Heart Disease - Cardiac Risk Factors
What do I need to know about Cardiac Risk Factors?
The existence of risk factors for cardiovascular diseases has led to a surge of interest in improving lifestyle in order to head off heart attacks and other related illnesses. Knowledge of cardiovascular risk factors provides a starting point for establishing lifestyle changes that will reduce the risks of cardiovascular illness. Regular physical check-ups, including lab exams, will detect any 'silent' risk factors, such as high blood pressure or a high cholesterol level that can be taken care of before they lead to disabling illness. Research has shown that healthy lifestyle changes, together with help and advice from your health professionals, will prolong your period of good health into your senior years.
Some diseases are believed to be pre-determined and unchangeable at least with our current scientific understanding. For instance hemophilia is a genetically transferred condition that is certain to occur in an individual who is a carrier of those genes. The risk factors (genetics) associated with unchangeable diseases are called Fixed Risk Factors.
On the other hand the onset or expression of some diseases can be delayed, prevented or even reversed by making healthy lifestyle changes. Heart disease is an example of a preventable/modifiable disease. The risk factors (genetics) associated with unchangeable diseases are called Changeable Risk Factors.
In the following sections we will discuss the most common risk factors of cardiovascular disease and some lifestyle options that can prevent or reverse cardiovascular disease.
What are my Fixed Cardiac Risk Factors?
Approximately four out of five people who die of coronary heart disease are age 65 or older. Certainly age is a significant risk factor of cardiac disease. In fact, heart disease is the number one cause of death among individuals over 65 and the number 2 cause of death among individuals form 45 to 64.
As women age they are more likely than men are to die within a few weeks after a heart attack.
Men have a greater risk of heart attack than women, and they have attacks earlier in life.
Even after menopause, when women's death rate from heart disease increases, it's not as great as men's.
Children of parents with heart disease are more likely to develop it themselves. Although heredity is commonly blamed for this observation lifestyle may at least in part account for this relationship.
For instance, African Americans have more severe high blood pressure than whites and a higher risk of heart disease. Heart disease risk is also higher among Mexican Americans, Native Americans, native Hawaiians and some Asian Americans. Although it is acknowledge that this is partly due to higher rates of obesity and diabetes many researchers believe these observation may to some degree reflect the socio-economic conditions of the various groups rather then just genetics.
Most individuals with a family history of heart disease have at least other cardiac risk factors. Just as age, sex and race are unchangeable family history also falls into this category. It therefore becomes important to treat and control any other changeable risk factors you have.
What are the Changeable Risk Factors?
One of the greatest risk factor associated with heart and blood vessel disease is cigarette smoking. Cigarette smokers have a 70% greater rate of death from heart and blood vessel disease as compared to non-smokers. Heavy smokers (two or more packs per day) have a death rate two to three times greater than non-smokers.
Inhalation of cigarette smoke causes profound effects on both the heart and blood vessels throughout the body. Nicotine increases blood pressure, heart rate and the amount of blood flowing from the heart to the coronary arteries and the other blood vessels of the body. It also causes narrowing of vessels in the extremities and is believed to contribute to excessive clot formation.
Carbon monoxide which is inhaled as part of cigarette smoke, interferes with the blood's ability to carry oxygen, In effect reducing the amount of oxygen available to tissues. As blood vessels progressively narrow the effect of reducing the oxygen-carrying capacity of the blood becomes more evident. It can cause or aggravate angina, muscle spasms, breathlessness and intermittent claudication.
Cigarette smoking also causes platelets to become sticky and clump together thereby increasing the risk of clotting and blood vessel damage. Smokers' risk of heart attack is more than twice that of nonsmokers.
Cigarette smoking is the biggest risk factor for sudden cardiac death. In the first few days after a heart attack the longer a person survives the greater becomes his/her chance of survival. Sudden cardiac death means that an individual dies soon after a heart attack. Cigarette smokers have two to four times the risk for sudden cardiac death as compared to non-smokers. Smokers who have a heart attack are more likely to die and die suddenly (within an hour) than are non-smokers. Cigarette smoking greatly amplifies the effect of other risk factors further increasing the risk for coronary heart disease.
Cigar and pipe smokers appear to have a higher risk of death from coronary heart disease (and possibly stroke), but their risk isn't as great as cigarette smokers'.
Constant exposure to second-hand smoke - also called passive smoking, or environmental tobacco smoke- increases the risk of heart disease even for non-smokers
Cholesterol is a necessary constituent of healthy cell as it is an important component of cellular membranes (cell's skin) and is a building block of Vitamin D, and several sex and stress hormones. These hormones include testosterone, estrogen and cortisol (steroid stress hormone).
The risk of coronary heart disease rises as blood cholesterol levels increase. Looking at cholesterol alone is not as helpful as looking at the individual constituents that make up cholesterol.
For instance there are three types of cholesterol in particular that have been found to be stronger indicators of risk than cholesterol alone. These factors are called LDL (low density lipoprotein) and HDL (high density lipoprotein) Lp(a) (Lipoprotein a). A possible fourth indicator apolipoprotein B (apoB) is currently being studied in relation to women.
LDL, a major cholesterol carrier, helps to carry cholesterol and other fats to the cells of the body. High levels of LDL, can lead to cholesterol build-up on blood vessel walls and eventually cause damage to those walls.
HDL another major cholesterol carrier, helps to cholesterol from the cells of the body to the liver. High levels of HDL, are protective in that they have the effect of carrying excess cholesterol from the cells of the blood vessels walls to the liver for eventual removal from the body through the bowels.
Lp(a) is a variation of LDL that is associated with an even higher cardiac disease risk that LDL. The method by with Lp(a) contributes to cardiac disease is unknown and under intense investigation. It is probable that Lp(a) will become at least as important a risk factor as LDL and HDL are.
(ApoB), another constituent of LDL, appears to be a stronger risk factor of coronary disease in women the LDL. Recent trials have shown that LDL is a less significant risk for women. In addition, analysis of the Framingham Offspring population demonstrated that concentrations of apoB were related to coronary artery disease in women.
When other risk factors (such as high blood pressure and tobacco smoke) are present, this risk increases even more. A person's cholesterol level is also affected by age, sex, heredity and diet.
Blood pressure is the measure of two opposing forces applied to the arteries of the cardiovascular system.
The first force is created each time the heart contracts. This creates a rise in normal pressure (systolic pressure) that helps propel the blood through the body. This rise in pressure is necessary for the delivery of nutrients throughout the body and in the formation of urine necessary for eliminating wastes from the body. The second is created by arterial resistant (diastolic pressure) to blood flow. Healthy arteries are muscular and elastic. They stretch with each heart beat and bounce back as the pressure begins to drop. This recoil also helps to propel the blood throughout the arterial system.
High blood pressure is the number one heart- related health condition in the North America today, affecting over 60 million people. In fact the most common cause of doctor visits is related of hypertension. Ninety percent of all high blood pressure is idiopathic, (unknown cause).
High blood pressure increase the amount of work the heart has to perform and over time will cause the heart to enlarge and eventually weaken. Some scientists believe that the constant excess pounding of blood vessels cause by high blood pressure may in part be responsible for blood vessel damage and eventually plaqueing, this is common in individuals with a long history of high blood pressure. Blood vessel damage has varying effects depending upon the location. Damage to blood vessels in the kidneys increase the risk of kidney failure, in the heart can increase the risk of heart attack and in the brain can increase the risk of strokes.
Normal blood pressure falls within a normal range; the high end of normal is generally agreed to be at 140/90. Blood pressure below 100/60 is considered to be low. Under normal conditions, blood pressure can rise above 140/90 or fall below100/60. Strenuous physical activity will routinely cause high blood pressure while relaxation and sleep can cause low blood pressure. While transient rises in blood pressure are generally insignificant, sustained rises in blood pressure are classified as Hypertension and considered to be a significant risk factor.
High blood pressure increases the heart's workload, causing the heart to enlarge and weaken over time. When considered in combination with other risk factors such as obesity, smoking, high blood cholesterol levels or diabetes, high blood pressure increases the risk of heart attack or stroke significantly.
An inactive lifestyle is a major risk factor for coronary heart disease. Individuals who do not get enough physical activity on a regular basis are more likely to develop high blood pressure, heart disease. Regular, moderate-to-vigorous exercise significantly reduces the risk of heart, strokes and blood vessel disease.
Even moderate-intensity physical activities done on a regular basis can over the long term promote better health and lower risk of heart disease. Vigorous activities are associated with greater benefits. Studies have shown that exercise can help lower blood cholesterol and triglycerides, improve diabetes and promote weight loss in obese and over-weight individuals, as well as lower blood pressure in some people.
Diabetes occurs when the body's ability to to produce insulin is impaired. Under normal conditions blood sugar levels begin to rise in the blood soon after a meal containing carbohydrates is ingested. Foods that contain carbohydrates include bread,pasta, rice, fruits, vegetables and sweets. In response to the increase in blood sugar levels the pancreas releases insulin. Insulin helps move the sugar from the blood into cells all over the body.
When insulin levels are low, the sugar concentrations rise far above normal and remains in the blood for an extended period of time. Over time these high concentrations can cause damage to blood vessels an accelerate the development of coronary vessel disease and other blood vessel diseases.
Diabetes seriously increases the risk of developing cardiovascular disease. Even when glucose levels are under control, diabetes greatly increases the risk of heart disease and stroke. About two-thirds of people with diabetes die of some form of heart or blood vessel disease. If you have diabetes, it's critically important to work with your health-care provider to manage your diabetes and control any other risk factors you can.
An individual's exposure and response to stress may be a contributing factor to the development of heart disease. Physiological changes occur when an individual is exposed to continued high levels of stress. These changes include increases in heart rate and blood pressure, release of body fats, increase secretions of stress related hormones like adrenal, rises in blood sugar and increases in chemicals that accelerate the blood's clotting mechanisms.
Stress levels may affect established risk factors. For example, people under high amounts of stress may over-eat, start smoking or smoke more than they otherwise would, start drinking alcohol or drink increased amounts alcohol.
Obesity is an unhealthy state that significantly increases the risk of developing heart disease, stroke and other blood vessel diseases. Excess weight puts strain on the heart and is closely related to the development of the following risk factors:
- Type II Diabetes,
- High Blood Pressure
- Low HDL ('good') Cholesterol levels
- High Cholesterol and Triglyceride levels.
People who have excess body fat - especially if a lot of it is in the waist area - are more likely to develop heart disease and stroke even if they have no other risk factors. Many obese and over-weight people have great difficulty losing weight. A 10 to 20 pounds weight loss can help lower your heart disease risk.
High levels of homocysteine in the blood is associated with increase risk of heart disease.
Homocysteine is an amino acid that plays a number important functions in the body. In 1969, Kilmer McCully, M.D., first proposed that a the amino acid homocysteine played a significant role in heart disease. His research was initially dismissed and his career abruptly damaged by the presentation of his research.
Subsequent studies have establish the relationship between heart disease and homocysteine levels in the blood. Folic Acid, Vitamin B-6 and Vitamin B-12 all play a part in the normal metabolism of homocysteine. These vitamins have been found to reduce homocysteine levels.
High blood levels of the blood-clotting protein fibrinogen are linked to an increased risk of heart attack. It is consider to be a strong and independent predictor for heart disease.
Studies have shown that patients who have had a heart attack have higher levels of fibrinogen in their blood. These fibrinogen-heart attack relationship remain constant regardless of the absence or presence of other risk factors.
Studies have also demonstrated a relationship between smoking and high fibrinogen levels in the blood. Reducing or quitting smoking dramatically reduces fibrinogen levels.