ATHEROSCLEROSIS
Athersclerosis is the process by which over time, due to the deposition of lipids and cholesterol along the inner lining of the arteries of the body, the lumen of the artery is narrowed resulting in high blood pressure. Over time this can result in the formation of plaques which serve as adhesion points by which thrombus may form. This contributes to a higher risk of stroke or heart attack as these plaques or the thrombus they form may break off from the initial point of formation and then block other blood vessels leading to tissue damage.
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Diagnosis and symptoms:
Due to the nature of the disease, atherosclerosis symptoms cannot be properly diagnosed until the blood vessel has become so narrow due to the formation of plaque or thrombus that blood flow is severely impacted. Furthermore, the risk of damage the disease may cause may depend on the location of the impacted blood vessel. This being said the disease is characterized the following conditions:
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Chest pain (if atherosclerosis occurs in arteries in heart)
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Numbness
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High blood pressure
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Low blood pressure in extremities
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Fatigue or general weakness in body
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To get a better idea of how the plaque may form in the arteries, let's take a closer look at the cross section of an artery and discuss the exact mechanism.
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Due to the high levels of low density lipoproteins, they may begin to be deposited in the region just under the endothelial cells in the wall of the arteries, in a region known as the Tunica Indica.
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Due to this deposition the Low density lipoproteins may become oxidized and as such activate the endothelial cells resulting in migration of immune cells into the tunica intima.
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Of these immune cells, macrophages may consume the low density lipoproteins resulting in them converting to foam cells, as they consume lipoprotiens they may secrete growth factors which result in increased proliferation of smooth muscle cells in the wall of the artery
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Due to the increased growth of the smooth muscle cells, collagen may be deposited into the plaque, resulting in hardening and further obstruction of the blood vessel.
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As time may pass and due to the increased activity of immune cells in the area of the plaque, foam cells may die releasing the low density lipids into the area and further cascading the immune response.
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This may progress to the point where eventually the plaque ruptures resulting in the formation of thrombus on top of the plaque, this typically results in complete obstruction of the blood vessel or if the thrombus is able to dislodge itself may result in stroke or heart attack due to other vital blood vessels being obstructed by the presence of the clot.
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Treatments for Atherosclerosis:
So far there are numerous treatments for atherosclerosis including stents which can be inserted into the obstructed vessel and manually widen the vessel without disrupting the plaque that has formed, this treatment however does have some downsides as it can cause scarring to occur and for that reason is typically used as a last resort if no other treatments are successful or if the situation is dire. Another treatment is by use of statins to prevent the accumulation of low density lipoproteins and as such prevent the initial formation or worsening of plaques. Other therapies including high density lipoproteins in diet as well as ensuring a diet high in antioxidants may not only prevent the formation of plaques along the walls of blood vessels but may also cause the regression and shrinking of plaques. Finally some studies even show that, by targeting the signaling and growth factors released by the endothelial cells which attract immune cells, the progression of the plaque can be minimized to the point that it stabilized and as such no rupturing of the plaque may occur. By using these approaches atherosclerosis may be treated. Personally I feel that the most promising treatments involve the regression of the disease and I believe that specific target drug molecules that are able to dissolve the plaques would be the most promising treatment going forward, however special care would need to be taken that once the plaque is able to be removed from its initial point of origin that it should not be able to cause harm to the rest of the body. It is through this mechanism that I believe that the future of treatments for atherosclerosis lies and once it is achieved the silent killer of numerous cardiovascular conditions may be solved.
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Sources:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2826222/
https://www.nature.com/articles/s41569-020-0431-7
https://my.clevelandclinic.org/health/diseases/16753-atherosclerosis-arterial-disease
https://www.youtube.com/watch?v=R6QTiBfzULE&ab_channel=ArmandoHasudungan
https://www.frontiersin.org/articles/10.3389/fcvm.2019.00046/full