Factors associated with dementia in subjects with cerebrovascular disease

The pathogenesis of vascular dementia (VD) is still uncompletely understood. In the present study, we investigated a number of risk factors, including four common DNA polymorphisms that have been associated with cardiovascular disease and dementia, in a sample of 88 older subjects affected by cerebrovascular disease, with (VD: n = 68) or without (WD: n = 20) vascular dementia. The diagnosis of VD was based on the NINDS-AIREN criteria. All subjects with VD had a Hachinski ischemic score over 7. The functional status was measured by the Barthel index. Subjects with VD were characterized by older ages (82.5 +/- 0.8, SEM and 75.6 +/- 1.4, SEM), lower Barthel score (8.1 +/- 0.8 and 13.7 +/- 1.5), and fewer years of education (4.6 +/- 0.4 and 6.6 +/- 0.7) as compared to WD, respectively. The prevalence of cerebral atrophy (72 vs 53 %), lacunar infarctions (75 vs 53 %), and leukoaraiosis (50 vs 26 %) was higher in VD, as compared to WD. On the contrary, the prevalence of cortical-subcortical ischemic lesions was lower in VD than in WD (25 vs 53 %). ACE gene DD homozygotes were about three times more frequent in VD (32 %) than in WD (12 %); similarly, homozygotes for the methyl en-tetrahydrofolate reductase (MTHFR) thermolable mutant allele were four times more frequent in VD (25 %) than in WD (6 %). In the WD group, no subjects with small vessel disease (SVD) were homozygous for the D allele or the MTHFR thermolable allele. In conclusion, in older individuals with cerebrovascular disease, dementia was associated with older age, fewer years of education, lower functional status, and with the presence of lacunar infarctions, leukoaraiosis and cerebral atrophy. Homozygosity for the ACE deletion and the MTHFR thermolable alleles seems also to be associated with the risk of dementia in these subjects.