“There’s a real plausability to it, based on the fact that the neurons of the substantia nigra are involved in this feedback loop with peripheral glucose levels,” she observed. “Under normal circumstances, dopaminergic neurons help to regulate blood sugar by helping to motivate feeding behavior when glucose levels are low. We know that medications that block dopamine in the brain can cause high blood sugar. By the time you’ve developed Parkinson’s [disease], you’ve lost 70% to 80% of those neurons, and so the question is, Could it be that, in fact, Parkinson’s disease is a cause of diabetes? Our results didn’t completely convince us of that, because if that were true, you’d expect that the longer people had Parkinson’s disease, the more diabetes they would get.” It is a possible explanation that Dr. Driver is hoping to tease out in further studies, including a planned study with a data set involving women.
—Fred Balzac