Self-reported health behaviors and longitudinal cognitive performance: Results from the Wisconsin Registry for Alzheimer’s Prevention

Abstract

Background3 Studies have suggested associations between self-reported engagement in health behaviors and 4 reduced risk of cognitive decline. Most studies explore these relationships using one health 5 behavior, often cross-sectionally or with dementia as the outcome. In this study, we explored 6 whether several individual self-reported health behaviors were associated with cognitive decline 7 when considered simultaneously, using data from the Wisconsin Registry for Alzheimer's 8 Prevention (WRAP), an Alzheimer's disease risk-enriched cohort who were non-demented and 9 in late midlife at baseline. 10 11 Method 12 We analyzed longitudinal cognitive data from 828 participants in WRAP, with a mean age at 13 baseline cognitive assessment of 57 (range = 36-78, sd = 6.8) and an average of 6.3 years 14 (standard deviation = 1.9, range = 2-10) of follow-up. The primary outcome was a multi-domain 15 cognitive composite, and secondary outcomes were immediate/delayed memory and executive 16 function composites. Predictors of interest were self-reported measures of physical activity, 17 cognitive activity, adherence to a Mediterranean-style diet (MIND), and interactions with each 18 other and age. We conducted linear mixed effects analyses within an Information-theoretic (IT) 19 model averaging (MA) approach on a set of models including covariates and combinations of 20 these 2-and 3-way interactions. The IT approach was selected due to the large number of 21 interactions of interest and to avoid pitfalls of traditional model selection approaches. 22 23 Results 2 2425 Model-averaged results identified no significant modifiable behavior*age interactions in 26 relationship to the primary composite outcome. In secondary outcomes, higher MIND diet scores 27 associated with slower decline in executive function. Men showed faster decline than women on 28 delayed memory, independent of health behaviors. There were no other significant interactions 29 among any other health behaviors and cognitive trajectories. 31 Conclusions32 When multiple covariates and health behaviors were considered simultaneously, there were 33 limited weak associations with cognitive decline in this age range. These results may be 34 explained alone or in combination by three alternative explanations: 1) the range of cognitive 35 decline is in middle age is too small to observe relationships with health behaviors, 2) the 36 putative associations of these health behaviors on cognition may not be robust in this age range, 37 or 3) the self-reported measures of the health behaviors may not be optimal for predicting 38 cognitive decline. More study may be needed that incorporates sensitive measures of health 39 behaviors, AD biomarker profiles, and/or other disease comorbidities. 40 3 41 Introduction 42 The estimated prevalence of dementia in America in 2019 was 5.8 million, and it is projected to 43 rise to 13.9 million by 2050 if prevention or cures are not identified. Delaying the onset of 44 dementia by five years would result in a financial savings of up ...