Do you have lupus? According to studies, you may have a higher risk of depression and cardiovascular disease
For patients with systemic lupus erythematosus (SLE), depression further increases their already elevated risk for cardiovascular disease, researchers said here.
In these patients, depression was associated with a nearly four-fold greater risk of sub-clinical atherosclerosis (OR 3.85, 95% CI 1.37 to 10.87), Carol Greco, PhD, of the University of Pittsburgh, reported at the meeting of the American College of Rheumatology.
This relationship was independent of several other factors, including age, presence of hypertension, years of education, C-reactive protein levels, and waist-to-hip ratio.
The finding is important, Greco said, because “depression is a modifiable risk factor and could be targeted for intervention.”
The relationship between cardiovascular risk and depression is well known based on studies in the general population, she said, but the issue had not been explored in depth in patients with lupus, who have higher rates of both conditions.
Greco and her colleagues addressed this knowledge gap by looking at data on 161 women who had lupus and no history of cardiac events.
The mean age of the patients was 50. The women were predominantly white (88%) and about two-thirds (68%) had taken corticosteroids.
For this study, the researchers defined subclinical atherosclerosis as the presence of coronary artery calcification detected by electron beam CT, the presence of carotid artery plaques detected by ultrasound, or both.
Overall, 27% of the women had meaningful symptoms of depression. and 63% met criteria for subclinical atherosclerosis.
After adjusting for other independent predictors of subclinical atherosclerosis — age (OR 1.11, 95% CI 1.06 to 1.17), years of education (OR 0.82, 95% CI 0.68 to 0.99), hypertension (OR 2.50, 95% CI 1.10 to 5.66), waist-to-hip ratio (OR 4.03, 95% CI 1.12 to 14.49), and C-reactive protein levels (OR 1.12, 95% CI 1.01 to 1.23) — depression was significantly associated with subclinical disease.
A second study, conducted by Laura Julian, PhD, of the University of California San Francisco, and colleagues, also identified an association between depression and cardiovascular disease, in both men and women with lupus.
The San Francisco researchers followed 725 lupus patients with annual interviews over five years as part of the Lupus Outcomes Study.
About half had no signs of depression, and about a quarter each had possible or probable depression.
Predictors of concurrent depression included living in poverty, a history of myocardial infarction or stroke, a composite of traditional cardiovascular risk factors, and lupus disease activity (P≤0.003 for all).
Over the course of the study, 163 incident cases of depression were identified. Predictors of developing depression included the following:
* Living in poverty: OR 3.26, 95% CI 1.23 to 8.24
* A history of MI or stroke: OR 2.00, 95% CI 1.01 to 3.96
* Lupus disease activity: OR 1.12, 95% CI 1.07 to 1.16
Julian and her colleagues also explored a possible interaction between cardiovascular events and poverty and its relationship with the development of depression. The interaction approached, but did not reach, statistical significance (P=0.09).
However, Julian said, the magnitude of the odds ratio for depression (OR 6.31, 95% CI 0.73 to 54.2) suggested the interaction could have an effect on the development of depression.
She said the link between social factors and biological outcomes could not be ignored because 80% of the patients who were living below poverty and had had a cardiac event were depressed. This compares with 38% of those who were living below poverty but had not had a cardiac event.
“I think this is a meaningful interaction, and we’ll have to see what it looks like in other studies,” she said.
Greco reported receiving research grants from Bristol-Myers Squibb and the NIH. Her co-authors reported relationships with Bristol-Myers Squibb, the NIH, Amgen, Aspreva, Genelabs Technologies, Genentech, Human Genome Sciences, Immunomedics, Cellatope Corporation, La Jolla Pharmaceutical, MedImmune, Centocor, and Cephalon.
Julian and her co-authors reported no conflicts of interest. Their study received funding from the National Institute of Arthritis and Musculoskeletal and Skin Diseases and the National Institute of Mental Health, as wells as from a Lupus Center Grant from the State of California.