Depression associated with increased mortality regardless of CVD
Increased risk for all-cause mortality was associated with the presence of depressive symptoms in adults aged 65 years or older, regardless of whether they developed incident CVD, according to a study published in the Journal of the American Geriatrics Society.
“Depressive symptoms have been repeatedly associated with the onset of coronary heart disease and stroke in both middle-aged and elderly individuals, including in our previous works,” Renaud Pequignot, MD, PhD, of the Paris Cardiovascular Research Center at Paris Descartes University, Sorbonne Paris Cité, and colleagues wrote. “It is therefore possible that depressive symptoms are associated with an increased risk of death, partly through a specific increased risk of cardiovascular disease events. On the other hand, depressive symptoms have been related to cancer-related mortality and traumatic falls, which could also contribute to the increased mortality. Addressing the role of incident CVD may help to evaluate how much preventing CVD represents a target for the prevention of mortality in depressed individuals.”
To explore the relationship between depressive symptoms and mortality — along with the influence of incident CVD on this relationship — researchers conducted a prospective study of adults aged 65 years or older with no history of CVD who were randomly selected from the electoral rolls of three large French cities between March 1999 and March 2001 (n = 7,377; 63.7% women; mean age, 73.8 years). Participants were examined at baseline and at years 2, 4, 7 and 10 through their scores on the 20-item Center for Epidemiologic Studies Depression Scale. A score of 16 or greater indicated the presence of depressive symptoms and 19% to 22% of participants had these symptoms at each study visit.
Considering depressive symptom status and incident coronary heart disease or stroke events, researchers then used Cox proportional hazard models of mortality, with all-cause and cause-specific mortality as separate outcomes.
Participants were followed for a median of 9.4 years.
During this time, 650 participants developed a first CVD event (CHD, 399; stroke, 251) and 1,255 died (CV origin, 20.9%; cancer, 30.6%; non-CV and noncancer, 25.7%).
After adjustment for baseline sociodemographic variables, vascular risk factors, impairment in daily life activities and antidepressants, researchers found that time-dependent depressive symptoms were associated with a 28% increased risk for mortality (HR = 1.28; 95% CI, 1.06-1.55).
Researchers also concluded that an incident CVD event was associated with a 63% increased risk for mortality (HR = 1.63; 95% CI, 1.3-2.04) but the association between depressive symptoms and mortality was not influenced by the occurrence of CVD (HR for depressive symptoms and CVD interaction = 1.03; 95% CI, 0.66-1.61). According to the researchers, incident CVD explained 6.9% of the mortality associated with depressive symptoms.
“Incident vascular events modestly explained the excess of mortality associated with depressive symptoms,” the researchers wrote. “These study results suggest that in depressed elderly individuals, the prevention for mortality will not be achieved by the sole prevention of CVD.” – by Melissa J. Webb
Disclosures: The authors report no relevant financial disclosures.