[Increased insulin secretion in dystrophia myotonica]

Serum insulin levels were determined in patients with myotonic dystrophy after intravenous administration of glucose and were found to be higher than in control persons in about 60%. Although several interpretations of this observation are possible we favor the assumption, that an increased sensitivity of the insulin producing system of the pancreas is the reason. With regard to the most accepted hypothesis that myotonic dystrophy is a disorder due to impaired membrane function, it is tempting to explain our findings by an altered membranal function of the insulin producing cells, too.