ABSTRACT
So far risk factors for cardiovascular disease (CVD) have been discussed individually in relation to the effects of physical activity (see Chapter 5). However, some risk factors tend to cluster together. These include dyslipidaemia (specifically, high triglycerides and low highdensity lipoprotein (HDL)-cholesterol), impaired glucose regulation or diabetes, obesity (particularly of the upper body type) and hypertension. The phrase ‘cluster together’ means that these risk factors coexist more commonly than would be expected by chance. For example, diabetes and obesity are twice as common among people with hypertension as among those with normal blood pressure. As a combination, risk factors become much more powerful predictors of disease. Data from the Framingham Offspring Study1 shows that
clusters of three or more factors increased the risk of coronary heart disease (CHD) more than two-fold in men and nearly 6-fold in women (Figure 8.1) (Wilson et al. 1999).
