Depression linked to heart disease in diabetics
Study relates optimism to reduced complications
Connections between depression and diabetes have been big news in diabetes care in the past year.
Now a University of Pittsburgh study shows that depressed Type 1 diabetic patients have nearly 50% greater risk of cardiovascular disease than diabetics with a more optimistic outlook. That increased risk goes well beyond the high rate of cardiovascular complications found in patients with diabetes.
Specifically, the study shows that diabetic patients who reported they were feeling down or experiencing sleep disturbances or appetite changes were much more likely to develop heart disease.
"We’re not yet at a point where we can say that treating depressive symptoms early can prevent heart disease, but we need to find out more about these mechanisms," says Trevor Orchard, MD, professor of epidemiology, medicine, and pediatrics at the University of Pittsburgh School of Public Health. "We don’t know the underlying cause. There are several possible mechanisms at work here."
Those possible mechanisms include:
- Individuals with excessive stress reactions and cortisone production are more prone to depression. Those same individuals tend to have more central adiposity and therefore more insulin resistance.
- There may be a link to autonomic neuropathy, but Orchard says that’s a remote possibility.
- There may be a distinctive personality type from birth that is characterized by depression and a more obsessive nature.
Orchard points out that Beck Depression Inventory scores have been linked to increased instances of angina and myocardial infarctions. (See sample of the Beck Depression Inventory, pp. 29-30.)
"The depression came before the heart disease, since none of the subjects had heart disease at the beginning of the study." While the reason for the link may not be clear, there is a clear message to clinicians treating diabetics, says Orchard.
"The standard of practice says physicians must carefully monitor blood pressure. I would say a careful monitoring of depressive symptoms is just as important," he says.
He notes there is a difference between a person with depressive symptoms and someone who is clinically depressed. "Every diabetic patient should be carefully evaluated, and if depressive symptoms are found, that patient should be considered at high risk for heart disease."
Orchard recommends the Beck Depression Inventory as a valuable tool to look at depressive characteristics in a patient. "There are many types of symptoms in the index that should raise the flag that a patient may be depressed."
Orchard stops short of recommending universal depression screening for all diabetic patients. "It simply warrants our attention as health care professionals, since we know diabetics are two to 10 times more likely to have heart disease than nondiabetics," he says. "This opens an avenue to explain the enormous risk of heart disease in diabetes."
Depressive disorders are more common in Type 1 diabetics than in Type 2, says Alan M. Jacobson, MD, director of the mental health unit at Joslin Diabetes Center and a professor of psychiatry at Harvard Medical School in Boston. "Depression is a risk factor for any illness, and it changes adherence to any regimen." Furthermore, depression is associated with worse glycemic control, says Jacobson, and with higher risk of retinopathy, probably because of that association.
While there has been no firm link established between poor control and heart disease, many experts think the leap wouldn’t be that difficult to make, considering the other evidence in existence.
"Temperament is a predictor of health outcomes. Pessimistic people do worse in the long term than optimistic people," he says.
Any type of depression can be hard to discover, considering the patient may not be showing signs to the physician, he says. "A patient can be sitting there smiling at you and still be severely depressed. You have to get to know the patient and spend a little time."
He recommends simple screenings during office visits that can be both efficient and effective in finding patients at risk. "Ask questions quickly. It can be done in just a couple of minutes if you just ask a few questions. Are they feeling a loss of interest in things that once interested them — experiencing . . . feelings of pessimism, mood swings, loss of energy, sleep disturbances, or a decrease in appetite? That should give you a good idea of whether they are depressed."
If the clinician suspects that a patient is severely depressed, matters of medication and counseling should be handed over to a specialist. There has been a great deal of criticism about physicians who routinely prescribe antidepressants without any other type of attention, and the antidepressants alone may not best serve the patient’s interest. The time to refer, Jacobson notes is "anytime you have the slightest feeling you are getting out of your element."
"It’s not hard to do this simple screening, if you practice it," he adds. "But if it is out of the ordinary, it should become ordinary."
Talking with family members also can be helpful, says Mary Amanda Dew, PhD, a professor of psychiatry and member of the cardiothoracic team at the University of Pittsburgh Medical Center.
"That’s just a part of good clinical care. Some-times the patient may not be very forthcoming or may not even recognize the symptoms of depression, but a family member may be able to shed a little more light on it." The stress of living with diabetes can lead to depression, anxiety, and other mental health problems, she says.
Dew suggests using the simplest possible depression screening techniques — "just a few simple questions. If you established rapport, you’ll get the full story, and then you might go a long way toward preventing further problems, both mental and physical."
[For more information, contact Trevor Orchard at (412) 383-1032, Alan Jacobson at (617) 732-2657, and Mary Amanda Dew at (412) 624-3373.]