From the Guidelines
A total bilirubin level of 2.1 mg/dL is mildly elevated and warrants further evaluation to determine the underlying cause, which may include liver diseases, bile duct obstructions, or genetic conditions like Gilbert's syndrome, as suggested by 1.
Possible Causes and Next Steps
The elevation in total bilirubin can be due to various conditions, and it is essential to fractionate the bilirubin to determine the percentage derived from direct bilirubin, as recommended by 1.
- Elevated bilirubin can result from liver diseases (hepatitis, cirrhosis), bile duct obstructions, certain medications, or genetic conditions like Gilbert's syndrome.
- Gilbert's syndrome is a common, harmless genetic condition that causes intermittent mild elevations in bilirubin without liver damage.
- The yellow pigment bilirubin is produced when your body breaks down red blood cells, and elevated levels can sometimes cause yellowing of the skin or eyes (jaundice).
Recommendations
You should schedule an appointment with your healthcare provider within the next 1-2 weeks for further assessment, as suggested by the guidelines for the management of abnormal liver blood tests 1. In the meantime, stay well-hydrated and avoid alcohol consumption. Your doctor will likely order additional tests, including:
- Direct and indirect bilirubin levels
- Liver function tests
- Possibly imaging studies to determine the cause The specific treatment will depend entirely on the underlying cause, so proper diagnosis is essential before any treatment plan can be recommended, as emphasized by 1.
From the Research
Elevated Bilirubin Levels
Elevated plasma bilirubin levels can be a frequent clinical finding, and it can be secondary to alterations in any stage of its metabolism 2.
Possible Causes
Some possible causes of elevated bilirubin levels include:
- Excess bilirubin production (i.e., pathologic hemolysis)
- Impaired liver uptake, with elevation of indirect bilirubin
- Impaired conjugation, prompted by a defect in the UDP-glucuronosyltransferase
- Bile clearance defect, with elevation of direct bilirubin secondary to defects in clearance proteins, or inability of the bile to reach the small bowel through bile ducts
Relationship with Other Conditions
Some studies have investigated the relationship between elevated bilirubin levels and other conditions, such as:
- Non-alcoholic fatty liver disease (NAFLD): One study found that elevated levels of total bilirubin were not causally associated with decreased risk of NAFLD based on Mendelian randomization analysis 3.
- Subclinical atherosclerosis and oxidative stress: A study found a relationship between mild hyperbilirubinemia and antioxidant balance in patients with Gilbert syndrome 4.
- NAFLD risk: Another study found that direct bilirubin was inversely associated with NAFLD risk, but no significant associations were found between total and indirect bilirubin and NAFLD risk 5.
- Carotid atherosclerosis: A study found that mildly elevated serum total bilirubin levels were negatively associated with carotid atherosclerosis among elderly persons with type 2 diabetes 6.
Measurement of Bilirubin
Bilirubin can be measured using various analytical methods, including:
- Diazo transfer reaction
- High-performance liquid chromatography (HPLC)
- Oxidative, enzymatic, and chemical methods
- Direct spectrophotometry
- Transcutaneous methods 2