PREVALENCE AND RISK FACTORS
Heart disease affects people of all ages, but is most frequent in middle age and is often caused by atherosclerosis. No single factor is an absolute cause either of atherosclerosis or of coronary heart disease. The greater number of risk factors present always increases the risk of the disease. Major risk factors are elevated serum cholesterol, hypertension, cigarette smoking, diabetes mellitus and marked obesity. Other risk factors include family history of heart disease, lack of physical activity and stress.
The various risk factors have been classified into four categories.
Category I - modifiable
Risk factors for which intervention have been proved to lower cardiovascular risk.
1. Cigarette smoking - This increases heart rate and blood pressure, lowers high density lipoprotein cholesterol and promotes thrombus formation.
2. High intake of saturated fat like butter, ghee, egg yolk and coconut oil increase plasma cholesterol and promote atheroma formation.
3. Elevated low-density lipoprotein cholesterol increases development of atherosclerosis.
4. Hypertension - High blood pressure increases the incidence of stroke and heart failure.
5. Food habits - Excess fat, excess sugar, excess salt.
Category - II
Risk factors for which interventions are likely to lower cardiovascular disease risk.
1. Diabetes Mellitus - People with diabetes have metabolic alterations like insulin resistance. hypertension and central obesity which lead to coronary heart disease.
2. Physical inactivity - A sedcntary life style is associated with a two fold increase in coronary heart disease (CHD) risk. Regular aerobic exercise reduces blood pressure, lowers triglyceride concentration, increases HDL - Cholestrol and helps in weight control. Inactivity leads to obesity.
3. Obesity - Obesity is a risk factor for CHD as it is associated with hypertension and diabetes.
Category - III
1. Risk factors for which interventions may lower cardiovascular disease.
2. Psychological factors - Depression and social isolation are associated with CHD incidence.
3. Elevated triglycerides - Elevated triglycerides are often associated with obesity, diabetes, hypertension and low HDL - Cholestrol
Category IV - Non-Modifiable
1. Age - Incidence of CHD increases with age around 50-55 years.
2. Sex - Coronary Artery disease is twice as high in men than women. This difference may be due to the fact that in women the ovarian hormones play an important role. But after menopause the incidence is increased in women.
3. Heredity - If there is a history of heart attack before 55 in father and before 65 in mother the offspring are likely to get a heart attack at an early age.