dromlakhani Interpret ALT for NAFLD screening
STEP 1 — Gather Information
Collect patient's sex, ALT level (U/L), and BMI percentile (or weight and height to calculate BMI percentile using CDC charts).
STEP 2 — Rule In / Rule Out
Is ALT >25 U/L for boys or >22 U/L for girls? If yes, rule in possible NAFLD; if no, rule out significant ALT elevation.
STEP 3 — Classify or Stratify
Classify ALT as normal (≤sex-specific threshold) or elevated (>sex-specific threshold); elevated ALT suggests possible NAFLD requiring further assessment.
STEP 4 — Decide
If ALT normal, continue routine obesity monitoring; if ALT elevated, obtain liver ultrasound and consider referral to gastroenterology/hepatology for NAFLD evaluation.
Clinical Guardrails / Mimics / Pitfalls
ALT elevation underestimates liver injury; NAFLD can be present with normal ALT; do not rely solely on ALT for diagnosis; exclude other causes of elevated ALT (viral hepatitis, medications, autoimmune hepatitis); avoid repeating ALT without clinical indication.
Concrete Clinical Example
A 12‑year‑old boy with BMI at the 98th percentile has ALT 30 U/L; exceeds the boy cutoff (>25 U/L), prompting liver ultrasound that shows hepatic steatosis, leading referral to hepatology for lifestyle‑focused management.
Source: Pediatric Obesity Assessment, Treatment, and Prevention: An Endocrine Society Clinical Practice Guideline, Endocrine Society, 2017, DOI:10.1210/jc.2016-2573
TODO: consider adding scripts/calc.py for the eso-pediatric-obesity-alt-interpretation calculator