PROTECT Norge: Online assessment of potentially modifiable risk factors for dementia on cognitive performance in a Norwegian ageing cohort

Abstract Background PROTECT Norge, a fully digital platform, aims to help determine the role of defined genetic, lifestyle and environmental factors on cognition, health and wellbeing in people 50+. Annual questionnaires on demographics, medical conditions and medication use, mental health and lifestyle are completed online. The current study aims to assess whether potentially modifiable risk factors for dementia as presented by the Lancet Commission by Livingston and colleagues (2020) are related to cognitive performance in cognitively healthy people aged 50 and above. Method A total of 2349 participants completed the PROTECT Cognitive Test System, an online cognitive battery containing six tasks which assess visual episodic memory, spatial and working memory, verbal reasoning, visual attention and task switching. The following risk factors were included in our analysis: physical activity, alcohol use, smoking, social isolation, age, BMI, education, depression, high blood pressure, head trauma and hearing loss. Multiple hierarchical regression analysis was performed. Separate analyses were conducted with the average performance across three sessions for each of the six cognitive measures as the dependent variable. Independent variables were included into the model in a hierarchy based on known risk factors for dementia. Result Results show that age was associated with reduced cognitive performance for all tasks (p<0.001). In addition, for the digit span test, the risk factors were found to influence the test score were: smoking and previously diagnosed stroke. For the paired associate learning task, the only additional significant risk factor appeared to be gender, with male gender associated with poorer performance. For the grammatical reasoning task, the risk factors associated with lower scores were lower education, older age and smoking. For the switching Stroop test, the risk factors of lower scores were older age, smoking and previously diagnosed depression. For Trail‐making B test, the risk factors of lower scores were age, stroke and the history of heart disease. Conclusion These preliminary results may improve our understanding of potentially modifiable risk factors for dementia and could inform the design and delivery of interventional trials as a mean to protect cognition in later life and to prevent or slow progression of cognitive decline.