eye, bending light from surroundings and focusing it onto the retina, where it's sent to the brain and interpreted as an image. But if the cornea is misshapen, it doesn't focus light properly, resulting in a blurry image. With LASIK, specialized lasers reshape the cornea by removing precise sections of the tissue. This common procedure is considered safe, but it has some limitations and risks, and cutting the cornea compromises the structural integrity of the eye. Hill explains that "LASIK is just a fancy way of doing traditional surgery. It's still carving tissue -- it's just carving with a laser."

But what if the cornea could be reshaped without the need for any incisions?

This is what Hill and collaborator Brian Wong are exploring through a process known as electromechanical reshaping (EMR). "The whole effect was discovered by accident," explains Wong, a professor and surgeon at the University of California, Irvine. "I was looking at living tissues as moldable materials and discovered this whole process of chemical modification."

In the body, the shapes of many collagen-containing tissues, including corneas, are held in place by attractions of oppositely charged components. These tissues contain a lot of water, so applying an electric potential to them lowers the tissue's pH, making it more acidic. By altering the pH, the rigid attractions within the tissue are loosened and make the shape malleable. When the original pH is restored, the tissue is locked into the new shape.

Previously, the researchers used EMR to reshape cartilage-rich rabbit ears, as well as alter scars and skin in pigs. But one collagen-rich tissue that they were eager to explore was the cornea.

In this work, the team constructed specialized, platinum "contact lenses" that provided a template for the corrected shape of the cornea, then placed each over a rabbit eyeball in a saline solution meant to mimic natural tears. The platinum lens acted as an electrode to generate a precise pH change when the researchers applied a small electric potential to the lens. After about a minute, the cornea's curvature conformed to the shape of the lens -- about the same amount of time LASIK takes, but with fewer steps, less expensive equipment and no incisions.

They repeated this setup on 12 separate rabbit eyeballs, 10 of which were treated as if they had myopia, or nearsightedness. In all the "myopic" eyeballs, the treatment dialed in the targeted focusing power of the eye, which would correspond to improved vision. The cells in the eyeball survived the treatment, because the researchers carefully controlled the pH gradient. Additionally, in other experiments, the team demonstrated that their technique might be able to reverse some chemical-caused cloudiness to the cornea -- a condition that is currently only treatable through a complete corneal transplant.

Though this initial work is promising, the researchers emphasize that it is in its very early stages. Next up is what Wong describes as, "the long march through animal studies that are detailed and precise," including tests on a living rabbit rather than just its eyeball. They also plan to determine the types of vision correction possible with EMR, such as near- and far-sightedness and astigmatism. Though the next steps are planned, uncertainties in the team's scientific funding have put them on hold. "There's a long road between what we've done and the clinic. But, if we get there, this technique is widely applicable, vastly cheaper and potentially even reversible," concludes Hill.

Title Electrochemical corneal refraction

Abstract The cornea is a transparent, highly organized anatomical structure that is responsible for ~2/3 of the refractive power of the eye. The corneal stroma consists of orthogonally stacked collagen- fibril lamellae whose molecular composition and precise macromolecular geometry eliminate backscattered light and maintain the shape of the cornea. Anatomical variation, birth defects, trauma, and various pathologies can alter the shape, structural stability, and transparency of the cornea, thus affecting vision. Surgical interventions to treat myopia, hyperopia, and astigmatism include laser-assisted in situ keratomileusis (LASIK) and photorefractive keratectomy (PRK). Despite their popularity, these procedures are expensive and permanently lower the biomechanical strength of the cornea. Here we report our efforts to apply electromechanical reshaping (EMR) as a molecular- based, non-ablative/non-incisional alternative to laser vision refraction, using ex vivo rabbit globes. EMR relies on short electrochemical pulses to electrolyze interstitial water, with subsequent diffusion of protons into the extracellular matrix of collagenous tissues; protonation of immobilized anions within this matrix disrupts the ionic-bonding network that provides structural integrity. This leaves the tissue transiently responsive to mechanical remodeling; subsequent re-equilibration to physiological pH restores the ionic matrix, resulting in persistent shape change of the tissue. Optical coherence tomography (OCT), second-harmonic generation (SHG), and confocal microscopy suggest that EMR enables control over corneal contouring while maintaining the underlying macromolecular collagen structure and stromal cellular viability.

This research was funded by the National Eye Institute of the National Institutes of Health and the John Stauffer Charitable Trust.

Read more …Forget LASIK: Safer, cheaper vision correction could be coming soon

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