Objective: To investigate the association between iron deficiency status and depressive symptoms in a national community sample of older people.
Methods: Cross-sectional data were analyzed from 1875 participants 65 years and older who had participated in the 2005 Health Survey for England. Serum hemoglobin (Hb), ferritin, and transferrin receptor levels and depressive symptoms (Geriatric Depression Scale) had been measured. Covariates included age, sex, occupation, multivitamin intake, smoking status, body mass index, hypertension, heart disease, stroke, diabetes, and cancer.
Results: Depressive symptoms were associated with anemia (Hb <12.0 g/dL for women and <13.0 g/dL for men; present in 10.8%; odds ratio [OR] = 1.53 [95% confidence interval = 1.08-2.18]) after adjustment for age, sex, social class, multivitamin intake, smoking status, and body mass index, but this association was reduced substantially after further adjustment for physical health status (OR = 1.14). Low serum ferritin level (<45 ng/mL; present in 21.6%) was associated with depressive symptoms after full adjustment (OR = 1.37 [95% confidence interval = 1.03-1.81]). Linear models, however, revealed significant associations between higher number of depressive symptoms and lower Hb level and higher serum transferrin receptor level but not with ferritin levels.
Conclusions: Iron deficiency commonly co-occurs with depressive symptoms in older people, although the association with anemia is accounted for by physical health status and may primarily reflect anemia of chronic disease.