koleszterint

Koleszterin, known as cholesterol in English, is a sterol lipid that is an essential component of animal cell membranes. It helps regulate membrane fluidity and serves as a precursor for several biologically important molecules, including steroid hormones, bile acids, and vitamin D.

In humans, cholesterol is obtained from two main sources: endogenous synthesis mainly in the liver and, to a lesser extent, dietary intake. It circulates in the bloodstream bound to lipoproteins, forming combinations such as LDL (low-density lipoprotein) and HDL (high-density lipoprotein). Very-low-density lipoproteins (VLDL) carry triglycerides and cholesterol from the liver to tissues.

Cholesterol is produced in the liver and packaged into lipoproteins for transport. LDL delivers cholesterol to cells, whereas HDL returns excess cholesterol to the liver for disposal in a process called reverse cholesterol transport. Imbalances in these lipoproteins can contribute to atherosclerosis, a condition characterized by the buildup of cholesterol-rich plaques in arteries.

Measurement and health implications: Blood cholesterol is usually measured as total cholesterol, LDL-C, HDL-C, and triglycerides. Reference ranges vary by guidelines; high LDL-C is a major risk factor for cardiovascular disease, while higher HDL-C is generally associated with lower risk. Diet, exercise, weight management, and, in some cases, lipid-lowering medications are used to manage cholesterol levels.

Dietary sources: Cholesterol occurs in animal products, but the dietary impact on blood cholesterol varies; saturated fats and trans fats influence liver cholesterol synthesis and blood levels more than cholesterol content in foods. Public health guidance emphasizes limiting saturated fat and refined carbohydrates, increasing fiber, and maintaining physical activity.