(HealthDay) -- Many people know diabetes -- both type 1 and type 2 -- can take a serious toll on physical health. But these blood-sugar disorders also can affect your emotions and, in turn, your emotions can wreak havoc on your diabetes control.
Extremes in blood-sugar levels can cause significant mood changes, and new research suggests that frequent changes in blood-sugar levels (called glycemic variability) also can affect mood and quality of life for those with diabetes.
Depression has long been linked to diabetes, especially type 2. It's still not clear, however, whether depression somehow triggers diabetes or if having diabetes leads to being depressed.
More recent research in people with type 1 diabetes has found that long periods of high blood-sugar levels can trigger the production of a hormone linked to the development of depression.
People with type 1 diabetes no longer can make their own insulin; people with type 2 diabetes need insulin treatment because their bodies can no longer produce it in sufficient quantities.
"Diabetes gives you so much to worry about that it's exhausting. It can make you feel powerless," said Joe Solowiejczyk, a certified diabetes educator and a manager of diabetes counseling and training at the Johnson & Johnson Diabetes Institute in Milpitas, Calif. "I think it's important to acknowledge that, from time to time, you're going to have a meltdown. You're going to have days when you feel exasperated, frustrated, sad, in denial and physically exhausted."
Solowiejczyk, who has type 1 diabetes himself, said these feelings become a problem "when you're not able to get on with your life, and you're persistently not taking care of your diabetes."
Not only does diabetes increase the risk of serious health complications, but uncontrolled diabetes also may worsen depression, causing a vicious cycle.
In addition to an increased risk of depression, diabetes can affect mood even from minute to minute. For example, someone who experiences low blood sugar may suddenly become irritable, even combative, and may act as if they are drunk, slurring their words.
Low blood-sugar levels (also known as hypoglycemia) occur when someone has taken too much insulin or hasn't eaten enough food. Exercise, alcohol and many other factors can lower blood-sugar levels unpredictably.
The problem, Solowiejczyk said, is "that the brain operates totally on glucose. When you don't have enough glucose, things start breaking down and your cognitive function doesn't work that well. This is a physiological, not an emotional, response."
Dr. Vivian Fonseca, president of medicine and science for the American Diabetes Association, said, "Hypoglycemia reactions are very understandable. There are also some fluctuations that are not quite in the hypoglycemia range that may affect anxiety levels."
High blood-sugar levels (hyperglycemia) also can lead to mood changes. "Hyperglycemia can affect your ability to concentrate and can make you feel grouchy," Solowiejczyk said. "Any change in the blood sugar outside of the normal ranges makes you feel weird and uncomfortable."
A small study in the April issue of the journal Diabetes Technology & Therapeutics found that frequent fluctuations in blood-sugar levels in women with type 2 diabetes were associated with a lower quality of life and negative moods.
Fonseca said, however, it's important for these findings to be replicated in a larger population.
Although diabetes and blood-sugar levels can affect emotions, emotions also can affect patients' blood-sugar levels and diabetes control.
In another study in the same journal issue, researchers tested blood-sugar levels in non-diabetic bungee jumpers, and found that the stress of the jump caused their blood-sugar levels to rise significantly. Not surprisingly, their stress hormones also were higher due to the body's normal fight-or-flight response. When this happens, the liver releases glucose to make energy available to the body's cells, according to the American Diabetes Association.
People with diabetes don't have sufficient insulin to let that glucose into the body's cells, however, so instead of providing energy, the sugar just builds up in the blood.
Another emotional minefield often associated with type 2 diabetes is the concept of blame. Most people with type 2 diabetes are overweight, and many are sedentary. Being overweight alone, however, doesn't cause type 2 diabetes. There are other factors, such as a genetic predisposition, at play. But because exercise and losing weight can help prevent -- or, in some cases, reverse -- type 2 diabetes, society often blames people with the disease. (Type 1 diabetes is an autoimmune disease that is not caused by diet or lack of exercise.)
"I think there is a prejudice against overweight people and people with type 2 diabetes, and that's something they have to deal with," Solowiejczyk noted.
What's important, he said, is that if you're persistently having trouble dealing with any of the emotions that come with diabetes, you talk with your doctor, diabetes educator or therapist.
"You should be feeling bad or resentful or angry sometimes," he said. "Diabetes is hard, and all of those feelings come along with the disease. But if you're [irritable] and angry or if you're sad all the time, you're not going to take care of yourself."
The same advice is true for partners of people with diabetes and parents of children with diabetes, he said.
Explore further: Diabetes may significantly increase your risk of dementia
Learn more about the emotional side of diabetes, and the signs of depression, from the American Diabetes Association.