Disturbed glucose metabolism is a well-recognized feature in cancer. This study was designed to elucidate the role of peripheral tissues for glucose metabolism in this disease. Ten cancer patients and 11 appropriate controls were subjected to insulin challenge (0.10 unit/kg body weight) and i.v. glucose tolerance test. The fractional uptake or release of insulin, glucose, free fatty acids, glycerol, acetoacetate, and lactate in the forearm was determined. In isolated skeletal muscle fibers obtained from biopsies from the rectus abdominal muscle, the incorporation rate of glucose carbon into glycogen and CO2 and the incorporation of palmitic acid carbon and leucine carbon into CO2 as well as insulin stimulation of the incorporation of glucose carbon into glycogen and leucine carbon into proteins were determined.
In cancer patients the response of blood glucose to insulin challenge was smaller than in controls. Neither the elimination rate of insulin from plasma nor the fractional uptake of glucose in the forearm was significantly changed in these patients. The incorporation rate of glucose carbon into glycogen and CO2 was significantly decreased, and the insulin stimulation of this incorporation was smaller in cancer patients than in controls. The incorporation rate of palmitic acid and leucine into CO2 did not differ between the groups.
Peripheral tissues are of importance for the disturbed glucose metabolism in cancer disease since skeletal muscles showed specifically lowered capacity for glucose utilization with and without insulin stimulation in vitro. All of these results were compatible with an insulin resistance in the liver and in the skeletal muscles in cancer.
This work was supported by grants from the Swedish Cancer Association (Project 93), the Swedish Medical Research Council (Project 536), the Assar Gabrielsson Foundation, and the Emil Andersson Foundation.