"When experiencing chronic stress or depression, cortisol levels can become permanently elevated," said study author Nicole Vogelzangs. "One effect of high cortisol levels is that it directs fat to the visceral regions by activating lipoprotein lipase and inhibiting lipid mobilization."
The research focused on 2,008 adults age 70 to 79. All were healthy and functioned independently. Interestingly, the researchers found no correlation between depression and overall obesity, only the subclass of abdominal obesity. They concluded that "there may be specific pathophysiological mechanisms that link depression with visceral fat accumulation."
Four percent of the study's subjects showed symptoms of depression at the beginning of the study. The scientists discovered that abdominal obesity did not seem to be related to poor dietary habits associated with depression. Rather, the key element in such obesity was the depression and the elevated cortisol levels associated with it. "A poor diet leads to high amounts of fat entering the body; [but] cortisol directs all this fat to the visceral area," said Vogelzangs.
Depressed people have a doubled risk of heart disease, so treatments for depression are becoming increasingly important. This is especially true as depression is on the rise and is expected to become much more common by 2020, affecting 10 percent to 15 percent of elderly people. Absent such treatments, society can only expect increased depression-related sickness and mortality among seniors.