135 Atherogenic index of plasma (AIP)

Atherogenic index of plasma, log(TG/HDL-C): calculation, proposed risk categories and link with small dense LDL.

The atherogenic index of plasma (AIP) is the logarithm of the ratio of triglycerides to HDL cholesterol, both in mmol/L. It was proposed by Dobiášová and Frohlich as a simple marker of the atherogenic lipid profile. AIP correlates with the size of LDL and HDL particles and with the esterification rate of HDL cholesterol: higher values indicate a predominance of small, dense, more atherogenic LDL particles. It rises with obesity, insulin resistance, type 2 diabetes and metabolic syndrome.

Lipid indicesSmall dense LDLMetabolic syndrome

Formulalog₁₀(TG / HDL-C), mmol/L

Low risk−0.3 to 0.1

Intermediate0.1 to 0.24

High risk> 0.24

How it is calculated

AIP = log₁₀ [ TG (mmol/L) / HDL-C (mmol/L) ]

Example: triglycerides 1.5 mmol/L and HDL-C 1.3 mmol/L give TG/HDL-C = 1.15 and AIP = log₁₀ 1.15 ≈ 0.06. With TG 3.0 and HDL-C 0.9 mmol/L, the ratio is 3.3 and AIP ≈ 0.52. If values are in mg/dL, convert them first (TG ÷ 88.6, HDL-C ÷ 38.67). Otherwise the result will be shifted.

Figure 1. Risk categories of AIP proposed by Dobiášová. They are research-based cut-offs, not guideline treatment targets.

Clinical significance

AIP combines two components of "atherogenic dyslipidaemia": high triglycerides and low HDL-C. In many observational studies higher AIP was associated with coronary artery disease, metabolic syndrome, fatty liver disease and obesity, and it predicted risk beyond LDL-C in some populations. AIP is not included as a treatment target in the European or American guidelines. It is an additional indicator that helps interpret the lipid profile, especially when LDL-C looks normal.

What raises and lowers AIP

Raises AIP

Abdominal obesity, insulin resistance, diabetes, excess sugar and alcohol, smoking, inactivity, hypothyroidism.

Lowers AIP

Weight loss, regular aerobic exercise, less sugar and refined carbohydrates, limiting alcohol, good glucose control; fibrates and omega-3 fatty acids lower triglycerides.

What to do

A high AIP is a reason to look at the whole metabolic picture: waist size, blood pressure, blood glucose and HbA1c, and liver tests. Discuss it with your doctor together with LDL-C and overall cardiovascular risk.

References

Dobiášová M, Frohlich J. The plasma parameter log (TG/HDL-C) as an atherogenic index: correlation with lipoprotein particle size and esterification rate in apoB-lipoprotein-depleted plasma (FER_HDL). Clin Biochem. 2001;34(7):583–588. doi:10.1016/S0009-9120(01)00263-6
Dobiášová M. AIP — atherogenic index of plasma as a significant predictor of cardiovascular risk: from research to practice. Vnitr Lek. 2006;52(1):64–71. PMID: 16526201
Mach F, Baigent C, Catapano AL, et al. 2019 ESC/EAS Guidelines for the management of dyslipidaemias: lipid modification to reduce cardiovascular risk. Eur Heart J. 2020;41(1):111–188. doi:10.1093/eurheartj/ehz455

This article is for general information and does not replace a consultation with a doctor. Laboratory results must be interpreted by a physician together with symptoms and other tests.

Published on 18 April 2024

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