In this week’s fitness blog we are looking at Coronary Heart Disease (CHD), its causes and prevalence, and how physical activity, such as an exercise programme devised by a personal trainer, can have direct benefits in the prevention and management of CHD.
Coronary Heart Disease is also known as Coronary Artery Disease or Ischaemic Heart Disease. Most CHD develops as a result of damaged arteries causing a reduction in the blood flow to the heart. The categories include:
- Heart failure
- Peripheral vascular disease
- Valvular heart disease
- Congenital heart disease
Diseases of the heart and circulatory system are the main causes of death in the UK, accounting for just over 191,000 deaths each year; more than one in three people die from Cardiovascual Disease. CHD is the most common cause of death in the UK: around one in five men and one in eight women die from the disease (British Heart Foundation figures from 2010).
Prevention of CHD
The primary prevention of CHD comprises of health education to promote awareness of the disease and encourage a healthier lifestyle, for example working with a personal trainer to increase levels of physical activity.
The secondary prevention involves educational lifestyle modifications, such as stopping smoking and going on cardiac rehabilitation programmes with the aim of halting the progression of CHD and preventing a further cardiac event.
The pathology of CHD
CHD causes the deterioration of the innermost lining of the large coronary arteries, known as the endothelium. This is a process referred to as atherosclerosis, which develops following damage to the endothelium leading to a susceptibility to the formation of plaques. High blood pressure, smoking and immunology are all thought to contribute to this damage.
Plaques are an accumulation of lipids (fats), collagen and macrophages (large scavenger cells that can ingest debris and bacteria but can also stick to damaged sites), in the lining of the coronary arteries.
These plaques progressively impede blood flow, which eventually leads to myocardial ischemia, where the demand for oxygen by the heart exceeds the supply. Symptoms develop when the blood flow to the surrounding tissues has been restricted by about 45%, so by the time people are made aware of the extent of the problem, it is already advanced. Atherosclerosis begins in childhood and progresses through adolescence, in fact it has been found in children as young as four.
The presentation of Coronary Heart Disease
The problem is often not noticed until the patient suffers one of the following:
- Angina – chest pain or discomfort resulting from inadequate blood flow in or around the heart
- Myocardial infarction or heart attack
- Sudden cardiac death
Non-modifiable risk factors
The non-modifiable risk factors include age, gender, ethnic origin, family history and Type 1 diabetes.
CHD rarely occurs before the age of 35 and the risk steadily increases with age as coronary atherosclerosis (the narrowing and hardening of the inner walls of the arteries) is a progressive, degenerative disease.
Men are more likely to develop CHD at a younger age; women appear to be protected by their hormones until they reach the menopause. However, the menopause can be a high-risk time for women since 50% of women over 55 have other risk factors, such as obesity, high-blood pressure, high cholesterol and inactivity.
People of Indian origin have a higher mortality rate from CHD than Caucasians, which is potentially due to the increased incidence of central obesity; eg holding more body fat around the major organs, which may be in part related to diet.
Family history and genetic predisposition to CHD
If one parent has CHD, the risk is 15% more than for the general population, if both parents develop early CHD then the risk rises by 50% for their children.
Research has shown a two- or three-fold increase incidence in CHD in men with Type 1 diabetes and a four- or five-fold in women.
Modifiable risk factors
The modifiable risk factors for CHD include:
- High cholesterol
- Physical inactivity
- Type 2 diabetes
- Levels of fibrinogen (a protein that helps blood clots to form)
A personal trainer will advocate following a fitness programme to reduce the risk of developing CHD and to help manage the symptoms for those who have the disease. Participating in regular exercise makes the heart stronger and can decrease blood pressure. Increasing fitness levels will also decrease the heart rate response, which means your heart is working more efficiently and so requires less oxygen.
A decrease in body fat percentage can help prevent the development of CHD and those taking part in regular exercise often make healthier lifestyle choices, such as eating well and managing their alcohol intake.