Chronicling an unusual approach to the treatment of type 2 diabetes, a small study of 10 patients by Allegheny General Hospital physicians led by neurosurgeon Peter Jannetta suggests that a type of brain surgery can lead to improvement in the onset and progression of the disease.
The study about the effects of surgery to decompress an artery pressing on the medulla oblongata was published on August 12 in the journal Surgical Neurology International. Dr. Jannetta is known for his work developing the surgery, called microvascular decompression. In the surgery, the artery is repositioned and a protective pad is placed between it and the nerve.
The medulla oblongata is responsible for, among other things, function of the pancreas, which is involved in the production of insulin. Type 2 diabetes is characterized by a resistance to insulin, which helps the body effectively use glucose for energy.
Dr. Jannetta noted that an earlier group of 15 of his patients had both type 2 diabetes and what was considered unrelated cranial nerve disease. They were given the decompression surgery. Reviewing results, he noted that nine of them had improved diabetes symptoms.
He hypothesized that the nerve compression affected the pancreas and surgery could mitigate the disease. He enrolled 10 diabetes patients for the followup study. All 10 patients had both steadily progressive type 2 diabetes and compression in the medulla, which had been detected through MRI scans. They underwent the decompression surgery in 1997-99 and were followed for a year, during which time they were not permitted to make any changes in diet, weight or activity.
Seven of the 10 showed significant improvement in their glucose control and decreased medication dosages. One patient went off medication altogether.
The study’s endocrinologist noted that the three who did not improve had higher body mass indexes, falling into the obese category. The other seven had BMIs in the overweight class.
Dr. Jannetta’s group is embarking on a larger study in partnership with the University of Minnesota and the University of Toronto. Prospective study subjects are undergoing MRI scans.
The research drew criticism from at least one diabetes expert. “It sounds very farfetched to me,” said Vijay Bahl, chief of endocrinology and metabolism at UPMC Shadyside. “We know the brain controls blood sugar … and other neurotransmitters like dopamine … but the decompression of a blood vessel (as a treatment) just doesn’t sound real.”
An accompanying editorial in the medical journal called for further investigation into the connection between the brain condition and diabetes.
Pohala Smith/Pittsburgh Post-Gazette