Patients with depression or diabetes have an increased risk of MI, but the risk is even higher in patients with both conditions, according to a new study.…
The authors suggest that, “Collaborative care models that incorporate cardiology, mental health, and primary care may improve outcomes in this complex patient population.” Evidence indicates that depression worsens cardiovascular outcomes in type 2 diabetes.
To analyze specific endpoints such as MI, Dr. Jeffrey F. Scherrer at the St. Louis Veterans Affairs Medical Center in Missouri, and colleagues examined Veterans Administration data on over half a million patients who were free of cardiovascular disease in 1999 and 2000.
The cohort consisted of 77,568 patients with major depressive disorder (MDD), 40,953 with type 2 diabetes, 12,679 with comorbid MDD and type 2 diabetes, and 214,749 people with neither condition.
During seven years of follow-up, MI rates were 3.5% in the MDD group, 5.9% in the diabetes group, 7.4% in patients with both, and 2.6% in the control group.
Compared to controls, multivariate-adjusted hazard ratios for MI were 1.29 for those with depression only, 1.33 for those with diabetes only, and 1.82 among patients with both conditions, the investigators reported online June 16th in Diabetes Care.
Receipt of at least 12 weeks of an antidepressant, however, was significantly associated with a lower risk of an incident MI.
“The current study confirms that MDD is associated with a greater hazard of incident MI in patients with type 2 diabetes,” Dr. Scherrer and colleagues conclude.
They suggest several possible mechanisms for their findings. For instance, MDD may impair diabetes self-care and increase inactivity and other behavioral risk factors. It might also induce physiologic changes; depressed patients have been shown to have abnormal glucose levels and glucose tolerance, as well as increased coagulation and fibrinolysis.
And conversely, insulin resistance in type 2 diabetics can interfere with MDD treatments, making it hard to bring patients out of their depression.
“It is possible that patients who have had depression and/or diabetes for longer periods of time, especially longer than our observation period, may be at an even greater increased risk of incident MI,” the authors say.
Diabetes Care June 16, 2011