Just one bout with shingles is associated with a 20% higher risk of long-term confusion and memory loss, according to a study published Wednesday in Alzheimer’s Research & Therapy.
Shingles, also called herpes zoster, is a painful rash that’s triggered by the virus that causes chickenpox.
A team of researchers from Brigham and Women’s Hospital evaluated data from 149,327 participants in the Nurses’ Health Study (NHS), the NHS II and the Health Professionals Follow-Up Study (HPFS). Participants were between 25 and 75 years old. Data was collected from 2000 to 2017.
Among those in the NHS dataset, the virus was linked to greater long-term odds of subjective cognitive decline. There was a 14% higher risk of a three-unit slide in cognitive decline score for those who were 13 years or more past their initial episode of shingles. In the NHS II dataset, the herpes zoster virus was linked to a higher risk of cognitive decline in people who’d had shingles one to four years earlier as well as those who were 13 years post-shingles. A higher risk for cognitive decline was seen at all points in time in the HPFS data.
The association between having shingles and cognitive decline was higher in males who carry the APOE ε4 gene, which is a leading genetic risk factor for Alzheimer’s disease. The long-term risk of cognitive decline appeared higher in women who were unvaccinated against shingles, data suggested. The association between shingles and cognitive decline didn’t differ among people with and without immunocompromising conditions, the authors noted.
Shingles may contribute to cognitive decline through neuroinflammation, neuron injury or activation of other herpesviruses. Vaccination may reduce the severity of cognitive decline but further study is needed, the authors noted.
“Given the growing number of Americans at risk for this painful and often disabling disease and the availability of a very effective vaccine, shingles vaccination could provide a valuable opportunity to reduce the burden of shingles and possibly reduce the burden of subsequent cognitive decline,” Sharon Curhan, MD, a researcher from Brigham and Women’s and a study author, said in a press release.
