For clinicians

HDL cholesterol

Unit
mg/dL

What is HDL cholesterol?

HDL cholesterol helps bring surplus cholesterol from your blood vessels back to the liver. That's why it's often called the 'tidying-up' cholesterol. A healthy HDL value is associated with more supple blood vessels. Here, slightly higher is usually more favourable, though the overall picture counts for more than this single number.

Clinical frame

HDL cholesterol is a risk marker, not a treatment target. HDL particles carry excess cholesterol from the vessel wall back to the liver and act as anti-inflammatory and antioxidant agents. A low value goes together with a higher cardiovascular risk and is a criterion of the metabolic syndrome [1] [2].

Yet HDL itself is not a causally protective factor: genetic studies show no effect of a higher HDL on coronary disease once triglycerides and ApoB are taken into account, and drugs that raise HDL did not prevent events. The low value mainly reflects the underlying profile: high triglycerides, insulin resistance and many ApoB particles [1] [3].

The relationship is not linear: below 40 mg/dL the risk rises, above 70 mg/dL more HDL gives no extra protection and very high values go together with higher mortality [3]. There are therefore no HDL targets. The gain lies in lifestyle and in lowering LDL, non-HDL and ApoB [2].

What moves this value?

Little movement, smoking and lots of fast sugars can lower it. Heredity also plays a role.

Regular movement, healthy fats (olive oil, nuts, oily fish) and quitting smoking lift this slowly but surely.

What this connects

Developed and reviewed with the Synapse medical advisory board.

References

  1. Pownall, H. J., Rosales, C., Gillard, B. K. & Gotto, A. M. High-density lipoproteins, reverse cholesterol transport and atherogenesis. Nat Rev Cardiol 18, 712–723 (2021). doi.org/10.1038/s41569-021-00538-z
  2. Visseren, F. L. J. et al. 2021 ESC Guidelines on cardiovascular disease prevention in clinical practice. Eur Heart J 42, 3227–3337 (2021). doi.org/10.1093/eurheartj/ehab484
  3. Razavi, A. C. et al. Does Elevated High-Density Lipoprotein Cholesterol Protect Against Cardiovascular Disease? J Clin Endocrinol Metab 109, 321–332 (2024). doi.org/10.1210/clinem/dgad406

The colour zones are personal: they depend on age, sex, risk and history, and appear in the patient's own report.

Insights to discuss with the patient, not a diagnostic instrument.