Anaemia: prevalence, risk factors and management with a focus on chronic kidney disease

The global prevalence of anaemia has decreased over the last 20 years from 40.2% in 1990 to 32.9% in 2010, but with a significant geographical variation. Iron deficiency, the commonest cause, decreased as a proportion, whereas the anaemia of chronic kidney disease increased. Anaemia due to haemoglobinopathies remained relatively constant. The increasing anaemia in kidney disease coupled with ageing and population growth resulted in a dramatic increase in the number of patients in this group. Higher income regions have a higher proportion of haemoglobinopathies, kidney disease and gastrointestinal bleeding. Among the elderly, nutrition, kidney disease and its other associated risk factors (diabetes mellitus, hypertension and cardiovascular disease) were the greatest contributors to anaemia. The focus of this article is iron deficiency anaemia related to kidney disease, its risk factors and management strategies. Iron supplementation remains the cornerstone treatment of iron deficiency and the anaemia of kidney disease. Early and correct diagnosis of iron deficiency along with optimisation of iron stores is also the primary aim of the management of the cardiorenal syndrome and anaemia in diabetes. Recent trials comparing various oral iron formulations have yielded conflicting results. Newer intravenous preparations including ferric carboxymaltose and ferumoxytol have simplified management by permitting safer high-dose administration. Erythropoietin stimulating agents are also established therapy for patients with anaemia and kidney disease, and are used in early kidney disease, diabetes and the cardiorenal syndrome. However recent large trials have raised concern over the safety of these agents in treating anaemia, particularly at high doses.