Causal Model Testing of the Relationship between Body Mass Index and Primary Hypertension: The Mediating Role of Depression, Stress, and Anxiety

Abstract

Introduction: Primary hypertension is one of the most prevalent diseases in Iran, leading to a significant number of deaths and disabilities annually. Given its high prevalence and associated health risks, the present study aimed to test a causal model of the relationship between body mass index (BMI) and primary hypertension, considering the mediating role of depression, stress, and anxiety.

Method: This study was a descriptive cross-sectional research based on structural equation modeling (SEM). The statistical population comprised individuals diagnosed with primary hypertension who were referred to Taleghani Hospital in Tehran. Using a convenience sampling method, 220 participants were selected as the final sample. Participants’ weight, height, and blood pressure were measured, and they completed the Depression, Anxiety, and Stress Scale (DASS).

Results: The model testing results indicated that BMI had a direct effect on depression (β = 0.29), anxiety (β = 0.28), and stress (β = 0.43), all significant at p < 0.01. Moreover, depression (β = 0.28), anxiety (β = 0.30), and stress (β = 0.20) had direct effects on blood pressure, all significant at p < 0.001. The mediation analysis further confirmed that depression, anxiety, and stress played mediating roles in the relationship between BMI and blood pressure.

Conclusion: The findings of this study demonstrated that the structural model linking BMI to primary hypertension via depression, stress, and anxiety had a good fit. These results highlight the psychological mechanisms underlying the relationship between BMI and hypertension, emphasizing the importance of considering mental health factors in hypertension management.