EUGLOREH project




5.2. Cardiovascular diseases

5.2.4. Risk factors

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5.2.4. Risk factors Risk factors in primary prevention

CVD is eminently preventable. WHO estimates that modest population-wide and simultaneous reductions in blood pressure, obesity, blood cholesterol and tobacco use would more than halve CVD incidence.

CVD has a multifactor aetiology, which means that several factors simultaneously affect its development. Age is the most important factor, followed by hypertension, obesity, smoking habit, diabetes and hyperlipidemia. These factors, with the obvious exception of smoke, are mostly caused by the interaction between unhealthy lifestyles and a genetic predisposition (the so-called thrifty genotype). Unhealthy life style includes a diet too rich of saturated and/or trans-unsaturated fats, salt, alcohol, free sugar and low consumption of fibres, associated with high levels of blood pressure, LDL and total cholesterol, physical inactivity and smoking habit.

Some of these risk factors are linked to a continuous association with CVD incidence (age, blood pressure, cholesterol, body mass index) and the fact that there are no level over or under which the disease does not develop: risk factors thresholds are arbitrary and the only way to reduce the risk of developing the disease is to keep levels of risk factors at a favourable level throughout our life.


Although the role of risk factors is well known, national level data are difficult to obtain due to the high cost of health examination surveys. Table 5.2.7 (, 2007) provides the most recent available data on hypertension prevalence by age range. It seems clear that hypertension prevalence increases with age and that it is higher in women than in men. These data have been collected using different methodologies (self-reported or measured) and different diagnostic criteria for the definition of hypertension prevalence (≥160 o 95 mmHg; ≥140 o 90 mmHg; ≥160 mmHg).

Table 5.2.8 shows data on total cholesterol: prevalence of hypercholesterolemia is difficult to describe due to the different existing definitions (≥5.2 mmol/l, ≥6.2, ≥6.5 or ≥7.8) and difficulties in the standardization of laboratory assays. Beyond that, prevalence, as expected, increases with age and is higher among elderly women.

Table 5.2.9 reports smoking habit collected through health interview surveys. Prevalence of smoking in women is lower except in Sweden, but in several countries this trend is changing. In men, smoking is generally higher in Southern, Baltic and Eastern Europe than in Northern countries. In women, it is generally higher in Northern Europe and Southern Europe than in Central Eastern and Eastern countries (see also Chapter 8).


Table 5.2.7. Estimated prevalence of hypertension for men and women of different age ranges in 22 EU countries.


Table 5.2.8. Estimated mean values of total cholesterol in mmol/l and prevalence of hypercholesterolemia in 27 EU countries for men and women of different age ranges.


Table 5.2.9. Estimated prevalence of smoking habit in 27 EU countries for men and women of different age ranges


Obesity and overweight (Table 5.2.10) are also included alongside the three already mentioned most important risk factors for the prediction of CVD. Actually, obesity is a key issue and is strongly related to blood pressure, total and high-density lipoprotein (HDL) cholesterol and glycaemia (Panico et al, 2008) (see Chapter 5.1.4). Recent evidence suggests that abdominal obesity, as evaluated by an enlarged abdominal circumference (Yusuf et al, 2004) may play a more significant role than obesity - as evaluated by BMI - in predicting CV risk (see also Chapter 10).


Table 5.2.10. Estimated prevalence of obesity (defined as BMI30kg/m2) in 27 EU countries for men and women of different age ranges.


Other factors associated with CVD include diabetes mellitus, excessive alcohol consumption and psychosocial stress (see the attached European Heart Health Charter Annex 1). Interestingly, moderate alcohol intake (20-30 g/day in men and 10-20 g/day in women) is associated with a reduced CVD incidence (Wellman J, 2004).

Due to differences in data collection methodology (self reported or measured), diagnostic criteria adopted for risk factor definition (hypertension and hypercholesterolemia) and age ranges, it was not possible to pool data, provide trends overview and comparison among high risk countries. Therefore, it is important to take into consideration some data from the WHO-MONICA Project (Table 5.2.11) collected between mid 1980s and 1990s through standardized methods (Kuulasmaa et al, 2000; Tolonen et al, 2002). Trends data show a decrease in systolic blood pressure in all participating countries and also in cholesterol in many of them. According to MONICA results, changes in classic risk factors explained only a part of the change in CVD (Kuulasmaa et al. 2000).

Both decreasing trend and observed country variation in CVD can be attributed to differences in ‘classical risk factors’ such as smoking, hypertension, hyperlipidemia, diabetes, overweight, alcohol use, physical activity, medical care and genetic and environmental conditions.


Table 5.2.11. Prevalence of smoking (%), mean values of systolic blood pressure (mmHg), total cholesterol (mmol/L) and BMI (Kg/m2) men and women aged 35-64 years


Also the INTERHEART (Yusuf et al, 2004) case-control study, conducted in patients with myocardial infarction in 52 countries, representing every inhabited continent, estimated that 22% of heart attacks in Western Europe and 25% in Central Eastern and Eastern Europe are due to a history of high blood pressure, between 45% and 35% of heart attacks are due to abnormal blood lipids, and around 30% to smoking and that smokers and former smokers are at almost twice the risk of heart attack compared to those who have never been smokers (see Chapter 5.1.2.).

Unfortunately, despite epidemiological studies demonstrated that the risk is reversible through healthy lifestyle and drug treatment for individuals at high risk (the North Karelia Project is an example of well-recognised approach to community-based primary prevention) and clinical trials have demonstrated the efficacy of therapies, recommendations on management of risk factors are still not properly followed, even in patients which have already experienced an event. This is confirmed by the results of the ‘European action on secondary prevention through intervention to reduce events’ (EUROASPIRE) surveys, presented by the European Society of Cardiology during the Congress held in Vienna (2007). The EUROASPIRE surveys were conducted in 1995-96, 1999-2000 and 2005-6 in different European countries to describe the management of risk factors in hospitalized patients with IHD and determine whether the European guidelines on CVD prevention had been properly implemented. It has been found that in over 10 years the prevalence of patients with hypertension undergoing adequate treatment has not changed and is still about 40%; thanks to the introduction of statins, about 60% of patients with hyperlipidemia are properly treated but no improvements were made with regards to the prevalence of smoking and obesity.