Glycemic response during exercise after administration of insulin lispro compared with that after administration of...

To examine the glycemic response during exercise after administration of short-acting insulin lispro, we compared changes in plasma glucose concentrations during exercise performed by patients with diabetes after the administration of either insulin lispro or regular human insulin. Seven patients with diabetes (two with type 1 and five with type 2) participated in this study. Each of the insulin-depleted subjects received the same number of units of either insulin lispro or regular human insulin, delivered subcutaneously to the abdomen. The next day, each subject received a similar injection of the solution not previously administered. After each injection, the subjects were fed a standard meal of approximately 9 kcal/kg body weight. One hour after eating the test meal, the subjects performed 30 min of cycle ergometer exercise at 50% maximal oxygen uptake. Plasma glucose, insulin, glucagon, growth hormone (GH), and catecholamine concentrations were then measured at specific intervals. Insulin concentrations were higher and peaked earlier after administration of insulin lispro than after administration of regular human insulin. The length of time, needed to reach minimum plasma glucose concentration after exercise was begun, was significantly shorter after administration of insulin lispro, and the percentage of plasma glucose decrease induced by exercise relative to the peak concentration was significantly greater. No differences were found in the concentration changes of counterregulatory hormones between the insulin lispro data and the regular human insulin data. Compared with regular human insulin, insulin lispro induces a more rapid and greater decrease in plasma glucose concentration during exercise because of its faster absorption.