The Optimal DX Research Blog

Cardiovascular Biomarkers: Atherogenic Index of Plasma (AIP)

Written by ODX Research | Jul 29, 2024 10:15:00 PM

Optimal Takeaways

The atherogenic index of plasma (AIP) is a mathematical calculation based on blood levels of triglycerides and HDL-C. The AIP increases as triglycerides increase or HDL-C decreases. The AIP also reflects the size and atherogenicity of LDL particles and increases as the size of LDL decreases. Small dense LDLs are the most dangerous type as they become oxidized, lodge inside arteries, and promote inflammation and atherosclerosis.

An elevated AIP is associated with cardiovascular disease and events, dyslipidemia, insulin resistance, inflammation, and inflammatory disorders, including rheumatoid arthritis and severe pancreatitis. A low AIP suggests a decreased risk of these chronic conditions.

Standard Range: Below 0.11  
The ODX Range: Below 0.11    

Low AIP is associated with a lower risk of cardiovascular disease, obesity, diabetes, and dyslipidemia. A lower AIP is also associated with a higher intake of saturated fatty acids from milk and dairy products, calcium, phosphorus, and riboflavin (Shin 2022).

High AIP is associated with hypertriglyceridemia, low HDL-C, atherosclerosis, small dense LDL, oxidized cholesterol, cardiovascular risk, myocardial infarction (Chen 2023), arterial cholesterol crystal accumulation, (Huang 2023), major adverse cardiovascular events (MACE), especially in those with diabetes (Kim 2022), and coronary artery bypass graft (CABG) (Celik 2021).

Higher AIP may also be associated with arterial stiffness, coronary calcification, fatty liver, acne inversa, osteomyelitis, obesity, diabetes, reduced eGFR, oxidative stress, insulin resistance (Ulloque-Badaracco 2022), metabolic syndrome (Li 2021), higher uric acid, hypertension (Kammar-García 2020, Li 2021), and low serum vitamin D (Shin 2022).

High AIP is also associated with inflammation and inflammatory conditions, including rheumatoid arthritis (Dessie 2022) and severe pancreatitis (Cho 2020).

Overview

The atherogenic index of plasma (AIP) is the logarithm of the triglyceride to HDL cholesterol ratio. This ratio indirectly reflects the size of LDL particles and the presence of small, dense LDL cholesterol (sdLDL-C). Small dense LDL particles can more easily infiltrate the artery wall and lead to oxidation of sdLDL cholesterol. This process promotes and accelerates atherosclerosis, the leading cause of cardiovascular disease. The sdLDL-C has more significant atherogenic potential than normal LDL cholesterol due to its low affinity for LDL receptors, strong affinity for intima proteoglycans, slow clearance, and extended retention time. Meta-analysis suggests that the AIP, a reflection of sdLDL-C and atherosclerosis risk, independently predicts acute myocardial infarction (AMI). The strength of association increases when evaluated alongside LDL cholesterol levels (Chen 2023).

The AIP also reflects the competence of the reverse cholesterol transport process, which facilitates the recycling or disposal of excess cholesterol. An increased AIP may be associated with increased arterial cholesterol crystal accumulation and adipose tissue triglyceride accumulation. The AIP in the general population was evaluated in a retrospective study of 52,380 community residents 40 years of age or older from a single province in China. Higher AIP was associated with carotid artery atherosclerosis, increased carotid intima-media thickness, and atherosclerotic plaque. Respectively, those with the highest versus lowest AIP had mean triglycerides of 274 vs. 82 mg/dL (3.10 vs. 0.93 mmol/L); HDL-C 42 mg/dL vs. 64 mg/dL (1.09 vs. 1.66 mmol/L); LDL-C 104 vs. 99 mg/dL vs. 2.69 vs. 2.56 mmol/L), total cholesterol 189 vs. 178 mg/dL (4.9 vs. 4.6 mmol/L. The atherogenic index of plasma (AIP) was defined as the logarithm to the base 10 of the ratio of fasting plasma triglyceride (TG) (mg/dL) to high-density lipoprotein cholesterol (HDL-C) [log (TG/HDL-C)] (Huang 2023).

A higher AMI was associated with cardiometabolic risk in a retrospective study of 267 hospitalized AMI patients and 73 hospitalized controls. Subjects who had an AMI were significantly more likely to smoke and have diabetes and had significantly higher AIP, triglycerides, fasting glucose, and LDL-C and significantly lower HDL-C.

Mean values for those with an acute MI included triglycerides 167 versus 129 mg/dL (1.89 vs. 1.46 mmol/L) with no MI, HDL-C 41 vs. 74 mg/dL (1.06 vs. 1.92 mmol/L), and fasting glucose 145 vs. 109 mg/dL (8.05 vs. 6.03 mmol/L) (Chen 2023).

The AIP can be considered a modifiable risk factor as nutrition and lifestyle changes can help improve triglyceride and HDL-C levels and their underlying physiology. A 70-person cohort study observed significant improvements in AIP, triglycerides, and HDL-C, as well as hemoglobin A1C, fasting glucose, insulin, neutrophil-lymphocyte ratio, vitamin D, total WBCs, absolute neutrophils, RDW, ESR, fibrinogen, and hs-CRP with a 9-month program of health coaching, lifestyle changes, and nutrition intervention (Lewis 2020).

Higher AIP is associated with inflammatory conditions and markers, including high-sensitivity C-reactive protein (hs-CRP) and white blood cell counts. One cross-sectional study of 40 controls and 73 patients with rheumatoid arthritis, a systemic inflammatory disorder, found that an AIP above 0.21 was 4.99 times more likely to be associated with elevated hs-CRP of 2 mg/L or higher than those with an AIP below 0.21 (Dessie 2022). A prospective observational study of 323 pancreatitis patients found that higher AIP was significantly associated with severe versus non-severe pancreatitis. Elevated AIP was also associated with higher CRP, white blood cell counts, and BMI (Cho 2020).

Elevated AIP is considered an independent risk factor for cardiovascular disease. A population-based cohort study of 514,866 individuals participating in a national screening program found that those with the highest AIP had a 28% higher risk of major adverse cardiovascular events (MACE). Those with the highest AIP had a mean triglyceride level of 262.9 versus 71.1 mg/dL (2.97 vs. 0.80 mmol/L) and HDL-C of 42.3 vs. 68.1 mg/dL (1.09 vs. 1.76 mmol/L), compared to those with the lowest AIP. The higher AIP was also associated with significantly higher fasting glucose and total cholesterol and a lower estimated glomerular filtration rate (Kim 2022).

Severe coronary artery disease requiring coronary artery bypass graft (CABG) was associated with significantly higher AIP, mean triglyceride levels of 194 vs. 154 mg/dL (2.19 vs. 1.74 mmol/L), and HDL-C of 41.26 vs. 47.25 mg/dL (1.07 vs. 1.22 mmol/L). Those requiring CABG also had a significantly higher incidence of peripheral artery disease, COPD, and diabetes (Celik 2021).

Research suggests that an AIP above 0.24 is associated with a high risk of cardiovascular disease, AIP of 0.10 - 0.24 represents medium risk, and an AIP below 0.1 represents the lowest CVD risk (Dobiasova 2006, Dobiášová 2017, Li 2021).

References

Çelik, Ersin et al. “The Effect of Untraditional Lipid Parameters in the Development of Coronary Artery Disease: Atherogenic Index of Plasma, Atherogenic Coefficient and Lipoprotein Combined Index.” Journal of the Saudi Heart Association vol. 33,3 244-250. 20 Sep. 2021, doi:10.37616/2212-5043.1266

Chen, Min et al. “Predictive value of atherogenic index of plasma and atherogenic index of plasma combined with low-density lipoprotein cholesterol for the risk of acute myocardial infarction.” Frontiers in cardiovascular medicine vol. 10 1117362. 26 May. 2023, doi:10.3389/fcvm.2023.1117362

Dobiásová, M. “AIP--aterogenní index plazmy jako významný prediktor kardiovaskulárního rizika: od výzkumu do praxe” [AIP--atherogenic index of plasma as a significant predictor of cardiovascular risk: from research to practice]. Vnitrni lekarstvi vol. 52,1 (2006): 64-71.

Dobiášová, M. “Atherogenic impact of lecithin-cholesterol acyltransferase and its relation to cholesterol esterification rate in HDL (FER(HDL)) and AIP [log(TG/HDL-C)] biomarkers: the butterfly effect?.” Physiological research vol. 66,2 (2017): 193-203. doi:10.33549/physiolres.933621

Huang, Qin et al. “The atherogenic index of plasma and carotid atherosclerosis in a community population: a population-based cohort study in China.” Cardiovascular diabetology vol. 22,1 125. 27 May. 2023, doi:10.1186/s12933-023-01839-y

Kammar-García, Ashuin et al. “Atherogenic index of plasma as a marker of cardiovascular risk factors in Mexicans aged 18 to 22 years.” Proceedings (Baylor University. Medical Center) vol. 34,1 22-27. 21 Aug. 2020, doi:10.1080/08998280.2020.1799479

Kim, Si Hyoung et al. “Association of the atherogenic index of plasma with cardiovascular risk beyond the traditional risk factors: a nationwide population-based cohort study.” Cardiovascular diabetology vol. 21,1 81. 22 May. 2022, doi:10.1186/s12933-022-01522-8

Lewis, Thomas J et al. “Reduction in Chronic Disease Risk and Burden in a 70-Individual Cohort Through Modification of Health Behaviors.” Cureus vol. 12,8 e10039. 26 Aug. 2020, doi:10.7759/cureus.10039

Li, Yen-Wei et al. “Atherogenic index of plasma as predictors for metabolic syndrome, hypertension and diabetes mellitus in Taiwan citizens: a 9-year longitudinal study.” Scientific reports vol. 11,1 9900. 10 May. 2021, doi:10.1038/s41598-021-89307-z

Shin, Hye Ran et al. “Atherogenic Index of Plasma and Its Association with Risk Factors of Coronary Artery Disease and Nutrient Intake in Korean Adult Men: The 2013-2014 KNHANES.” Nutrients vol. 14,5 1071. 3 Mar. 2022, doi:10.3390/nu14051071

Ulloque-Badaracco, Juan R et al. “Atherogenic index of plasma and coronary artery disease: A systematic review.” Open medicine (Warsaw, Poland) vol. 17,1 1915-1926. 6 Dec. 2022, doi:10.1515/med-2022-0590