Glucose intolerance and insulin resistance accompany immobilization.

Physical activity is known to increase glucose tolerance and insulin sensitivity. To examine the influence of physical inactivity on insulin sensitivity, we measured oral glucose tolerance (OGTT) and insulin response to glucose in 18 patients immobilized to bed for six weeks after acute spine fracture. The results were compared to those of nine chronically immobilized spinal cord injury patients and to eight healthy mobile controls. During the first week after trauma both glucose and insulin responses in the OGTT were two- to three-fold above normal (p less than 0.01). The index of insulin resistance (glucose area X insulin area) was seven-fold greater than in healthy controls (p less than 0.001). After three weeks' immobilization insulin resistance had declined by 30-35% (p less than 0.05) being then at the level observed in chronically immobilized subjects. After remobilization the insulin resistance was further decreased but remained still 2.3 times higher than in controls. Thus, trauma causes a manifold increase in insulin resistance, which is reduced but not normalized during the subsequent immobilization and remobilization.