Key Terms

The following definitions are provided for quick reference. Full context for each appears in the relevant section of the guide.

ApoB (Apolipoprotein B)

A protein present on the surface of every atherogenic lipoprotein particle, including LDL. Counting ApoB gives a direct measure of the number of artery-damaging particles in the blood, considered more mechanistically accurate than LDL cholesterol mass alone.

Atherogenic

Capable of contributing to atherosclerosis. Used throughout this guide to describe cholesterol-carrying particles — LDL and VLDL among them — that can lodge in artery walls and drive plaque formation.

Atherosclerosis

The slow, decades-long process by which cholesterol-carrying particles and inflammatory cells build up in artery walls, forming plaque that narrows and stiffens arteries — the underlying process behind most heart attacks and many strokes.

Familial Hypercholesterolemia (FH)

A genetic condition causing markedly elevated LDL cholesterol from birth. Affects an estimated 1 in 200 to 1 in 500 people, yet is diagnosed in fewer than 1% of cases in most countries.

HbA1c

A blood test reflecting average blood sugar over roughly the preceding three months. Below 5.7% is normal; 5.7–6.4% is prediabetes (reversible); 6.5% or above meets the threshold for diabetes.

HDL (High-Density Lipoprotein)

Often called "good cholesterol." Higher levels are associated with lower cardiovascular risk in observational data, but drugs designed to raise HDL directly have largely failed to reduce cardiovascular events — so it's treated more as a risk marker than a factor worth chasing upward on its own.

HOMA-IR

A calculation using fasting glucose and fasting insulin values to estimate insulin resistance, developed in 1985 and still widely used in research and clinical practice.

hs-CRP (High-Sensitivity C-Reactive Protein)

A blood marker of whole-body inflammation. Below 1.0 mg/L indicates lower cardiovascular risk; above 3.0 mg/L indicates higher risk, roughly double that of the lowest tier in underlying studies.

Insulin Resistance

A state in which cells respond less effectively to insulin, requiring the pancreas to produce more of it to keep blood sugar normal. Develops years before fasting glucose itself becomes abnormal, and is reversible at that early stage.

LDL (Low-Density Lipoprotein)

The main cholesterol-carrying particle measured on a standard lipid panel. Each LDL particle is atherogenic, meaning it can contribute to plaque formation in artery walls — ApoB counts these particles directly and is considered a more precise risk measure.

Lipoprotein(a) [Lp(a)]

A distinct, largely genetically determined lipoprotein particle that is an independent, causal cardiovascular risk factor. Not responsive to diet, exercise, or standard cholesterol-lowering medication — typically only needs testing once in a lifetime.

Metabolic Syndrome

A cluster of at least three of five specific risk factors — elevated waist circumference, triglycerides, blood pressure, and fasting glucose, plus low HDL — occurring together, which compound cardiovascular risk beyond what each factor would predict alone.

Statin

A class of cholesterol-lowering medication among the most rigorously trial-tested drugs in medicine, reducing cardiovascular event risk by roughly one-fifth per 1 mmol/L reduction in LDL cholesterol achieved.

Triglycerides

The form in which the body stores and transports fat in the blood. Particularly sensitive to refined carbohydrate and alcohol intake; a core component of metabolic syndrome when elevated.

Visceral Fat

Fat stored around the abdominal organs rather than under the skin. More metabolically active than subcutaneous fat, and more strongly linked to insulin resistance, inflammation, and cardiovascular risk. Waist circumference is a simple proxy measure for it.

VLDL (Very-Low-Density Lipoprotein)

A cholesterol- and triglyceride-carrying particle produced by the liver and, like LDL, atherogenic. Counted alongside LDL when ApoB measures total atherogenic particle number.