Our body is a highly complex organism, formed by diverse systems that act together to allow our survival.

These systems interact with each other, often being interdependent, in such a way that the functioning of some affects or even allows others to perform their function. This is what happens with the vascular system, which allows blood to be carried from the heart to the organs and vice versa, in such a way that it can bring oxygen and nutrients to the cells of the body.

However, the vascular system can suffer some alterations that can hinder the correct functioning of the body, such as atherosclerosis. This problem is linked to our body’s cholesterol levels, and being able to know the risk of suffering from it can save our lives. One way to do this is to calculate the atherogenic index , which we will talk about throughout this article.

What is the atherogenic index?

The atherogenic index is a mathematical formula formulated in order to be able to calculate a person’s risk of suffering from atherosclerosis from their blood cholesterol levels. Thus, and based on certain values of this index which are taken as criteria for this, we can determine or predict the probability that the person’s arteries will end up being obstructed if no modification is made to their levels.

The atherogenic index, also called Castelli’s index based on the director of the study that gave rise to the formula (William Castelli), expresses at a mathematical level the relationship or proportion between total cholesterol levels and the levels of high-density lipoprotein or HDL (also popularly known as good cholesterol), in milligrams. Specifically, the general formula is as follows: Atherogenic index = Total cholesterol/HDL cholesterol.

However, even though this is the most commonly considered atherogenic index, it should actually be noted that different atherogenic indexes could be discussed: there are different formulas that allow us to obtain an index with which to assess the risk of the appearance of atherosclerosis . In addition to the relationship between total cholesterol and good cholesterol, we can calculate the relationship between bad and good cholesterol (LDL/HDL) or the relationship between triglycerides and HDL cholesterol.

Interpretation and reference values

The interpretation of the results of the atherogenic index (considering the first of the formulas mentioned) should take into account that the presence of high values of HDL cholesterol will cause us to have a relatively low index , which implies less risk of obstruction and heart problems.

Conversely, proportionally lower levels of HDL cholesterol than the rest will cause or make more likely the presence of heart problems, assuming that low-density lipoprotein bad cholesterol will be more prevalent in the total cholesterol. The resulting rate will be low.

With regard to the values, we can find that as reference values there is a minimum risk of atherosclerosis when we obtain an index of 3.5 or less. The risk becomes moderate when the values are between 3.5 and 4.5, at which point it becomes necessary to start controlling cholesterol and it would be useful to carry out prevention strategies. Finally, values greater than 4.5 represent a maximum risk of atherosclerosis, that is, there is a very high risk of suffering from some type of coronary disease. It is necessary to establish measures to lower cholesterol and to monitor these levels.

These levels should also take into account the sex of the person in question : the high risk is in men in values of 4.5-5 or more, while in women we can consider as high risk any value above 4.

Atherosclerosis and its risks

The atherogenic index serves, as we have said, to visualize through numerical values the risk of suffering from atherosclerosis.

Atherosclerosis is a disease or vascular disorder characterized by the accumulation of cholesterol particles and lipids on the walls of the arteries . The walls of the vessels are lined, so there is less room for blood to flow and the risk of blockage increases. It is also common for the walls of the arteries to become hard and less flexible, which together with the increase in blood pressure (because the passage of blood is narrower) can lead to rupture of the vessels and bleeding.

Atherosclerosis is a relatively common condition but if left unchecked it can be very dangerous and lead to death . It is a disease that can lead to bleeding, thrombosis or stroke and can also cause severe heart problems. The brain, kidneys or liver can also be greatly affected, as it can lead to cell death. One of the biggest risks of this disease is that it does not really generate symptoms until it causes complications, so treatment can be delayed.

Fortunately this risk can be controlled by reducing bad cholesterol or raising good cholesterol , controlling diet, weight or exercise. Risk factors must also be controlled and taken into account: age, diabetes, smoking, hypertension, sedentary lifestyle or the presence of a family history are risk factors to be assessed. Some of them, such as sedentary lifestyle, hypertension, diabetes or tobacco use can be controlled to reduce cholesterol levels.

Bibliographic references:

• Herrera-Villalobos, J.E., Sil Jaimes, P.A. Pinal GonzÃ¡lez, F.M., GarduÃ±o AlanÃ­s, A.; SantamarÃ­a Benhumea, A.M. and Rueda Villalpando, J.P. (2012). Atherogenic index as a risk factor for preeclampsia syndrome. CorSalud; 4 (4): 261-265.
• LÃ³pez, A.A.; Rivero, Y.I.; Vicente, T.; Gil, M.; TomÃ¡s, M. and Riutord, B. (2015). Atherogenic indices in workers from different labour sectors in the Spanish Mediterranean area. Clinical and Research in Arteriosclerosis, 27 (3): 118-128.
• NÃºÃ±ez, M.V.; Ferrer, M.; Meneau, T.X.; CabalÃ©, B.; GÃ³mez, O. and Miguelez, R. (2007). Atherogenic risk factors in the 19-39 year-old population of 2 family doctor’s offices. Rev Cubana Invest Biomed, 26(2).