Concentration of which is inversely related to the risk of coronary hea disease

Role of LDL and HDL Recent studies have shown that atherogenic significance of the total cholesterol concentration must be viewed with restrictions. From numerous studies, it is now concluded that LDL is the carrier of 70 percent of total cholesterol and it transpos cholesterol to tissues and thus is most potential atherogenic agent. On the other hand, an increase of second cholesterol-rich class HDL is not associated with 'risk' at all. An inverse relation between CHD and HDL concentration has been found. A raised HDL concentration is beneficial and protective against CHD. This protective mechanism is explained by the following two mechanisms operating in parallel: * "Reverse transpo" of cholesterol from peripheral tissues into the Liver by way of HDL which thus reduces the intracellular cholesterol content (scavenging action of HDL). * Control of catabolism of TG rich lipoproteins. High HDL concentrations are associated with a faster elimination from the plasma of TG rich lipoproteins and their atherogenic intermediate.Ref: Textbook of Medical Biochemistry, Eighth Edition, Dr (Brig) MN Chatterjea, page no: 441