PFLPhysiological Fitness Landscape

Biomarkers · Liver & Nutritional

Gamma-Glutamyl Transferase (GGT)

Lower values go with lower risk of death. In NHANES 1999–2018 with linked mortality to 2019, each standard deviation above average goes with 26% higher risk of death. We found the same pattern in NHANES

GGT 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)1.26×95% CI 1.23–1.29 · 48,360 adults, 7,025 deaths
Published risk of death1.07×per 5 U/l increment in GGT (95% CI 1.04–1.10) · Meta-analysis of 19 prospective cohort studies in general populations (over 9.24 million participants)
Value of the measurement+0.020gain in concordance within age bands; rank 20 of 56 · all tests

GGT 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
All20-398.0013.018.029.071.01,431NHANES 2017-2018
All40-5910.015.022.037.096.31,547NHANES 2017-2018
All60+9.0014.020.029.072.41,890NHANES 2017-2018
Allall9.0014.020.031.080.04,868NHANES 2017-2018
Men20-3911.016.724.035.0102684NHANES 2017-2018
Men40-5913.020.026.043.0107722NHANES 2017-2018
Men60+11.016.024.034.083.3958NHANES 2017-2018
Menall11.017.925.040.01022,364NHANES 2017-2018
Women20-398.0010.514.021.047.6747NHANES 2017-2018
Women40-598.0013.018.027.064.8825NHANES 2017-2018
Women60+9.0014.018.026.053.0932NHANES 2017-2018
Womenall8.0012.017.025.058.02,504NHANES 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 GGT, study by study

3 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
behavioralCessation of alcohol intake (supervised abstinence)Elevated GGT usually normalised within 1 to 3 weeks of supervised abstinence in alcohol-dependent patients (12 patients)case seriesHelander A, et al. Carbohydrate-deficient transferrin and gamma-glutamyl…
dietRegular coffee consumption (≥3 cups/day)≥3 cups/day coffee associated with lower odds of abnormal GGT (OR 0.69; 95% CI 0.57-0.83) vs none, and lower continuous GGTcross-sectionalXiao Q, et al. Inverse associations of total and decaffeinated coffee with…
pharmacologicOnce-weekly subcutaneous tirzepatide 15 mg for 72 weeks in adults with obesity without diabetesGGT geometric mean -32.7% vs placebo at 72 weeks (5 mg -18.6%, 10 mg -21.6%)RCTSattar N, et al. J Am Coll Cardiol. 2026. Comprehensive Long-Term Changes in…
pharmacologicElafibranor 80 mg once daily for 12 weeks in PBC with incomplete response to ursodeoxycholic acidGGT -37.0% (SD 25.5) at 12 weeks vs +0.2% with placeboRCTSchattenberg JM, et al. J Hepatol. 2021. A randomized placebo-controlled trial…
supplementSoluble fiber supplementation (0.0025-40 g/day, 3-52 weeks); effect per 5 g/day incrementNo effect on GGT: MD 0.12 U/L (95% CI -0.81 to 1.05) per 5 g/day soluble fibermeta-analysisGhavami A, et al. Int J Vitam Nutr Res. 2024. No benefit of soluble fiber on…

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
dietChronic heavy alcohol consumptionGGT significantly higher in heavy drinkers than moderate drinkers or abstainers; 62% of heavy drinkers had elevated GGTcross-sectionalAlatalo P, et al. Biomarkers of liver status in heavy drinkers, moderate…
pharmacologicEnzyme-inducing anticonvulsants (Phenytoin, Carbamazepine, Phenobarbital)Enzyme-inducing anticonvulsants raise serum GGT; drug score correlated with total GGT (r=0.382) in 90 treated patientscross-sectionalTutor-Crespo M, et al. Isoforms of serum gamma-glutamyltransferase in epileptic…

Sources

Map Gamma-Glutamyl Transferase (GGT) against another biomarker.

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

Map GGT against another marker