Unlike conventional lipid markers such as low-density lipoprotein cholesterol (LDL-C) and total cholesterol (TC), AIP serves as a composite measure of triglycerides (TG) and high-density lipoprotein cholesterol (HDL-C), offering enhanced sensitivity to lipid metabolism disorders and insulin resistance—pathophysiological states strongly linked to functional decline in older adults. This evidence concerns the gene AIP and Disorder of lipid metabolism.