Interrelationships of Social Determinants with Cognition, Vascular Health, and Physical Functioning

The primary aim of the current analysis was to evaluate the cumulative effect of different social determinants of health (SDoH) factors on vascular burden, cognition, and physical functioning.

We conducted a secondary data analysis of the Midlife in the United States (MIDUS 2) cross-sectional study using data from participants aged 55 and older. Measures derived from the Framingham Stroke Risk Profile, Brief Test of Adult Cognition by Telephone, and physical functioning scores from the Medical Outcomes Study - Short Form 36 items (MOS-SF36) were used to represent vascular burden, cognition, and intermediate activities of daily living, respectively. SDoH variables included education, income, health insurance, stress, and support from family and friends. Associations were evaluated using a composite-based structural equation model (c-SEM) embedded in an overall SEM.

Among MIDUS participants with no clinical diagnosis of cognitive impairment or neurological disorder (N=568; mean age=64.6), higher education, less stress, and higher income significantly contributed to the SDoH composite. Positive SDoH was associated with better physical functioning (beta=-0.21, p<0.001) and higher cognition (beta=0.54, p<0.001). Significant direct effects of SDoH on vascular burden (beta=-0.12, p<0.05) and cognition (beta=0.51, p< 0.001) and of vascular burden on cognition (beta=-0.28, p<0.001) were found. Mediation analysis indicated that the unique effects of SDoH on cognition remained significant after controlling for vascular burden (beta=0.04, p< 0.05). After accounting for vascular burden and cognition, SDoH did not have a significant unique effect on physical functioning.

Our results support the disablement theory, suggesting that factors outside of the disease model (such as SDoH factors) impact diseases that underlie physical and functional limitations.