The relationship between depression based on patient health questionaire-9 and cardiovascular mortality in patients with hypertension.

Background: Depression and hypertension are increasingly prevalent in the U.S., with evidence suggesting significant comorbidity. Despite this, the specific relationship within the U.S. hypertensive population is underexplored. Our study investigates this link using data from the 2007-2014 NHANES database and mortality data from the National Death Index.

Methods: A total of 8677 participants were included in this cohort study. Depression diagnosis was made based on the Patient Health Questionnaire-9. Hypertension was defined either through a self-reported previous diagnosis, current antihypertensive medication use, or blood pressure exceeding standard thresholds. Cardiovascular disease mortality was determined by mortality recorded with National Death Index on December 31, 2019. The cox proportional hazards regression method was applied to analyze the association of depression with cardiovascular mortality in hypertension.

Results: During an average follow-up of 8.2 years, 599 deaths were confirmed from cardiovascular disease. The association of depression with cardiovascular mortality in hypertension was significantly positive (HR, 1.0263(95%CI = 1.0033, 1.0498), p = 0.0247). In addition, the risk of cardiovascular mortality increased gradually with the severity of depressive symptoms (p for trend =0.0259). This positive relationship was basically stable in different subgroup analyses and sensitivity analyses.

Limitations: The observational design of our study hinders establishment of a causal relationship. Potential bias due to subjective reporting and the absence of depression treatment data represent limitations, although their impact on the conclusions is deemed minimal.

Conclusions: Depression is associated with cardiovascular mortality risk in patients with hypertension. The worsening depressive symptoms, the higher risk of cardiovascular mortality.