Insulin and the efficacy of total parenteral nutrition.

This study examined the effect of insulin on the efficacy of total parenteral nutrition (TPN). Patients were randomized to receive either crystalline zinc insulin (CZI) in each liter of TPN solution (insulin group) or no additional insulin (control group). The efficacy of TPN was evaluated by measuring body composition at 2-wk intervals. In malnourished patients the body cell mass (BCM) increased significantly with 2 wk of TPN both with and without additional insulin. The rate of change of BCM was correlated to the total caloric intake, serum insulin concentration, age, and nutritional state. The resulting multiple linear regression demonstrated that the restoration of a depleted BCM was directly related to the caloric intake, plasma insulin concentration, and degree of malnutrition and was inversely related to age. The addition of insulin to TPN solutions increases the rate at which a malnourished state is corrected.