What is endothelium?(Part 4)

Ways of preventing injury to the endothelium

Avoiding or stopping smoking

One of the products of smoking is nicotine, and this substance injures the endothelium which ultimately leads to atherogenesis. Specifically, smoking promotes the oxidation of the low-density lipoprotein (LDL) which—aside from decreasing the concentration of nitric oxide {Consult Powertec (149)}—promotes the migration of the white blood cells (monocytes) in the midst of endothelium, thereby injuring it[1]. Hence, avoid, or stop, smoking as soon as possible.

Simplified steps in protecting your endothelium

  • Consult a medical doctor and have your blood pressure checked;
  • If your blood pressure is elevated, your medical doctor will prescribe youwith medication(s). If so, take them regularly. After two weeks or one month, go back to your medical doctor, and have your blood pressure checked again. If your blood pressure is still high, he will add another medication. If already controlled, he will advise you to continue your medication(s);
  • If you have elevated blood pressure, aside from giving you the necessary medication(s), your medical doctor will request you to have blood chemistry examination, complete blood count, and urinalysis.The blood chemistry examination will consist of the fasting blood sugar, blood urea nitrogen, creatinine, uric acid, aspartate aminotransferase (AST), alanine aminotransferase (ALT), and the lipid profile. The lipid profile, in turn, will consist of the total blood cholesterol and triglyceride, high-density lipoprotein, low-density lipoprotein, and the vey low-density lipoprotein;
  • The lipid profile test is very important because it will tell you if you need additional medication(s). If your total cholesterol, and/or your total triglyceride, and/or your LDL cholesterol is (are) high, you need to take drug belonging to the statins. If the predominant elevation falls on the triglycerides, you need to take drug under fenofibrates;
  • If your fasting blood sugar is elevated, it is possible that you are suffering fromdiabetes mellitus. Initially, your medical doctor may design for you dietary therapy and try it for some months. If it does not work after giving a try, you will be prescribed with anti-diabetic drug(s).
  • If your blood pressure is elevated and/or you have abnormalities with your blood lipids and/or your blood sugar is elevated, you need to be very careful with your diet. Avoid high salt and high fat diet. Avoid taking simple carbohydrates like candies, chocolates, sugar, ice cream, and soft drinks. Limit your intake of rice to one cup per meal, and take a lot of foods rich in fibers, such as corn, vegetables, fruits, and cereals;
  • Have a regular and periodic physical exercises. If you are over 50 years old, a 30-minute walking, three times per week, will do you a lot of good! If you are below 50 years old, you can do more than what is prescribed for the elderly. In addition to walking, you can run and you can do bicycling;
  • Stop, or avoid, smoking.

Implement preventive measures with dispatch

The secret of successful preventive measures is to implement them as early as possible. The moment you realized that you have hypertension, and/or hyperlipidemia, and/or diabetes mellitus, you need to start implementing all the measures that have been enumerated in the preceding. The reason for this is that as you withhold doing the preventive actions, complications of the disease have been setting in. Physically, you will not feel it (them)! However, in the recesses of your different organs, such as your heart, kidneys, and blood vessels—be it small, medium, or large—structural destructions have been going on! By the time you want to do something, it is too late! Hence, act without delay!

(End of a series of 4)

Reference:

  1. Powell JT. Vascular damage from smoking: disease mechanisms at the arterial wall. Vasc Med. 1998;3(1):21-8.http://www.ncbi.nlm.nih.gov/pubmed/9666528.

What is endothelium?(Part 3)

Ways of preventing injury to the endothelium

Correcting yourhigh level of LDL-cholesterol

It has been reported that if the level of your LDL-cholesterol is very much above the normal ranges, the production of nitric oxide (NO) by your endotheliumwill be reduced[1]. When this takes place, the following complications will follow {other complications were discussed in Powertec (148)}:

Leukocyte adhesion[1]

As mentioned inPowertec (148), there are three types of cells in the blood. One type of these cells is called the white blood cells (WBCs). The WBCs are also called the leukocytes.When the production of NO is depressed, the adhesion of leukocytes to each other and to other substances is very much increased, conducive to the formation of clots and plugs that will obstruct the passageway of blood. In fact, this change in the property of the leukocytes will further accelerate the formation of the so-called plaques which attach themselves in the endothelium, leading to the narrowing of the tubular blood vessels.

Oxidative stress[1]

When the LDL-cholesterol is oxidized, the formation of the substance called caveolin-1 leads to decrease in the concentration of NO. This biochemical mechanism has been considered as the initial and primary cause of atherosclerosis. Since NO is known to prevent the oxidation of LDL-cholesterol, its availability in your blood should always be high. If its level is low and the level of yourLDL-cholesterol is high, the probability that the lipoprotein will be oxidized is high. Thus, the level of yourLDL-cholesterol should always be checked and controlled.

Drug of choice to correct your elevated LDL-cholesterol

To correct your high level of LDL-cholesterol, your medical doctor will prescribe you with a class of drug known as statins. Generic names belonging to this class of drug are rosuvastatin, atorvastatin, and fluvastatin—to mention some. Your medical doctor needs to prescribe you with this class of drug because statins have been found to not only lower your LDL-cholesterol but it has other beneficial effects for the improvement of your endothelial function[1].

 

Correcting your blood sugar

The other disease which could be injurious to your endothelium is diabetes mellitus (DM)[3]. If you have DM, your blood sugar is very much increased—also called hyperglycemia in medical parlance. As much as possible, when you have detected for the first time—with the help of your medical doctor—that your blood sugar is increased, that you have immediately taken action to correct it. If your medical doctor prescribed you with a certain drug, or set of drugs, you should have taken them regularly and religiously.If your blood sugar is left unchecked for a considerable number of years, it will enhance the attachment of plaques in your endothelium, leading to the development of atherosclerosis, hypertension, and other cardiovascular complications of diabetes. However, up to the present time, a detailed explanation, in terms of biochemical and cellular connections, between high blood glucose levels and complications in the cardiovascular structures remains incompletely understood [2].

While there has been no clear and detailed explanation on the link between hyperglycemia and endothelial dysfunction, it is known that in diabetic state there is an increased tendency for oxidative stress and oxidation of lipoproteins, especially the LDL-cholesterol[2]. As mentioned in the preceding, these two factors have been established as possible causes ofNO depletion. Hence, hyperglycemia has a big role in the destruction of endothelium, and there is a need to control it.

The simplest way to find out if your diabetes has more or less adversely affected the competence of your endothelium is to request for urinalysis. If protein, specifically albumin, is detected in your urine, it is possible that endothelial dysfunction has started[2], and you really need to control your blood sugar.

(To be continued)

References:

  1. Davigon J, Ganz, Peter. Atherosclerosis: evolving vascular biology and clinical implications, role of endothelial dysfunction in atherosclerosis. Circulation. 2004;109: III-27-III-32. doi: 10.1161/01.CIR. 0000131515.03336.f8.
  2. Hadi H, and Suwaidi J. Endothelial dysfunction in diabetes mellitus. Dovepress, Vascular Health and Risk Management. 2007;Dec; 3 (6):853-876.

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2350146/

  1. Preston RA, WencheJy, Jimenez, JJ, Mauro, LM, Horstman, LL, Valle, M, Aime, G, and Ahn, YS. Effects of severe hypertension on endothelial and platelet microparticles. Hypertension. 2003;41:211-217. doi: 10.1161/01.HYP.0000049760.15764.2D.

What is endothelium?(Part 2)

Ways of preventing injury to the endothelium

Controlling your high blood pressure

In the study of Preston, RA et al, titled “Effects of severe hypertension on endothelial and platelet microparticles”, two markers were used to find out if indeed hypertension injures the endothelium. One of these markers is called endothelial microparticles (EMP), and it   is released in the bloodstream when the lining of the endothelium is damaged or destroyed. In this study, investigators found out that EMP was very much elevated in the subjects with high blood pressure[1]. This shows that existing high blood pressure could continually and inevitably injure your endothelium, and there is an urgent need to control it.

There is therefore a need to see your medical doctor soonest to control your high blood pressure. If synthetic drugs will be prescribed to you, the drug of choice should be any one belonging to the class of angiotensin-converting enzyme (ACE) inhibitors, because this has been shown to contribute in the restoration of good endothelial function [2]. Examples of generic names belonging to this classare captopril, perindopril, imidapril, and many more. The generic names underthis class of drugs end in “pril”. Thus, if you have elevated level of LDL-cholesterol, in addition to having high blood pressure, ensure that yourmedical doctor prescribes you with any pill belonging to this class of anti-hypertensive drug.

Correcting yourhigh level of LDL-cholesterol

It has been reported that if the level of your LDL-cholesterol is very much above the normal ranges, that the production of nitric oxide (NO) by your endotheliumwill be reduced[2]. When this takes place, the following complications will follow:

Arteries constrict[2]

Since NO is responsible for the dilation of your blood vessels, the arteries in particular, its low level will lead to the elevation of your blood pressure, since the constriction of your arteries will predominate.

Platelets clump and attach themselves in the endothelial injury[2]

In your blood, there are three types of cells: (1) white blood cells, (2) red blood cells, and (3) platelets. The platelets play a significant role in the formation of blood clots which serve as plugs to any cut in your arm, legs, or in any external part of your body. Without platelets, it is difficult to stop any form of bleeding. When the level of NO in your blood is very much reduced, theplateletseasily form a clump and attach themselves at the injured site in your endothelium forming the so-called plaques which eventually block your arteries and make them inelastic.

This change in the properties of platelets was also shown in the study of Preston, RA et al as stated in the preceding wherein platelet microparticles (PMP) were elevated in subjects whose blood pressure was very high[1], indicating that platelets have changed in their biological behavior. It is possible that low NO initiates this change in the platelets, and severe hypertension aggravates it.

Smooth muscle cells grow in number and migrate[2]

Your smooth muscle cells which compose the walls of your blood vessels are well-behaved when the level of NO in your blood is normal. However, when its level decreases as a result of having elevated LDL-cholesterol in your blood, your smooth muscle cells become active and aggressive, such that they go out of their way and go to other places which normally are not their territories. They cannot be controlled, and they go astray! Consequently, even in the lining of your endothelium which is in intimate contact with your flowing blood, they grow and invade. These seemingly foreign invaders make your endothelium thicker and more inelastic leading to the development of atherosclerosis and hypertension.

(To be continued)

References:

  1. Preston RA, WencheJy, Jimenez, JJ, Mauro, LM, Horstman, LL, Valle, M, Aime, G, and Ahn, YS. Effects of severe hypertension on endothelial and platelet microparticles. Hypertension. 2003;41:211-217. doi: 10.1161/01.HYP.0000049760.15764.2D.
  2. Davigon J, Ganz, Peter. Atherosclerosis: evolving vascular biology and clinical implications, role of endothelial dysfunction in atherosclerosis. Circulation. 2004;109: III-27-III-32. doi:10.1161/01.CIR. 0000131515.03336.f8.