A recent study published in JAMA Network Open has found that hospital-diagnosed infections are associated with an increased risk of dementia. The researchers also investigated the potential link between autoimmune diseases and dementia, but found no significant association.
The study, conducted over a 40-year period from 1978 to 2018, used data from Danish national registries. A total of 1,493,896 individuals were included in the study, and the follow-up period amounted to 14,093,303 person-years. The researchers excluded individuals with a prior dementia diagnosis or HIV infections. They found that approximately 45% of individuals had infections during the study period, while 9% had autoimmune diseases.
The results showed that infections were associated with a 1.49-fold increase in the rate of dementia, with a greater impact in the short term. On the other hand, autoimmune diseases were associated with a smaller 1.04-fold increase in dementia risk, which became even less significant after adjusting for the presence of infections. This indicates that infection-specific processes may play a role in the development of dementia, rather than systemic inflammation.
The study also highlighted the limitations of previous research on the association between infections and dementia. Many prior studies focused on specific infections or pathogens, studied postmortem brains, or had short follow-up periods with selected populations.
The researchers identified respiratory infections as the most common type, followed by gastrointestinal and urinary infections. For autoimmune diseases, rheumatoid arthritis and polymyalgia rheumatica were the most common.
In conclusion, this study suggests that hospital-diagnosed infections are associated with an increased risk of dementia. The findings underscore the importance of preventing and effectively treating infections to reduce the risk of cognitive decline and dementia.
References:
– Janbek J, Laursen TM, Frimodt-Møller N, Magyari M, et al. Hospital-diagnosed infections, autoimmune diseases, and subsequent dementia incidence. JAMA Netw Open. 2023;6(9):e2332635. doi:10.1001/jamanetworkopen.2023.32635
