Heart disease: The lesser known risk factors – 06/07/2023 – Health

Most people know that risk factors for heart disease are high blood pressure, smoking, high cholesterol and being overweight.

However, many people who have a heart attack have none of these traditional risk factors.

Research reveals that conditions like gout, psoriasis, inflammatory bowel disease, and rheumatoid arthritis are also risk factors for heart disease. What these patients have in common is chronic inflammation.

In fact, some researchers have begun to repackage cardiovascular disease as a chronic inflammatory disease of the arteries. Scientists sometimes refer to this as the inflammatory hypothesis of atherosclerotic cardiovascular disease (DASCV or ASCVD).

inflammatory process

Atherosclerosis occurs when fatty plaques develop on the walls of our arteries, making them stiff. When this happens in the arteries that supply oxygenated blood to the heart, it is called coronary artery disease.

It can cause heart attacks, in which not enough blood is supplied to the heart, and ischemic strokes, in which not enough blood is supplied to the brain. To understand why atherosclerosis is an inflammatory condition, we must consider how this process begins.

The first stage in the development of atherosclerosis is believed to be some type of damage to the endothelium, the single layer of cells that lines the arteries. This can be caused by high levels of low-density lipoprotein (LDL) cholesterol, sometimes called “bad cholesterol”.

The toxins in cigarettes can also irritate the lining of the arteries, causing this initial damage. When endothelial cells are damaged, they release chemical messages that attract white blood cells, an important component of the immune system, to the site.

These white blood cells enter the artery wall and cause inflammation in the artery. White blood cells also consume the cholesterol in their walls, leading to the formation of “fat streaks,” one of the first visible signs of atherosclerosis.

Fat streaks begin to form at a young age. By the time we hit our 20s, most of us have some evidence of fatty streaks in our arteries.

This process of endothelial cell damage, white blood cell infiltration, and chronic inflammation can silently continue over the years, eventually leading to plaque buildup in the arteries.

It may also explain why people with chronic inflammatory conditions are at greater risk for cardiovascular disease.

Long-term inflammation of the arteries that supply the heart and brain can lead to heart attacks and strokes.

silent inflammation

A heart attack occurs when plaque in the artery that supplies the heart becomes unstable. This can lead to plaque rupture (burst), leading to a clot forming in the artery and cutting off the blood supply to the heart muscle.

People who have a heart attack often have increased levels of inflammation and plaque instability in the days and weeks leading up to the event. The eventual “heart attack” and the resulting damage to the heart muscle can be seen as this unstable inflammatory process reaching its peak.

Because this chronic inflammatory process occurs without symptoms, many patients without traditional risk factors for heart disease do not realize that they are at increased risk for heart disease.

How to measure inflammation

Fortunately, there is a way to measure inflammation in the body. One way to do this is with a blood test called a high-sensitivity C-reactive protein (hs-CRP) test.

People with elevated hs-CRP levels are at greater risk for heart attacks and strokes. Elevated levels of LDL cholesterol are also a risk factor for atherosclerosis.

Several studies have shown that people with high LDL cholesterol and hs-CRP appear to be at increased risk of cardiovascular disease.

A large clinical trial called Cantos tested the inflammatory hypothesis of cardiovascular disease by treating post-heart attack patients with high hs-CRP levels with an anti-inflammatory called canakinumab.

The use of this anti-inflammatory drug reduced hs-CRP levels and resulted in a small but statistically significant reduction in the number of heart attacks experienced by these patients. Unfortunately, there also appeared to be an increased risk of infections in the group that received the drug.

That risk, along with the drug’s high cost, means that we’re not likely to start using canakinumab to treat atherosclerosis anytime soon.

However, the study was considered groundbreaking because it supported the hypothesis that inflammation plays an important role in atherosclerosis and that addressing inflammation may be helpful in reducing the risk of recurrent cardiovascular events.

Changing the way we think about risk factors for atherosclerosis may allow us to better identify patients at risk for heart attacks and strokes.

Furthermore, this may allow us to focus on treating inflammation to reduce cardiovascular risk. Several studies are already looking at the use of cheaper anti-inflammatories, such as colchicine and methotrexate, to reduce inflammation and prevent the progression of cardiovascular disease.

Life style changes

Fortunately, it is possible to reduce inflammation in our body without resorting to medication. We can think of everything we do in our lives as pro-inflammatory or anti-inflammatory.

Smoking is pro-inflammatory as the toxins in cigarettes irritate the body. High blood cholesterol levels and a diet high in ultra-processed foods can also lead to chronic inflammation in our arteries.

On the other hand, a diet rich in fruits, vegetables, whole grains and oily fish is believed to be anti-inflammatory.

Exercise also reduces levels of inflammation in the body. Obesity, particularly excess weight around the waist, appears to cause chronic inflammation. Losing weight around the belly will help reduce this inflammation.

Stress can also induce a chronic, low-grade inflammatory response in the body, and it’s important to try to manage our stress levels. It’s also vital to maintain healthy blood pressure, cholesterol and body mass index, traditional markers of heart disease risk.

By choosing anti-inflammatory options and leading a healthy lifestyle, we can all reduce our chances of developing heart disease and improve our quality of life.

*Robert Byrne is Director of Cardiovascular Research at the RCSI University of Medicine and Health Sciences in Ireland. JJ Coughlan is a research fellow in interventional cardiology at the RCSI University of Medicine and Health Sciences in Ireland.

*This article was originally published on The Conversation and is reprinted here under a Creative Commons license. Click here to read the original version (in English).