Lever
Lifestyle
- Regular exercise
- Avoid excessive alcohol consumption
- Maintain a healthy weight
Blutwerte · Marker
ALT (GPT)
Alanin-Aminotransferase · ALAT · GPT · SGPT
Leberwerte
- Einheit:
- IU/L
- Abbreviation
- ALT / GPT
ALT measures the activity of the enzyme alanine aminotransferase, which is involved in amino acid metabolism in the liver.
Reference Ranges
Reference
7–56IU/L
7
10
30
56
LowNormalHigh
Reference
Optimal
Unit · IU/LReference ranges may vary slightly between laboratories. ALT levels can be higher in males compared to females.
Overview
Übersicht
Alanine aminotransferase (ALT), also known as glutamate pyruvate transaminase (GPT), is an enzyme primarily found in the liver. It plays a crucial role in amino acid metabolism by catalyzing the conversion of alanine and alpha-ketoglutarate to pyruvate and glutamate. Clinically, ALT is a key marker for liver health, as elevated levels often indicate liver damage or inflammation. Conditions such as non-alcoholic fatty liver disease (NAFLD), hepatitis, and liver cirrhosis are commonly associated with increased ALT levels. Researchers have also observed that ALT levels can be elevated in cases of muscle injury and certain infections, such as infectious mononucleosis. For athletes and biohackers, monitoring ALT can provide insights into liver function and overall metabolic health. While ALT is not directly linked to athletic performance, maintaining optimal liver function is crucial for metabolic efficiency and recovery. However, ALT levels can be influenced by factors such as recent physical activity, medications, and alcohol consumption, which may confound results. Therefore, it is recommended to interpret ALT levels in conjunction with other liver function tests and consider lifestyle factors that may affect the readings.
Klinische Bedeutung
Elevated ALT levels typically indicate liver damage or inflammation, which can occur in conditions such as hepatitis, NAFLD, and cirrhosis. Low ALT levels are generally not clinically significant but may occur in cases of vitamin B6 deficiency.
Dynamics
Trend Interpretation
Rising Values
Progressively rising ALT values suggest worsening liver function and warrant further investigation. Retest in 4 weeks if outside optimal range.
Falling Values
Falling ALT values may indicate improvement in liver health or resolution of an acute liver injury.
Re-test Interval
4 weeks if outside optimal range
Etiology
Causes — High & Low
Cause
Elevated Levels
- Liver disease
- Hepatitis
- Alcohol consumption
- Muscle injury
- Infectious mononucleosis
Cause
Low Levels
- Vitamin B6 deficiency
- Chronic kidney disease
- Malnutrition
- Severe liver damage
Protocol
How to Optimize
Lever
Nutrition
- Consume a balanced diet rich in fruits and vegetables
- Limit intake of processed foods
- Ensure adequate hydration
Lever
Supplementation
- Milk thistle
- N-acetylcysteine
Note:
Consult a healthcare provider before making significant lifestyle changes, especially if liver disease is suspected.
Testing Guidelines
✓Fasting Not Required
✓Not Time-Sensitive
ALT levels can vary throughout the day; morning samples are preferred for consistency.
Testing Frequency
Annually for healthy adults, more frequently if liver disease is suspected.
Interfering Factors
- Recent intense exercise
- Certain medications
- Alcohol consumption
Open Research Questions
Current research suggests that the reference ranges for ALT may not adequately reflect the severity of liver disease, particularly in non-alcoholic fatty liver disease (NAFLD), where its predictive value remains debated. Researchers have not yet established optimal ALT targets for monitoring liver health or the influence of confounding factors such as obesity and metabolic syndrome. Additionally, clinical questions remain unanswered regarding the role of ALT in predicting cognitive decline in conditions like atrial fibrillation.
23 Research Publications
183
Total Citations
16
Human/RCT
2.0
Avg. Influence
2025
Latest
Sort
Filter
01Top
#01
Use of enzymes for the diagnosis of alcohol-related organ damage.
ReviewInfluence3.0
88
Researchers discussed the challenges in using serum enzyme levels, including ALT, for diagnosing alcohol-related organ damage. They noted that while elevated ALT can indicate liver injury, it is not specific enough for definitive diagnosis, necessitating a combination of tests for better accuracy.
02Top
#02
Sarcoidosis of the liver: to treat or not to treat?
HumanInfluence2.0
45
This study explored the effects of ursodeoxycholic acid (UDCA) on liver function in patients with hepatic sarcoidosis. Researchers found that serum liver tests, including alanine aminotransferase (ALAT), improved in patients treated with UDCA compared to those who received no treatment. The study involved 17 patients and highlighted the need for further research.
03Top
#03
Covid-19: contribution of clinical characteristics and laboratory features for early detection of patients with high risk of severe evolution.
Human
16
Researchers identified clinical and laboratory features, including ALT levels, that could predict severe outcomes in COVID-19 patients. The study found that elevated ALT was among several biomarkers associated with worse prognosis, aiding in the early detection of high-risk patients.
04
#04
Non-alcoholic fatty liver disease and correlation of serum alanin aminotransferase level with histopathologic findings.
HumanInfluence1.0
8
Researchers investigated the correlation between serum ALT levels and histopathological findings in patients with non-alcoholic fatty liver disease (NAFLD). They found that ALT levels had little predictive value for the severity of NAFLD, suggesting that other factors may be more relevant in assessing disease severity.
05
#05
Haematology and clinical blood chemistry in harbour porpoises (Phocoena phocoena) from the inner Danish waters.
Animal
6
This research presented hematology and blood chemistry data from harbour porpoises to assess population health. Researchers noted that alanine aminotransferase (ALAT) values were lower in captive porpoises compared to free-ranging individuals, suggesting environmental influences on health markers. The study included blood samples from both wild and captive porpoises.
06
#06
Reference intervals for 12 clinical laboratory tests in a Danish population: The Lolland-Falster Health Study.
Human
6
Researchers established reference intervals for various laboratory tests, including ALT, in a Danish population. They found that local reference limits for ALT differed from previously established norms, indicating the importance of population-specific data for accurate laboratory assessments.
07
#07
IL-28 and IL-29 as protective markers in subject with dengue fever.
Human
5
This study assessed the role of interleukins IL-28 and IL-29 in dengue fever patients. Researchers found that higher levels of these interleukins were associated with lower alanine aminotransferase (ALAT) levels, indicating better liver function. The study included 45 dengue patients and 24 controls.
08
#08
[Hypertriglyceridemia--diagnostics, risk and treatment].
Review
3
This review article discussed hypertriglyceridemia and its associated laboratory evaluations, including alanine aminotransferase (ALAT). Researchers emphasized the importance of measuring ALAT among other parameters to assess metabolic health. The article provided insights into the diagnostics and risk factors related to hypertriglyceridemia.
09
#09
Biomarker and cognitive decline in atrial fibrillation: a prospective cohort study.
Krisai Philipp, et al. · Scientific reports · 2025
Human
3
Researchers examined the relationship between various biomarkers, including ALT, and cognitive decline in patients with atrial fibrillation. They found that 6.5% of patients experienced cognitive decline over four years, with specific biomarkers like GDF-15 and ALT showing significant associations. The study suggests that inflammation and neuronal damage may contribute to cognitive decline in this population.
Key findings
- 01Researchers observed that patients with cognitive decline were more likely to have permanent AF and a history of stroke.
- 02The biomarkers GDF-15, Cystatin C, and high-sensitivity Troponin T were strongly associated with cognitive decline.
- 03The best prediction model for cognitive decline included several biomarkers, indicating complex underlying mechanisms such as inflammation and neuronal damage.
10
#10
[Chronic polyneuropathy--evaluation and diagnosis].
Review
2
This review focused on the evaluation and diagnosis of chronic polyneuropathy, emphasizing the importance of routine laboratory assessments. Researchers highlighted that tests including alanine aminotransferase (ALAT) should be conducted to identify common causes of polyneuropathy. The article provides guidelines for physicians to approach diagnosis effectively.
Publication Trend
Research publications about ALT (GPT) over time
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