Glucose tolerance,plasma insulin,and lipids in intermittent claudication with reference to muscle metabolism

Sixteen nondiabetic patients with intermittent claudication (IC) due to peripheral arterial insufficiency had as low plasma insulin values after a peroral glucose tolerance test as healthy, well-trained, middle-aged men, and both these groups had considerably lower values than controls. The low plasma insulin concentrations were more pronounced in IC patients with a high arterial stenosis than in those with a low stenosis. There was also a lower plasma triglyceride concentration in the former group than in the latter. Together with the normal glucose tolerance the low plasma insulin values in the IC patients and in the well-trained men indicate a high insulin sensitivity in the periphery. Succinic oxidase activity as well as the incorporation rate in vitro of glucose carbon into glycogen, lipids, and carbon dioxide were elevated above controls in muscle specimens from the IC patients and the well-trained men. This finding indicates that the adaptation of muscle metabolism might be of importance for insulin sensitivity after physical training, because the IC patients are physically inactive. This supposition seems to be considerably strengthened by the fact that a quantitative factor could be introduced in the comparisons. Higher arterial stenoses, with presumably a larger mass of adapted muscle tissue, showed the most pronounced increase in insulin sensitivity.