Biomarkers · Renal & Purine

Serum Cystatin C

Lower values go with lower risk of death. Not measured in our NHANES panel. The curve is drawn from the published study (source below).

Serum Cystatin C and risk of death

Published curve higher than the NHANES fitNHANES fit higher

Risk of death relative to the curve's reference value, drawn from the published study (source below).

Published risk of death2.32×fifth vs first quintile of serum cystatin C (95% CI 1.86–2.89) · General US population cohort, median baseline age 44 years

Serum Cystatin C 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 (mg/L), 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	0.62	0.72	0.80	0.88	1.05	678	NHANES 1999-2002
All	40-59	0.65	0.74	0.83	0.94	1.16	693	NHANES 1999-2002
All	60+	0.74	0.88	1.00	1.20	1.79	2,787	NHANES 1999-2002
All	all	0.64	0.75	0.84	0.97	1.31	4,158	NHANES 1999-2002
Men	20-39	0.66	0.74	0.81	0.89	1.05	364	NHANES 1999-2002
Men	40-59	0.67	0.77	0.85	0.96	1.14	376	NHANES 1999-2002
Men	60+	0.76	0.90	1.02	1.21	1.81	1,406	NHANES 1999-2002
Men	all	0.67	0.77	0.85	0.98	1.27	2,146	NHANES 1999-2002
Women	20-39	0.59	0.68	0.77	0.84	1.04	314	NHANES 1999-2002
Women	40-59	0.64	0.72	0.79	0.92	1.27	317	NHANES 1999-2002
Women	60+	0.73	0.86	0.99	1.19	1.78	1,381	NHANES 1999-2002
Women	all	0.62	0.73	0.82	0.96	1.34	2,012	NHANES 1999-2002

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 Serum Cystatin C, 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
diet	Higher plant-sourced dietary protein intake	Each 10 g plant protein associated with 0.12 mL/min/1.73 m2 slower yearly decline in creatinine-cystatin C eGFR (95% CI 0.01-0.23)	prospective cohort	Bernier-Jean A, et al. Dietary plant and animal protein intake and decline in…
lifestyle	Anti-inflammatory Mediterranean lifestyle and exercise	Smaller twelve-month decline in cystatin C-based eGFR vs control (between-group difference -1.77 mL/min/1.73 m2, 95% CI -2.92 to -0.63)	RCT	Martínez-Montoro JI, et al. Effect of an intensive lifestyle intervention on…
pharmacologic	SGLT2 inhibitors (canagliflozin)	Chronic eGFR-cystatin C slope -0.4 vs -4.9 ml/min per 1.73 m2/year with canagliflozin vs control (difference 4.4, 1.3-7.6)	RCT	Miyamoto S, et al. Cystatin C Confirms the Canagliflozin eGFR Slope Benefit in…

Things that worsen it

Each row is one study: what was changed, the effect it reported on this marker, and the source.
Type	Condition or exposure	Reported effect	Evidence	Source
clinical	Severe untreated hyperthyroidism	Cystatin C 1.32 mg/L in hyperthyroidism fell to 0.95 mg/L once free thyroxine normalized, while creatinine rose (13 patients)	case series	Fricker M, et al. Impact of thyroid dysfunction on serum cystatin C. Kidney…
pharmacologic	Glucocorticoid administration (high-dose methylprednisolone)	High-dose methylprednisolone raised cystatin C by +22.8% while creatinine fell -12.9% (renal transplant recipients)	cohort	Pöge U, et al. Time course of low molecular weight proteins in the early kidney…

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.
What	Effect on the marker	Comparison · population	Source
↑ Acute kidney injury (children) · children with AKI vs children without AKI	SMD +0.96 (95% CI 0.68 to 1.24)	AKI vs non-AKI children (serum cystatin C) · 24 studies; 1948 children (645 AKI, 1302 non-AKI)	meta analysis · PMID 28372557

Sources

Risk curve: Yuan 2025 (PMID 40983592): all-cause HR 2.32 (1.86-2.89) fifth vs first quintile of serum cystatin C. Scaled to US values (NHANES).
Yuan et al. Association of cystatin C with 20-year mortality risk in the general US population: a cohort study. Renal failure. 2025;47:2549401.

Map Serum Cystatin C against another biomarker.

Map Serum Cystatin C against another marker