Researchers at Oxford Population Health have found that having metabolic syndrome in late midlife (between the ages of 60 and 69) is associated with an increased risk of dementia when compared with people who have metabolic syndrome later in life. The study is published in The Lancet Healthy Longevity.
Poor metabolic health, also known as “metabolic syndrome”, is defined as having three or more of the following conditions: a large waist circumference, high levels of triglycerides, high blood pressure, high blood sugar levels, and lower levels of high-density lipoprotein (HDL) cholesterol, sometimes known as “good” cholesterol. One in four people around the world are thought to be currently living with metabolic syndrome.
Previous studies have shown that living with metabolic syndrome is associated with an increased risk of developing dementia and worse brain health than people without metabolic syndrome. In this study, researchers aimed to determine whether the length of time that a person has metabolic syndrome and the age at which they develop the condition have an impact on their risk of developing dementia.
The researchers looked at data collected from 20,150 participants in the European Prospective Investigation into Cancer - Norfolk (EPIC-Norfolk) study. Participants were between ages 50 to 79 years when they joined the study. To find out how long the participants with metabolic syndrome had been living with the condition, the researchers looked at data from 12,756 participants who had attended two or more health assessments.
Key findings of the study:
- In all participants, poor metabolic health was associated with an increased risk of developing dementia over 25 years of follow-up;
- When looking at the age of the participants, having poor metabolic health in late midlife (ages 60 to 69 years) was associated with a higher increased risk of developing dementia;
- Having poor metabolic health in early midlife (ages 50 to 59 years) was also associated with an increased risk of dementia (although results were not statistically significant);
- There was no association between poor metabolic health in late life (ages 70 to 79 years) and risk for dementia;
- Living with poor metabolic health over a prolonged period of time significantly increased the risk of developing dementia.
Danial Qureshi, DPhil candidate at Oxford Population Health, said ‘These findings provide evidence that metabolic syndrome may be a key risk factor for developing dementia. Importantly, we were able to look at these associations over a long follow-up period of 25 years, and explore how changes in metabolic syndrome status over time impacts dementia risk. Understanding more about the critical age windows and duration of time exposed to dementia risk factors could be important for improving our ability to prevent this devastating disease.’
A supporting commentary on this paper was published in The Lancet Healthy Longevity on 26 November 2024.