Is a ferritin level of 166 considered mildly elevated?

Is a Ferritin Level of 166 Mildly Elevated?

A ferritin level of 166 μg/L is mildly elevated for females (>200 μg/L is considered elevated) but within normal range for males (<300 μg/L is considered normal) according to the American Association for the Study of Liver Diseases guidelines. 1

Interpretation of Ferritin Levels

Ferritin is an iron storage protein whose concentration in blood typically reflects iron stores. However, it's important to understand that ferritin is also an acute phase reactant that can be elevated in inflammatory conditions, making interpretation more complex.

According to current guidelines, ferritin levels should be interpreted as follows:

• For males: Values >300 μg/L are considered elevated
• For females: Values >200 μg/L are considered elevated 1

A ferritin level of 166 μg/L falls into these categories:

• Within normal range for adult males
• Approaching but still below the threshold for elevation in adult females

Clinical Significance

When evaluating a ferritin level of 166 μg/L, consider:

1. Gender context: This level has different implications depending on whether the patient is male or female

2. Inflammatory status: Since ferritin is an acute phase reactant, its elevation may reflect inflammation rather than true iron overload 2

   • Consider checking inflammatory markers like C-reactive protein (CRP)
   • In overweight or obese individuals, ferritin correlates more strongly with BMI and CRP than with iron status 2

3. Transferrin saturation: This is the primary screening test for iron overload

   • A transferrin saturation >45% suggests iron overload and should prompt further investigation 1
   • Evaluating ferritin without transferrin saturation can be misleading

Next Steps

If a ferritin level of 166 μg/L is found:

1. For males: This is within normal range and generally requires no further action unless there are other concerning clinical features

2. For females: This is approaching the upper limit but still below the 200 μg/L threshold for elevation. Consider:

   • Checking transferrin saturation to complete the iron profile
   • Evaluating for inflammatory conditions that might affect ferritin levels
   • Assessing for symptoms of iron overload (fatigue, joint pain, liver dysfunction)

3. For all patients: If there are clinical concerns despite this borderline level:

   • Complete iron studies including transferrin saturation
   • Consider inflammatory markers (CRP, ESR)
   • Evaluate liver function tests

Common Pitfalls

1. Relying solely on ferritin: Ferritin alone can be misleading due to its role as an acute phase reactant 1

2. Ignoring clinical context: Obesity, inflammation, and liver disease can all elevate ferritin independent of iron status 2

3. Using inappropriate reference ranges: Different guidelines and laboratories may use slightly different cutoffs for what constitutes "elevated" ferritin

4. Initiating treatment based on isolated ferritin values: Phlebotomy or other treatments for iron overload should not be initiated based on mildly elevated ferritin alone without evidence of true iron overload 1

In conclusion, a ferritin level of 166 μg/L should be interpreted in the context of gender, inflammatory status, and other iron studies, particularly transferrin saturation. This level alone does not definitively indicate iron overload or deficiency.