Low levels of high density lipoprotein increase the severity of cerebral white matter changes: implications for prevention and treatment of cerebrovascular diseases.

BACKGROUND AND
PURPOSE: Cerebral White matter changes (WMC) are a frequent finding on CT and MRI scans of elderly individuals, particularly in those with vascular risk factors, cerberovascular disease, and cognitive impairment.
METHODS: 56 subjects were included in the study after the review of reports of more than 200 consecutive brain Computerized Tomography (CT) and magnetic resonance imaging (MRI) examinations from the out-patient and in-patient units of the Department of Geriatric Medicine at Karolinska University Hospital, Huddinge during 2001-2002. MRI was performed using a 1.5 T system and WMC lesions were graded 1-3 using a visual scale. Total-cholesterol (TC), high density lipoprotein (HDL), low density lipoprotein (LDL) and triglyceride (TG) levels were determined using enzymatic techniques after 12 hours overnight fasting. Apo E genotyping was performed as described.
RESULTS: Low HDL levels were associated with higher severity of WMC on MRI (p=0.002). Subjects with the Apo E4 allele had higher LDL (p=0.02) and apoB levels (p=0.005). The presence of the Apo E4 allele was higher in the group of subjects with severe WMC (grade 3). However, there was no statistically significant group difference in severity of WMC lesions between carriers and non-carriers of Apo E4 allele.
CONCLUSIONS: Low HDL is strongly associated with adverse coronary and cerebrovascular outcomes. Our results indicate that low HDL levels are also associated with more severe WMC lesions on MRI. Dietary or medical adjustment of HDL levels could have important implications for treatment and prevention of cerebral WMC, cerebrovascular and neurodegenerative diseases such as stroke and dementia.