Persistent smell loss after SARS-CoV-2 infection predicted cognitive impairment in older adults, a longitudinal study in Argentina showed.
Twelve months after acute infection, anosmia was more strongly connected with cognitive impairment than severity of SARS-CoV-2 infection, reported Gabriela Gonzalez-Aleman, MSc, PhD, of Pontificia Universidad Catlica Argentina in Buenos Aires, at the 2022 Alzheimer’s Association International Conference.
“The more insight we’ve into what can cause or at the very least predicts who’ll go through the significant long-term cognitive impact of COVID-19 infection, the higher we are able to track it and commence to develop solutions to prevent it,” Gonzalez-Aleman said.
The findings are section of a global brain study of chronic neuropsychiatric sequelae of COVID, a consortium of researchers led by the Alzheimer’s Association and representatives from a lot more than 25 countries with technical guidance from the planet Health Organization (WHO).
“We’re learning more each day concerning the link between COVID-19 and the mind,” noted Claire Sexton, PhD, senior director of scientific programs and outreach at the Alzheimer’s Association. “Lack of smell is usually a signal of an inflammatory response in the mind. We realize inflammation is area of the neurodegenerative process in diseases like Alzheimer’s.”
“With other viruses, such as for example SARS and MERS, there were similar associations between infection and cognition, but you may still find big questions about cause and effect,” Sexton described.
The Argentina study followed 865 people over age 60 recruited from the provincial health registry that included all SARS-CoV-2 testing data for the spot. Researchers randomly invited older adults with a confident PCR COVID test to participate between 3 and six months after acute SARS-CoV-2 infection.
Assessments followed the recommendations of the global consortium and included the WHO Schedules for Clinical Assessment in Neuropsychiatry (SCAN) scale, the Clinical Dementia Rating scale, neurocognitive and emotional reactivity assessments, and evaluations of semi-quantitative olfactory function, motor function, coordination, and gait.
On the list of 865 participants, 84.2% had COVID and 15.8% were controls without history of a confident SARS-CoV-2 test. Median age was 67 and just over fifty percent (56.5%) were female. Participants had a median of 10.35 years of education. Most participants with COVID didn’t have severe infection, with hardly any (2% or less) admitted to the ICU.
At 12 months, about one-fourth of the analysis sample had no cognitive impairment; this group included control participants and about 20% of post-COVID patients, Gonzalez-Aleman said. Scores of remaining participants were normalized to the mean of the cognitively normal group, with impairment thought as z-scores below -2. Remaining participants were clustered into groups predicated on deficits in memory, attention, executive function, and language, with some individuals showing impairment in multiple domains.
PCR status and age predicted post-COVID cognitive problems, Gonzalez-Aleman said. Logistic regression analyses showed severity of anosmia, however, not severity of SARS-CoV-2 infection, was significantly connected with cognitive impairment.
All anosmia was reported after acute SARS-CoV-2 infection, Gonzalez-Aleman noted. Some individuals in the control group also had anosmia, but their olfactory dysfunction was significantly less frequent — and less severe — than that of participants with COVID, she added.
The outcomes are section of ongoing research about COVID among older Amerindian adults in Argentina. “It is important to supply the most up-to-date research to the general public so we are able to be familiar with the evolving ways this virus impacts us,” Sexton said.
“But it is also worth stressing that a lot more research is required to paint a far more complete picture of what COVID-19 does to your bodies and brains,” she added. “We should also study the direct impact that 24 months of pandemic-related isolation has already established on our health and wellness.”
The study was supported by the Alzheimer’s Association and the FULTA foundation.
Gonzalez-Aleman disclosed no relationships with industry.