Depression Increases Risk

Depression Increases Risk of Death in Stable COPD

GRONINGEN, The Netherlands, March 5 — Depression worsens the survival outlook for patients with stable chronic obstructive pulmonary disease (COPD), as well as those with uncontrolled COPD, researchers here found.Among patients with stable disease, those who also had moderate to severe depressive symptoms were nearly twice as likely to die from any cause during follow-up as those with lesser symptoms (OR 1.93, 95% CI 1.12 to 3.33), according to Jacob de Voogd, M.S., of University Medical Center Groningen, and colleagues.

“What is needed next is explication of both the determinants of depressive symptoms and of the pathway between these symptoms and mortality,” the researchers reported in the March issue of Chest.

Future studies should examine whether improvement in depressive symptoms will decrease mortality in these patients, they said.

Although depression increases the risk of death in patients with COPD during or shortly after an exacerbation, conflicting data have clouded the nature of same relationship in patients with stable disease, the researchers said.

To find out, the researchers monitored 121 patients (mean age 61.5) with stable COPD (mean forced expiratory volume in one second 36.9% of predicted). They were studied from hospital admission for pulmonary rehabilitation through follow-up lasting up to 8.5 years.

All patients were clinically stable for at least six weeks before entering the study.

Depressive symptoms were measured using the Beck Depression Inventory, a 21-item self-administered survey measuring attitudes and symptoms of depression. A score of at least 19 out of 63 was used to indicate the presence of depressive symptoms.

Nearly one in five patients (19.8%) met that threshold.

Through follow-up, 63% of the patients died. Overall median survival was 5.3 years.

In a multivariate analysis, depressive symptoms were associated with all-cause death (P0.05), independent of gender, age, and exercise capacity.

Male sex (OR 1.73, 95% CI 1.03 to 2.92) and older age (OR 1.05, 95% CI 1.02 to 1.08) were associated with an increased risk of mortality, and better exercise capacity (OR 0.98, 95% CI 0.97 to 0.99) was associated with a slightly decreased risk.

There were two possible explanations for the link between depression and mortality in patients with COPD, according to the researchers.

First, some studies have shown that depression can detrimentally affect the functioning of the hypothalamic-pituitary-adrenal axis, they noted.

Second, depressive symptoms can result in patients paying less attention to personal care, as indicated by poor nutrition, smoking, sedentary lifestyle, poor medication compliance, and failure to seek adequate healthcare.

However, the researchers did not collect information on either of these possibilities.

The study had several limitations, they said, including inability to generalize results to patients with COPD who were not referred for pulmonary rehabilitation; lack of information on comorbidities, cause of death, and medication; use of a single assessment of depressive symptoms that can change over time; and the lack of data on behavioral changes, interventions, and hospitalizations during follow-up.