People who have a higher biological age than their actual chronological age have a significantly increased risk of stroke and dementia, especially vascular dementia. These are the results of a study from Karolinska Institute in Sweden published in the Journal of Neurology, Neurosurgery and Psychiatry.
The study, which was led by Sara Hägg, associate professor, and Jonathan Mak, doctoral student at the Department of Medical Epidemiology and Biostatistics, Karolinska Institute, shows that the increased risk persists even if other risk factors such as genetics, lifestyle and socioeconomics are taken into account.
In order to measure biological age and the link to disease, the researchers used data from the UK Biobank. They studied a cohort of 325,000 people who were all between 40 and 70 years old at the time of the first measurement.
Biological age was calculated using 18 biomarkers, including blood lipids, blood sugar, blood pressure, lung function and BMI. The researchers then investigated the relationship between these biomarkers and the risk of developing neurodegenerative diseases such as dementia, stroke, ALS and Parkinson's disease within a nine-year period.
When compared to actual, chronological age, high biological age was linked to a significantly increased risk of dementia, especially vascular dementia, and ischemic stroke, (i.e. blood clot in the brain).
“If a person's biological age is five years higher than their actual age, the person has a 40 percent higher risk of developing vascular dementia or suffering a stroke,” says Jonathan Mak.
The risk of developing ALS also increases with higher biological age. However, no such risk increase was seen for Parkinson's disease.