Risk factors for cardiovascular disease

A risk factor is something that increases the likelihood of a person developing a disease. There are several risk factors that increase the risk of cardiovascular disease (CVD) – some that can be changed, and some that cannot.

A large portion of New Zealand's disease burden for chronic disease including CVD is due to preventable risk factors.

The main preventable risk factors for CVD that can be changed or managed include smoking, high blood pressure, high cholesterol, diabetes, being overweight or obese, inactivity, poor nutrition and excessive alcohol consumption.

Almost all adults have at least one risk factor for CVD, while one third of adults have a combination of two risk factors and 57 per cent have three or more. Men are more likely than women to have three or more risk factors in combination.

Smoking

Current smokers have an almost three times as high risk of death from CVD as people who have never smoked, and over one third of CVD deaths have been attributed to smoking.

However, quitting smoking by the age of 45 can avoid almost all of the excess risk of CVD.

High blood pressure

The risk of cardiovascular diseases like stroke, coronary heart disease, and heart failure are directly related to high blood pressure levels.

High blood pressure affects an estimated one in every three adults. Men are more likely to have uncontrolled high blood pressure than women, ie, they are less likely to be taking medication for high blood pressure.

High cholesterol

Approximately one in four New Zealand adults need to manage their cholesterol levels for their heart health. LDL cholesterol is considered the “bad” cholesterol, as excess amounts can build up on the walls of the arteries, forming plaques that narrow the arteries. This is known as atherosclerosis. Narrowed arteries make it harder for blood to flow to the heart and other organs, increasing the risk of heart attack, stroke and peripheral artery disease.

Diabetes

People living with diabetes are between two to four times more likely to develop CVD as people without diabetes, and CVD is the number one cause of death for people with diabetes. People with diabetes may also develop CVD 10 to 15 years earlier than people without diabetes.

Over 250,000 people in New Zealand are living with diabetes.

Overweight and obesity

Around one in three adults and one in nine children in NZ are obese. Rates of obesity are higher in Māori and Pacific Islanders. The rates of overweight and obesity have increased in the past decades.

Inactivity

Global recommendations are for adults to take part in at least 150 minutes of moderate-intensity or 75 minutes of vigorous-intensity physical activity per week, as well as muscle-strengthening activities on two or more days per week.

In a recent NZ Health Survey, just over half of adults were physically active in the past week.

Poor nutrition

Most adults do not meet the recommended guidelines for intake of vegetables.

Improving vegetable intake to meet the recommendation of five serves per day could reduce the risk of CVD by 16 per cent.

Excessive alcohol consumption

Excessive drinking over the long-term is linked to ongoing high blood pressure and can also lead to narrowed arteries through atherosclerosis, a weakened heart muscle and atrial fibrillation (irregular heartbeat), all of which also increase the risk of heart attack and stroke.

Guidelines recommend that healthy adults drink no more than 10 standard drinks a week, and no more than four standard drinks on any day to reduce to the risk of alcohol-related disease or injury.

Around one in five adults in NZ have a hazardous drinking pattern.

CVD can affect anyone, young or old, and people of any ethnicity. However, some groups of people who have certain risk factors are at higher risk of developing CVD. These include the following.

• Increasing age: The risk of developing CVD increases with age, and CVD is most common in people aged 50 and over.
• Gender: Men are slightly more at risk of CVD than women, but CVD is still a leading cause of death and disability in women. CVD risk in women can also be under-recognised and under-treated, and there are several heart health mistakes women can avoid. The CVD risk for women also increases after menopause.
• Family history: People with a family history of CVD may be more predisposed to developing CVD. An immediate family member, such as a parent or sibling, being diagnosed with CVD before the age of 60 may indicate a family history of premature CVD. This means that the chances of developing the same condition may be higher than normal.
• Ethnicity: Māori and Pacific Islanders are at higher risk of developing CVD and are more likely to develop it at a younger age. This can be attributed to the greater prevalence of CVD risk factors in that population than in the general population.

People who have one or more preventable risk factors for CVD are also more likely to develop CVD. These risk factors include smoking, high blood pressure, high cholesterol, diabetes, being overweight or obese, inactivity, poor nutrition and excessive alcohol consumption.

Risk of other cardiovascular diseases and conditions

Along with the main preventable risk factors, other health conditions and CVDs can increase the risk of developing further CVDs.

• Atherosclerosis is the main underlying cause of CVD. In this slow, progressive process, atherosclerotic plaques that are made up of fat, cholesterol, calcium and other substances build up in the walls of the arteries. Over time, these plaques harden, narrow the opening of the arteries and restrict the blood flow. If these plaques break open, they form a blood clot. Unwanted blood clots within blood vessels (thrombosis) can form as a result.
• Blood clots can block blood flow around the body. If this occurs in an artery to the heart, it can lead to a heart attack. If it occurs in an artery to the brain, it can cause a stroke. If it occurs in arteries in the limbs, it can lead to peripheral artery disease.
• People who have the irregular heartbeat condition atrial fibrillation (AF) have an increased risk of other CVDs, such as heart failure and stroke. One in every three strokes is linked to AF, and AF-linked strokes are more severe than other strokes. People with AF are also five times more likely to have a stroke compared to those who do not have AF. People with AF are also at increased risk of dementia.

Making lifestyle changes to manage and prevent modifiable risk factors can prevent up to 80 per cent of premature CVD, stroke and diabetes. Tips to manage these factors include the following.

Smoking

Smoking can increase the risk of CVD by damaging the arteries. It also affects blood flow through the arteries and can make blockages more common. Quitting smoking can almost immediately improve health as well as decrease some of the risk of developing CVD. Health benefits continue to build over the non-smoking period.

High blood pressure

High blood pressure can overload the heart and arteries and speed up atherosclerosis, the main underlying cause of CVD. High blood pressure can be managed through dietary changes, such as lowering salt intake. Medications are also available.

High cholesterol

High cholesterol, or high levels of the “bad” cholesterol (LDL cholesterol), can add to the build-up of atherosclerotic plaques in the arteries. High cholesterol can be managed through medication and dietary changes.

Diabetes

People living with diabetes are over twice as likely to develop CVD. In some cases, diabetes can be managed through diet and a healthy lifestyle.

Overweight and obesity

Being overweight or obese can increase the risk of a number of health problems, including other CVD factors like high blood pressure and high cholesterol. Eating a healthy diet and getting regular exercise can help you get to and maintain a healthy weight.

Inactivity

Being inactive can contribute to being an unhealthy weight and increase the risk of other risk factors like high blood pressure and cholesterol levels. It’s important to make exercise or physical activity a regular part of your day, and also important to stay active after a CVD diagnosis. Aim for at least 30 minutes of moderate-intensity physical activity on most days, but being active for any amount of time is better than none.

Poor nutrition

Poor nutrition and a diet high in saturated fat, trans fat, LDL cholesterol, salt and sugar can contribute to being an unhealthy weight. Eating a balanced, nutritious diet can help improve overall health and wellbeing.

Excessive alcohol consumption

Drinking too much alcohol can raise the levels of some fats in the blood, reduce our HDL “good” cholesterol and increase blood pressure, all risk factors for CVD. Limiting alcohol intake will help decrease these risks.

Stress

Ongoing stress can damage the arteries and worsen other CVD risk factors. Try to identify what is causing you stress and take steps to help you feel more relaxed and release tension. For example, step away from the computer for a break if you’re feeling overwhelmed at work. It’s important to take the time for some self-care to help put your wellbeing first.

HRI conducts groundbreaking research to fight cardiovascular disease from a broad range of angles, including finding better ways to prevent it through managing risk factors.

Our Clinical Research Group designs interventions to treat a wide range of abnormalities, with a particular focus on the prevention of atherosclerosis in children and young adults who have risk factors for early heart disease, obesity, exposure to passive smoke in the home, those who smoke themselves, or those with high levels of cholesterol.

Our Heart Rhythm and Stroke Prevention Group aims to prevent as many strokes as possible through early detection of the risk factor atrial fibrillation, and to implement appropriate guideline-based management.