Iron Deficiency and Depressive Mood in Hispanic Women
Iron deficiency and depression occur predominantly in women, in both developed and developing countries. Our aim was to improve understanding of the association between iron deficiency and depressive mood. We explored the role of fatigue in the relationship between iron deficiency and depressive mood, the effect of confounding factors, and whether stress was a modifier of the association of iron deficiency and depressive mood. Two cross-sectional data sets were used to implement our research objectives. One was the 1982-1984 Hispanic Health and Nutrition Examination Survey (HHANES). The other was an observational study with Spanish-speaking Mexican factory workers that was conducted in 2001. In the HHANES, iron status was represented by the continuous variable body iron stores. Severe depressive mood and a fatigue index were assessed with a modified Center of Epidemiologic Studies Depression Scale. Stress was operationalized by variables representing social and biological stressors. In the Mexican study, the variables were hemoglobin, the Beck Depression Inventory, the Fatigue Severity Scale, and cortisol response over two work days. In both studies, only women who were premenopausal and not pregnant were included. Results were consistent between the two studies. With improving iron status, the risk of severe depressive mood decreased significantly. Fatigue had no or a minor impact on the effect of iron status. No confounders were identified for the main effect model. Stress was a significant, synergistic modifier of the association between iron status and severe depressive mood. Women exposed to both stress and iron deficiency were at significantly higher risk of severe depressive mood compared to women who experienced none or one of the risk factors. In the Mexican sample, socioeconomic status was a negative confounder of this interaction. This research indicates that studies that explore the biological association between iron deficiency and depressive mood should focus on women who experience high stress levels. In a population with limited access to medical services, improving iron status in women of reproductive age might be a good alternative to drug therapy in order to alleviate severe depressive mood.
iron; depression; Hispanic; stress; fatigue; Mexico