Study: Abdominal Fat Associated with Depression in Older Adults

Scientists have discovered another connection between excess weight and poor mental health.

Following a five-year study during which they analyzed more than 2,000 adults ages 70 to 79, researchers with Wake Forest University and VU University Medical Center in Amsterdam, the Netherlands, have established a link between abdominal fat and depression. Also referred to as visceral fat, abdominal fat has previously been identified as a risk factor for developing diabetes and heart disease.

"For the depressed public, [this study] should be another reason to take one's symptoms seriously and look for treatment," co-author Stephen Kritchevsky, director of Wake Forest's Sticht Center on Aging, said in a Dec. 1 article by Associated Press writer Carla K. Johnson.

About the Study
At the outset of the study, the 2,088 adults who participated were screened for depression and had their obesity levels (both overall and abdominal) measured and recorded:

• Overall obesity was recorded by body mass index and body fat percentage, while abdominal obesity was determined by measuring waist circumference and sagittal diameter (the distance between the back and the highest point of the abdomen), as well as by reviewing CT scans.
• Depression was determined by the 20-item, 60-point Center for Epidemiological Studies Depression Scale.
• Depression screenings were repeated annually. Obesity levels were re-calculated at the five-year point.

The study subjects also provided a wide range of socioeconomic, health, and lifestyle information, including data related to smoking, consumption of alcohol, and regular levels of physical activity. The study, which began in 1998 and ended in 2003, was published in the December 2008 edition of the journal Archives of General Psychiatry.

Making the Connection
According to a Dec. 8, 2008 article by Medscape Medical News writer Pauline Anderson, the study revealed that "baseline depression was associated with an increase in abdominal obesity ... for all subjects except for black women." (The study evaluated men and women of both Caucasian and African-American ancestry.)

This relationship between visceral fat and depression was found to exist in subjects who were depressed at the start of the study as well as those who experienced recurring depressive episodes throughout the five years, Anderson reported. The researchers also found that the association remained even after the data were adjusted to account for alcohol/tobacco use, pre-existing diabetes or cardiovascular disease, and the use of antidepressants.

"Our longitudinal results suggest that clinically relevant depressive symptoms give rise to an increase in abdominal obesity, in particular visceral fat, which seems to be stronger than and independent of overall obesity," the authors wrote in the conclusion of their study. "This could also help explain why depression is often followed by diabetes or cardiovascular disease."

Searching for a Cause
Among theories that have been proposed to explain the cause of this fat-depression connection is the presence of elevated levels of cortisol (a stress-related hormone) in the bodies of affected individuals. Produced within the adrenal gland, cortisol increases a person's blood pressure and blood-sugar levels while temporarily reducing the body's immune response.

Though cortisol naturally occurs at varying levels throughout the day (usually higher in the morning and lower at night), it is perhaps best-known for the brief energy burst and lowered pain sensitivity that result when it floods into the body as part of the "fight or flight" response to stress. However, because cortisol triggers the body to convert proteins into blood sugars (excesses of which are stored as fat), overproduction of the hormone has been associated with overweight and obesity.

Depression and chronic stress are believed to be precursors to the excessive creation of cortisol, which would explain the findings that were documented during the 1998-2003 study.

Getting Help
Regardless of the specific nature of the relationship between abdominal obesity and depression, the recent study is merely the latest in a long line of scientific research into the connection between obesity and a wide range of health concerns. And though the research described in this article was conducted on older adults, there is little doubt that overweight and obesity can cause significant problems for individuals of all ages.

Depending upon the degree and duration of an individual's struggle with excess weight, professional treatment may be required in order to address any existing medical problems as well as to preclude any future damage. Treatment options include nutritional education, outpatient therapy, short-term weight-loss programs, and long-term residential care.

If you or someone you love is having problems achieving or maintaining a healthy weight, getting the help you need today may enable you to enjoy many happier and healthier tomorrows.