Atherogenic index of plasma (AIP)

The Atherogenic Index of Plasma (AIP) is a mathematical marker used to predict the risk of atherosclerosis and cardiovascular disease, calculated as the logarithmically transformed ratio of molar concentrations of triglycerides to high-density lipoprotein cholesterol [log10(TG/HDL-C)]. It serves as a surrogate measure for lipoprotein particle size, specifically correlating strongly with the presence of small dense low-density lipoprotein (sdLDL) particles, which are highly pro-atherogenic. Values of AIP below 0.11 are generally associated with low cardiovascular risk, while values above 0.24 indicate high risk. Because AIP is a calculated ratio and not a distinct protein or receptor, it is not a therapeutic target in the traditional sense; instead, it is a clinical biomarker used to assess the efficacy of lipid-lowering therapies. Drugs such as statins, fibrates, and niacin affect the AIP by modulating the individual lipid fractions that comprise the index. In clinical practice, AIP is often considered a more sensitive predictor of coronary artery disease than individual lipid parameters because it reflects the complex balance between atherogenic and protective lipoproteins.

Other names

Log(TG/HDL-C) ratioAtherogenic indexPlasma atherogenic index

Drugs do not target the AIP directly; rather, they modulate the components of the index by inhibiting HMG-CoA reductase to lower LDL and triglycerides, activating PPAR-alpha to lower triglycerides and raise HDL-C, or inhibiting CETP to increase HDL-C levels, thereby lowering the calculated AIP value.