Social support, plasma amyloid, and cognitive function: Findings on cognitive resilience from the African Americans Fighting Alzheimer’s in Midlife (AA‐FAIM) study
Authors: Zuelsdorff Megan , Fischer Barbara L. , Gooding Diane C. , Van Hulle Carol A. , McLester‐Davis Lauren W. Y. , Wyman Mary F. , Carter Fabu P. , Norris Nia , Livingston Sydnee , Johnson Sterling C , Asthana Sanjay , Kirmess Kristopher M. , Meyer Matthew R. , Gleason Carey E. , Green‐Harris Gina 
Published: December 2023

Background

Epidemiological evidence suggests that excess risk for Alzheimer’s disease and related dementias (ADRD) in minoritized populations is preventable. Social connectedness associates with reduced ADRD risk: plausible mechanisms include (I) direct influence on AD pathology, and (II) indirect influence through cognitive reserve processes. Inclusive, resilience‐focused ADRD research will accelerate equitable translation into communities facing high disease burden. In a richly characterized sample of Black middle‐aged and older adults, we explored (i) associations between social support and cognition, and (ii) moderation of those relationships by plasma amyloid level.

Method

Participants (N = 118) enrolled in AA‐FAIM through the Wisconsin Registry for Alzheimer’s Prevention (WRAP) or Alzheimer’s Disease Research Center (ADRC). Participants were cognitively healthy, and had plasma amyloid, neuropsychological, and psychosocial data from at least one visit. Multivariable linear regression models assessed cross‐sectional predictor‐outcome relationships. The key predictor was perceived availability of social support, self‐reported via the Medical Outcomes Study Social Support Survey (MOS‐SS). Cognitive outcomes included performance on tests of (a) speed and flexibility and (b) episodic memory. Cognitive reserve mechanisms were tested with a model term interacting social support scores with plasma Aβ42/40 ratio (C2N, USA) to predict cognition.

Result

Table 1 provides sample characteristics. In adjusted models (Table 2), MOS‐SS scores positively associated with episodic memory performance, but not speed and flexibility. However, MOS‐SS*amyloid interaction was significant in this domain; greater support predicted better mental flexibility most substantially in the presence of accumulated amyloid pathology. Small samples limit precision when plasma Aβ42/40 ratio is dichotomized, but for visualization purposes the interaction between MOS‐SS and amyloid positivity is presented (Figure 1).

Conclusion

Greater availability of a modifiable resource, social support, predicted better cognitive health within this small sample of Black participants. Mechanisms and implications vary by cognitive domain. For episodic memory, cognitive benefits are consistent across amyloid level. In mental flexibility, social support contributes to cognitive reserve, with noteworthy benefits for participants with elevated AD pathology. Future studies must examine additional ADRD neuropathologies, and in larger samples. Nonetheless, we provide preliminary evidence that facilitating social connection is a promising mitigation strategy, acting via multiple pathways to reduce ADRD‐related impairment in a community experiencing disproportionate risk.