In a study of more than 20,000 heart failure patients, influenza vaccination was associated with a lower risk of dementia.
The current study investigated whether heart failure patients who had received the flu vaccine had a lower risk of dementia. The study included all patients over 60 years of age who visited healthcare facilities in Taiwan with a diagnosis of heart failure during 2000 to 2012. Those who had dementia prior to being diagnosed with heart failure were excluded from the study. Patients were recruited from the National Health Insurance Research Dataset, which holds information on 98% of Taiwan residents.
The study included 20, 509 patients with heart failure. Of those, 10,797 received at least once vaccination against influenza and the other 9712 were not vaccinated during the 12 year follow-up period.
After adjusting for factors that might influence the association, the investigators found that heart failure patients who had received the flu vaccine were 35% less likely to develop dementia than those who had not been vaccinated. Those who had been vaccinated more than three times had a 55% lower dementia risk.
“We think that the flu virus can activate the immune response and cause inflammation which may injure the brain cells,” said Dr Ju-Chi Liu. “Respiratory infection during flu can induce changes in blood pressure and heart rate, referred to as an unstable haemodynamic status, which may also harm the brain tissue.”