Sustained expression of hepcidin during infection or inflammatory conditions including autoimmune diseases such as rheumatoid arthritis and inflammatory bowel disease, cancer, and chronic disorders such as kidney disease and heart failure results in anaemia due to reduced availability of iron for erythropoiesis (functional ID).135 In the elderly, low-grade chronic inflammation (‘inflammaging’) may also contribute to anaemia. This evidence concerns the gene HAMP and rheumatoid arthritis.