Frailty and Cognition. Fellow Travelers or Partners in Crime?

Frailty and cognitive impairment are prevalent in older adults and often coexist. The concurrent presence of both physical frailty and cognitive impairment has been proposed as a distinctive entity that predicts dementia. However, it remains controversial whether frailty alone, cognitive frailty, or the combination of cognitive impairment and physical frailty are different entities or if they pose different risks of incident dementia. Older adults with frailty have a higher prevalence of cognitive impairment compared to those without frailty, and increased risk of converting to dementia. Older adults with cognitive frailty have an increased incident rate of dementia, about 80/1000 person-year. However, various cognitive and motor markers of frailty have been shown to better predict dementia, with a hazard risk of 3 to 6-fold. Collectively, emerging evidence suggest that cognitive frailty is an entity that predicts progression to dementia syndromes that may embody two different clinical manifestations, slow gait and low cognition, with shared underlying pathological mechanisms.