Abstract
BACKGROUND: Evidence suggests that lifetime exposure to stressful life events and chronic stressors may be linked to geriatric depression. Allostatic load (AL) is considered a mediator of the stress-health relationship and has been linked to psychosocial factors reflecting health disparities. The purpose of this study was to examine the longitudinal associations of AL with depressive symptoms scores among urban adults, before and after stratifying by sex and race. METHODS: Secondary analyses were performed using Visit 1 (2004-2009), Visit 2 (2009-2013) and Visit 3 (2013-2017) data collected on 2298 Healthy Aging in Neighborhoods of Diversity across the Life Span study participants (baseline age: 30-64 y). AL at Visit 1 (AL(v1)) and z-transformed probability of higher AL trajectory (AL(traj)) between Visits 1 and 3 were calculated using cardiovascular, metabolic and inflammatory risk indicators. The 20-item Center for Epidemiologic Studies Depression (CES-D) scale was used to calculate total and domain-specific depressive symptoms scores. Mixed-effects linear models controlled for socio-demographic, lifestyle and health characteristics. RESULTS: In fully adjusted models, a positive cross-sectional relationship was observed between AL(v1) and "somatic complaints" depressive symptoms (β = 0.21, P = 0.006) score at Visit 1, whereas AL(traj) was associated with increasing depressive symptoms score (β = 0.086, P = 0.003) between Visits 1 and 3. An inverse relationship was observed between AL(traj) and "positive affect" depressive symptoms score at Visit 1 among women (β = -0.31, P < 0.0001) and White adults (β = -0.32, P = 0.004). Among women, AL(traj) was also positively related to change in "somatic complaints" depressive symptoms score between Visits 1 and 3 (β = 0.043, P = 0.020). CONCLUSIONS: Among urban adults, AL may be associated with "somatic complaints" depressive symptoms at baseline. Higher AL trajectories may predict increasing depressive symptoms (overall) and increasing "somatic complaints" depressive symptoms (among women). A higher AL trajectory may be associated with lower "positive affect" depressive symptoms at baseline among women and White adults only.