PFLPhysiological Fitness Landscape

Biomarkers · Liver & Nutritional

Alanine Aminotransferase (ALT)

Higher values go with lower risk of death. In NHANES 1999–2018 with linked mortality to 2019, each standard deviation above average goes with 10% lower risk of death. We found the same pattern in NHANES

ALT and risk of death

NHANES, our fit with 95% CIPublished curve

Published curve higher than the NHANES fitNHANES fit higher

Risk of death relative to each curve's own reference value, so the two curves need not cross 1 at the same point. The dotted vertical line marks the NHANES median.

Risk of death per SD (NHANES)0.90×95% CI 0.87–0.93 · 48,280 adults, 7,007 deaths
Published risk of death0.82×extreme thirds (top vs bottom third) of baseline ALT, North American populations (95% CI 0.78–0.86) · Meta-analysis of 19 prospective general-population cohorts (>9.24 million participants, 242,953 deaths); ALT estimate for North American cohorts
Value of the measurement+0.021gain in concordance within age bands; rank 18 of 56 · all tests

ALT by age and sex

Each bar runs from the 5th to the 95th percentile, the darker part from the 25th to the 75th, and the tick is the median. Not a reference range or a target.

The percentiles as a table
Each row is one sex and age band: the values below which 5%, 25%, 50%, 75% and 95% of people fall (U/L), from the survey named in the row. Not a reference range or a target.
SexAge5th25thMedian75th95thnCycle / source
All20-399.0013.018.028.060.01,431NHANES 2017-2018
All40-5910.014.020.029.048.01,547NHANES 2017-2018
All60+9.0413.017.023.040.01,890NHANES 2017-2018
Allall9.0013.018.026.051.04,868NHANES 2017-2018
Men20-3911.016.023.035.077.0684NHANES 2017-2018
Men40-5913.019.025.033.058.0722NHANES 2017-2018
Men60+10.014.018.026.047.0958NHANES 2017-2018
Menall11.016.022.032.061.02,364NHANES 2017-2018
Women20-398.0011.014.019.047.0747NHANES 2017-2018
Women40-599.0013.017.023.043.0825NHANES 2017-2018
Women60+9.0013.016.021.033.1932NHANES 2017-2018
Womenall9.0012.015.021.041.02,504NHANES 2017-2018

What studies found when this marker was changed

They describe what happened in those study groups, not a recommendation. See all catalogued interventions.

Measured changes in ALT, study by study

4 effects with a numeric size, each from one study arm: the dot is the reported change, the line its 95% interval where one was given. Green points move the marker the way lower risk of death lies; amber the other way. Study results in the groups studied, not predictions for a person.

Each row is one study: what was changed, the effect it reported on this marker, and the source.
TypeInterventionReported effectEvidenceSource
dietIntensive weight-loss interventions (mainly behavioural programmes; also drugs or surgery) in adults with NAFLDALT -9.81 U/L (95% CI -13.12 to -6.50) vs no or lower-intensity intervention, with weight change -3.61 kg (median 6 months)meta-analysisKoutoukidis DA, et al. Association of Weight Loss Interventions With Changes in…
dietDaily coffee consumption (≥3 cups/day)≥3 cups/day coffee associated with lower odds of abnormal ALT (OR 0.75; 95% CI 0.63-0.89) vs none (NHANES, n = 27,793)cross-sectionalXiao Q, et al. Inverse associations of total and decaffeinated coffee with…
dietProvided household diet restricting free sugars to <3% of daily calories for 8 weeks in adolescent boys with histologically confirmed NAFLDGeometric mean ALT fell from 103 to 61 U/L vs 82 to 75 U/L on usual diet; adjusted ratio of geometric means 0.65 (95% CI 0.53 to 0.81) at week 8RCTSchwimmer JB, et al. JAMA. 2019. Effect of a Low Free Sugar Diet vs Usual Diet…
pharmacologicPioglitazone 30 mg/day in non-diabetic NASHSerum ALT reduced vs placebo over 96 weeks (P<0.001; effect size not reported)RCTSanyal AJ, et al. N Engl J Med. 2010;362:1675-1685.
pharmacologicCotadutide 600 ug subcutaneously once daily for 19 weeks in adults with biopsy-proven non-cirrhotic MASH with fibrosis (PROXYMO)Reduces ALT by 23.5 U/L (95% CI -47.1 to -1.8) vs placebo at 19 weeks (600 ug dose)RCTShankar SS, et al. Clinical gastroenterology and hepatology : the official…
supplementOral vitamin E 298-1000 IU daily for 2-24 months in people with non-alcoholic fatty liver disease, usually alongside lifestyle/low-calorie diet adviceLowers ALT by 9.29 U/L (95% CI -13.69 to -4.89) vs placebo/no intervention (follow-up 2 months to 24 months)meta-analysisWen H, et al. The Cochrane database of systematic reviews. 2024. Vitamin E for…

Things that worsen it

Each row is one study: what was changed, the effect it reported on this marker, and the source.
TypeCondition or exposureReported effectEvidenceSource
dietExcessive chronic ethanol consumptionALT significantly higher in heavy drinkers than moderate drinkers or abstainers; 39% of heavy drinkers had elevated ALTcross-sectionalAlatalo P, et al. Biomarkers of liver status in heavy drinkers, moderate…
pharmacologicAcetaminophen overdose with hepatotoxicityAcetaminophen overdose with toxicity produced ALT ≥ 1000 IU/L, correlating with APAP-protein adducts (r = 0.93)cohortCurry SC, et al. The Relationship Between Circulating Acetaminophen-Protein…

What else moves this marker

They describe those study groups, not an individual, and an association is not a cause.

Diseases and conditions

Each row is one study: what it compared and the change it reported in this marker.
WhatEffect on the markerComparison · populationSource
↑ Dengue progressing to severe disease · ALT during first 4 days of illness, patients who progressed to severe dengue vs those who did notSMD +0.73 (95% CI 0.36 to 1.09)progressors to severe dengue vs non-progressors, febrile phase · Dengue patients (children and adults), 122 articlesmeta analysis · PMID 33640077

Sources

Map Alanine Aminotransferase (ALT) against another biomarker.

Related markers: Albumin:Globulin Ratio (A/G) · Alkaline Phosphatase (ALP) · Aspartate Aminotransferase (AST) · De Ritis Ratio (AST/ALT) · FIB-4 Index (NAFLD Fibrosis Score) · Gamma-Glutamyl Transferase (GGT) · Serum Albumin · Serum Total Bilirubin

Map ALT against another marker