Researchers at the University of California, Los Angeles suggest that the higher mortality rate could be because depressed people are less likely to be compliant with their prescribed medications, diet, exercise and glucose self-monitoring.
Researchers acknowledge that the link between depression and premature death among diabetics has been the subject of many studies, but they note theirs is among the first to compare different age groups.
For their study, the researchers analyzed information on 3,341 people with diabetes, including 1,402 who were 65 years and older and 1,939 between the ages of 18 and 64. The data came from Translating Research Into Action for Diabetes, a study that collected health insurance claims, medical chart review and phone interviews from 10 health plans in eight states.
Each person was given a baseline survey and was contacted for a follow-up survey six to seven years after the initial interview, according to the researchers.
The scientists measured mortality risk as the number of days until death since the time of the interview. The researchers note they controlled for age, gender, race and ethnicity, income, and co-morbidities such as heart and kidney disease associated with diabetes.
“We found that depression mainly increases the risk of mortality among older persons with diabetes,” said Lindsay Kimbro, M.P.P., project director in the division of general internal medicine and health services research at the David Geffen School of Medicine at University of California, Los Angeles, and the study’s lead author.
“Although depression is an important clinical problem for people of all ages, when you split the different age groups, depression in the younger group doesn’t lead to increased mortality six to seven years later.”
As in previous studies, the results revealed that the risk for early death among depressed people with diabetes was 49 percent higher than among those without depression.
However, the correlation was even more pronounced among older adults, according to the researchers. They found a 78 percent higher mortality risk among diabetics 65 and older than they did among non-depressed people with diabetes in that age group.
For the younger diabetics, the effect of depression on their risk for early death was not statistically significant, the researchers report.
“Our findings highlight the importance of screening for depression among older adults with diabetes, and of encouraging treatment for those who screen positive,” said Dr. Carol Mangione, a study co-author who holds the Geffen School’s Barbara A. Levey, M.D., and Gerald S. Levey, M.D., endowed chair.
The study was published in the Journal of the American Geriatrics Society.