3 Risk factors
3.1 Lifestyle choices
Health is generally considered to be the absence of disease. However, the absence of any symptoms of disease may cause us to mistakenly believe we are healthy. We can't see inside our arteries to know how blocked up they are with fatty deposits without specialised equipment, but that doesn't mean it isn't gradually happening.
You may consider that your heart is healthy. What are your chances, as a member of the general population, of developing cardiovascular diseases now, next year or in 20 years' time? What are your risk factors for developing a heart problem in the future, and what can you do to minimise them? These appear to be simple questions, but what is the difference between chance and risk?
Chance is the likelihood of something happening (or not happening) randomly. It is not something that can be controlled. What determines who will succumb to cardiovascular diseases within the population has been studied scientifically. Rather than being just down to chance, it may be described in terms of risk factors.
Risk has a connotation of something bad possibly (but not definitely) happening. Everyone has an absolute risk of developing cardiovascular diseases, or any other disease over their lifetime. We can express an individual's risk in a variety of ways: a 1 in 10 risk can also be written as a 10 per cent risk or as a risk of 0.1. The absolute risks for men and women in Europe are actually much higher; approximately 43 per cent of deaths in men and 55 per cent of deaths in women in Europe are due to cardiovascular diseases (Petersen et al., 2006).
There are some activities and lifestyle choices that increase an individual's risk of disease. These can also be calculated and combined with their absolute risk. An assessment of relative risk in epidemiology (the study of the distribution of diseases in populations and their causes) looks at, for example, the risk of cardiovascular diseases occurring in smokers relative to the risk of cardiovascular diseases occurring in non-smokers, comparing two probabilities. There is no assessment of how bad the cardiovascular diseases are or even if smoking is the cause, but for whatever reasons, the risk of cardiovascular diseases in smokers is found to be greater than in non-smokers. To summarise, chance relates to the whole population and the likelihood of developing cardiovascular diseases, but risk can be specifically calculated for a subset of the population, such as smokers or those with pre-existing diabetes.
There are many scientific studies that have looked at a whole host of lifestyle risk factors for cardiovascular diseases, such as smoking, raised blood cholesterol and elevated blood pressure. (Others are listed in Table 2.) Unlike chance, once identified, a modifiable risk factor can be acted upon to reduce its possible negative effect on health or future health, hence reducing the risk of developing cardiovascular diseases. Many of these factors can also be termed modifiable risk factors because they can be changed through personal choice (but often not without considerable effort!).
Table 2 Cardiovascular risk factors can be separated into three broad categories: biological risk factors that are non-modifiable; biological risk factors that are modifiable by treatment or altered lifestyle; and lifestyle factors that are modifiable
|Biological risk factors: non-modifiable||Biological risk factors: modifiable by treatment or altered lifestyle||Lifestyle risk factors: modifiable|
|age (increasing)||high blood cholesterol||smoking|
|male||high blood pressure (hypertension)||diet (unhealthy or unbalanced)|
|family history (genetic)||overweight and obesity||inactivity (sedentary lifestyle)|
|race/ethnicity||diabetes (Type 2)||excessive alcohol consumption|
|diabetes (Type 1)||psychosocial factors, e.g. stress, depression, anger|
You read about both decreasing and increasing rates of cardiovascular diseases in Section 1. Even though some major risk factors have been identified from studies that date back to the 1940s, and although some reductions in cardiovascular diseases have been achieved based on these investigations, changes in society and global factors since then have led to the emergence of new or more prevalent risk factors. Why is it that cardiovascular diseases are expected to continue increasing throughout certain areas of the world? The habits or ‘lifestyle risk factors’ of people and populations have changed over recent years, often described as becoming more ‘Westernised’. The trend has been towards the consumption of more energy-dense but nutrient-poor food, such as saturated fats and trans fatty acids (see Section 3.2.1 later), salt and refined carbohydrates, and a correspondingly lower consumption of fresh fruit and vegetables. At the same time, many societies have reduced their physical activity, perhaps due to more time spent watching television, playing computer games and other sedentary activities, rather than on physical or outdoor activities. At the same time, there has been more travel taking place in cars and other motorised vehicles rather than by bicycle or walking.
There are also some biological risk factors that are not modifiable (Table 2). These include gender, increasing age, any genetic disorders and some diseases, e.g. Type 1 diabetes (see Section 3.2). Type 2 diabetes and its precursor, insulin resistance, can be modified to some extent during their early stages.
Some of the modifiable risk factors could fall equally well into the biological or lifestyle risk category, especially if they have arisen as a result of lifestyle. Examples are: hypertension due to a diet high in salt; high blood cholesterol due to a diet high in saturated fat; being overweight or obese due to excessive or indiscriminate eating behaviour; and Type 2 diabetes developed following weight gain. The development of such risk factors may be unavoidable, but with medical management they may be influenced positively.
In the following case study, where you are introduced to Winifred Fowler, you will start to investigate how an individual may consider their lifestyle in relation to their cardiovascular disease risk.
Case study 1: Winifred Fowler
Winifred Fowler is a bus driver in Norwich. She is 61 and will be retiring soon. Winifred is counting the years to finishing work, but with one of her children at college, the family still needs her income. She recently had a medical examination, arranged by her employer, and was found to have high blood pressure. Winifred smokes at least 20 cigarettes a day, spends most of her time sitting down and snacks on chocolate and sweets. She has to keep to a tight bus schedule, working the 2 to 8 p.m. shift, so lunch is often a takeaway bacon roll or a portion of chips with plenty of salt from the café on the way to her bus depot.
Activity 4: Risk factors and simple ways of changing them
Make a list of the modifiable risk factors that Winifred could change to improve her overall health and reduce her risk of cardiovascular diseases. For each one that you have listed, write a sentence identifying at least one way in which she could change.
You should have been able to identify at least a few modifiable risk factors that Winifred could work towards changing. These might have included: reducing or giving up smoking; reducing or replacing her snacks with healthy options; improving her general diet; reducing her salt intake; and taking up exercise to counteract the amount of time she sits during her working day.