Impact of frailty status on the effect of a multidomain lifestyle intervention on cognition

Background: Frailty often precedes and co-occurs with dementia. A multidomain lifestyle intervention has shown favourable effects on cognition. We aimed to investigate if frailty status modifies this intervention effect. Methods: The Finnish Geriatric Intervention Study to Prevent Cognitive Impairment and Disability (FINGER) recruited 1259 participants aged 60-77 years who were at risk of dementia. They were randomised to receive a multidomain intervention (diet, exercise, cognitive training and vascular risk monitoring) or regular health advice for two years. The outcome was a change in cognition (neuropsychological test battery composite score). Frailty and prefrailty were defined according to the Fried phenotype. Mixed models were used to investigate if frailty status at baseline modified the intervention effect on cognition. Results: Frailty status (prefrail/frail n = 520, robust n = 625) at baseline did not modify the effect of intervention on global cognition during the 2-year follow-up (P-value for frailty × intervention × time interaction >. 05). Concerning cognitive subdomains, similar results were found. Among prefrail/frail persons, within-group analyses suggested a beneficial intervention effect on executive function and processing speed and also on global cognition when frail participants (n = 15) were excluded from the analyses. Being prefrail/frail was related to less improvement in global cognition, memory and executive function domains compared with being robust when intervention was not taken into consideration. Conclusions: A multidomain intervention is likely to be beneficial to cognition regardless of frailty status. Prefrail participants seemed particularly responsive to preventive intervention. Thus, an optimal time for a multidomain lifestyle intervention may be at the prefrailty stage.