Tag: atherosclerosis

Long-term Use of RAS Inhibitor Drugs Could Damage Kidneys

Photo by Robina Weermeijer on Unsplash

New research is raising concerns that long-term use of renin-angiotensin system (RAS) inhibitor drugs such as ACE inhibitors could be contributing to kidney damage.

The researchers stress that patients should continue taking the medications. But the scientists are urging studies to better understand the drugs’ long-term effects.

“Our studies show that renin-producing cells are responsible for the damage. We are now focusing on understanding how these cells, which are so important to defend us from drops in blood pressure and maintain our well-being, undergo such transformation and induce kidney damage,” said UVA’s Dr Maria Luisa Sequeira Lopez. “What is needed is to identify what substances these cells make that lead to uncontrolled vessel growth.”

A billion people around the world are affected by chronic hypertension. In a study published in JCI Insight, University of Virginia (UVA) researchers were seeking to better understand why severe forms of the condition are often accompanied by atherosclerosis in the kidney, leading to organ damage.

They found that renin cells, which help regulate blood pressure through renin production, play an important role. Harmful changes in the renin cells can cause the cells to invade the walls of the kidney’s blood vessels. The renin cells then trigger a buildup of another cell type, smooth muscle cells, that cause the vessels to thicken and stiffen, resulting in impeded kidney blood flow.

Long-term use of RAS inhibitor drugs, such as ACE inhibitors, or angiotensin receptor blockers, have a similar effect. But the study found that long-term use of the drugs was associated with hardened kidney vessels in both lab mice and humans

The researchers note that the medications can be lifesaving for patients, so they stress the importance of continuing to take them. But they say additional studies are needed to better understand the drugs’ long-term effects on the kidneys.

“It would be important to conduct prospective, randomised controlled studies to determine the extent of functional and tissue damage in patients taking medications for blood pressure control,” said UVA’s Dr Ariel Gomez. “It is imperative to find out what molecules these cells make so that we can counteract them to prevent the damage while the hypertension is treated with the current drugs available today.”

Source: University of Virginia

Research Suggests Vitamin C Beneficial for Severe COVID

According to Associate Professor Anitra Carr of Otago University in New Zealand, research provides evidence that large doses of Vitamin C is beneficial for severe COVID. A 2019 study previously showed that giving Vitamin C to patients with Acute Respiratory Distress reduced mortality rates.

“A recent study that came out of the US showed that patients with coronavirus in ICU with Covid-19 also had very low vitamin C levels,” Carr said. “That’s because the body chews through a lot more of it when you get an infection – and your requirements increase significantly. But the standard doses given in the intensive care unit aren’t enough to compensate, given a severe case of the disease comes with a huge inflammatory response and oxidative stress.”

 Carr said that delivering the drug intravenously was critical to supplying the high levels of Vitamin C needed. One study from Wuhan, China showed Vitamin C conferred a survival benefit to placebo, though Carr noted that many more studies are needed and will come throughout the next year.

However, besides its normal dietary role, there was little research to show that Vitamin C had much of a preventative role. Carr said, “Some research has shown that, if you’re under enhanced stress, your risk for infection increases, so in those people vitamin C may decrease the risk of getting it. But in the general everyday population, who aren’t under extreme physical stress, it may not decrease your chances of catching the disease.”

Source: NZ Herald