Vascular biomarkers of cognitive performance in a community-based elderly population: the Dublin Healthy Ageing study

Background: population studies suggest that cardiovascular risk factors may be associated with cognitive impairment. Epidemiological studies evaluating individual markers of vascular disease as risk factors for cognitive dysfunction have yielded inconsistent results. Homocysteine has emerged as a marker consistently associated with poorer outcomes. Existing studies have largely examined individual vascular risks in isolation and have tended to ignore patient psychological status. Objective: to investigate the association between markers of vascular disease and cognition in a community-dwelling non-demented elderly population while adjusting for vascular and non-vascular confounds. Design: cross-sectional community based assessment. Participants: 466 subjects with mean age 75.45 (s.d., 6.06) years. 208 (44.6%) were male. Results: higher levels of homocysteine were consistently associated with poorer performance in tests assessing visual memory and verbal recall. No other vascular biomarker was found to be associated with cognitive performance. Factors such as alcohol use, tea intake, life satisfaction, hypertension and smoking were positively correlated with global cognitive performance. Negative correlations existed between cognitive performance and depression, past history of stroke, intake of fruit and use of psychotropic medication. Conclusions: homocysteine was the only vascular biomarker associated with poorer function in a number of domains on neuropsychological testing, independent of vascular and non-vascular confounds. Other psychosocial factors may need to be taken into account as potential confounds in future studies investigating cognition.