Biomarker
ApoA1 and ApoB/ApoA1 Ratio
Last updated Sat May 30 2026 00:00:00 GMT+0000 (Coordinated Universal Time)
Observational— Strongest lipid predictor in INTERHEART
What apoA1 measures
ApoA1 is the structural protein of HDL particles. Like apoB for LDL, each HDL particle contains apoA1 molecules, so apoA1 partially indexes HDL particle count.
The ratio
ApoB/apoA1 = atherogenic particles / protective particles. In INTERHEART (52-country MI case-control study), it was the single strongest lipid predictor of MI, outperforming all individual lipids.
Where it sits today
- ApoB alone now considered the primary modifiable target.
- ApoB/apoA1 ratio remains useful when both are measured.
- Some lipidologists prefer apoB alone for simplicity; others retain the ratio for risk stratification.
What raises apoA1
- Aerobic exercise.
- Moderate alcohol (with all the alcohol caveats).
- Weight loss.
- Niacin (rarely used due to side effects).
Related entries
References
- Yusuf, S. et al. Effect of potentially modifiable risk factors associated with myocardial infarction in 52 countries (INTERHEART). Lancet 364, 937–952 (2004).