Depression may trigger diabetes in older adults

April 23, 2007

CHICAGO -- Chronic depression or depression that worsens over time may cause diabetes in older adults, according to new Northwestern University research.

This is the first national study to suggest that depression alone -- and not lifestyle factors like being overweight -can trigger Type 2 diabetes in adults 65 and older, a population with a high prevalence of diabetes and depression. The report will be published April 23 in Archives of Internal Medicine.

The study examined 4,681 men and women 65 and older from Forsyth County, N.C.; Sacramento County, Calif.; Washington County, Md.; and Pittsburgh, Pa., annually for 10 years.

"This means doctors need to take depressive symptoms in older adults very seriously because of the effect it has on the likelihood of developing diabetes," said Mercedes Carnethon, lead author of the study and assistant professor of preventive medicine at Northwestern's Feinberg School of Medicine.

An estimated 2 million older adults suffer from clinical depression, the second highest incidence of any age group. People 65 and older also have the highest prevalence of Type 2 diabetes.

"Diabetes is a scourge," said Carnethon. "It causes heart disease, blindness, kidney disease, leg amputations and lowered cognitive function because it essentially degrades the small and large blood vessels."

The study differed from prior research in several ways. It is the first to examine the connection between increasing symptoms of depression over time and the incidence of diabetes.

Previous studies linking diabetes to depression have been based on a one-time measure of depressive symptoms. A single measure could be based on an episode or event that has caused a person to feel blue for a limited amount of time.

Carnethon's study measured depressive symptoms at a single point in time as well as depressive symptoms over time. This approach paints a more accurate depiction of depressive symptoms. By measuring depressive symptoms before diabetes developed, she and colleagues were better able to investigate the causal effect between mood and diabetes.

The Northwestern study also factored out other known lifestyle causes of diabetes such as being overweight or getting little physical exercise.

"We know that overweight and obesity are the primary risk factors for diabetes and most people with Type 2 diabetes are overweight or obese," Carnethon said. "But even after we adjusted for [statistically accounted for] body mass index (measure of height versus weight), we still saw a residual association between depression and diabetes."

In addition, the study considered a key biological factor - a high level of inflammation common in depressed people -- that might have explained the link between depression and diabetes. Inflammation is estimated by the levels of an inflammatory protein in the blood called C-reactive protein. But even after accounting for levels of the protein, depressive symptoms were still associated with the development of diabetes.

Carnethon theorizes that the culprit responsible for diabetes in persons who are depressed is a high level of a stress hormone, cortisol. High levels of cortisol may decrease insulin sensitivity and increase fat deposits around the waist (a risk factor for diabetes). While her study was limited to older adults, she believes high cortisol levels in depressed younger adults may also put them at risk for diabetes.

Insulin enables glucose (sugar) to enter the body's cells to be used as fuel. When people are under acute stress or are depressed, the cells in the pancreas are suppressed and secrete less insulin to enable the body to sweep glucose out of the bloodstream. Compounding the problem, high cortisol levels decrease the muscles' sensitivity to insulin, which also could result in elevated glucose levels, Carnethon said.

"When you're depressed or under stress your body is trying to keep glucose in the bloodstream because it needs it for immediate energy," Carnethon noted. "So, it's blocking insulin action. And you may even be producing more glucose because your body thinks it needs the sugar."

Carnethon said the study shows the importance of screening older adults for depressive symptoms. "It's not a normal condition for older adults to be depressed," she said. "I think a lot of people say, 'Oh, they're old, they should be depressed. What does it matter if they're a little bit down?' Well, it does matter and you should treat it aggressively because it has effects on health beyond that of mood."
-end-
Collaborators on the report are from the University of Washington, Emory University and Wake Forest University.

Northwestern University

Related Diabetes Articles from Brightsurf:

New diabetes medication reduced heart event risk in those with diabetes and kidney disease
Sotagliflozin - a type of medication known as an SGLT2 inhibitor primarily prescribed for Type 2 diabetes - reduces the risk of adverse cardiovascular events for patients with diabetes and kidney disease.

Diabetes drug boosts survival in patients with type 2 diabetes and COVID-19 pneumonia
Sitagliptin, a drug to lower blood sugar in type 2 diabetes, also improves survival in diabetic patients hospitalized with COVID-19, suggests a multicenter observational study in Italy.

Making sense of diabetes
Throughout her 38-year nursing career, Laurel Despins has progressed from a bedside nurse to a clinical nurse specialist and has worked in medical, surgical and cardiac intensive care units.

Helping teens with type 1 diabetes improve diabetes control with MyDiaText
Adolescence is a difficult period of development, made more complex for those with Type 1 diabetes mellitus (T1DM).

Diabetes-in-a-dish model uncovers new insights into the cause of type 2 diabetes
Researchers have developed a novel 'disease-in-a-dish' model to study the basic molecular factors that lead to the development of type 2 diabetes, uncovering the potential existence of major signaling defects both inside and outside of the classical insulin signaling cascade, and providing new perspectives on the mechanisms behind insulin resistance in type 2 diabetes and possibly opportunities for the development of novel therapeutics for the disease.

Tele-diabetes to manage new-onset diabetes during COVID-19 pandemic
Two new case studies highlight the use of tele-diabetes to manage new-onset type 1 diabetes in an adult and an infant during the COVID-19 pandemic.

Genetic profile may predict type 2 diabetes risk among women with gestational diabetes
Women who go on to develop type 2 diabetes after having gestational, or pregnancy-related, diabetes are more likely to have particular genetic profiles, suggests an analysis by researchers at the National Institutes of Health and other institutions.

Maternal gestational diabetes linked to diabetes in children
Children and youth of mothers who had gestational diabetes during pregnancy are at increased risk of diabetes themselves, according to new research published in CMAJ (Canadian Medical Association Journal).

Two diabetes medications don't slow progression of type 2 diabetes in youth
In youth with impaired glucose tolerance or recent-onset type 2 diabetes, neither initial treatment with long-acting insulin followed by the drug metformin, nor metformin alone preserved the body's ability to make insulin, according to results published online June 25 in Diabetes Care.

People with diabetes visit the dentist less frequently despite link between diabetes, oral health
Adults with diabetes are less likely to visit the dentist than people with prediabetes or without diabetes, finds a new study led by researchers at NYU Rory Meyers College of Nursing and East Carolina University's Brody School of Medicine.

Read More: Diabetes News and Diabetes Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.