Deficient catecholamine release as the basis of orthostatic hypotension in pernicious anaemia.

A patient with peripheral neuropathy and orthostatic hypotension was found to have pernicious anaemia. Symptoms improved after vitamin B12 replacement therapy. Insulin tolerance testing showed that the patient lacked catecholamine, heart rate, and sweating responses to hypoglycaemia. This indicates that pernicious anaemia may cause orthostatic hypotension owing to failure of noradrenaline release.