Lipoprotein(a), vascular dementia and Alzheimer's disease

Serum levels of lipoprotein(a) (Lp(a)) represent an independent risk factor for atherosclerosis. In this study, we measured serum lipoprotein(a) in a group of patients with vascular dementia (VD) and in a group of patients with Alzheimer's disease (AD), in order to evaluate the importance of this risk factor. We studied 15 VD patients, (mean age 71 ± 9 years, 11 males and 4 females), and 15 AD patients (mean age 74 ± 10 years, 9 males and 6 females), as well as 10 normal control subjects (C) comparable of age and sex distribution. VD and AD were diagnosed according to the DSM-IV criteria. Lp(a) was measured by means of the ELISA method. The statistical analysis was carried out by using the non-parametric Mann-Whitney test. The average level of Lp(a) in VD patients (33 ± 26 mg/dl) was significantly higher than in AD patients (14 ± 9 mg/dl) and in controls (13 ± 5 mg/dl). If we divide the VD patients into three subgroups: (i) patients with cardioembolic stroke, and (ii) patients with stroke caused by cerebral arterial atherosclerosis; (iii) patients with multiple-region atherosclerosis, the Lp(a) level in the first group was 15±10 mg/dl, not different significantly from that of AD patients, and of controls. Lp(a) was only slightly increased in the second group, however, in the third subgroup of VD patients, Lp(a) was particularly high: 58.20 ± 29 mg/dl. Therefore, our data confirm that Lp(a) is an important risk factor in the multiple-region atherosclerosis and seem to exclude the direct correlation between Lp(a) and dementia.