Being affected by several cardiometabolic diseases such as diabetes, heart disease and stroke is an increasingly common clinical situation in patients, with the aging of populations. The authors estimate that this cardiometabolic multimorbidity now affects about 30% of the elderly and leads to a significant increase in mortality. However, this cardiometabolic multimorbidity turns out to be linked to a considerably increased risk of dementia and Alzheimer’s disease.
The same risk genes for cardiometabolic and neurodegenerative diseases?
Cardiometabolic diseases such as type 2 diabetes, heart disease and stroke represent a growing challenge for society, says lead author Abigail Dove, a researcher at the Aging Research Center at Karolinska Institutet: “We knew that type 2 diabetes, heart disease and stroke are individual risk factors for dementia, but few studies have addressed the effect of this multimorbidity on dementia risk and how genetic factors affect the relationship “.
The study is carried out on more than 17,000 twins aged over 60 registered between 1998 and 2002 in the Swedish twin register and classified according to their number of cardiometabolic diseases. All were in good cognitive health at baseline and their condition was followed for 18 years, allowing the team to monitor the incidence of dementia. This analysis reveals that:
- cardiometabolic multimorbidity is linked to a more than doubled risk of vascular dementia and a 50% increased risk of Alzheimer’s disease;
- for each additional cardiometabolic disease, the risk of all types of dementia increases by 42%, Alzheimer’s by 26% and vascular dementia by 64%;
- the risk of developing dementia is higher with cardiometabolic disease in middle age vs. later in life: earlier cardiometabolic disease is arguably also more aggressive, the researchers suggest.
Same genetic factors of cardiometabolic risk and dementia: thus the analysis of the data of approximately 400 pairs of mono and dizygotic twins, reveals that,
- among dizygotic twins who share 50% of their genes, the twin with cardiometabolic disease was more likely to also be the one who develops dementia;
- among identical twins, the risk of dementia is similar for both twins, regardless of cardiometabolic disease status.
These results suggest that the same genetic factors may contribute to both cardiometabolic disease and dementia and emphasize the need for special monitoring of cognitive health in patients with cardiometabolic disorders.