Educational level as a moderator of the relationship between body mass index, blood pressure, and depressive symptoms in the Peruvian population: a moderated mediation analysis

ObjectiveTo analyze whether systolic blood pressure influences the relationship between body mass index and depressive symptoms, and whether educational level moderates these associations in Peruvian adults.MethodsCross-sectional study using data from the Peruvian Demographic and Health Survey (ENDES). Individuals aged ≥15 years were included. Depression was assessed with the PHQ-9 (continuous score); BMI and SBP were treated as continuous variables. A moderated mediation model (PROCESS model 59) was applied, adjusting for alcohol consumption, age, mother tongue, ethnic identity, and marital status.ResultsIn the moderated analysis, BMI showed a positive association with SBP (B=0.61; 95% CI: 0.57–0.66), with a stronger effect in individuals with higher education (B=0.81) compared to those with basic education (B=0.61). Alcohol consumption (B=1.20), speaking an indigenous mother tongue (B=1.26), and age (B=0.42 per year) were associated with higher SBP, while living with a partner was protective (B=−2.05). In the model for depressive symptoms, BMI (B=0.04) and SBP (B=0.02) increased PHQ-9 scores; the effect of SBP was greater among higher-educated individuals (B=0.036) than those with basic education (B=0.022). The moderated mediation showed that the indirect component via SBP was higher in individuals with higher education (B=0.081) than in those with basic education (B=0.035), with a moderated mediation index of 0.040 (95% CI: 0.028–0.052).ConclusionsEducational level modulates the relationship between BMI, blood pressure, and depression, highlighting health inequalities that can inform public health strategies and prevention policies.