Infection linked to increased risk of Alzheimer’s and Parkinson’s disease

The study is based on data from people diagnosed with Alzheimer’s disease, Parkinson’s disease or amyotrophic lateral sclerosis during the years 1970-2016 in Sweden.

The results show that infections treated in hospital five or more years before diagnosis are associated with a 16 percent increased risk of Alzheimer’s disease and a 4 percent increased risk of Parkinson’s disease. The association was only seen for people diagnosed before age 60 and not for people diagnosed later in life.

Highest risk of infection before the age of 40

The risk was higher among people who had repeated infections in the hospital before they reached the age of 40. Among them, the risk of Alzheimer’s disease doubled, and the risk of developing Parkinson’s disease was 40 percent higher.

The researchers note that there is no association between infection and amyotrophic lateral sclerosis. amyotrophic lateral sclerosisRegardless of age at diagnosis.

These findings suggest that infection can trigger or amplify an already existing disease process, leading to the prevalence of neurodegenerative disease at a relatively young age, says Jiangui Sun, researcher in the Department of Medical Epidemiology and Biostatistics, Karolinska Institutet.

However, he points out that the results do not prove a causal relationship because the study is an observational study.

Scientific material:

Hospitalized infection in early and middle life and the risk of Alzheimer’s disease, Parkinson’s disease and amyotrophic lateral sclerosis: a nationwide cross-control study in Sweden.

Contact:

Jiangwei Sun, Postdoctoral Fellow at Karolinska Institutet, [email protected]