Over a lifetime, the risk of developing dementia is affected by both modifiable and non-modifiable factors, such as blood pressure and sex. In an article recently published in The Journal of Prevention of Alzheimer's Disease, MultiPark researchers Sebastian Palmqvist and Isabelle Glans, together with colleagues, elucidated how various risk factors impact brain pathology linked to the two most common forms of dementia – Alzheimer’s disease and vascular dementia.
"Much of the existing evidence on modifiable risk factors and dementia incidence is on all-cause dementia. There is more limited understanding of how individual risk factors influence distinct dementia subtypes and their underlying neuropathological changes over time," explained the last author, Sebastian Palmqvist.
The study included 494 cognitively unimpaired participants with a mean age of 65 years and a mean follow-up of 4 years. At several time points, they measured the white matter changes, usually linked to vascular dementia, as well as the Alzheimer’s-associated proteins Aβ and tau.
"The aim of this study was to examine the effect of both modifiable and non-modifiable risk factors on longitudinal accumulation of white matter hyperintensities, Aβ, and tau," explains the first author, Isabelle Glans.
The majority of modifiable risk factors, such as high blood pressure, ischemic heart disease, and smoking, were linked to vascular pathology.
We found that modifiable risk factors for dementia primarily influence the accumulation of cerebrovascular pathology rather than Aβ or tau.
"We found that modifiable risk factors for dementia primarily influence the accumulation of cerebrovascular pathology rather than Aβ or tau. High blood pressure, hyperlipidemia, smoking, and pre-existing cardiovascular disease were associated with a faster accumulation of white matter hyperintensities," says Isabelle Glans.
However, modifiable risk factors were not only limited to vascular pathology; some were associated with Alzheimer pathology.
"Having diabetes was associated with increased Aβ pathology, whereas lower BMI was linked to greater tau accumulation," describes Isabelle Glans.
"Targeting vascular and metabolic risk factors may still help reduce the synergistic effects of co-existing neuropathologies."
Nevertheless, having a healthy lifestyle and managing modifiable risk factors such as high blood pressure and diabetes may still be critical for delaying cognitive problems linked to Alzheimer’s, as many patients with dementia suffer from mixed forms. Sebastian Palmqvist underscores the importance of a healthy lifestyle in Alzheimer's disease: "Targeting vascular and metabolic risk factors may still help reduce the synergistic effects of co-existing neuropathologies."
