Interaction Effects of Diabetes and Depression on Hypertension Among US Adults: A Cohort Study

BACKGROUND: Hypertension, depression, and diabetes are major public health concerns that are closely interlinked. This study examined the independent associations of depression and diabetes with hypertension, as well as their combined effects, using data from the National Health and Nutrition Examination Survey (NHANES) between 2005 and 2018. METHODS: Data from NHANES 2005-2018 were analyzed for diabetes, depression, hypertension, and potential confounders. Weighted multivariate logistic regression models were used to assess the associations of depression and diabetes with hypertension, with subgroup analyses by depression severity. Additive interaction effects of depression and diabetes on hypertension were evaluated using the relative excess risk due to interaction (RERI), attributable proportion (AP), and synergy index (SI). RESULTS: A total of 29,747 participants were included, of whom 10,682 (35.9%) had hypertension. Diabetes was associated with a significantly higher risk of hypertension (odds ratio (OR) = 2.67, 95% confidence interval (CI): 2.40-2.96). Depression was also associated with an increased risk of hypertension (OR = 1.69, 95% CI: 1.48-1.94). Significant additive interaction effects were observed between depression and diabetes on hypertension risk (RERI = 0.75, 95% CI: 0.01-0.48; AP = 0.20, 95% CI: 0.04-0.36; SI = 1.38, 95% CI: 1.04-1.82). CONCLUSION: Depression and diabetes demonstrated a synergistic interaction in increasing the risk of hypertension, particularly in patients with moderate depression. These findings highlight the importance of integrated management of mental health and diabetes to prevent or mitigate hypertension.