SSDOH Influence on Cognitive Decline in Older Patients Warrants Further Study on Policy, Intervention Strategies

While there is extensive research behind the behavioral and biological risk factors associated with Alzheimer disease and Alzheimer disease and related dementia (AD/ADRD), there is a significant lack of data on the potential relationship between risk of AD/ADRD, diagnosis, and disease prognosis as influenced by social and structural determinants of health (SSDOH). As a result, there is a great need for research on the potential influence of SSDOH on patients and their disease outcomes in this setting.

Investigators from the Quantitative Health Science, Neurology, and Radiology departments of Mayo Clinic investigated if and how SSDOH might influence mild cognitive impairment (MCI) and/or risk of dementia among participants of the Mayo Clinic Study of Aging. They presented their findings on Sunday, April 23, at the American Academy of Neurology 2023 annual meeting.¹

The study cohort was made up of 2961 patients with a mean (AD) age of 68.8 (9.7) years who were cognitively unimpaired and had complete SSDOH data at baseline. Just over half of the participants (50.2%) were female patients.

“We used the recently proposed multidimensional SSDOH framework² for AD/ADRD studies that includes a microsystem, which measures social stressors, social support, and health literacy; an exosystem, which considers the built environment/neighborhood; and a macrosystem, which looks at social identity,” the study authors said.

Within the microsystem dimension, mean Beck Anxiety Inventory and Beck Depression Inventory-II scores were 2.6 (4.0) and 4.4 (4.7), indicating low levels of each, respectively; these were used to evaluate social stressors and perceived stress. Regarding social support, 81.3%, 70.6%, and 37.8% reported participating in more than 1 monthly social activity, game, or group activity, respectively, in the past year. And for the final domain of health literacy, participants demonstrated a mean 14.9 (2.5) years of education, an education-occupation score of 12.7 (2.4), 96.3% reported contact with a health care system in the past year, 60.8% said they were retired, and 47.6% noted multivitamin intake.

For the exosystem dimension, results of the Area Deprivation Index showed participants’ neighborhood mean state rank (decile) was 4.6 (2.6) and their national rank, 40.2% (17.5%). Most (82.6%) also reported living in a metropolitan area with primary flow within that area and a residence that was a house (78.0%) or an apartment/townhouse/condo (18.2%).

Demographics measured in the macrosystem were race; English as a first language; marital status; hearing, visual, and walking difficulties; and health rating. Most patients were White (97.6%), had English as their first language (95.5%), were married/living together but not married (75.5%), and rated their health as good (29.2%) or very good (43.3%). Hearing, visual, and walking difficulties were reported in 17.8%, 6.0%, and 12.0%, respectively.

From this information, the study investigators used principal component analyses on the 3 SSDOH subdimensions, drilling these data down to 3 components:

• PC1: cognitive/physical activities/exercise
• PC2: education-occupation score/female-marital-hearing status/anxiety
• PC3: health/depression/exosystem

Risks for MCI and incident dementia, respectively, were then determined as to potential negative influences from each PCA component, and the following results were seen:

• 20% (HR, 0.80, 95% CI, 0.72-0.89; P < .001) and 17% (HR, 0.83; 95% CI, 0.70-1.00; P = .044) reduced risks from cognitive and physical activities/exercise
• 17% (HR, 1.17; 95% CI, 1.06-1.29; P = .002) and 12% (HR, 1.12; 95% CI, 0.94-1.33; P = .2) higher risks in connection with education-occupation score, female sex, and when adverse marital or hearing status and anxiety were reported
• 33% (HR, 1.33; 95% CI, 1.22-1.46; P < .001) and 21% (HR, 1.21; 95% CI, 1.01-1.44; P = .034) higher risks associated with worse reported health, depression, and living in a more deprived exosystem

By reducing the high dimensionality of the SSDOH variables that they evaluated, the study authors noted their investigation found different associations with the different groups of variables. In particular, they noted the importance of the positive findings linked to cognitive and physical activities/exercise and of the negative findings linked to adverse health, depression, and exosystem. However, they also noted that all 3 PCs were “important aspects of SSDOH for MCI and dementia.”

“Having in mind the decades lag time between the onset of AD/ADRD and clinical symptomatology, there is time for individual-, community-, and policy-level interventions,” they concluded. “Studies are warranted to delineate these associations further, facilitate our understanding, and inform policy and intervention strategies.Research on the influence of SSDOH on cognitive decline would provide essential information for such policies.”

Reference

1. Jack CR, Graff-Radford J, Vassilaki M, et al. Identifying key patterns of social and structural determinants of health and their association with dementia risk in a population-based study of cognitive aging. Presented at: AAN 2023; April 22-27, 2023; Boston, MA. Accessed April 23, 2023. https://cattendee.abstractsonline.com/meeting/10872/Presentation/6804

2. Stites SD, Midgett S, Mechanic-Hamilton D, et al. Establishing a framework for gathering structural and social determinants of health in Alzheimer's disease research centers. Gerontologist. 2022;62(5):694-703. doi:10.1093/geront/gnab182