Risk is a difficult concept. Most of what we do in life involves making choices and taking risks. Sometimes the risks are small, and sometimes they are large. It can be difficult sometimes to know what the risk of doing something is. Past experience can also influence the way we think about risk. If one was knocked over by a car crossing the road, then even though the risk of it happening again is small we may remain worried and concerned about crossing the road.
How you explain risk is also important. As mentioned earlier, 10 per cent of people over the age of 65 years have diabetes. That means that 90 per cent do not. Do you think that is a high or a low risk? If it is said that 1 in 10 people has a risk of developing diabetes over the age of 65 years, does the risk sound greater? A 1 in 10 risk is quite high. The risk of developing diabetes is influenced not only by age but by the presence of other risk factors.
For Type 2 diabetes many factors are important.
Certain ethnic groups, e.g. people of Asian and African–Caribbean backgrounds are at an increased risk (genetic factors) when living western lifestyles.
A family history of diabetes also increases your chances of developing diabetes (genetic factors).
Being overweight is a risk factor. The distribution of the fat also appears to be important. A fat abdomen is more of a risk than fat hips.
Lack of exercise. The western lifestyle and progressive decrease in walking and manual labour have increased the risk of developing diabetes (environmental factors).
Previous gestational diabetes (a combination of environmental and genetic factors).
For Type 1 diabetes factors that may be important include the following.
Viruses. There is an increase in cases of diabetes in the months when viruses are more common, although the reasons for this seasonality are not fully understood.
Breast feeding – having been breast fed as a baby may be protective against developing Type 1 diabetes.
Genetic factors, as previously discussed.
Thus, a 70-year-old Indian man who is overweight and taking no exercise and who has a strong family history of diabetes has a higher risk than a 70-year-old slim Indian man without a family history who takes lots of exercise. The age-adjusted incidence of diagnosed Type 2 diabetes is slightly higher amongst men than women.
Working through Activity 6 will help you to think about risk.
Activity 6: Risk of developing Type 2 diabetes
When you are next in your town, take a minute or two to look at people in a shop or restaurant. First, see if you could judge how many of them might be at risk of developing diabetes and why? Then look to see if anyone seems to be at low risk of Type 2 diabetes and why? Finally, calculate your own body mass index (BMI) (at home, not in the town!) by dividing your weight measured in kilograms by your height in metres, multiplied by itself, (expressed as kg/m2) as shown in the equation below. What do you think your body mass index means?
A person at higher risk of developing diabetes tends to be older, overweight and relatively inactive – you might have noticed people not walking very fast, or confined to a wheelchair who were also overweight. Those at low risk are leaner and more active. A body mass index of 20–25 kg/m2 is a healthy one, 26–30 kg/m2 is overweight and 30 kg/m2 or more indicates obesity. In 1980, 8 per cent of women and 6 per cent of men in the UK were obese – by 1998 that had almost trebled to 21 per cent of women and 17 per cent of men. A further 32 per cent of women and 46 per cent of men were overweight, meaning that most people in the UK are now either overweight or obese (National Audit Office, 2001).