Atherogenic index of plasma calculator

The formula

AIP is the base-10 logarithm of triglycerides divided by HDL cholesterol (Dobiásová 2001), with both in molar units, mmol/L (Dobiásová 2006). If your lab reports mg/dL, as most US labs do, we first convert: triglycerides divided by 88.57 and HDL cholesterol divided by 38.67. For example, triglycerides of 150 mg/dL (1.69 mmol/L) and HDL of 40 mg/dL (1.03 mmol/L) give log10(1.69 ÷ 1.03) = 0.21.

Because of the logarithm, AIP is 0 when triglycerides and HDL are equal in mmol/L, negative when HDL is higher, and positive when triglycerides are higher. A ratio worked out from mg/dL numbers is on a different scale, so do not take the log of that. The plain ratio, in both units, is on the triglyceride to HDL ratio calculator.

What the studies found

In the 2001 study of 1,433 people from 35 groups, AIP correlated strongly (r = 0.803) with a lab measure of how fast cholesterol is processed in HDL, which reflects lipoprotein particle size. In 35 healthy people, a higher AIP went with smaller LDL particles (r = -0.776). The authors proposed the name "atherogenic index of plasma" and said it could be used as a marker of how atherogenic the blood is (Dobiásová 2001).

A 2006 summary of 8,394 people from 6 studies found that AIP went up with cardiovascular risk: cord blood, young children and healthy women had values below 0.1, while men and people with high blood pressure, diabetes or abnormal blood fats had values up to 0.4. Men had higher values than women. In a group having coronary angiography, AIP was the best predictor of positive findings among the lipid and risk factor measures in that model (Dobiásová 2006).

The suggested bands

From those data, the author suggested that AIP values of -0.3 to 0.1 are linked with low, 0.1 to 0.24 with medium, and above 0.24 with high cardiovascular risk (Dobiásová 2006). The calculator shows which band your value falls in. Please read them with care:

• They come from one research group's data and were not tested as a screening rule. No US guideline uses them.
• They do not give a chance of a heart attack or stroke. For that, use a heart risk calculator that also counts age, blood pressure, smoking and diabetes, such as the PREVENT heart risk calculator.
• The abstract does not say which band 0.1 and 0.24 belong to; we place both in the medium band.

Your triglycerides and HDL on their own

Each number in AIP has its own adult ranges, and those are what your clinician will look at. High triglycerides together with high LDL or low HDL cholesterol add to heart risk (MedlinePlus). See triglyceride levels for the triglyceride categories, and the LDL calculator for LDL, HDL and non-HDL ranges (MedlinePlus).

Related research indexes

Other research markers also use triglycerides. The TyG index pairs fasting triglycerides with fasting glucose as a marker of insulin resistance. The lipid accumulation product pairs them with waist size, and the visceral adiposity index adds waist, BMI and HDL. The cardiometabolic index multiplies the triglyceride-to-HDL ratio (in mg/dL) by the waist-to-height ratio. Remnant cholesterol is total cholesterol minus LDL and HDL. METS-IR combines triglycerides, HDL, fasting glucose and BMI as a marker of insulin resistance. None of these diagnoses a disease.

Getting the right numbers

Use triglycerides and HDL cholesterol from the same cholesterol test. You may be asked to fast for 9 to 12 hours before it (MedlinePlus). If you compare AIP over time, use results taken the same way each time, fasting or not.