Midlife chronic conditions associated with higher dementia risk as we age
Middle-aged people with multiple chronic conditions may have a higher risk of developing dementia later in life according to a new study.
French researchers found that middle aged people with at least two chronic conditions - including diabetes, high blood pressure, coronary heart disease and chronic lung disease (COPD) - have a higher risk of dementia than those who develop these conditions when they are older.
While studies have shown that having two or more chronic conditions - known as multimorbidity - is common, especially among older people and those with dementia, little is known about how multimorbidity affects one’s risk of dementia.
The new study, published in the BMJ, saw the team use data collected from over 10,000 British men and women involved in the Whitehall II Study, which looks at the association between social, behavioural and biological factors and long-term health.
Of the 10,095 participants in the study, about 600 people (6.6 percent) had multimorbidity at 55, while 3200 people (32 percent) did by 70.
When participants first joined the study between the ages of 35 and 55, they were free of dementia.
Over a median follow-up period of 32 years, the team identified 639 people with dementia.
The researchers then found that, considering factors such as age, sex, diet and lifestyle, people with multimorbidity at 55 had a 2.4-times higher risk of dementia compared to those without any of the 13 chronic conditions they looked at.
They also found that this association weakened as the age that people were diagnosed with multiple chronic conditions increased.
Though the team did find an association between age, multimorbidity and dementia risk, they stressed it was an observational study that can’t establish cause and effect.
They also noted some limitations to their study, such as the misclassification of some dementia cases, and that the study participants were likely to be healthier than the general population.
Despite these limitations, the researchers said their findings could be promising for finding ways of preventing dementia.
“Given the lack of effective treatment and its personal and societal implications, finding targets for prevention of dementia is imperative,” they write.
“These findings highlight the role of prevention and management of chronic diseases over the course of adulthood to mitigate adverse outcomes in old age.”
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