Charalampos Dragonas

Uric Acid and Dementia in Community-Dwelling Older Persons

Background: The biological action of uric acid (UA) in humans is controversial. UA is considered an antioxidant compound, but preclinical evidence suggests a proinflammatory action. Epidemiological studies found that hyperuricemia is associated with conditions leading to dementia. Our aim is to investigate the relationship between UA levels and dementia in older persons. Methods: Cross-sectional study performed in 1,016 community-dwelling older persons participating in the InCHIANTI study. Participants underwent determination of circulating UA levels and neuropsychological evaluation. A multivariate logistic regression model was used to estimate the probability of participants belonging to the highest and middle UA tertile to be affected by dementia compared to those in the lowest tertile. Results: Demented persons had higher UA levels (p = 0.001) and the prevalence of persons affected by dementia increased across UA tertiles (p < 0.0001). Independent of several confounders, persons belonging to the highest UA tertile had a threefold (OR = 3.32; 95% CI: 1.06–10.42) higher probability to suffer from a dementia syndrome while those in the middle UA tertile tended to have a higher probability of being demented compared to those in the lowest tertile. Conclusion: In a population-based sample, high circulating UA levels are associated with an increased likelihood to be affected by a dementia syndrome.

Plasmalogens as a marker of elevated systemic oxidative stress in Parkinson's disease.

Experimental evidence indicates a significant role of oxidative stress in the pathogenesis of idiopathic Parkinson’s disease (PD). However, some studies report no decrease in common antioxidants in blood plasma as a marker of oxidative stress (1). The aim of this study was to estimate plasmalogen levels in blood plasma samples of patients with PD, a group of 1-alkenyl-2-acyl-sn-glycero-3-phospholipids considered to be a sensitive surrogate marker of oxidative stress. The precise role played by plasmalogen phospholipids of lipoproteins and cell membranes is not well understood. Considerable attention has been focused on the role of plasmalogens as a source of lipid mediators, based on the activity of calcium-independent phospholipase A2 which was shown to catalyze the hydrolysis of arachidonic acid located at the sn2 position of plasmalogens (2). However, plasmalogen status appears to have no influence on stimulated arachidonic acid release in plasmalogendeficient macrophages (3). In addition, plasmalogens can act directly as endogenous antioxidants in defending cell membranes and lipoproteins from reactive radical species. This is accomplished primarily by means of the radical scavenging activity of their vinyl ether bond at the sn1 position (2, 4–6). The present study describes plasmalogen-derived hexadecanal dimethyl acetal (16:0 DMA) concentrations in blood plasma total phospholipid samples from patients with PD, and from age-matched control sub-

Procalcitonin: Inflammatory Biomarker for Assessing the Severity of Community-Acquired Pneumonia – A Clinical Observation in Geriatric Patients

Community-acquired pneumonia is a common disease of the elderly and involves a high mortality risk. Demographic developments are creating new challenges for acute medical treatment strategies in geriatric patients with their underlying multimorbidity. In addition to the diagnostic parameters recorded on hospital admission, such as white cell count and C-reactive protein, procalcitonin, more than the risk scores CRB- and CURB-65 evaluated to date, appears to be a promising parameter for assessing the severity of pneumonia in elderly patients to allow early detection of severe courses and initiation of suitable treatment. The decisive factor is the dynamic course of the procalcitonin values over 3 consecutive days, as demonstrated in this case series.