Understanding the link between heart disease and diabetes
Did you know that people with type 2 diabetes are two to four times more likely to develop heart disease? Yet research shows that only 12% of people with type 2 diabetes think they are personally at risk. The connection between diabetes and heart disease is closer than many people realise.
People with type 1 diabetes are also at increased risk of heart disease.
What is heart disease?
Heart disease is a collective term for different problems that affect the structure and function of the heart muscle. It includes coronary artery disease, heart failure, arrhythmias and valve disease.
The medical term cardiovascular disease includes all types of heart problems, as well as blood vessel damage and stroke. The most common type of cardiovascular disease is coronary artery disease.
Coronary artery disease
Coronary artery disease (CAD) is very common and is caused by a build-up of plaque in the arteries, the blood vessels that supply blood and oxygen to the heart. Plaque is the build-up of fats and other substances in the artery walls. This build-up of plaque can cause a narrowing or complete blockage of blood vessels, which affects the blood flow.
Coronary artery disease is also associated with a hardening of the arteries, referred to as atherosclerosis. Hardening of the arteries can also happen in other parts of the body, for example in your feet and legs – this is referred to as peripheral artery disease (PAD).
Coronary artery disease is sometimes also called coronary heart disease (CHD) or ischaemic heart disease (IHD); it usually takes years to develop.
Heart attack
If the blood flow to the heart is decreased it can cause a heart attack. Similarly, if the blood flow to the brain is decreased it can cause a stroke.
Heart attacks happen when the plaque in a blood vessel bursts and clogs the coronary artery. Heart attacks require urgent medical treatment to restore the blood flow to the heart.
It is important to note that heart attacks are different from a cardiac arrest. Heart attacks are a circulatory problem, whereas a cardiac arrest is an electrical problem.
Cardiac arrest
Cardiac arrests are often caused by arrhythmias (abnormal heart rhythms) that cause the heart to malfunction and stop beating. This stops blood from flowing to the brain and other vital organs and can lead to death if not treated urgently.
A person who is having a cardiac arrest will be unconscious, will not be breathing, and may die within three minutes unless chest compressions are started immediately and medical care is provided.
Arrythmias
Arrythmias, as mentioned above, are abnormal heart rhythms caused by the heart’s electrical system which controls the heart’s pumping action. People often describe arrythmias as palpitations or fluttering feelings in the chest.
Arrythmias can cause the heartbeat to become too slow, too fast, or irregular. The most common type of arrythmia is atrial fibrillation (AF). Other examples of arrythmias include atrial flutter, ectopic heartbeats, and supraventricular tachycardia (SVT).
Heart failure
Heart failure happens when the heart muscle is damaged and does not pump properly. Causes can include heart attacks, high blood pressure and valve problems, which can all lead to the heart becoming weaker, stiffer and bigger. This can lead to tiredness, shortness of breath, oedema (swelling in legs and feet) and a decreased ability to do physical activity. Treatment involves medications to strengthen the heart as well as managing other conditions that can affect the heart.
Valve disease
The four cardiac valves mentioned above keep the blood flowing in the right direction. If one or more of these valves become damaged they may stop opening and closing properly and this can lead to chest pain and shortness of breath. Some people are born with valve disease (this if often called congenital heart disease), but it can also be caused by rheumatic heart disease, acute rheumatic fever or a heart condition such as heart failure or a heart attack.
There are three main types of heart valve disease:
- Stenosis – where the valves are thick or stiff
- Regurgitation – where the valve flaps don’t close properly and ‘leak’
- Atresia – this is a condition where the valve is not formed correctly and tissue blocks the blood flow.
One of the first signs of heart valve problems is a heart murmur. However, having a heart murmur does not always mean that there is a problem. If your client has symptoms of heart valve disease it is important to see a doctor because, if left untreated, heart valve disease can lead to heart failure.
Diabetes and heart disease
Diabetes puts people at risk of heart disease because diabetes can change the chemical makeup of some of the substances found in the blood. This can cause a narrowing or complete blockage of blood vessels through the build-up of plaque, even if cholesterol levels are normal.
High blood pressure can put further strain on the heart. For this reason, people with diabetes are regularly recommended to take blood pressure lowering medications, often in combination with cholesterol lowering medication.
What are the symptoms of heart disease?
The most common symptom of heart disease is chest pain or discomfort. This is referred to as angina.
For many people with diabetes the symptoms are very subtle and the first clue that they have coronary artery disease is a heart attack. Symptoms of a heart attack include:
- Angina
- Shortness of breath
- Pain or discomfort in the arms and/or shoulder
- Tingling in the lips
- Weakness
- Light-headedness or dizziness
- Nausea, vomiting or heartburn
- Cold sweat
Sometimes heart disease is not diagnosed until a person experiences arrhythmia or heart failure. Symptoms of heart failure include:
- Shortness of breath
- Fatigue
- Swelling of the feet, ankles, legs or veins in the neck
What are the risk factors for heart disease?
The main risk factors for developing heart disease are high blood pressure, high cholesterol and smoking. Lifestyle choices can also increase risk, particularly through an unhealthy diet, excessive alcohol use, physical inactivity and overweight or obesity. Having a family history of heart disease can also increase risk.
Several other medical conditions can put people at a higher risk as well. And diabetes is on top of this list.
Reducing the risk of heart disease
Taking care of heart is important, especially for people with diabetes. Here are some actions clients can take to reduce their risk of heart disease:
- Be physically active
- Make healthy food choices
- Reduce the intake of saturated fats, trans fat, salt/sodium and alcohol
- Keep blood fats such as cholesterol and triglycerides in the target range
- Manage high blood pressure
- Try and lose weight if weight is above the healthy weight range
- Don’t smoke
- Visit Diabetes Australia’s heart-focused campaign takediabetes2heart.com.au.
Take Diabetes 2 Heart Campaign
The Take Diabetes 2 Heart campaign is about inspiring people with diabetes to take positive steps to avoid cardiovascular disease. Visit the website for helpful information, resources and a heart healthy recipe book that your clients can download for free.
Blood pressure
High blood pressure, or hypertension, is a main risk for heart disease, especially heart attacks and strokes. High blood pressure can also increase the risk of kidney disease, eye disease and nerve damage.
Many people have high blood pressure without knowing it, so it is important to check blood pressure regularly.
There are a number of things that can increase the risk of developing hypertension, including having a family history of hypertension, being overweight, insufficient physical activity, smoking, alcohol intake and food choices such as eating too much salt.
Blood pressure targets can vary depending on age, existing heart disease, kidney disease, other medical conditions and the risk of a stroke. In Australia it is generally recommended to aim for a blood pressure of less than 140/90 millimetres of mercury (mmHg).
High cholesterol
High cholesterol and diabetes increase the risk of heart disease. There is not one single cause of high cholesterol, but there are risk factors that are modifiable. These include smoking, being overweight or obese, and unfavourable lifestyle choices such as an unhealthy diet and a lack of physical activity. Blood fats should be checked regularly as your client may need cholesterol-lowering medications to help keep blood fats in their target range.
By Credentialled Diabetes Educator, Carolien Koreneff