High Prevalence of Iron Deficiency among Educated Hospital Employees in Switzerland

Abstract

Iron deficiency is known to cause symptoms such as fatigue, depression and restless legs syndrome resulting in impaired quality of life and working capacity. We sought to examine the iron status of reportedly healthy individuals by a framed study design in 58 highly educated Swiss hospital employees and to compare the use of non invasive tests for assessing iron deficiency (ID). A structured interview was used to assess health status, nutritional intake and potential blood loss, blood counts as well as parameters proposed to diagnose iron deficiency were determined. All subjects felt well and were working at their maximum capacity. The male subjects were neither anaemic nor had decreased iron parameters however 50% (23/46) of the women had a serum ferritin of below 22 μg/L, still 33% (15/46) of the women had a ferritin value below the more stringent cut off value of 15 μg/L. In 15% (7/46) of the women we diagnosed iron deficient anaemia. Red meat consumption correlated with ferritin values as did the menstrual blood loss which was estimated by asking the amount of tampons used. Of the additionally analysed iron parameters only the percentage of hypochromic erythrocytes, soluble transferrin receptor and transferrin values were significantly correlated with ferritin and reached an AUCROC of ≥0.7 indicating good predictive tests. Nevertheless neither soluble transferrin receptor nor transferrin showed diagnostic advantages for the diagnosis of ID compared to ferritin alone or together with erythrocyte parameters. Working in a hospital environment and having access to health education does not seem to correlate with prevention of ID or ID anaemia in female hospital employees.

Keywords: anaemia; hospital epidemiology; iron deficiency.

Figure 1

ROC curve for serum ferritin in diagnosing IDE and/or IDA (ID stage II or higher). Cut off values for ferritin are given in μg/L. The estimated AUC is 0.85 (95% CI 0.62 to 0.99; n=58).

Figure 2

Correlation between ferritin and alternative tests; iron, transferrin, transferrin saturation, soluble transferrin receptor, percentage of hypochromic erythrocytes, microcytic erythrocytes, mean corpuscular erythrocyte volume (MCV) and reticulocyte hemoglobin content. Parameter specific values for correlation, the 95% CI for the slope and R-squared are given in Table 2; n=58.

Figure 3

Using a ferritin cut off value of 22 μg/L the study population was split into subjects without ID and patients with ID. Receiver operator curves were calculated for iron, transferrin, transferrin saturation, soluble transferrin receptor, hypochromic erythrocytes, mean corpuscular erythrocyte volume and reticulocyte hemoglobin content. For each test parameter the estimated AUC with 95%CI is summarized in Table 3; n=58.

Figure 4

The combined information on red meat consumption and number of monthly used tampons was correlated to the value of serum ferritin in femals (R-squared 0.12; n=46).