[Biochemistry of risk factors for cardiovascular diseases in laboratory medicine]

This paper provides a broad overview of biochemical risk factors such cholesterol and triglyceride in atherosclerotic cardiovascular diseases from the perspective of clinical laboratory medicine, since additional knowledge is needed in the genetic, biochemical, clinical and epidemiological spheres. Lipids play an important role in cell metabolism. Fatty acids and triglycerides, their storage form, are a high energy metabolic fuel. Cholesterol and phospholipids are essential components of cell membranes and cholesterol is a precursor of steroids. Cholesterol is delivered to the liver either from the intestine following dietary intake or is transported from extrahepatic tissues. It is removed from the liver through incorporation into lipoproteins by conversion into bile acids, and by secretion into bile. Lipoproteins are transported between tissues and organs in the form of particles. Lipoproteins are metabolically inert and apolipoproteins involve enzyme activation and inhibition of lipoprotein lipase, hepatic triglyceride lipase and lecithin-cholesterol acyltransferase. There is an exchange of components between lipoprotein particles facilitated by the cholesterol ester transfer protein. Lipoprotein receptors control the rate of cellular uptake and degradation and indirectly the rate of de novo cholesterol synthesis and individual subclasses of major lipoprotein species as well as the apolipoproteins and even the products of oxidative damage inflicted on the lipoprotein. This paper summarizes the relevant physiological and clinical knowledge and reviews a series of very practical data that must be understood to accurately quantify laboratory parameters.