Vitamin K concentration and cognitive status in elderly patients on anticoagulant therapy: a pilot study

Objectives. Recent studies have suggested that vitamin K may exert significant effects on the central nervous system. The present study investigates the relationship between vitamin K plasmatic levels and cognitive functions in elderly patients on oral anticoagulant therapy (OAT). Design. At the Thrombosis Centre of Haematology, "Sapienza" University of Rome, 85 patients on OAT, aged between 75 and 92, were randomly enrolled in the study. Patients were on OAT with vitamin K antagonists (VKAs). Vitamin K1 concentrations were determined using standardized High-Performance Liquid Chromatography (HPLC). Cognitive functions were assessed using the Milan Overall Dementia Assessment (MODA). Results. MODA scores are positively correlated to vitamin K1 concentration. Patients with vitamin K1 below 0.100 μg/L and between 0.100 and 0.400 μg/L showed a mean MODA score of 79 ± 5 and 82 ± 3, respectively. Patients with vitamin K1 above 0.400 μg/L had a significantly greater MODA score (89 ± 1). After binning the data into bicentiles, MODA scores are shown to be linearly dependent on vitamin K1 concentrations (p<0.001). Even long-term OAT (>10 years) does not affect MODA scores. Education seems to exert a greater role on the cognitive status in comparison with aging. Conclusions. The study shows a positive association between vitamin K1 concentration and cognitive status in elderly patients (≥75 years) on OAT. The relationship between vitamin K1 concentration and MODA scores is described by a linear model. Cognitive status is not influenced by the duration of OAT but by the years of education. © 2020 Ludovico Alisi et al.