Metabolic profile distinguishes causes of anemia, study finds

Researchers in Estonia have found that a detailed analysis of metabolism can distinguish whether anemia is caused by iron deficiency or chronic inflammation, ERR reports.

Doctors often order blood tests when patients experience unexplained fatigue to rule out anemia. While iron deficiency is the most common cause, chronic inflammation can also lead to anemia and may be difficult to distinguish using routine tests.

Researchers from the University of Tartu, Tartu University Hospital and the North Estonia Medical Centre analysed blood samples from 70 patients with anemia and 27 without the condition using mass spectrometry. They measured the levels of more than 600 metabolites.

The blood of patients with anemia contained significantly lower levels of polyunsaturated fatty acids. Researchers also observed an increase in the ratio between two omega-3 fatty acids, DHA and EPA.

When the researchers fed the metabolic data into a computer model, it distinguished iron-deficiency anemia from inflammation-related anemia with 88 percent accuracy. The method also helped determine the diagnosis of 18 patients whose underlying condition had not been identified through earlier tests. In most of those cases, the model detected iron deficiency.

The researchers believe the differences are linked to how the body responds to oxygen deprivation and inflammation. Anemia is associated with a lack of oxygen in tissues and insufficient iron, which could affect enzymes that process certain fatty acids. The study suggests that oxygen deprivation may instead increase the production of some of these fatty acids.

In inflammation-related anemia, levels of certain amino acids and inflammatory molecules changed instead. While iron deficiency shifted the balance between kynurenine and tryptophan in one direction, inflammation shifted it in the opposite direction.

These markers could eventually help doctors identify the underlying cause of anemia even when a patient has both a chronic illness and iron deficiency. However, the method is not expected to reach family health centres soon. The researchers said the study was preliminary and limited by the small number of participants. The study also did not include bone marrow samples, which are used to assess iron stores directly.

The researchers published their findings in the journal Metabolites.