Accelerated brain age in young to early middle-aged adults after mild to moderate COVID-19 infection

Cognitive decline is a common adverse effect of the Coronavirus Disease of 2019 (COVID-19), particularly in the post-acute disease phase. The mechanisms of cognitive impairment after COVID-19 (COGVID) remain unclear, but neuroimaging studies provide evidence of brain changes, many that are associated with aging. Therefore, we calculated Brain Age Gap (BAG), which is the difference between brain age and chronological age, in a cohort of 25 mild to moderate COVID-19 survivors (did not experience breathlessness, pneumonia, or respiratory/organ failure) and 24 non-infected controls (mean age = 30 +/- 8) using magnetic resonance imaging (MRI). BAG was significantly higher in the COVID-19 group (F = 4.22, p = 0.046) by 2.65 years. Additionally, 80% of the COVID-19 group demonstrated an accelerated BAG compared to 13% in the control group (X2 = 20.0, p < 0.001). Accelerated BAG was significantly correlated with lower cognitive function (p < 0.041). Females in the COVID-19 group demonstrated a 99% decreased risk of accelerated BAG compared to males (OR = 0.015, 95% CI: 0.001 to 0.300). There was also a small (1.4%) but significant decrease in risk for accelerated BAG associated with longer time since COVID-19 diagnosis (OR = 0.986, 95% CI: 0.977 to 0.995). Our findings provide a novel biomarker of COGVID and point to accelerated brain aging as a potential mechanism of this adverse effect. Our results also offer further insight regarding gender-related disparities in cognitive morbidity associated with COVID-19.