Plasma homocysteine, cobalamin/folate status, and vascular disease in a large population of psychogeriatric patients.

BACKGROUND

Cobalamin/folate deficiency and vascular disease are prevalent in elderly subjects and may lead to mental symptoms, but may even more often influence the severity of other organic and non-organic mental diseases. In the present study, we have evaluated cobalamin-folate status and the presence of vascular disease in 1,982 psychogeriatric patients investigated and diagnosed in a psychogeriatric clinic. The objective of the present study is to obtain information on the role of cobalamin/folate status and vascular disease in different diagnoses of psychogeriatric patients and their association with plasma homocysteine (tHcy).

METHODS

We have measured serum cobalamin, blood/serum folate, serum creatinine, plasma tHcy and evaluated the presence of vascular disease in 1,982 well-defined psychogeriatric patients.

RESULTS AND CONCLUSIONS

The present study indicates that cobalamin/folate deficiencies do not play an important role in cognitive dysfunction in psychogeriatric patients, since only about 7% of the study population had metabolic cobalamin/folate deficiencies. Furthermore, cobalamin/folate deficiencies were rare in younger patients (below 70 years of age). We were also able to confirm our previous finding that there was no association between dementia of Alzheimer type (AD) and plasma tHcy level or metabolic cobalamin/folate deficiencies. Furthermore, we observed a low proportion of vascular disease in patients with AD, which does not give support for an association between well-defined AD and the presence of vascular disease. The presence of vascular disease was higher and of similar degree in patients with mild cognitive impairment and depression, which indicates an association between these diagnoses and the presence of vascular disease. The present study also shows that at plasma tHcy levels below 14 micromol/l, the likelihood of cobalamin/folate deficiency is small and further investigation of cobalamin/folate status could be omitted.