<prompt> The main component of hyperlipidemia constituting a major risk factor for atherosclerosis is-High densely lipoprotein HDL cholesterolIntermediate densely lipoprotein IDL cholesterol. Low densely lipoprotein LDL cholesterolVery low density lipoprotein VLDL cholesterol  <response>: Sodium fluoride Ref: Satyanarayana- 1st EdPg 255 In glycolysis, i.e. the pathway in which, glucose is utilized to form energy, Enolase is an enzyme which conves 2- phosphoglycerate to a high energy compound phosphoenolpyruvate. This enzyme requires Mg Mn is inhibited by fluoride. For blood glucose estimation, fluoride is added to the blood to prevent glycolysis by cells, so that the blood glucose is correctly estimated. 