Biomarkers · Liver & Nutritional

De Ritis Ratio (AST/ALT)

Lower values go with lower risk of death. In NHANES 1999–2018 with linked mortality to 2019, each standard deviation above average goes with 24% higher risk of death. We found the same pattern in NHANES

AST/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)1.24×95% CI 1.21–1.28 · 48,262 adults, 7,006 deaths

Published risk of death1.58×Q4 vs Q1 of De-Ritis ratio (95% CI 1.12–2.22) · NHANES U.S. adults, mortality analysis n=8,063 (linkage to National Death Index)

Value of the measurement+0.023gain in concordance within age bands; rank 15 of 56 · all tests

AST/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 (ratio), from the survey named in the row. Not a reference range or a target.
Sex	Age	5th	25th	Median	75th	95th	n	Cycle / source
All	20-39	0.54	0.80	1.06	1.33	1.80	1,427	NHANES 2017-2018
All	40-59	0.59	0.79	1.00	1.24	1.65	1,543	NHANES 2017-2018
All	60+	0.70	0.93	1.14	1.36	1.82	1,885	NHANES 2017-2018
All	all	0.59	0.83	1.06	1.31	1.78	4,855	NHANES 2017-2018
Men	20-39	0.49	0.69	0.91	1.18	1.67	682	NHANES 2017-2018
Men	40-59	0.56	0.73	0.87	1.06	1.53	718	NHANES 2017-2018
Men	60+	0.68	0.88	1.08	1.27	1.75	956	NHANES 2017-2018
Men	all	0.55	0.75	0.94	1.18	1.65	2,356	NHANES 2017-2018
Women	20-39	0.71	0.95	1.18	1.40	1.90	745	NHANES 2017-2018
Women	40-59	0.67	0.89	1.12	1.36	1.82	825	NHANES 2017-2018
Women	60+	0.72	0.96	1.19	1.43	1.89	929	NHANES 2017-2018
Women	all	0.70	0.94	1.16	1.40	1.88	2,499	NHANES 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 AST/ALT, study by study

1 effect 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.
Type	Intervention	Reported effect	Evidence	Source
clinical	Fecal microbiota transplantation in patients with mild-moderate COVID-19 (randomized, double-blind, placebo-controlled; n=40)	AST/ALT (De Ritis) ratio fell from 0.966 to 0.817 after FMT	RCT	Jiang X, et al. Journal of medical virology. 2024. Fecal microbiota…

Sources

Risk curve: Zhang H 2026 (PMID 42437929): all-cause HR 1.58 (1.12-2.22) Q4 vs Q1 of De-Ritis ratio. Scaled to US values (NHANES).
Zhang H, Feng S. Association of the De-Ritis (AST/ALT) ratio with coronary heart disease prevalence and all-cause mortality in U.S. adults: a national health and nutrition examination survey analysis. J Cardiothorac Surg. 2026;21:article.
NHANES curve: our Cox model adjusted for age and sex, NHANES 1999–2018 with linked mortality to 2019.

Map De Ritis Ratio (AST/ALT) against another biomarker.

Map AST/ALT against another marker