Iron deficiency anaemia in older people: investigation, management and treatment.

Anaemia is the commonest haematological abnormality in the older population. It should never be considered as a normal physiological response to ageing [1]. The overall prevalence of anaemia in older people in the UK is 20.1% in elderly men and 13.7% in elderly women [2]. The causes of anaemia are diverse: the anaemia of chronic disease is probably the commonest in old age [3]. However, iron deficiency anaemia is also common and merits investigation and treatment [1]. In one study, almost a quarter of patients admitted to an acute elderly care ward were found to be anaemic with anaemia of chronic disease (35%) and iron deficiency anaemia (15%) being the commonest causes [4]. The World Health Organisation (WHO) criteria for diagnosing anaemia are a haemoglobin (Hb) level of less than 13 g/dl in men and 12g/dl in women [5]. There is considerable variation regarding this lower cutoff value between studies (Hb-10–11.5 g/dl for women and Hb-12.5–13.8 g/dl for men): perhaps the lower limit of the reference range of haemoglobin concentration for the laboratory performing the test should be used to define anaemia [6]. With advancing age there is a progressive and apparently physiological decrement of marrow haematopoiesis [7]. However, in older patients with haemoglobin levels of less than 12 g/dl or a haematocrit below 36% there can be an underlying cause for the anaemia [8]. In one study, anaemia—as defined by the WHO criteria—was associated with an increased mortality in people aged 85 years and older [9]. In the United States, iron deficiency anaemia occurs in up to 4% of elderly patients [10]. Similarly in the UK 3.5–5.3% of older people admitted in the hospital have iron deficiency anaemia [11]. Iron deficiency typically presents with a microcytic anaemia. Microcytosis is not specific for iron deficiency but may be found in chronic inflammation, sideroblastic anaemia and thalassaemia, and may not be present in combined deficiency with vitamin B12 or folate. The serum ferritin is the best non-invasive test for the diagnosis of iron deficiency in patients of all ages [12]. However, in the older population it should be interpreted judiciously. Serum ferritin level tends to rise with ageing [13]. In one study of healthy 85-year-old individuals, men had a mean serum ferritin level of 130 mg/l, women a value of 98 mg/l and there was no significant difference between the two sexes [14]. Whereas a low serum ferritin level always indicates …