Anaemia is common and predicts mortality in diabetic nephropathy
From the Renal Unit and 1Diabetic Unit, Glasgow Royal Infirmary, Glasgow, UK
Address correspondence to Dr C. Stirling, Renal Unit, Glasgow Royal Infirmary, Castle Street, Glasgow G4 0SF, UK. email: cath.stirling{at}northglasgow.scot.nhs.uk
Received 8 December 2006 and in revised form 29 June 2007
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Abstract |
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Background: Diabetes is the single largest cause of chronic renal failure, accounting for 18% of patients on renal replacement therapy in the UK.
Aim: To investigate the chronic kidney disease stage at which patients with diabetic nephropathy are referred to renal services, determine the prevalence of anaemia in patients with diabetic nephropathy, examine patient outcome and identity prognostic factors.
Design: Retrospective review.
Methods: Patients with diabetic nephropathy referred to our renal services between 1989 and 2004 were identified from electronic records. Estimated glomerular filtration rate (calculated using the MDRD formula) and haemoglobin at referral were collected. Times to renal replacement therapy and death were noted.
Results: We identified 508 patients. At referral, mean eGFR was 34 ml/min/1.73 m2 and 48% of patients were at CKD stages 4 and 5. Mean haemoglobin was 11.7 g/dl; 21% had a haemoglobin <10 g/dl at referral. Median survival was 37.9 months (95%CI 33.2–42.6); median survival independent of renal replacement therapy (RRT) was 21 months (95%CI 17.8–24.6). Of patients starting RRT, 38% did so within 1 year of referral. Older age (RR 1.02, 95%CI 1.01–1.04) and lower haemoglobin (RR 0.9, 95%CI 0.85–0.99) at referral predicted death on multivariate analysis.
Discussion: At referral to renal services, almost 50% of patients with diabetic nephropathy were at CKD stages 4 and 5. Anaemia was common and predicted mortality. All diabetic patients from CKD stage 3 should be screened for anaemia. We believe that patients with diabetic nephropathy should be discussed with renal services when they reach CKD stage 3 with evidence of progression of renal disease.