The difference between apolipoprotein a1 and lipoprotein a is that they represent different meanings. Elevation of the former has an inhibitory effect on atherosclerosis, while the latter promotes the development of atherosclerosis. Apo a1 is the main component of HDL, and an increase in its value reflects the level of HDL in the body, which has an inhibitory effect on the development of atherosclerosis. Lipoprotein a is a lipoprotein synthesized by the liver that inhibits the dissolution of blood clots in the body. Elevated levels of lipoprotein a increase and promote the incidence of atherosclerosis, which is an independent risk factor for cardiovascular and cerebrovascular diseases. Apolipoprotein a1 and lipoprotein a have completely different meanings in the body, clinical laboratory tests, pay attention to the changes in the various indicators, if necessary, under the guidance of a physician to carry out targeted treatment.