Multidomain lifestyle intervention provides cognitive benefits regardless of baseline p-tau217 levels in older adultsLifestyle changes may help those at risk of Alzheimer's disease

This study is a secondary analysis of a randomized controlled trial involving 1260 older adults at risk of dementia. The primary objective was to evaluate the cognitive benefit of a multidomain lifestyle intervention and to determine if baseline biomarkers influenced the efficacy of the intervention. The study period included a follow-up of 2 years to assess both cognitive outcomes and various neurodegenerative biomarkers.

The intervention consisted of a multidomain lifestyle program, while the control group received standard care or a different control protocol. The specific dosing and components of the multidomain intervention were not detailed. The study specifically looked at the relationship between these interventions and several biomarkers, including Aβ, p-tau181, p-tau217, p-tau231, NFL, and GFAP, as well as brain amyloid accumulation on PET scans.

The primary outcome was the cognitive benefit of the multidomain lifestyle intervention. The analysis found no indication that baseline biomarker levels significantly modified the cognitive benefits of the intervention. This suggests that the intervention's efficacy was consistent across different biomarker profiles. Regarding the specific biomarker p-tau217, 85% of participants were below the pathological threshold at baseline. After the 2-year follow-up period, 82% of participants remained below the pathological p-tau217 threshold, indicating that changes in biomarkers over the two-year period were small.

Secondary outcomes included the analysis of several biomarkers and their relationship to cognitive trajectories. The study found a negative association where higher biomarker levels were associated with less favorable cognitive trajectories. Additionally, p-tau217 showed a modest ability to predict brain amyloid accumulation, with an AUC of 0.72. Other biomarkers such as Aβ, p-tau181, p-tau231, NFL, and GFAP were monitored, but specific quantitative changes for these were not detailed in the primary results summary.

Safety and tolerability data were not reported in the provided results. There were no specific figures provided for adverse events, serious adverse events, or participant discontinuations. Consequently, the tolerability of the multidomain lifestyle intervention cannot be quantified from this specific data set.

These results provide a nuanced view of how biomarkers interact with lifestyle interventions. While the study confirms that higher biomarker levels correlate with poorer cognitive outcomes, it suggests that the intervention itself remains effective regardless of the initial biomarker status. This contrasts with some views that biomarkers might serve as predictors of treatment response, as no significant modification of benefit was found based on baseline levels.

Methodological limitations include the modest ability of p-tau217 to predict brain amyloid accumulation (AUC 0.72). As a secondary analysis, the study may have specific limitations regarding the original trial's design and power. Furthermore, the cognitive benefits of the intervention may involve mechanisms not captured by the specific Alzheimer's disease blood biomarkers measured.

Clinically, these findings suggest that a multidomain lifestyle intervention is a viable strategy for older adults at risk of dementia, regardless of their baseline p-tau217 status. It clarifies the role of AD blood biomarkers for risk stratification and prediction of response to lifestyle interventions. However, questions remain regarding the specific mechanisms of action that are not captured by the current blood biomarkers and how other biomarkers like p-tau181 or p-tau231 might interact with lifestyle interventions over longer periods.