Severe Infections Linked to Increased Dementia Risk, Study Finds
A new study conducted by researchers at the University of Helsinki in Finland demonstrates that severe infection increases the risk of dementia, independently of other coexisting illnesses. The research, published in PLOS Medicine, found that infections like urinary tract infections (UTIs) and unspecified bacterial infections are significantly associated with an increased risk of dementia, even after accounting for other health conditions.
Study Details
Researchers analyzed nationwide Finnish Health Register data, encompassing over 374,000 individuals. The data included individuals aged 65 or older who were diagnosed with late-onset dementia between 2017 and 2020. They examined all hospital-treated diseases over a 20-year period, identifying 29 conditions linked to an increased risk of dementia.
Study Results
The study revealed that nearly half of dementia cases (47%) had at least one of the 29 identified diseases prior to diagnosis. Of these, cystitis (UTIs) and bacterial infections of unspecified sites were the most robustly linked to late-onset dementia. Other non-communicable diseases strongly associated with dementia included mental disorders resulting from brain damage or physical disease, Parkinson’s disease, and alcohol-related mental and behavioral disorders.
Importantly, the association between infection and dementia remained strong even after adjusting for the 27 non-communicable diseases. Less than one-seventh of the dementia risk associated with severe infections could be attributed to pre-existing conditions, suggesting infections are a standalone risk factor.
The link between infection and dementia was particularly pronounced for early-onset dementia (diagnosed before age 65). Five types of infections – including pneumonia and tooth decay – showed a significant association with increased risk in this group.
On average, dementia-associated infections occurred 5 to 6 years before a formal dementia diagnosis, suggesting that severe infections may accelerate underlying cognitive decline.
“our results support the possibility that severe infection increases the risk of dementia; however, interventional studies are needed to determine whether effectively preventing or treating infection yields benefits for dementia prevention,” the researchers state.
Implications and Future Research
This research highlights the importance of preventing and effectively treating severe infections, particularly in older adults. Whereas the study demonstrates a strong association, further research is needed to establish a definitive cause-and-effect relationship. Interventional studies are crucial to determine whether preventing or treating infections can reduce the risk of dementia.