[Plasma, red cell, and cerebrospinal fluid folate in Alzheimer's disease]

This study compares plasma, red cell, and cerebrospinal fluid (CSF) folate levels in subjects with mild or moderate Alzheimer's disease (AD) of senile onset and in non-demented control subjects. Twelve subjects with mild or moderate (Folstein's Mini-Mental-State-MMS--between 10 and 23) AD (DSM3 R criteria) and 12 control subjects without dementia and with MMS above 23 were included. To avoid any change in plasma folate levels due to dehydration, all dehydrated subjects were excluded. Were also excluded all subjects obviously suffering from malnutrition or alcoholism, or taking drugs likely to interfere with folate metabolism. Changes in folate levels due to posture or prolonged venous occlusion were carefully avoided. Patients with AD were 5 males and 7 females aged (Mean +/- SD) 80.2 +/- 5.7 years, MMS 14.8 +/- 2.6; controls were 7 males and 5 females aged 78.9 +/- 7.2 y, MMS 28.3 +/- 1.5. The two groups were not statistically different for these variables, except for the MMS. Plasma folate levels were lower (p < 0.006) in patients with AD (4.5 +/- 1.5 micrograms/l) compared with controls (7 +/- 2.2 micrograms/l). Red cell folate levels were lower (p < 0.007) in patients with AD (183.7 +/- 91.1 micrograms/l) compared with controls (300.4 +/- 96.1 micrograms/l). CSF folate levels were lower in AD (18.9 +/- 9.7 micrograms/l) than in controls (21.9 +/- 8.2 micrograms/l) but the difference was not statistically significant (p > 0.05). Our results indicate poorer nutrition in patients with AD.