A recent publication in in the British Medical Journal Open, highlights the prevalence of dementia risk factors in a real-world sample of community-dwelling adults over 50 years old in Ireland, and illuminates their role in cognitive decline. In this analysis, which involved participants enrolled in The Irish Longitudinal Study of Aging (TILDA), the authors examined the prevalence of dementia risk factors at different time points and examined how these interplayed with declines in cognitive performance which were assessed via the Montreal Cognitive Assessment (MOCA) score. The dementia risk factors used were those recently published in the Lancet Commission on dementia which includes 14 modifiable risk factors: lower educational attainment, hearing loss, high cholesterol, high blood pressure, physical inactivity, diabetes, social isolation, excessive alcohol consumption, air pollution, smoking, obesity, traumatic brain injury, depression and visual loss.
The study reported that 70.6% of the population had four or more risk factors, which decreased a little between the first and last groups enrolled (called waves in TILDA). Over time, 224,938 people or 24.9% of the population had evidence of moderate or severe decline in cognitive performance. The people who experienced severe decline had higher numbers of modifiable risk factors compared to people who experienced nil/mild or moderate decline. The authors determined that 68,742 moderate cases, and 32,480 severe cases of decline in cognitive performance could have been prevented over the eleven years of TILDA follow-up, if these risk factors had been addressed. The overall conclusions drawn were that 1) high prevalence rates indicate significant room for improvement and 2) national policies are needed to drive wholescale change. More information on this study is available here:
