From the Guidelines
A total bilirubin level of 1.7 mg/dL is mildly elevated and does not necessarily indicate a serious condition, but it warrants monitoring and discussion with a healthcare provider, especially if symptoms are present 1. This mild elevation is above the normal range, which is typically 0.1-1.2 mg/dL for adults. According to a recent study, a serum bilirubin level of 1.7 mg/dL has a specificity of 60% for common bile duct stones (CBDS) 1. However, the mean level of bilirubin in patients with CBDS is generally lower, ranging from 1.5 to 1.9 mg/dL 1.
Key Considerations
- The elevation of bilirubin can be due to various conditions affecting the liver, bile ducts, or red blood cells, ranging from benign conditions like Gilbert's syndrome to more serious issues like hepatitis, cirrhosis, or gallstones.
- The pattern of elevation (whether direct/conjugated or indirect/unconjugated bilirubin is predominantly elevated) helps determine the underlying cause, so additional testing may be recommended by the healthcare provider.
- It is essential to discuss this result with a healthcare provider, especially if symptoms like yellowing of the skin or eyes (jaundice), dark urine, light-colored stools, or abdominal pain are present.
Recommendations
- Stay well-hydrated and avoid alcohol and medications that can stress the liver.
- Follow up with a healthcare provider to discuss the results and determine the best course of action.
- Additional testing may be recommended to determine the underlying cause of the elevated bilirubin level, such as liver function tests, imaging studies, or other diagnostic tests 1.
From the Research
Bilirubin Levels and Their Implications
- A total bilirubin level of 1.7 can be associated with various conditions, including liver disease, hemolysis, and other disorders 2, 3.
- Elevated plasma bilirubin levels can be secondary to alterations in any stage of its metabolism, such as excess bilirubin production, impaired liver uptake, impaired conjugation, and bile clearance defect 2.
- Bilirubin is a well-established marker of liver function, but it does not always identify a lesion in this organ; therefore, alterations in bilirubin concentrations should be assessed in relation to patient anamnesis, the degree of the alteration, and the pattern of concurrent biochemical alterations 2.
Clinical Usefulness of Bilirubin Measurement
- Various analytical methods are available for measuring bilirubin and its metabolites in serum, urine, and feces, including diazo transfer reaction, high-performance liquid chromatography (HPLC), oxidative, enzymatic, and chemical methods, direct spectrophotometry, and transcutaneous methods 2.
- Bilirubin is among the most potent of the endogenous antioxidants, and mildly elevated serum bilirubin concentrations have been associated with protective effects, whereas lower levels have been associated with an increased risk of various diseases of civilization 4.
- The clinical chemistry methods used for bilirubin determination have not been standardized, and the data from epidemiological studies are not always comparable; therefore, it is highly recommended to conduct properly-designed large epidemiological studies to establish decision limits for serum bilirubin concentrations 4.
Associations with Other Conditions
- Plasma free hemoglobin is associated with lactate dehydrogenase (LDH), aspartate aminotransferase (AST), total bilirubin, reticulocyte count, and the hemolysis score in patients with sickle cell anemia 3.
- Prediagnostic serum levels of bilirubin have been associated with risk of gastrointestinal cancers, including esophageal adenocarcinoma, colorectal cancer, hepatocellular carcinoma, and intrahepatic bile duct cancer 5.
- Elevated total serum bilirubin levels should be fractionated to direct and indirect bilirubin fractions, and an elevated serum conjugated bilirubin implies hepatocellular disease or biliary obstruction in most settings 6.