Lever
Lifestyle
- Regular exercise
- Adequate hydration
- Avoidance of nephrotoxic substances
Blutwerte · Marker
Cystatin C
Cystatin C · CysC
Nierenwerte
- Einheit:
- mg/L
- Abbreviation
- CysC
Cystatin C measures the concentration of a cysteine protease inhibitor in the blood, reflecting kidney function and glomerular filtration rate.
Reference Ranges
Reference
0.6–1.2mg/L
0.6
1.2
LowNormalHigh
Reference
Unit · mg/LReference ranges may vary slightly based on age and laboratory methods.
Overview
Übersicht
Cystatin C (CysC) is a cysteine protease inhibitor that serves as a biomarker for kidney function. It is produced at a constant rate by all nucleated cells and is freely filtered by the glomeruli in the kidneys. Unlike creatinine, CysC levels are not significantly affected by muscle mass, age, or sex, making it a more reliable indicator of glomerular filtration rate (GFR). Clinically, CysC is particularly valuable in diagnosing and monitoring chronic kidney disease (CKD) and acute kidney injury (AKI). Researchers have found it to be a sensitive marker for early detection of renal impairment, especially in populations where creatinine measurements are less reliable, such as in neonates or patients with low muscle mass. In the context of athletic performance and biohacking, maintaining optimal kidney function is crucial for overall health and longevity. CysC can provide insights into renal health, which is essential for recovery and performance optimization. However, researchers observed that factors such as inflammation and certain genetic variants can influence CysC levels. It is important to consider these potential confounders when interpreting results. Fasting is not required for CysC testing, and it is not sensitive to the time of day, making it a convenient biomarker for regular monitoring.
Klinische Bedeutung
Elevated cystatin C levels indicate reduced kidney function and can signal chronic kidney disease or acute kidney injury. Lower levels are generally not clinically significant but may suggest improved kidney function.
Dynamics
Trend Interpretation
Rising Values
Progressively rising cystatin C levels suggest worsening kidney function. Re-test in 4-6 weeks if levels are outside the optimal range.
Falling Values
Progressively falling levels may indicate improving kidney function or effective treatment.
Re-test Interval
4 weeks if outside optimal range
Etiology
Causes — High & Low
Cause
Elevated Levels
- Chronic kidney disease
- Acute kidney injury
- Cerebrovascular disorders
- Inflammation
- Genetic variants
Cause
Low Levels
- Improved kidney function
- Overhydration
- Laboratory error
- Specific genetic conditions
Protocol
How to Optimize
Lever
Nutrition
- Low-sodium diet
- Adequate protein intake
- Antioxidant-rich foods
Note:
Consult a healthcare provider before making significant lifestyle or dietary changes.
Testing Guidelines
✓Fasting Not Required
✓Not Time-Sensitive
Testing Frequency
Annually for healthy adults, more frequently if monitoring kidney disease.
Interfering Factors
- Inflammation
- Certain medications
- Genetic variants
Open Research Questions
Current research suggests that reference ranges and optimal thresholds for cystatin C in various populations, particularly neonates, remain inadequately defined. Researchers have not yet established standardized protocols for transitioning to the newly established International Standard for cystatin C measurements. Additionally, unanswered clinical questions include the frequency of cystatin C testing in chronic kidney disease management and its role in predicting outcomes in cerebrovascular disorders.
19 Research Publications
847
Total Citations
7
Human/RCT
3.8
Avg. Influence
2025
Latest
Sort
Filter
01Top
#01
Creatinine: From physiology to clinical application.
ReviewInfluence12.0
365
This review examined the limitations of serum creatinine as a kidney function biomarker and discussed alternative biomarkers, including cystatin C. Researchers found that understanding the shortcomings of creatinine is crucial for accurate kidney function assessment.
02Top
#02
Cystatin C as a biomarker of chronic kidney disease: latest developments.
ReviewInfluence7.0
169
This study assessed the utility of serum cystatin C as a biomarker for chronic kidney disease (CKD). Researchers found that cystatin C is an early and accurate indicator of CKD, particularly in patients where creatinine is inadequate.
03Top
#03
Cystatin C: a kidney function biomarker.
Onopiuk Anna, et al. · Advances in clinical chemistry · 2015
ReviewInfluence3.0
155
This chapter discussed the role of cystatin C as a kidney function biomarker. Researchers found that cystatin C is a promising indicator of glomerular filtration rate, being less influenced by factors like age and muscle mass compared to traditional markers.
Key findings
- 01Cystatin C is a protein that can serve as a more accurate marker for kidney filtration compared to traditional methods.
- 02Its levels remain consistent regardless of age, gender, or muscle mass, which are common variables that can skew results.
- 03The review discusses the biological role of cystatin C and the methods used to measure its concentration in the blood.
04
#04
Exploring Renal Function Assessment: Creatinine, Cystatin C, and Estimated Glomerular Filtration Rate Focused on the European Kidney Function Consortium Equation.
ReviewInfluence1.0
40
This review focused on serum creatinine and cystatin C as renal biomarkers for estimating glomerular filtration rate (eGFR). Researchers observed the advantages and disadvantages of these biomarkers and their clinical utility in assessing kidney damage.
05
#05
Detecting Neonatal AKI by Serum Cystatin C.
Xu Xin, et al. · Journal of the American Society of Nephrology : JASN · 2023
HumanInfluence4.0
35
This multicenter study evaluated serum cystatin C as a biomarker for neonatal acute kidney injury (AKI). Researchers found that cystatin C is a sensitive marker for detecting AKI in neonates, identifying significantly more cases than traditional creatinine criteria.
Key findings
- 01Cys-C detected 6.5 times more cases of AKI compared to traditional creatinine criteria.
- 02Neonates identified with AKI by Cys-C alone had a nearly three times higher risk of in-hospital death.
- 03Cys-C levels remained stable across different gestational ages and birth weights, making it a reliable marker.
06
#06
Cystatin C in Cerebrovascular Disorders.
Zhang Yaru & Sun Li · Current neurovascular research · 2017
ReviewInfluence1.0
22
This review explored the role of cystatin C in cerebrovascular disorders. Researchers found that cystatin C may serve as a novel biomarker due to its involvement in various mechanisms related to cerebrovascular diseases.
Key findings
- 01Researchers observed that the CysC variant can aggregate and interact with harmful proteins like Amyloid-β.
- 02They found that an imbalance between CysC and certain enzymes may contribute to cerebrovascular issues.
- 03The study noted CysC's role in promoting inflammation and autophagy, which are important in brain health.
07
#07
Role of cystatin C in urogenital malignancy.
ReviewInfluence1.0
20
This review explored the potential role of cystatin C in urogenital malignancies. Researchers found that cystatin C may serve as a promising biomarker for early tumor identification and prognosis. The study emphasizes the need for further investigation into cystatin C's clinical applications in cancer.
08
#08
Biomarkers for sarcopenia, muscle mass, muscle strength, and physical performance: an umbrella review.
Liu Gaoming, et al. · Journal of translational medicine · 2025
Meta-Analysis
19
This umbrella review identified biomarkers associated with sarcopenia, including the creatinine to cystatin C ratio. Researchers observed that this ratio is frequently used and demonstrates moderate diagnostic accuracy for sarcopenia.
Key findings
- 01The creatinine to cystatin C ratio is the most commonly used diagnostic biomarker for sarcopenia, showing moderate accuracy.
- 02Inflammatory biomarkers like interleukin-6 and C-reactive protein were found to be elevated in patients with sarcopenia.
- 03Most biomarkers studied showed weak correlations with sarcopenia, indicating a need for further research.
09
#09
Urine MMP7 as a kidney injury biomarker.
Review
14
This study focused on matrix metalloproteinase 7 (MMP-7) as a kidney injury biomarker and its relationship with cystatin C. Researchers found that urinary MMP-7, along with cystatin C, could provide insights into tubular injury in kidney diseases. The study highlights the potential of these biomarkers in assessing kidney function.
10
#10
Cystatin C and uncontrolled hypertension.
Human
5
This observational study investigated the predictive value of serum cystatin C in patients with uncontrolled hypertension. Researchers found that higher cystatin C levels were associated with uncontrolled hypertension, independent of serum creatinine levels.
Publication Trend
Research publications about Cystatin C over time
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