AST to Platelet Ratio Index
Liver Function marker
APRI
AST to Platelet Ratio Index
Calculated fibrosis index combining AST and platelet count. Used as a non-invasive screen for significant liver fibrosis and cirrhosis without a biopsy.
PED Notes
Heavily confounded in lifters. AST is released from skeletal muscle after heavy or eccentric training, so APRI is inflated by exercise alone with a completely normal liver. Interpret only alongside GGT (which does not rise from muscle damage) and ideally recalculate from an AST drawn after 5-7 days of no training. Genuine elevation matters most in users of oral 17-alpha-alkylated compounds, where cholestatic injury and, rarely, peliosis hepatis or hepatic adenoma are the concern. Chronic AAS use also lowers platelets in some users, which raises APRI from the denominator side.
When high
First step: rule out the muscle artefact
- Recheck AST after 5-7 days fully rested -- exercise-driven AST normalises quickly; liver-driven AST does not
- Check GGT alongside -- GGT is not released from skeletal muscle, so a high APRI with a normal GGT points strongly at muscle, not liver
- Check the AST/ALT pattern -- muscle sources push AST above ALT with a normal ALT; hepatocellular injury usually raises both
- Confirm the platelet count is real -- a clumped or diluted sample inflates APRI from the denominator
If APRI stays elevated when rested (>0.7, and especially >1.0):
- Stop all 17-alpha-alkylated orals -- anadrol, dianabol, winstrol, superdrol, and similar are the highest-risk group
- Transient elastography (FibroScan) -- non-invasive and far more specific than APRI; the appropriate next test rather than repeating bloods indefinitely
- Screen for other causes -- hepatitis B and C serology, ferritin and transferrin saturation for haemochromatosis, autoimmune screen, alcohol history
- Hepatic ultrasound -- looks for steatosis, focal lesions, and portal hypertension
Supportive options while investigating:
- TUDCA -- 500-1000mg/day; bile acid that reduces cholestatic injury; the most evidence-supported option for AAS cholestasis
- NAC -- 600-1200mg/day; glutathione precursor
- Neither substitutes for stopping the offending compound, and neither has been shown to reverse established fibrosis
Physician oversight is required for any persistently elevated APRI. A value above 1.0 in a rested athlete warrants hepatology referral, not self-management.
Interpretation thresholds (from the validation literature):
- <0.5 -- significant fibrosis effectively excluded
- 0.5-1.0 -- indeterminate; recheck rested, correlate with GGT and elastography
- >1.0 -- suggestive of cirrhosis, sensitivity 76% and specificity 72% in chronic hepatitis C
- These cut-offs were derived in viral hepatitis cohorts, not in athletes, so they are a screening aid rather than a diagnosis.
History Chart
Reading History
Frequently Asked Questions
Reference Ranges
Standard Range
VitalMetrics Range