Abstract 11979: Red Cell Distribution Width and Depression Among Patients Undergoing Angiography
Background: Red cell distribution width (RDW) is a measure of the variation of red blood cell widths and has often been used to differentiate forms of anemia. However, recent studies have shown it to be a powerful indicator of poor outcomes, particularly among cardiovascular (CV) patients. Depression is a known risk factor for adverse CV outcomes and associated with anemia. Therefore, we evaluated whether RDW was associated with depression.
Methods: A total of 49,257 patients of the catheterization registry of the Intermountain Heart Study were evaluated. RDW was evaluated as a continuous variable and also by quintiles (Q)1: ≤12.8%, Q2: 12.9%-13.4%, Q3: 13.5%-14.0%, Q4: 14.1%-14.9%, and Q5: >14.9%. Follow-up depression diagnosis was determined by ICD-9 codes: 296.2 to 296.36 and 311. Cox hazard regression was utilized to determine the association between RDW and depression adjusted by standard cardiac risk factors, medications, and components of the CBC and the BMP. Average length of follow-up was 5.3±5.0 years.
Results: Age averaged 60.6±15.5 years, 41.3% were female, 8.2% had a prior depression diagnosis, 43.8% were diagnosed with angiographic CAD, and 3.8% were taking anti-depressant medications. A follow-up depression diagnosis was significantly associated with increasing RDW quintiles (Q1-Q5): 20.9%, 24.5%, 30.2%, 34.2%, and 43.7% (p-trend≤0.0001) and elevated RDW levels (no depression vs. follow-up depression): 14.0±1.7% vs. 14.3±2.0%, p≤0.0001. After adjustment, RDW as a continuous parameter (HR=1.10 + 1% of RDW, p≤0.0001) and by quintiles (vs. Q1) was significantly associated with a follow-up depression diagnosis: Q2: HR=1.22, p≤0.0001, Q3: 1.40, p≤0.0001, Q4: 1.50, p≤0.0001, and Q5: HR=1.81, p≤0.0001. This association persisted when those with a prior history of depression were excluded.
Conclusion: This study showed for the first time an association between increasing levels of RDW and a follow-up depression diagnosis, which persisted despite adjustment by risk factors, medications, and indicators of other disease states. Whether depression may be a direct result of abnormal RDW or rather an indirect result of anemia or other comorbidity needs further study.
- © 2013 by American Heart Association, Inc.