Full Lipid Panel
Full Lipid Panel — TC, LDL-C, HDL-C, Triglycerides
What it is
The standard lipid panel measures four values: total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and triglycerides (TG). Total cholesterol is the sum of all cholesterol in the blood — it is the broadest and least specific measure. LDL-C is conventionally calculated using the Friedewald equation (TC minus HDL-C minus triglycerides/5), though direct LDL-C measurement and the more accurate Martin-Hopkins equation are increasingly used. LDL-C estimates the cholesterol content of LDL particles — the principal atherogenic lipoprotein — but does not count the particles directly. HDL-C reflects the cholesterol associated with high-density lipoprotein particles; high HDL-C was long considered cardioprotective, though Mendelian randomisation studies have shown that genetically elevated HDL-C does not reduce cardiovascular events, challenging the causal interpretation. Triglycerides — the primary form of stored fat in circulation — reflect dietary fat intake, hepatic VLDL synthesis, and, in individuals with fasting hypertriglyceridaemia, remnant lipoprotein accumulation. Non-HDL-C (total cholesterol minus HDL-C) captures all atherogenic lipoprotein cholesterol and is increasingly preferred over LDL-C alone.
Why we measure it
The lipid panel is the foundation of conventional cardiovascular risk assessment and treatment monitoring. The Framingham Heart Study, the INTERHEART study, and decades of statin trial data have established LDL-C as a causal cardiovascular risk factor — every 1 mmol/L reduction in LDL-C produces approximately a 20% reduction in major cardiovascular events. For all the superiority of ApoB as a direct particle count (covered in its own library page), LDL-C remains the primary variable in cardiovascular risk calculators (Framingham, SCORE2, PCE), is the treatment target in most clinical guidelines, and is the language in which most clinicians and patients understand cardiovascular risk. The lipid panel and ApoB are therefore complementary, not redundant: LDL-C provides the clinical communication standard and the risk calculator input; ApoB provides a more accurate measure of actual atherogenic particle burden, particularly in individuals with hypertriglyceridaemia, metabolic syndrome, or insulin resistance — where LDL-C and ApoB are most likely to be discordant. Triglycerides provide additional metabolic information: fasting hypertriglyceridaemia above 2.0 mmol/L is associated with metabolic syndrome, insulin resistance, and pancreatitis risk; levels above 5.0 mmol/L carry significant pancreatitis risk and require treatment. The non-HDL-C value (not always printed on the panel but easily calculated) is the guideline-preferred secondary target in many national frameworks.
Why every 3 months
Fasting lipids — particularly LDL-C and triglycerides — respond to dietary changes, physical activity, weight change, and medications on a timescale of weeks to months. Triglycerides are particularly sensitive to recent carbohydrate and alcohol intake and must be measured fasting for reliable results. Quarterly measurement provides the resolution to track the lipid response to dietary intervention, medication titration, or body composition change — and to catch meaningful lipid deterioration before it compounds cardiovascular risk for a full year.
What movement means
The 2019 ESC/EAS guidelines and the AHA/ACC provide risk-stratified LDL-C targets. Non-HDL-C targets are typically 0.8 mmol/L higher than the corresponding LDL-C target. Triglyceride thresholds for clinical action are broadly consistent across guidelines.
LDL-C — Very High Risk Target
< 1.4 mmol/L (< 55 mg/dL)
ESC/EAS 2019 target for very high-risk individuals (established CVD, diabetes with organ damage, severe CKD, or 10-year CVD risk ≥ 10%). Also requires ≥ 50% reduction from baseline.
2019 ESC/EAS Guidelines for the Management of Dyslipidaemias — doi:10.1093/eurheartj/ehz455
LDL-C — High Risk Target
< 1.8 mmol/L (< 70 mg/dL)
ESC/EAS 2019 target for high-risk individuals (markedly elevated single risk factors, 10-year CVD risk 5–10%).
2019 ESC/EAS Guidelines for the Management of Dyslipidaemias — doi:10.1093/eurheartj/ehz455
Triglycerides — Elevated
1.7 – 5.6 mmol/L (150 – 500 mg/dL)
Mild to moderate hypertriglyceridaemia. Associated with metabolic syndrome, insulin resistance, and non-HDL-C elevation. Dietary modification (reduced refined carbohydrate and alcohol), weight loss, and omega-3 supplementation are effective first-line interventions.
ESC/EAS 2019 Guidelines; AHA Triglycerides Statement, Circulation, 2011
Triglycerides — Severely Elevated
> 5.6 mmol/L (> 500 mg/dL)
Severe hypertriglyceridaemia with significant pancreatitis risk. Requires urgent clinical management including dietary fat restriction, alcohol cessation, and pharmacotherapy (fibrates, omega-3 acids). Possible genetic cause (familial hypertriglyceridaemia, familial chylomicronaemia syndrome).
Berglund L et al., Journal of Clinical Endocrinology & Metabolism, 2012 — doi:10.1210/jc.2011-3213
References
- 1.
Mach F, Baigent C, Catapano AL, et al.. “2019 ESC/EAS Guidelines for the Management of Dyslipidaemias: Lipid Modification to Reduce Cardiovascular Risk.” European Heart Journal. 2020.
- 2.
Cholesterol Treatment Trialists' (CTT) Collaboration. “Efficacy and Safety of LDL-Lowering Therapy Among Men and Women: Meta-analysis of Individual Data from 174,000 Participants in 27 Randomised Trials.” The Lancet. 2015.
- 3.
Miller M, Stone NJ, Ballantyne C, et al.. “Triglycerides and Cardiovascular Disease: A Scientific Statement from the American Heart Association.” Circulation. 2011.
- 4.
Grundy SM, Stone NJ, Bailey AL, et al.. “2018 AHA/ACC/AACVPR/AAPA/ABC/ACPM/ADA/AGS/APhA/ASPC/NLA/PCNA Guideline on the Management of Blood Cholesterol.” Circulation. 2019.