C-reactive protein levels are associated with cerebral small vessel-related lesions.

OBJECTIVE: Inflammation has received increasing attention as a cause of stroke. Although several lines of evidence suggest that inflammatory processes have a role in arteriosclerotic vascular events, their involvement remains to be determined. The purpose of this study was to examine the associations between serum high-sensitive C-reactive protein (hs-CRP) levels and cerebral small vessel (CSV)-related lesions as a manifestation of arteriosclerosis. MATERIALS AND METHODS: Neurologically normal subjects without any history of neurologic or psychiatric diseases were enrolled (n = 519). All the participants underwent magnetic resonance imaging (MRI), and their CSV-related lesions (i.e., lacunar infarcts, cerebral microbleeds, deep white matter hyperintensity, and periventricular hyperintensity) were evaluated. The serum levels of hs-CRP were evaluated as common inflammatory markers. RESULTS: Subjects with higher C-reactive protein (CRP) levels had more lacunar infarcts (P = 0.02). After adjusting for the traditional cardiovascular risk factors, higher hs-CRP levels were still associated with the presence of lacunar infarcts [odds ratio for the highest vs the lowest tertile of hs-CRP, 3.57 (95% confidence interval: 1.30-9.80)]. These associations did not change when the logarithmically transformed values for hs-CRP were included. Furthermore, subjects with higher CRP levels had more cerebral microbleeds (P = 0.03), more severe deep white matter hyperintensity (P = 0.04), and periventricular hyperintensity (P = 0.04); however, these associations were not observed after adjusting for the cardiovascular risk factors. CONCLUSIONS: Higher levels of hs-CRP were associated with lacunar infarcts. Thus, inflammatory processes may be involved in the pathogenesis of small-vessel disease.

Impact of five SNPs in dopamine-related genes on executive function.

OBJECTIVES: Dopamine neurotransmission is a critical factor for executive function, which is controlled by the prefrontal cortex in humans. Although the contribution of genetic factors to the regulation of brain dopaminergic activity is widely acknowledged, identification of a genotype-phenotype association has not yet been clearly established. In this study, we therefore evaluated the effects of five functional single-nucleotide polymorphisms (SNPs) in specific genes related to dopamine neurotransmission on executive function in a general population. MATERIALS AND METHODS: Participants of the health examination at the Shimane Institute of Health Science were recruited for this study (n = 964). To evaluate executive function, the Frontal Assessment Battery (FAB) was administered. SNPs were genotyped using the TaqMan method. RESULTS: A significant association was found between an SNP in the catechol-O-methyltransferase (COMT) gene (rs4680) encoding the low-activity Met allele and FAB score (P = 0.003). Of note, the flexibility subset of the FAB was associated with the SNP in COMT (P = 0.003) after adjustment for confounding factors. The generalized multifactor dimensionality reduction method identified that the combination of two SNPs in the COMT gene (rs4680) and the dopamine D4 receptor gene (rs1800955) had a significant effect on FAB score. CONCLUSIONS: Our study indicates a contribution of rs4680 in the COMT gene to the variability in executive function, as assessed by the FAB. In addition, we have indicated that a complex gene-gene interaction between SNPs in the genes related to dopamine neurotransmission may influence executive function in a general population.