Skip to main content
MedCalcHub

Lipid and Cardiometabolic Markers

Published October 11, 2026 · Last updated October 11, 2026

The relationships among the laboratory lipid calculators — calculated LDL, non-HDL cholesterol, TC/HDL, ApoB/ApoA1, and the atherogenic index of plasma — and the metabolic markers TG/HDL, the TyG index, and metabolic syndrome criteria.

Lipid panels and metabolic markers are used to estimate cardiovascular risk, to set and monitor treatment targets, and to flag insulin resistance. The library contains a set of lipid calculations and a set of metabolic markers, and the numbers relate to one another through the lipoproteins they describe.

This guide groups those calculators and explains what each one measures.

Primary and secondary lipid measures

Calculated LDL estimates LDL cholesterol from a standard lipid panel by the Friedewald equation and is widely used for cardiovascular risk assessment and treatment targets, though it becomes unreliable at high triglyceride levels. Non-HDL cholesterol — total cholesterol minus HDL — captures all apolipoprotein B-containing particles and is used as a secondary target.

Ratios: TC/HDL, ApoB/ApoA1, and the atherogenic index of plasma

The total cholesterol to HDL ratio compares total cholesterol with the protective HDL fraction. The ApoB/ApoA1 ratio weighs atherogenic against anti-atherogenic lipoproteins and has been studied as a risk marker. The atherogenic index of plasma is the logarithmically transformed ratio of triglycerides to HDL cholesterol and reflects the balance of atherogenic and protective lipids.

Markers of insulin resistance: TG/HDL and the TyG index

The triglyceride to HDL ratio is a lipid-based marker of insulin resistance studied in overweight, non-diabetic adults. The triglyceride-glucose (TyG) index combines fasting triglycerides and fasting glucose as a surrogate for insulin resistance. Both are indirect markers rather than direct measures of insulin sensitivity.

Metabolic syndrome criteria

The metabolic syndrome calculator applies the updated NCEP ATP III criteria, which require several of a defined set of components including waist circumference, triglycerides, HDL cholesterol, blood pressure, and fasting glucose. It is a categorical definition rather than a continuous risk score.

Reading the markers together

These values are interpreted against treatment targets, fasting status, and the analytic method used. The Friedewald estimate in particular depends on an accurate triglyceride measurement, and all of the ratios are population-level markers rather than individual diagnoses. They support — but do not replace — formal cardiovascular risk scoring and clinical assessment.

Calculators in this guide

Related guides

References

  • Friedewald WT, Levy RI, Fredrickson DS. Estimation of the concentration of low-density lipoprotein cholesterol in plasma, without use of the preparative ultracentrifuge. Clin Chem. 1972;18(6):499-502.
  • Grundy SM, et al. 2018 AHA/ACC guideline on the management of blood cholesterol. Circulation. 2019;139(25):e1082-e1143.
  • Stampfer MJ, et al. A prospective study of cholesterol, apolipoproteins, and the risk of myocardial infarction. N Engl J Med. 1991;325(6):373-381.
  • Walldius G, Jungner I. The apoB/apoA-I ratio: a strong, new risk factor for cardiovascular disease and a target for lipid-lowering therapy — a review of the evidence. J Intern Med. 2006;259(5):493-519.
  • Dobiásová 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 (FERHDL). Clin Biochem. 2001;34(7):583-588.
  • McLaughlin T, Abbasi F, Cheal K, et al. Use of metabolic markers to identify overweight individuals who are insulin resistant. Ann Intern Med. 2003;139(10):802-809.
  • Simental-Mendía LE, Rodríguez-Morán M, Guerrero-Romero F. The product of fasting glucose and triglycerides as surrogate for identifying insulin resistance in apparently healthy subjects. Metab Syndr Relat Disord. 2008;6(4):299-304.
  • Grundy SM, et al. Diagnosis and management of the metabolic syndrome: an American Heart Association/National Heart, Lung, and Blood Institute scientific statement. Circulation. 2005;112(17):2735-2752.
  • Alberti KG, et al. Harmonizing the metabolic syndrome: a joint interim statement of the IDF Task Force on Epidemiology and Prevention; NHLBI; AHA; WHF; IAS; IASO. Circulation. 2009;120(16):1640-1645.