People With Diabetes And Depression Have High Levels of This Protein. Is There A Link?

People with diabetes are three to four times more likely to experience serious depression than people without diabetes. What’s not entirely clear is the relationship between diabetes and depression. There’s a strong correlation, but is depression a symptom of diabetes, or a cause (at least a cause for type 2)? Obviously having diabetes is difficult and isolating, but is that really enough to account for such a strong association with depression?

A new study has found a link between depression and the prevalence of galectin-3, an inflammatory protein. The study’s authors now hope that studying galectin-3 will shed light on depression and possible treatment methods.

Photo: AdobeStock/Andrea Danti
Photo: AdobeStock/Andrea Danti

The Study

The study, published in May 2018 and conducted at Lund University in Sweden, followed 283 adults with type 1 diabetes for a year or more. Researchers assessed depression and other lifestyle factors using the Hospital Anxiety and Depression Scale.

Since neuroinflammatory processes are linked to depression, and galectin-3 is an inflammatory protein, researchers theorized that increased levels of galectin-3 could be associated with depression in people with type 1 diabetes. They were correct.

Study participants with self-reported depression had higher levels of galectin-3 in their blood. Higher levels of the protein were not associated with A1C, blood pressure, obesity, medications, or cardiovascular complications—it was independently correlated with depression. This association is new, and may lead to better ways of identifying and treating depression.

Photo: AdobeStock/pixelheadphoto
Photo: AdobeStock/pixelheadphoto

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More about Galectin-3

Higher galectin-3 levels have been linked to heart failure and all-cause mortality, but it’s not all doom and gloom. The protein may help remodel damaged central nervous tissue and trigger inflammation when needed. It may also have a protective role by acting as a decoy to advanced glycation end-products, which are more prevalent in people with high blood sugar and can clog blood vessels.

So it’s not all bad. High galectin-3 levels are associated with Alzheimer’s disease, hypertension, renal dysfunction, and type 2 diabetes. It could be that the protein plays a protective role by triggering inflammation, which explains its correlation with inflammatory diseases.

Photo: AdobeStock/rocketclips
Photo: AdobeStock/rocketclips

However, since depression is linked to neuroinflammatory response, it’s hard to say if galectin-3 is a cause or a symptom of depression, and researchers are now calling for more studies. They want to know if monitoring galectin-3 levels can be helpful in evaluating treatments for depression, and if it can help predict Alzheimer’s risk and risk for cardiac and renal failure.

Dr. Eva Melin lead researcher of the study, is looking forward to what her research could reveal. “Depression is a common disorder with very serious and debilitating consequences, so these findings suggest that further investigating the role of galectin-3 could lead to improved diagnosis and maybe better treatment outcomes for patients in the future,” she said.

Photo: AdobeStock/hakat
Photo: AdobeStock/hakat

In short, there’s more work to be done, and researchers are eager to get started.

Depression is associated with type 1 and type 2 diabetes, Alzheimer’s disease, cardiovascular complications, and all-cause mortality, and we need to find answers. The more we know about the root causes of depression, the more hope we can give to those who are struggling.

Stay healthy, friends!

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