People whose biological age is greater than their actual chronological age have a significantly increased risk of stroke and dementia, especially vascular dementia. The results of a study at the Karolinska Institute in Sweden that have been published Journal of Neurology, Neurosurgery and Psychiatry.
The study, which was led by Associate Professor Sara Haag and doctoral student Jonathan Mack in Karolinska Institutet’s Department of Medical Epidemiology and Biostatistics, shows that other risk factors such as genetics, lifestyle and socioeconomics also contribute to increased risk. taken into account
As we age, the risk of chronic diseases such as cancer, cardiovascular disease and neurodegenerative disorders increases. Researchers have traditionally relied on chronological age—how many years a person has lived—as an approximate measure of biological age.
But since people age at different rates, chronological age is a rather inaccurate measure.
Sarah Hague, Associate Professor, Karolinska Institutet
To measure the link between biological age and disease, the researchers used data from the UK Biobank. They studied a cohort of 325,000 people who were aged between 40 and 70 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 over a nine-year period.
Compared with actual, chronological age, higher biological age was associated with a significantly increased risk of dementia, particularly vascular dementia and ischemic stroke (i.e. blood clots in the brain).
“If a person’s biological age is five years older than their actual age, that person has a 40 percent higher risk of developing vascular dementia or stroke,” says Jonathan Mack.
Since this is an observational study, a causal relationship cannot be established. However, the results indicate that by slowing down the body’s aging process in terms of measured biomarkers, it may be possible to reduce or delay the onset of the disease.
“Several values can be influenced by lifestyle and medication,” says Sara Haag.
The results are particularly interesting because the study included such a large cohort. This makes it possible to slice the material into smaller pieces and capture less common diagnoses such as ALS.
The risk of developing ALS also increases with higher biological age. However, no such increased risk was observed for Parkinson’s disease.
“We already know that Parkinson’s disease is somewhat unique in other contexts, for example, when it comes to smoking,” says Sarah Haag.
Researchers will now move on to explore links between biological age and other diseases such as cancer.
The study was funded by the Swedish Research Council, the KI Foundation and the Strategic Research Area in Epidemiology and Biostatistics at KI (SFOepi).
Mack, JKL, etc (2023). Clinical biomarker-based biological aging and future risk of neurological disease in the UK Biobank. Journal of Neurology, Neurosurgery and Psychiatry. doi.org/10.1136/jnnp-2023-331917.