Iron deficiency, anemia, and patient-reported outcomes in kidney transplant recipients

Kidney transplant recipients (KTRs) experience more fatigue, anxiety, and depressive symptoms and lower concentration and health-related quality of life (HRQoL) compared with the general population. Anemia is a potential cause that is well-recognized and treated. Iron deficiency, however, is often unrecognized, despite its potential detrimental effects related to and unrelated to anemia. We investigated the interplay of anemia, iron deficiency, and patient-reported outcomes in 814 outpatient KTRs (62% male, age 56 ± 13 years) enrolled in the TransplantLines Biobank and Cohort Study (Groningen, The Netherlands). In total, 28% had iron deficiency (ie, transferrin saturation < 20% and ferritin < 100 μg/L), and 29% had anemia (World Health Organization criteria). In linear regression analyses, iron deficiency, but not anemia, was associated with more fatigue, worse concentration, lower wellbeing, more anxiety, more depressive symptoms, and lower HRQoL, independent of age, sex, estimated glomerular filtration rate, anemia, and other potential confounders. In the fully adjusted logistic regression models, iron deficiency was associated with an estimated 53% higher risk of severe fatigue, a 100% higher risk of major depressive symptoms, and a 51% higher chance of being at risk for sick leave/work disability. Clinical trials are needed to investigate the effect of iron deficiency correction on patient-reported outcomes and HRQoL in KTRs.