SGPT (ALT)
What it measures
Reported in U/L, which some labs write as IU/L — the same unit under two names, not a conversion. What is being measured is enzyme activity rather than a concentration, which is why there is no mg or mmol form of it. Because the enzyme sits mostly inside liver cells, a raised SGPT points at the liver more specifically than most other numbers on a liver panel, which is why it is usually read alongside SGOT rather than alone.
Why there is no universal normal for SGPT
Enzyme results are measurements of activity, not concentration, and that activity depends on the method and the temperature the assay runs at. Two labs using different methods can return genuinely different numbers from the same sample, which is why the upper limit printed beside your result varies from lab to lab and why no single national figure exists to quote. The same applies to SGOT, alkaline phosphatase and GGT. Read the value against the range in the column next to it, and the pattern across the panel rather than any one enzyme.
Reading it in a different unit
This lab reports SGPT (ALT) in u/l. Reports from other labs — especially ones using European or US-style formatting — sometimes use a different unit for the same measurement. The relationship between them:
iu/l is the same value as u/l under a different name — nothing to calculate, just a different label on the same number.
| Reported unit | How it relates to u/l |
|---|---|
| ukat/l | u/l = ukat/l × 60 |
Unit conversions verified against published molar masses and LOINC definitions. This is not a diagnostic reference — the normal range for any test is set by the laboratory that ran it and printed on your report.
Why this matters for tracking a trend
A value plotted next to earlier results only tells you something if every point is on the same scale. Two readings of the same test from two different labs, in two different units, can look like a dramatic change when nothing about your actual result changed — only the unit did. Converting to one scale before comparing is what keeps a trend line honest.
LOINC codes for this test: 1742-6, 1743-4.
General information about laboratory measurement, not medical advice. Whether a specific result is normal for you depends on your lab's reference range, your history and your doctor's judgement — not on this page.