Public Health.

Background: Dementia risk scores have been suggested a promising surrogate outcome for lifestyle interventions targeting cognitive function and dementia risk. First evidence suggests beneficial effects of multidomain lifestyle interventions on dementia risk scores. We investigated effects of the multidomain AgeWell.de-intervention on dementia risk, assessed using the LIfestyle for BRAin health (LIBRA)-index.

Method: Secondary analyses of AgeWell.de, a multicomponent intervention (including optimization of nutrition, medication, physical, social and cognitive activity) in older adults at increased risk for dementia (trial registration: German Clinical Trials Register, DRKS; ID: DRKS00013555). We analyzed data from n = 461 participants (age: 60-77 years) with available information on all n = 12 risk/protective factors comprised by the LIBRA (coronary heart disease, diabetes, hypercholesterolemia, hypertension, depression, obesity, smoking, physical inactivity, renal disease, low-to-moderate alcohol use, high cognitive activity, healthy diet) at baseline and 24 months-follow-up. Intervention effects on LIBRA-scores and individual LIBRA-components were assessed using generalized linear models.

Result: The intervention reduced total LIBRA-scores, indicating a decreased risk for dementia at 24 months follow-up (b = -0.63, 95% CI: -1.14, -0.12). Intervention effects on LIBRA-scores were particularly due to favorable changes in diet (OR = 1.60, 95% CI: 1.16, 2.22) and hypertension (OR = 1.61, 95% CI: 1.19, 2.18). In younger participants (60-69 years), the intervention increased the odds of high cognitive activity at follow-up (OR = 2.00; 95% CI: 1.20, 3.34).

Conclusion: The AgeWell.de-intervention successfully reduced dementia risk, assessed using the LIBRA-score, underscoring the usefulness of the LIBRA as a surrogate outcome when interpreting success of multidomain lifestyle interventions. However, several risk factors for dementia captured in the LIBRA, e.g., physical inactivity, did not change due to the intervention, possibly requiring more intensive interventions and support of participants in conducting the intervention.