What does it mean?
Low cholesterol, termed hypocholesterolemia in medical terms, is a metabolic disorder characterized by low concentrations of cholesterol in the blood. While the opposite problem, defined as hypercholesterolemia, is quite common in the inhabitants of industrialized countries due to the well-known food excesses, particularly low cholesterol levels are recorded above all in the regions suffering from malnutrition.
Causes
Generally speaking, we talk about hypocholesterolemia when blood cholesterol levels fall below 130 mg / dl.
Among the many causes that lead to the decrease in blood cholesterol, we recall hyperthyroidism (thyroid hyperactivity), liver diseases (such as cirrhosis, hepatitis and liver failure), malabsorption syndrome, celiac disease, malnutrition, abetalipoproteinemia and hypobetalipoproteinemia (two rare genetic diseases), Smith-Lemli-Opitz syndrome, leukemias, other blood disorders and some cancers (such as the brain one). Then there is a "false" or iatrogenic hypocholesterolemia, in which low cholesterol levels are due to taking certain drugs, such as statins used in the presence of high cholesterol.
Health risks
In the human body, cholesterol performs numerous and important functions. Let's see them briefly.
Together with phospholipids it is present in the cell membrane and in the membranes of the intracellular organelles of all cells, and is therefore responsible for their physical integrity and permeability.
A certain amount of cholesterol is converted to cholic acid, which in turn is conjugated with other substances to form bile salts, necessary for the absorption and digestion of fats.
Cholesterol is used - especially in the adrenal glands, ovaries and testicles - to synthesize very important hormones, such as adrenal cortical hormones, progesterone, estrogens and androgens. Vitamin D is also derived from cholesterol, which is necessary for the correct mineralization of the bones.
Finally, in the most superficial layers of the skin, cholesterol - and in particular one of its precursors, squalene - prevents the evaporation of water, giving it resistance to several chemical agents.
Very low cholesterol levels are associated with increased mortality, mainly due to depression, cancer, and respiratory diseases; it is not clear, however, whether hypocholesterolemia is somehow responsible for these diseases or simply represents a consequence, thus acting as a simple marker of poor health and not as a risk factor. Malignant neoplasms, for example, cause a decrease in cholesterol levels.
Low cholesterol levels are associated with impaired health and functional decline especially in elderly and hospitalized patients.
