Diabetes and Heart Disease

Specific Heart Diseases and Diabetes

In the longer term, diabetes can cause damage to many different organs. This damage may result in diseases with their own symptoms. Many heart diseases are caused by diabetes.

Coronary heart disease (angina and heart attacks) and diabetes

Diabetes roughly doubles the chance of narrowing of the arteries that supply blood to the heart muscle. Narrowed or blocked coronary arteries can cause chest pain called angina, which typically feels tight or heavy, spreads to the arms or jaw, and comes on at times of exercise or emotional upset.

Sometimes because of damage to the nerves that sense chest pain, patients with diabetes experience angina as shortness of breath rather than pain. Sudden blockages in the coronaries causes heart attacks, and patients with diabetes tend to suffer more heart attacks and worse heart attacks than patients without diabetes.

To reduce risk of heart attack and angina, patients with diabetes should concentrate on lowering their blood pressure and cholesterol, following a generally healthy diet and active lifestyle, and avoid smoking or vaping. Controlling blood glucose levels in the long term may also be important.

Atrial fibrillation and diabetes

Patients with diabetes are 40% more likely to develop a form of irregular heartbeat called atrial fibrillation. This is due to changes in the structure and function of the heart muscle, as well as large swings in blood pressure that tend to happen more often in diabetes.

Atrial fibrillation can cause a wide range of symptoms including palpitations, breathlessness, dizziness, and chest pain. Palpitations are an abnormal awareness of the heartbeat, felt in the chest or neck. There are many causes for palpitations, but in diabetes the diagnosis of atrial fibrillation is particularly important to make because the combination of diabetes plus atrial fibrillation is a potent cause of stroke, which can cause significant disability. Treatments are available to lower the risk of stroke in atrial fibrillation, so it is important to make this diagnosis to enable treatment.

High blood pressure (“hypertension”) and diabetes

Around two thirds of people with diabetes also suffer with high blood pressure. Patients with both these conditions are at much higher risk of stroke or heart attack than people with only one of the conditions, and people with neither. People with diabetes and high blood pressure are four times more likely to develop heart disease than someone without either diabetes or high blood pressure. Controlling high blood pressure is a very important way that patients with diabetes can improve their chance of living a long and healthy life, free from heart disease.

High blood pressure does not often cause symptoms: if you don’t measure your blood pressure (or get it measured at a doctor’s surgery) you won’t know that you have the condition. It is important for patients with diabetes to have regular blood pressure checks and to get their blood pressure treatment tailored to achieve the best possible blood pressure result.

High cholesterol (“hyperlipidaemia”) and diabetes

Patients with diabetes tend to have low levels of good cholesterol (HDL – high density lipoprotein) and high levels of bad cholesterol (LDL – low density lipoprotein). High cholesterol contributes to the risk of coronary heart disease and other complications of diabetes. High cholesterol is yet another condition that does not commonly cause symptoms, and the only way you will know that you have the condition is with regular blood tests.

It is important for patients with diabetes to know their cholesterol and to have it treated if necessary, as this is one way to reduce the risk of heart disease associated with diabetes.

Cardiac hypertrophy, heart failure and diabetes

People with diabetes may develop thickened and slightly stiff cardiac muscle (“cardiac hypertrophy”) over the long term. This process takes years or even decades, and generally causes no symptoms early on. However in some people this can progress to a stage where the heart muscle becomes weak and cannot meet the demands of the rest of the body, a condition called “heart failure”. Heart failure can cause breathlessness and fluid retention, resulting in swelling of the ankles, legs or abdomen. As the disease progresses it may cause fluid pooling in the lungs, particularly on lying down, so that patients with severe heart failure may find they need to sleep propped up on pillows, or even fully upright in a chair. The diagnosis of cardiac hypertrophy or heart failure is generally confirmed with an ECG test and echocardiogram.