There are varied risk factors for heart disease. We have an influence over some of these, such as smoking and diet, but there are others that we have no control over, such as age, sex and genetics.

It is essential to appreciate multiple risk factors and how they relate to each other.

Sex, genetics, and age - beyond our control

We cannot control our sex, family history, or age - these factors will contribute to our cumulative risk of heart disease.

Sex

Men are at greater risk of developing heart disease than women.  Heart disease accounts for 30% of all male deaths and 23% of female deaths in the UK.

Up to the age of 45, deaths from heart disease in the UK are 6 - 7 times higher in men than women.

Up to the point of the menopause, women are offered protection through oestrogen and comparatively greater levels of high-density lipoprotein (HDL).  HDL is the fatty protein package that carries cholesterol away from the artery walls to the liver.

Oestrogen is produced by the ovaries and fat tissue, and acts by relaxing artery muscles and widening the arteries to allow improved blood flow.

Around the time of the menopause hormonal protection is reduced, and the rate of heart disease increases for women.  The difference in death rates between the sexes falls 3-fold in the 55-65 group.  By the age of 75, there is virtually no difference in risk.

Genes

Family history influences the risk of heart disease.  A condition known as familial hypercholesterolaemia is a major factor to consider, as naturally high levels of cholesterol are passed on from generation to generation.

Other risk factors that have a strong genetic component are elevated blood pressure and homocysteine levels, diabetes and obesity.

With advancing years comes increased atherosclerosis.  Most people, by the age of 40 have some plaque build-up of consequence in the arteries. 

This gradual deposition of oxidised fatty material narrows the arteries, making it more difficult for the heart to pump blood through them, rather like pinching a hose pipe in action, causing an increase in pressure. 

We can modify blood pressure, cholesterol, obesity and diabetes

High blood pressure, high LDL cholesterol levels, obesity and diabetes are all risk factors that can be modified and controlled to a degree through diet, exercise and medication.

Blood pressure

The risk of heart disease rises with an increase in blood pressure. This is significant as 1 in 5 of the UK population are likely to develop hypertension.  Even mildly elevated blood pressure may promote heart disease.

Hypertension increases wear and tear on the heart and blood vessels.  It can add to the deposition of cholesterol and other substances in the lining of damaged blood vessels, compounding the effect.

Cholesterol

Cholesterol is an essential fatty substance found in the nervous tissue and blood cells.  It is required for the production of bile acid and sex hormones, and occurs in the body as a protein complex known as lipoprotein.

The two main forms of cholesterol are high-density lipoprotein (HDL), which transports cholesterol out of the arteries to the liver, minimising the damaging arterial accumulation; and low-density lipoprotein (LDL), which transports cholesterol in the opposite direction and is susceptible to oxidative damage, leading to the build-up of atherosclerotic lesions.

Blood tests carried out by your GP have been devised to look at both total cholesterol and the ratio of HDL and LDL.  See the Tests section for further information.

Obesity

Being overweight is a well-established risk factor for heart disease.  The incidence is high in obese men and women. There is a graded increase in the risk of cardiovascular mortality when Body Mass Index (BMI) is above 25.

When we put on a significant amount of weight as body fat, our blood pressure tends to increase, as does the circulating levels of LDL cholesterol. 

This is due to the expanding reservoir of cholesterol stored in the fat tissue, the adipose. 

The distribution of fat influences the risk of heart disease.  People with excessive abdominal fat (central obesity) are at greater risk.  They have an unfavourable plasma lipoprotein pattern, with low HDL cholesterol.  As we age, fat tends to accumulate around the trunk area of the body.  Higher circulation of lipid levels and increased lipoprotein production in the liver, along with other associated factors, accelerate the atherosclerosis process.

Following on from this, people with central obesity may have reduced insulin sensitivity, which leads to diabetes.

Diabetes (disorder of carbohydrate metabolism)

Heart disease risk increases in all diabetics, with a twofold greater mortality rate from heart disease in older generations.  The greater risk is primarily due to the associated vascular changes that occur with the condition.  Insulin resistance and the central distribution of fat associated with diabetes partly explains why the threat of disease is significantly increased.

We can control smoking, alcohol, stress and exercise

A healthy lifestyle is ours to embrace, so bear in mind factors that increase the risk of heart disease.

Smoking

Smoking can double the risk of heart disease for the middle-aged; the more we smoke, the higher the risk.  Even the amount of nicotine from one cigarette is enough to constrict a small artery.

Smoking generates an influx of free radicals into the body, causing greater oxidative damage that helps the initiation of atherosclerosis.  Smokers tend to have a lower antioxidant status than non-smokers, usually as a result of a low dietary intake of fruits and vegetables, but also due to a greater turnover of antioxidants in the body, in particular vitamin C.

Alcohol

Alcohol, in excess, increases blood pressure and serum triglyceride levels.  Moderation is the key, as the occasional glass of red wine offers some protection, due to the component antioxidants, polyphenols.

Stress

Stress that affects health needs to be taken as a warning sign.  We should make changes in our lives to prevent stress adding to the risk of heart disease.  Over a period of time, stress may elevate blood pressure and can lead to an increase in smoking and alcohol consumption.

Sedentary lifestyle

An inactive life doubles the risk of heart disease.  The details of why and how exercise can help are discussed in the Exercise section.

Share your experience, advice and knowledge with other members of the 50+ Health community in the Heart disease discussion forum.

20/05/2009