SPOUSES OF DEMENTED PATIENTS WITH LOW COBALAMIN LEVELS - A NEW RISK GROUP FOR COBALAMIN DEFICIENCY

Low serum cobalamin levels are common in conditions such as dementia a nd often represent mild deficiency. We surveyed serum cobalamin levels prospectively in spouses and blood relatives of demented patients to determine if any familial predisposition exists for the low levels. Co balamin status in most of the relatives found to have low levels was a ssessed further by means of blood counts, metabolic tests, neurologic evaluation, absorption studies and response to cobalamin therapy. Seru m cobalamin levels in 36 spouses correlated with those of the 36 demen ted patients related to them (r=0.46, p=0.004). A significant associat ion was not seen in 34 blood relatives of 34 demented patients (r=0.27 ). Most importantly, 67% of the spouses of demented patients with low serum cobalamin had low values themselves, compared with only 3% of th e spouses of patients with normal levels (p=0.001). Detailed study of 4 of the 5 spouses (and 3 blood relatives) with low cobalamin levels s howed no anemia in any case. Nevertheless, 4 of the subjects had metab olic evidence of deficiency and one had electrophysiological abnormali ties; all these defects improved with cobalamin therapy. These observa tions identify a hitherto unsuspected group of people at high risk for cobalamin deficiency and suggest that spouses of demented patients wi th low cobalamin levels should also have their cobalamin levels measur ed. The increased frequency of low serum cobalamin levels in spouses o f demented patients with low levels represents in most cases a true, m ild cobalamin deficiency that responds to treatment.