In the Forum
Risk Factors for Atherosclerosis
Atherosclerotic disease develops through non-modifiable and modifiable risk factors. Age, gender and genetic predisposition are all factors that cannot be changed. Environmental factors are related to diet, physical activity and behavior. The main external factors affecting both men and women include hypertension, hypercholesterolemia, glucose intolerance and obesity. Men are also affected by cigarette smoking and left ventricular hypertrophy.
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| The development of atherosclerosis |
The Framingham study found smoking to be an independent factor. The effect of smoking was only evident in men ages 45 to 64 but not for older men and women. The Nutrition Canada Survey found high cardiovascular mortality among 47% of men who smoked and only 10% among women who smoked.
Risk factors related to diet include increased concentration of serum cholesterol, lower HDL level cholesterol, hypertension and high blood sugar levels (Goto 1990). Those with diabetes mellitus were 3 times more likely to develop atherosclerosis than those without (Yamada 1997). Food rich with antioxidants and enzymes like glutathione peroxidase work to disable the reactive oxygen species (ROS) that produces oxidized LDL that ultimately leads to atherosclerosis (Blankenberg et al 2003). Incorporating a variety of diet choices might work better in lowering the risk of atherosclerosis than merely taking supplementation. Traditional Mediterranean diet was found to be capable of overcoming oxidative stress whereas clinical trials using antioxidant was not as effective (Trichopoulou et al 2003).
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35-55% of ischemic heart disease can be prevented with increased physical activity. Exercise improves insulin sensitivity and increases HDL cholesterol leading to decreased risk factors connected to heart disease. HDL cholesterol has antiatherosclerotic activity (Tarui 1987) in which low HDL levels increase heart disease complications.
Nevertheless 2 or more factors and not just a single mechanism must be present to lead to ischemic heart disease. Other factors are not so common but research has found strong links for them. Acute respiratory infection through pathogens like Chlamydia pneumonae, Helicobacter pylori and cytomeglalovirus has been linked to atherosclerosis. A Polish study compared the state of periodontitis between patients with myocardial infarction and the general public and found a strong link between periodontal and coronary heart disease (Bochniak et al 2004).
Recently a pathogenic gene in the MEF2A signaling pathway was found to be involved in the development of coronary artery disease. According to Wang and colleagues in 2003, deletion mutation that occurred in the gene may affect coronary artery walls that ultimately make it vulnerable to plaque buildup.
Electron beam tomography measures calcium score and is used for early detection of the development of atherosclerotic plaque (Cooil & Raggi 2005).
REFERENCES
Goto Y. (1990). Etiology and prevention of ischemic heart diseases. Asian Med J.:33(5);265-274
Yamada N. (1997). Atherosclerosis and control of risk factors. Asian Med J.:40(8); 423-428.
Blankenberg S, Rupprecht HJ, Bickel C, Torzewski M, Hafner G, Tiret L, Smieja M, Cambien F, Meyer J and Lackner KJ. (2003). Glutathione peroxidase 1 activity and cardiovascular events in patients with coronary artery disease. N Engl J Med 349;1605-1613.
Trichopoulou A, Costacou T, Bamia C and Trichopoulos D. (2003). Adherence to a Mediterranean diet and survival in a Greek population. N Engl J Med :348;2599-2608.
Tarui S. (1987). A report by the research committee on primary hyperlipidemia of the Ministry of Health and Welfare.
Bochniak M, Sadlak-Nowicka J, Tyrzyk S, Sobiczewski W, Rynkiewicz A.(2004). Periodontal and dental state of patients with coronary heart disease. Przegl Lek.: 61(9);910-3
Wang et al. (2003). Mutation of MEF2A in an inherited disorder with features of coronary heart disease. Science: 302; 1578-1581
Cooil B, Raggi P. (2005). On the prediction and prevention of myocardial infarctions: models based on retrospective and doubly censored prospective data. Stat Med.
