Abstract 12367: “I Need a Nap”: Excessive Daytime Sleepiness Impacts How Age and Depression are Associated in Heart Failure
Introduction: Adults with heart failure (HF) are at significantly higher risk for depression, which has been linked to higher rates of mortality. Both age and excessive daytime sleepiness (EDS) have been linked to depression but the relationships between age, EDS and depression are not yet clear.
Objective: To explore whether EDS mediates the relationship between age and depression in HF.
Methods: 208 adults with stage C chronic HF were enrolled into a prospective cohort study. Those with severe depression, dementia, a prior significant neurologic event, terminal illness, recent drug or alcohol abuse, and night shift workers were excluded. Depression was measured using the PHQ-9 (scores range from 0–27, higher scores indicate more depressive symptoms). EDS was measured using the Epworth Sleepiness Scale (scores range from 0–24, higher scores indicate more EDS). Multiple regression analysis was used to test for a mediator effect. All analyses were adjusted for NYHA class, comorbidity measured by the Charlson Comorbidity Index, and overall health perception.
Results: Subjects (M age 61.9, SD 12.5) were 64% male and 77% NYHA III/IV. EDS mediated the relationship between age and depression. Age was a significant determinant of EDS (β = −.14 , t = −2.29, P= .02 ) and a significant determinant of depression (β = −.15 , t = −2.57, P= .01 ). When age and EDS were regressed simultaneously on depression, both variables were significant determinants, explaining 24% of the variance in depression and the direct relationship of age to depression was less significant than it had been (β = −.11, t = −1.99, P= .05) providing evidence of a mediator effect.
Conclusions: It is often assumed that daytime sleepiness is a function of either depression or pathophysiology in HF. However, this study shows that EDS acts as a mediator in the relationship between age and depression and should be evaluated in adults with HF and depression.
- © 2010 by American Heart Association, Inc.