Ferritin level is decreased in iron deficiency (ID) and increased in inflammation as an acute-phase reacting protein. In the case of inflammation ferritin, level may not decrease even if ID is present. Inflammation is regarded as one of the mechanisms of aging. This subclinical systemic inflammatory state is named as “inflammaging”. The aim of this study is to assess whether serum ferritin levels could indicate aging-associated inflammation rather than ID in older adults.

Consecutive 1310 patients admitted to the geriatric medicine outpatient clinic were enrolled. The clinical conditions, which could alter acute-phase reactants, were excluded. ID diagnosis was made by transferrin saturation (<15%), MCV and serum iron. Patients with increased levels of either one of Erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), white blood cell (WBC), or decreased level of albumin were diagnosed as having subclinical inflammatory state. The correlations of ferritin with those groups were analyzed.

Mean age was 71.8±6.9 years and 827 (63.1%) were female. Ferritin levels were significantly higher in patients with subclinical inflammatory state and significantly lower in patients with ID. The interrelationships of the ferritin with acute-phase reactants were stronger than its relationship with the ID.

The results of this study suggested that the ferritin level can increase with aging as a part of the ongoing asymptomatic chronic systemic inflammatory state called inflammaging. Inflammaging can result with increased ferritin levels, even if there is ID. Normal or elevated levels of ferritin in the geriatric population should not exclude ID in clinical practice.