The burden of anaemia in type 2 diabetes and the role of nephropathy: a cross-sectional audit

Background. Anaemia is a common finding in patients with diabetes and constitutes an additional burden in patients with advancing age and comorbid vascular disease. This study examines the prevalence and predictors of anaemia in long-term outpatients with type 2 diabetes from three large clinical centres. Methods. A full blood count was obtained in addition to routine testing in a cross-sectional survey of all patients with type 2 diabetes in long-term follow-up at the Austin Medical Centre, Melbourne (n = 670) and the Royal Prince Alfred Hospital (n = 915) and the Royal North Shore Hospital (n = 540), Sydney, Australia. The prevalence and correlates of anaemia (haemoglobin < 130 g/l in men and < 120 g/l in women) were identified using multivariate logistic regression. Results. Roughly, one in five patients in each centre had anaemia. Patients at greatest risk could be readily identified by the presence of renal disease, manifested as impaired renal function and/or albuminuria in >75% of patients with anaemia. Patients with diabetes and mild renal impairment [creatinine clearance (CCr) 60-90 ml/min/1.73 m(2)] were twice as likely to have anaemia as those with normal renal function (CCr >90 ml/min/1.73 m(2)). Diabetics with moderate renal impairment (CCr <60 ml/min/1.73 m(2)) were also twice as likely to have anaemia as those with mild renal impairment. Patients with anaemia were also more likely to have macrovascular disease, reflecting the high prevalence of nephropathy in these patients. Conclusions. Anaemia is a prevalent finding in patients with type 2 diabetes and represents a significant unrecognized burden. Patients at greatest risk can be identified by the presence of renal disease, either in the form of renal impairment and/or albuminuria.