An analysis of Swedish health records shows that people diagnosed with Alzheimer’s before the age of 60 are more likely to have been treated for an infection in hospital more than five years earlier.
September 15, 2022
People who are treated in the hospital for infections may be at higher risk of developing early-onset Alzheimer’s disease years later.
Jiangwei Sun at the Karolinska Institute in Sweden and colleagues analyzed the health records of about 290,000 people in Sweden with Alzheimer’s disease and 1.4 million age- and sex-matched people who had not been diagnosed with the disease.
Among those diagnosed with Alzheimer’s before age 60, 17.4 percent had been treated in hospital for an infection at least five years earlier, compared with 9.8 percent of age-matched people without a diagnosis of Alzheimer’s. Alzheimer’s.
Bacterial infections and those of the urinary and genital organs were most strongly linked to an increased risk of Alzheimer’s disease, but viral, central nervous system and gastrointestinal infections were also seen.
The researchers took into account differences in people’s education and their family history of neurodegenerative diseases and other conditions, including cardiovascular disease and diabetes.
Many previous studies have hinted at potential links between Alzheimer’s disease and specific pathogens, such as the herpes virus. The findings build on this by adding evidence that there is a general link between the infection and the condition.
“Despite the abundance of preclinical data… there are not many well-conducted observational studies in this area. Therefore, the findings of the current study should be viewed as an important addition,” he says. antonio dueros at McGill University in Montreal, Canada.
“The results are broadly consistent with the concept, supported by some 500 articles using a wide variety of approaches, that microbes play an important role in Alzheimer’s disease,” he says. ruth itzhaki at the University of Manchester, UK.
However, the results do not necessarily show that infections increase the risk of Alzheimer’s. Another possibility is that undetected early changes in the body due to Alzheimer’s disease may make people more prone to infections. Alternatively, other factors may have increased the risk of both Alzheimer’s disease and infections, such as immune dysfunction or alcohol or drug abuse, he says. Pyry sipilae at the University of Helsinki in Finland.
“To translate this work into clinical practice, we need to investigate whether strategies aimed at reducing infections reduce the risk of later dementia,” he says. Rutendo Muzambi at the London School of Hygiene and Tropical Medicine.
Magazine reference: PLOS Medicine DOI:
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