• Diabetes & Endocrinology Clinical Trials
• Mood Disorders
• Diabetes Mellitus

The ACCORD Health-Related Quality of Life (HRQL) study demonstrated that depression is a strong predictor of increased mortality and may increase the risk of cardiovascular (CV) events in people with type 2 diabetes mellitus (T2DM). The findings of the study were reported by Patrick J. O'Connor, MD, MPH, HealthPartners, Minneapolis, Minnesota, USA.

Approximately 20% to 25% of people with diabetes have depression, and the condition has been shown to predict all-cause mortality in older patients with diabetes. However, the ACCORD HRQL trial is one of few studies designed to investigate the effects of depression on composite CV disease outcomes, macrovascular complications, or microvascular complications in people with T2DM.

The trial included 2053 participants who completed the depression measure from the Patient Health Questionnaire (PHQ-9) at baseline and at 1, 3, and 4 years. The depression measure consists of nine items, each of which is scored 0 to 3 points. Participants were classified as having depression in three different ways: (a) a score of 10 or more on the PHQ-9 (which has been shown to have 77% sensitivity and 94% specificity for the diagnosis of major depression); (b) major depression, defined as five PHQ symptoms scored at least 2, one of which was depressed mood or lack of pleasure; or (c) minor depression, defined as three or four PHQ symptoms scored at least 2, one of which was depressed mood or lack of pleasure.

Nearly one-third of the participants had depression at baseline. Depression at baseline was associated with female gender, higher rate of tobacco use, higher body-mass index (BMI), higher median triglyceride level, and higher mean HbA1C level (p<0.0001 for all). Because of the potentially confounding effects of such differences on subsequent mortality risk, Cox proportional-hazards regression models were used to adjust for several variables, including age, gender, race/ethnicity, HbA1C level, blood pressure, lipid levels, tobacco use, and coronary heart disease status.

Analysis of the data showed that major depression was a significant independent predictor of increased mortality, with a greater risk for all-cause mortality among participants with a PHQ score of 10 or more (HR=1.84) or with major depression (HR=2.24; p=0.008 for both; Table 1). This excess mortality risk was not accounted for by worse HbA1C level, lipid levels, aspirin use, BMI, tobacco use, or other baseline characteristics.

Major depression had a borderline impact on the ACCORD combined macrovascular endpoint, which included major coronary artery disease events, specifically fatal events, nonfatal myocardial infarction (MI), and unstable angina (HR=1.42; p=0.055; Table 1). Major depression was not significantly related to the ACCORD microvascular composite outcome, defined as fatal or nonfatal renal failure, retinal photocoagulation, or vitrectomy (HR=0.93; p=0.79), or to the ACCORD primary composite outcome, defined as CV death, nonfatal MI, or stroke (HR=1.53; p=0.153; Table 1). Minor depression had no significant impact on any outcome.

These findings underscore the importance of early identification and effective treatment of depression in patients with T2DM.

• © 2011 MD Conference Express