**10. Sitosterolemia**

**6. HDL**

98 Cholesterol - Good, Bad and the Heart

effective in reverse cholesterol transport.

prevent oxidative modification of LDL.

**7. Lipoprotein (a)**

**8. Atherogenic dyslipidemia**

HDL is a molecule that is antioxidant, antiinflammatory, antiapoptotic and increases macrophage cholesterol excretion and endothelial healing. The removal of cholesterol from the body by the liver via HDL is called reverse cholesterol transport. ABCA-1, ABCG-1, and SR-B1 are

ApoA1 and ApoA2 are mainly found in the structure of HDL, and also HDL includes apoCs, ApoE, apoD, apoJ, lecithin-cholesterol acyltransferase (LCAT), serum paraoxonase (PON1) and platelet-activating factor acetylhydrolase (PAF-AH) molecules. Enzymes carried by HDL

Pentraxin 3 (PTX-3) in HDL controls leukocyte level. Defective PTX-3 was associated with

The association between low HDL and atherosclerotic cardiovascular disease was first shown by the Framingham study. Hypertension, diabetes mellitus, elevated total cholesterol, low HDL cholesterol, smoking, and age is considered as risk factor for coronary artery disease. The association between a low HDL cholesterol and atherosclerosis has been proven, but the increase in HDL has not been associated with a reduction in the incidence of atherosclerotic cardiovascular disease. Due to HDL being a molecule that prevents inflammation, some

Lipoprotein (a) (Lp (a)) consists of an LDL molecule bound to apolipoprotein (a). Lipoprotein (a) is structurally similar to plasminogen and is thought to play a role in atherothrombosis with antifibrinolytic properties. In a study with patients with normal LDL and elevated Lp(a) levels, it was determined that increased Lp(a) levels was associated with high cardiovascular risk [17]. Cholesterol ester transfer protein (CETP) is responsible for transferring cholesterol esters. CETP inhibitors are associated with increased HDL and decreased LDL levels. In the study conducted with anacetrapib, there was no significant difference in mortality despite a significant increase

in HDL and a significant decrease in non-HDL cholesterol compared to placebo [18].

In atherogenic dyslipidemia which is the result of an increase in triglyceride levels, triglyceride content is increased. The primary source of triglycerides is the VLDL. While LDL molecules are more easily oxidized, HDL molecules are more easily eliminated from the kidneys. Metabolic syndrome, type 2 diabetes, insulin resistance, abdominal obesity, and polycystic

In the case of atherogenic dyslipidemia, since chylomicrons have no effect on atherosclerosis, non-HDL cholesterol level is used rather than triglyceride level. Although levels of

large atherosclerotic plaques and higher level of inflammation [15, 16].

changes in HDL structure occur in chronic inflammatory processes.

ovary syndrome are associated with atherogenic dyslipidemia.

Sitosterol is a plant-derived molecule and its structure resembles cholesterol. Cytosterolemia is a progressive disease with an increase in the absorption and a decrease in biliary secretion of cholesterol and sitosterol molecules. Sitosterolemia is also called pseudohomozygous familial hyperlipidemia.

Recommendations for ESC 2016:


In a meta-analysis involving 90,056 patients, a reduction of 38.6 mg/dl in LDL was shown to be associated with a 20% reduction in major cardiovascular events [21]. In MIRACLE study: increased plaque stability with statin therapy reduces death, incidence of acute coronary syndrome and frequency of recurrent coronary ischemia [13]. In the PROVE IT TIMI-22 trial, atorvastatin 80 mg and pravastatin 40 mg were compared and it was determined that highdose statin therapy was more effective than low-dose statin therapy in reducing cardiovascular events. The 2017 ESC STEMI guidelines recommended that high-dose statin therapy was independent of cholesterol level. In the FOURIER study, it has been shown that the addition of the evolocumab in patient with LDL level ≥ 70 mg/dl, despite the use of high dose statin, is

Role of Cholesterol as a Risk Factor in Cardiovascular Diseases

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The coronary calcium score began to be used in the 1990s and the method was prepared by Agatson et al. Zero coronary calcium score has a high negative predictive value. It is the most commonly used method. In the 2016 ESC Guidelines for Cardiovascular Disease Prevention, the use of coronary calcium scoring has been proposed for predicting cardiovascular risk in

CARDIA study showed a correlation between elevated LDL or non-HDL cholesterol and

Peripheral arterial disease is a concept that involves diseases of arteries other than coronary arteries. It most commonly occurs as a result of atherosclerotic process. In addition to atherosclerosis, vasculitis, and injuries, trapping syndromes are also effective in the formation of peripheral arterial disease. Approximately one-third of the individuals with peripheral artery

associated with a decrease in cardiovascular deaths [22].

**Figure 1.** Structural differences between vulnerable and stable plaques.

individuals with a SCORE risk threshold of 5–10%.

**14. Peripheral arterial diseases and cholesterol**

**13. Coronary calcium score**

coronary calcium score [23].
