The high prevalence of unrecognized anaemia in patients with diabetes and chronic kidney disease: a population-based study

Background Anaemia occurs early in the course of diabetes-related chronic kidney disease (CKD). There is little evidence about the prevalence of anaemia in people with diabetes. The aim of this study was to assess the prevalence of anaemia, by stage of CKD, in the general diabetic population. Methods Haemoglobin (Hb) was measured on all glycated haemoglobin (HbA_1c) samples and the most recent (< 4 months) estimated glomerular filtration rate (eGFR) was obtained. Anaemia (at treatment level) was defined as Hb < 110 g/l or the use of erythropoetic stimulating agents (ESA). Results Twelve per cent (10–14%) of people had Hb < 110 g/l. The prevalence of anaemia increased progressively with worsening CKD. People with CKD stage 3 accounted for the largest number of people with anaemia; 18% (95% CI 13–24%) had Hb < 110 g/l. Those with eGFR < 60 ml/min/1.73 m² and not on ESA or dialysis were four (2–7) times more likely than patients with better renal function to have Hb < 110 g/l. The relation between Hb and eGFR became approximately linear below an eGFR of 83 ml/min/1.73 m², where, for every 1 ml/min/1.73 m² fall in eGFR, there was a 0.4 (0.3–0.5) g/l fall in haemoglobin. Conclusions This study demonstrates that anaemia, at levels where treatment is indicated, occurs commonly in people with diabetes and CKD stage 3 or worse. The screening for anaemia in current diabetes management should be extended.