hsCRP (High-Sensitivity C-Reactive Protein)

What it is

C-reactive protein (CRP) is an acute-phase protein produced by the liver in response to IL-6. The “high-sensitivity” (hsCRP) assay measures concentrations in the range relevant to chronic low-grade inflammation (typically <10 mg/L), as opposed to the much higher levels seen in infection.

Why it matters

hsCRP is one of the best-validated biomarkers of cardiovascular risk independent of LDL cholesterol. It also tracks the chronic inflammation of aging (“inflammaging”). The CANTOS trial showed that lowering IL-1β-driven inflammation (and hsCRP) reduces cardiovascular events and lung cancer incidence in high-risk patients.

Typical interpretation

For cardiovascular risk stratification (in the absence of acute infection):

• <1 mg/L: low risk
• 1–3 mg/L: average risk
• >3 mg/L: high risk

Values bounce around with infections, dental issues, recent vigorous exercise, and surgery. A single high reading should be repeated weeks later before interpretation.

What moves it

• Down: weight loss, exercise training, smoking cessation, Mediterranean-pattern diet, statins, GLP-1 agonists, canakinumab, colchicine.
• Up: obesity (particularly visceral), smoking, periodontal disease, poor sleep, chronic infections, autoimmunity.

Related entries

See also: Chronic inflammation, GlycanAge, Mediterranean diet.