As many of us are aware, a good number of scientific findings, such as the discovery of penicillin, have been made by accident. Well here’s another one to add to the list.
A May 23, 2018 article published in the journal Science Translational Medicine reports a surprising side effect of deep brain stimulation (DBS), which is sometimes used in the hardest to treat cases of obsessive-compulsive disorder. It was observed that an obese man with type 2 diabetes underwent DBS for OCD, and his blood sugar levels improved to the extent that his daily insulin requirements decreased by approximately 80 percent.
Diabetes occurs when the level of glucose in a person’s bloodstream is chronically high. Type 1, which typically begins in childhood, results when the immune system destroys the pancreatic cells that make insulin, the hormone that lets our cells use sugar as food. Type 2 diabetes, however, is typically triggered by a combination of genetics, less-than-optimal eating habits, and a lack of exercise. Type 2 diabetes also affects the body’s ability to produce its own insulin. As time goes on, cells are hard-pressed to remove sugar from the blood, and people require larger and larger amounts of insulin to keep their blood sugar stable. Currently there is no cure for either type of diabetes.
Back to the study. To research further, scientists recruited 14 people who had OCD and had undergone DBS. These study participants did not have type 2 diabetes. The researchers found that the DBS therapy affected the subjects’ insulin sensitivity and turning the brain stimulators off and on made the levels rise and fall. The metabolic function of the study participants was better when the brain stimulators were turned on, as opposed to when they were turned off.
So, what is happening here? Researchers believe that a boost in the activity of dopamine (a neurotransmitter involved in DBS) not only quiets OCD but also improves the body’s ability to process sugar. It is interesting to note that when we eat a lot of sugar, our dopamine levels increase as well.
Previous studies in mice have shown that dopamine released by neurons in the same general decision-making region the researchers stimulated — called the ventral striatum — plays a key role in regulating glucose throughout the body. As part of the research discussed above, the scientists also used optogenetics to stimulate striatal neurons in mice. Optogenetics involves the insertion of genes for light-sensitive proteins into the brains of animals. The researchers can then control and study neurons which have been genetically sensitized to light. As the neural cells released more dopamine, the rate at which other cells absorbed glucose from the rodents’ blood picked up.
Whether these findings actually lead to using DBS as a treatment for diabetes remains to be seen. Perhaps future research might lead to even less invasive procedures that target dopamine.
While I wouldn’t say that OCD and diabetes go hand-in hand, I am personally aware of quite a few people, including children, who have both illnesses, and scientists have recognized a connection between diabetes and anxiety disorders.
Sometimes studies raise more questions instead of giving us easy answers. It is clear that additional research is needed to understand the connection, if any, between OCD and diabetes, and also to figure out the best way to help those who suffer from these often-debilitating disorders.