Lower Levels of Eicosapentaenoic Acid and the Ratio of Docosahexaenoic Acid to Arachidonic Acid in Sera of Patients with Multi-Infarct Dementia

Abstract

To survey the risk factors in multi-infarct dementia (MID), the levels of fatty acids in serum were measured for MID patients and compared with those of healthy individuals. Examined were 40 MID patients aged 57-94 and 152 healthy control subjects aged 50-89. The mean levels of polyunsaturated fatty acid (PUFA), monounsaturated fatty acid and saturated fatty acid of MID were lower than those of the control subjects (p<0.001, respectively). The total amounts of n-3 PUFA and n-6 PUFA in MID were significantly lower than those in control subjects (p<0.01 and p<0.05, respectively) but there were no differences among those of the ratios of n-3/n-6 PUFA. When compared with those of control subjects, low eicosapentaenoic acid (EPA, C20:5n-3) and high arachidonic acid (AA, C20:4n-6) were found in MID (p<0.001, respectively). No significant differences were found in the mean levels of docosahexaenoic acids (DHA, C22:6n-3) between MID and control subjects. The levels of EPA/AA and DHA/AA ratios were lower and the levels of DHA/EPA ratios were higher for the MID than for the control subjects (p<0.001, p<0.01, and p<0.001, respectively). The EPA/AA ratios showed a positive correlation with the DHA/AA ratios in MID patients and control subjects (r=0.65 and r=0.77, p<0.001, respectively). The ratios of DHA/AA showed a positive correlation with the DHA/EPA levels in control subjects (r=0.25, p<0.01), but there was no correlation in the dementia patients. These results suggest that the low EPA and high AA levels and the high DHA/EPA and low DHA/AA ratios might be useful indicators of MID.