Alternative Pathway Analyses Indicate Bidirectional Relations between Depressive Symptoms, Diet Quality, and Central...

Temporality between socioeconomic status (SES), depressive symptoms (DS), dietary quality (DQ), and central adiposity (CA) is underexplored.

Alternative pathways linking SES to DQ, DS, and CA were tested and models compared, stratified by race and sex.

With the use of data from the Healthy Aging in Neighborhoods of Diversity across the Life Span (baseline age: 30-64 y; 2 visits; mean follow-up: 4.9 y), 12 structural equation models (SM) were conducted and compared. Time-dependent factors included the Center for Epidemiologic Studies-Depression [CES-D total score, baseline or visit 1 (v1), follow-up or visit 2 (v2), mean across visits (m), and annual rate of change (Δ)], 2010 Healthy Eating Index (HEI) (same notation), and central adiposity principal components' analysis score of waist circumference and trunk fat (kg) (Adipcent) (same notation). Sample sizes were white women (WW, n = 236), white men (WM, n = 159), African American women (AAW, n = 395), and African American men (AAM, n = 274), and a multigroup analysis within the SM framework was also conducted.

In the best-fitting model, overall, ∼31% of the total effect of SES→Adipcent(v2) (α ± SE: -0.10 ± 0.03, P < 0.05) was mediated through a combination of CES-D(v1) and ΔHEI. Two dominant pathways contributed to the indirect effect: SES→(-)CES-D(v1)→(+)Adipcent(v2) (-0.015) and SES→(+) ΔHEI→(-)Adipcent(v2) (-0.017), with a total indirect effect of -0.031 (P < 0.05). In a second best-fitting model, SES independently predicted Adipcent(v1, -0.069), ΔHEI(+0.037) and CES-D(v2, -2.70) (P < 0.05), with Adipcent(v1) marginally predicting ΔHEI(-0.014) and CES-D(v2, +0.67) (P < 0.10). These findings were indicative of DS's and CA's marginally significant bidirectional association (P < 0.10). Although best-fit-selected models were consistent across race × sex categories, path coefficients differed significantly between groups. Specifically, SES→Adipcent[v1(+0.11), v2(+0.14)] was positive among AAM (P < 0.05), and the overall positive association of Adipcent(v1)→CES-D(v2) was specific to AAW (+0.97, P < 0.10).

Despite consistent model fit, pathways linking SES to DQ, DS, and CA differed markedly among the race × sex groups. Our findings can inform the potential effectiveness of various mental health and dietary interventions.