Iron Deficiency Prevalent in Older Patients Admitted to Geriatric Units

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More than half of older patients admitted to geriatric units in France had iron deficiency, including patients without anemia.

Iron deficiency was diagnosed in more than half of patients admitted to a geriatric unit in France, including those with anemia and those who were not anemic, according to new cross-sectional findings.1

The CARENFER PA study evaluated patients aged >75 years for iron deficiency, defined as serum ferritin <100 µg/L and/or transferrin saturation coefficient (TSAT) <20%. These data showed iron deficiency was associated with both the presence of inflammation and a low Short Physical Performance Battery (SPPB) score, a predictive marker of adverse event risk.

“These new data underline the importance of more systematic screening of iron deficiency in the older population,” wrote the investigative team led by Bertrand Fougère, MD, PhD, division of geriatric medicine, Tours University Hospital.

Iron deficiency is a frequent cause of anemia but can also be responsible for physiological and clinical disorders before the condition’s onset. In geriatric practice, anemia is the most common hematological disorder, with a prevalence between 10-15% after age 65.2 It has been linked with increased morbidity, ranging between cardiac complications, impaired quality of life, and mortality.

Better diagnosis of iron deficiency could benefit an older population, who are typically frail and have severe comorbidities. However, Fougère and colleagues indicate the lack of a consensus definition of iron deficiency without specific thresholds for biomarkers of iron metabolic makes it poorly documented in the older population.

Using the consensus definition of iron deficiency by serum ferritin or TSAT levels3, the team examined its prevalence in patients aged >75 years in the CARENFER PA study.1 All patients were admitted to a geriatric unit in France. Investigators collected data on demographics, admission to the geriatric unit, comorbidities, treatment of anemia and/or iron deficiency, and concomitant treatments with potential influence on iron deficiency or anemia.

A blood test was conducted within 48 hours after study inclusion to evaluate serum ferritin, TSAT, hemoglobin, albumin, and serum creatinine. The SPPB test helped identify older patients at high risk of disability, falls, hospitalization, and death. It comprised 3 tests, including balance, repeated chair stands, and gait speed, with the domains scored from 0 (worst) to 4 (best) for a total score of 0 to 12.

Overall, 902 patients were included in 16 centers from October to December 2022. After 14 exclusions due to ineligibility criteria and lack of iron workup, the analysis set included 888 patients. Patients had a mean age of 85.2 years and 63.5% were women.

Upon analysis, the prevalence of iron deficiency was 57.6% (95% CI, 54.3 - 60.9) in the cohort admitted to geriatric units. Among this population, iron deficiency was absolutely in 56.2% of patients, and functional in 43.8%. The prevalence of anemia was 48.5% (95% CI, 45.2 - 51.8).

Fougère and colleagues identified iron deficiency as significantly more frequent in anemic patients (62.6%; 95% CI, 57.8 - 67.1) than in non-anemic patients (53.3%; 95% CI, 48.6 - 57.9; P = .0062). Iron deficiency was significantly increased in patients with >3 comorbidities (65.6% vs. 55.9%; P = .0274), those receiving a treatment that may influence iron deficiency or anemia (60.5% vs. 49.6%; P = .0042), or those with C-reactive protein ≥12 mg (73.0% vs. 49.3%; P <.001).

In multivariate analysis, only C-reactive protein ≥12 mg/L remained an independent predictive factor of iron deficiency (odds ratio [OR], 2.78; 95% CI, 1.92 - 4.08; P <.001).

Among 661 patients with available data on iron and SPPB test, scores were significantly lower in patients with iron deficiency than those without deficiency. Data showed SPPB scores were low (0–6) in 60.5% of patients with iron deficiency versus 48.6% of patients without iron deficiency (P = .0076).

Unable to conclude a causal relationship between iron deficiency and low SPPB scores, Fougère and colleagues still indicated these data are of interest as low performance has been associated with falls, hospitalizations, frailty, and all-cause mortality in older patients.

“Future randomized controlled trials will have to assess the efficacy of iron supplementation on physical performance and outcome of older iron-deficient patients,” investigators wrote.


  1. Fougère B, Puisieux F, Chevalet P, et al. Prevalence of iron deficiency in patients admitted to a geriatric unit: a multicenter cross-sectional study. BMC Geriatr. 2024;24(1):112. Published 2024 Jan 30. doi:10.1186/s12877-024-04719-6
  2. Guralnik JM, Eisenstaedt RS, Ferrucci L, Klein HG, Woodman RC. Prevalence of anemia in persons 65 years and older in the United States: evidence for a high rate of unexplained anemia. Blood. 2004;104(8):2263-2268. doi:10.1182/blood-2004-05-1812
  3. Cacoub P, Vandewalle C, Peoc'h K. Using transferrin saturation as a diagnostic criterion for iron deficiency: A systematic review. Crit Rev Clin Lab Sci. 2019;56(8):526-532. doi:10.1080/10408363.2019.1653820