Association between iron deficiency anaemia and mid-arm circumference in Crohn's disease.

The relation between nutritional anthropometry and haematological disturbance was studied in 55 outpatients with Crohn's disease and 30 healthy subjects. Patients with Crohn's disease were divided into undernourished (25) and well-nourished (30) groups, depending on whether their mid-arm circumference was below or above 90 per cent ideal standard. Undernourished patients with Crohn's disease had significantly reduced haemoglobin and red cell indices compared with well-nourished patients who were similar to the control group. In malnourished patients serum ferritin levels were usually below 50 micrograms/l and this level, rather than 15 micrograms/l indicates possible iron deficiency in patients with active inflammation. Results suggest that undernourished patients with Crohn's disease whose mid-arm circumference is less than 90 per cent ideal standard should be screened regularly for iron deficiency and anaemia.