Gender-specific design and effectiveness of non-pharmacological interventions against cognitive decline and dementia – systematic review and meta-analysis of randomized controlled trials

 

Einleitung The number of people living with dementia worldwide is increasing rapidly. Preventive approaches constitute a promising strategy to counter the dementia epidemic, and growing numbers of lifestyle interventions are being conducted around the globe. Gender differences with respect to modifiable risk factors for dementia have been reported, however, little is known about gender-specific effectiveness of lifestyle trials against cognitive decline and dementia. A systematic review and meta-analysis was conducted to assess evidence on gender-specific design and effectiveness of randomized controlled trials against cognitive decline and dementia.

Methoden We conducted a systematic literature search following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines in MEDLINE, PsycINFO, Web of Science, Cochrane Central and ALOIS. Studies assessing global and/or domain-specific cognitive function in older adults free from dementia were eligible for the systematic review. We assessed between-group effect sizes using random-effects meta-analysis. Methodological quality of included studies was assessed using the Scottish Intercollegiate Guidelines Network (SIGN)-checklist.

Ergebnisse The systematic review included 34 studies, of which 31 were included in the meta-analysis. Effects of lifestyle-interventions on global cognition were non-significant in the overall sample (g = ,27; 95% CI: -,01; .56), and small for female subsamples (g = ,38; 95% CI: ,05; ,72). Small beneficial effects were found for memory (overall: g = ,38; 95% CI = ,17; ,59). Stratifying results by gender, significant effects were observed only in women (g = ,39; 95% CI = ,13; ,65; men: g = ,37; 95% CI = ,05; ,73). Comparable results were observed for executive function and verbal fluency. Methodological quality was deemed high in 17.6% of studies, acceptable and low quality in 52.9% and 29.4%, respectively.

Schlussfolgerung We found evidence for small differences in the effectiveness of lifestyle interventions on global cognition and memory in favour of women. However, small numbers of trials 1) targeting men and 2) reporting gender-specific results for older adults with mild cognitive impairment warrant further attention. Assessing differences in modifiable risk factors for dementia in men and women and systematically addressing aspects of gender in trial conduction and recruitment in future studies might increase knowledge on gender-specific effectiveness of lifestyle trials against cognitive decline and dementia.

Publication History

Article published online:
22 August 2022

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