Haematological changes and infectious complications in anorexia nervosa: a case-control study.

To determine the prevalence of haematological abnormalities in patients with anorexia nervosa (AN), and assess the relationships between these changes, the severity of AN and the propensity to infections, we retrospectively studied 67 patients who met the DSM-III-R diagnostic criteria for AN. We recorded physical findings and routine haematological data on admission, and infectious events during hospitalization. The patients were compared with 67 normal controls matched for age and sex. Mean haemoglobin (Hb) was normal but lower in AN patients than in controls (131 +/- 19 vs. 137 +/- 11 g/l, p = 0.03) and the prevalence of anaemia (Hb < 120 g/l) was higher in the AN group (27% vs. 1.5%, p < 0.0001). Patients had a lower leucocyte count (4.94 +/- 1.9 vs. 6.78 +/- 2.4 x 10(9)/l, p < 0.0001), and increased prevalence of leucopenia (< 4 x 10(9) cells/l)(36% vs. 1.5%, p < 0.0001), neutropenia (< 1500 x 10(6) cells/l)(17% vs. 0%, p = 0.0015) and thrombocytopenia (< 150 x 10(9)/l) (10% vs. 0%, p = 0.03). Only 2 patients (3%) had pancytopenia, but 9/17 patients with anaemia (53%) also had leucopenia. There was a slight but significant correlation between body-mass index (BMI) and total leucocyte, neutrophil and red blood cell counts. Severe infectious complications occurred in 9% of AN patients vs. 0% in controls (p = 0.01); they were more frequent with neutropenia (relative risk, 15.1: 95% CI, 10-20.2) or low (< 12) BMI (relative risk, 11.6: 95% CI, 6.6-16.6) on admission. Compared with controls, AN patients thus had an increased prevalence of anaemia, leucopenia and thrombocytopenia.(ABSTRACT TRUNCATED AT 250 WORDS)