Depression is thought of as a mental disorder, but it can affect the rest of the body too. Having symptoms of depression may be linked to risks for other diseases.
A recent study found possible risk factors for diabetes or heart disease in women with greater depression symptoms. These risk factors were based on tests that measure inflammation and insulin resistance in the body.
Inflammation is a way the body reacts when it is trying to protect itself from further harm.
A link was also found between higher inflammation levels and women who took antidepressants.
The study, led by Yunsheng Ma, MD, PhD, of the Division of Preventive and Behavioral Medicine at the University of Massachusetts Medical School, looked for patterns in women related to depression symptoms, antidepressants, diabetes risk and body mass index (BMI).
BMI is a ratio of a person's height to weight. It is used to classify people as being underweight, a healthy weight, overweight or obese.
The researchers gathered information from 71,809 women who were recruited into the study from 1993 to 1998, after which data was regularly collected until 2005.
All the women were aged 50 to 79 when they first joined the study, and none had alcoholism, drug abuse problems or dementia.
Throughout the study, the researchers regularly assessed the women's medication use, symptoms of depression, their weight, height and waist circumference and risk factors related to diabetes and cardiovascular disease based on blood samples. The women were also asked if they were taking antidepressants.
Overall, 15 percent of the women had elevated depression symptoms, and 7 percent took antidepressants.
These antidepressants included selective serotonin reuptake inhibitors (SSRIs), monoamine oxidase inhibitors (MAOIs), tricyclic antidepressants (TCAs) and other medications designed to treat depression.
The researchers found that women with more symptoms of depression and/or those taking antidepressants had higher BMI and waist circumference measurements than those without as many depression symptoms and/or not taking antidepressants.
To look at any possible link between depression symptoms or taking antidepressants and the women's metabolic health, the researchers focused on the 1,950 women who had enough data for all metabolic measurements.
Metabolic health relates to how well the body processes food. One disease that can result from poor metabolic health is diabetes.
In the analysis, they took into account the women's age, race/ethnicity, BMI, education, physical activity levels, sleeping patterns, use of hormone therapy and amount of smoking or alcohol use.
The results showed that women with more depression symptoms had higher levels of insulin resistance, which is a risk factor for diabetes. There was no link between metabolic measurements and antidepressant use.
To look for links between depression symptoms or antidepressant use and inflammation, the researchers focused on the 2,242 women who had enough data to confirm inflammation.
The researchers found an increasing level of inflammation among women as BMI increased based on their C-reactive protein levels. C-reactive protein is a non-specific blood test that increases when there's inflammation in the body.
Even considering this link to BMI and other factors, women taking antidepressants or women with higher depression symptoms had higher levels of C-reactive protein than those without greater depression symptoms or not taking antidepressants.
This finding meant there was a link between greater depression symptoms or antidepressant use and higher amounts of inflammation in the body.
"Being that women of color have a higher risk for cardiovascular disease, hypertension and diabetes, it is imperative that we are educated concerning the correlation of such chronic disease processes and depression and overall health and well-being," Patricia Adams, LMFT, President of Zeitgeist Wellness Group, told dailyRx News.
The researchers concluded that it may be wise to regularly monitor women for risk factors for diabetes or cardiovascular disease if they showed greater depression symptoms or took antidepressants.
"We still live in an age where depression is the disease that we do not have, just pray on it and things will get better," Adams continued, "Metabolically the body is prone to some disease processes and again the more we are informed the more successful we can be in our own care."
This study was published in the June issue of the American Journal of Public Health.
The research was funded by the National Institute of Diabetes and Digestive and Kidney Diseases, the National Heart, Lung and Blood Institute and the National Institutes of Health. No conflicts of interest were noted.