The pituitary-thyroid axis in severe falciparum malaria: evidence for depressed thyrotroph and thyroid gland function

Abstract
Abnormal thyroid function is strongly associated with mortality in severe non-thyroidal illness. We have assessed the pituitary-thyroid axis serially in 18 Thai adults with severe falciparum malaria and in 18 matched controls. The admission total serum thyroxine (T4) concentrations of the patients (median [range]: 64 nmol/litre [P < 0·01), and remained depressed until alter fever and parasite clearance. Two patients who died in hospital had admission serum T4 concentrations n = 10, 2P < 0·01) and controls (5·6 mU/litre [3·3–12·9], n = 9, 2P < 0·05). These findings suggest that thyrotroph and thyroid gland function are depressed during acute, severe malaria. As these changes may be an adaptation to accelerated catabolism, the role of thyroid replacement in such patients is uncertain.