Blood lipids
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Blood lipids (or blood fats) are
Fatty acids
Intestine intake
In any case, the concentration of blood fatty acids increase temporarily after a meal.
Cell uptake
After a meal, when the blood concentration of fatty acids rises, there is an increase in uptake of fatty acids in different cells of the body, mainly
. As a result, the blood concentration of fatty acid stabilizes again after a meal.Cell secretion
After a meal, some of the fatty acids taken up by the liver is converted into
In addition, when a long time has passed since the last meal, the concentration of fatty acids in the blood decreases, which triggers
In any case, also the fatty acids secreted from cells are anew taken up by other cells in the body, until entering fatty acid metabolism[clarification needed].
Cholesterol
The fate of cholesterol in the blood is highly determined by its constitution of
The 1987 report of
The average amount of blood cholesterol varies with age, typically rising gradually until one is about 60 years old. There appear to be seasonal variations in cholesterol levels in humans, more, on average, in winter.[3] These seasonal variations seem to be inversely linked to vitamin C intake.[4][5]
Intestine intake
In
In lipoproteins
Cholesterol is minimally soluble in water; it cannot dissolve and travel in the water-based bloodstream. Instead, it is transported in the bloodstream by lipoproteins that are water-soluble and carry cholesterol and triglycerides internally. The apolipoproteins forming the surface of the given lipoprotein particle determine from what cells cholesterol will be removed and to where it will be supplied.
The largest lipoproteins, which primarily transport fats from the
Standard chemistry panels typically include total triglyceride, LDL and HDL levels in the blood. Measuring the concentration of sd-LDL is expensive. However, since it is produced from VLDL, it can be inferred indirectly by estimating VLDL levels in the blood. That estimate is typically obtained by measuring triglyceride levels after at least eight hours of fasting, when chylomicrons have been totally removed from the blood by the liver. In the absence of chylomicrons, triglyceride levels have a much larger correlation with risk of cardiovascular diseases than total LDL levels.
Intestine excretion
After being transported to the liver by HDL, cholesterol is delivered to the intestines via bile production. However, 92-97% is reabsorbed in the intestines and recycled via enterohepatic circulation.
Cell uptake
Cholesterol circulates in the blood in
Cell secretion
In response to low blood cholesterol, different cells of the body, mainly in the
Related medical conditions
Hyperlipidemia
Hyperlipidemia is the presence of elevated or abnormal levels of lipids and/or lipoproteins in the blood.
Lipid and lipoprotein abnormalities are extremely common in the general population, and are regarded as a highly modifiable risk factor for cardiovascular disease. In addition, some forms may predispose to acute pancreatitis. One of the most clinically relevant lipid substances is cholesterol, especially on atherosclerosis and cardiovascular disease. The presence of high levels of cholesterol in the blood is called hypercholesterolemia.[6]
Hypertriglyceridemia
Hypercholesterolemia
Hypercholesterolemia is the presence of high levels of cholesterol in the blood.[6] It is not a disease but a metabolic derangement that can be secondary to many diseases and can contribute to many forms of disease, most notably cardiovascular disease. Familial hypercholesterolemia is a rare genetic disorder that can occur in families, where sufferers cannot properly metabolise cholesterol.
Hypocholesterolemia
Abnormally low levels of cholesterol are called hypocholesterolemia.