High plasma interleukin-2: a potential cause of insulin resistance

Low-density lipoproteins, infections and smoking are closely associated with insulin resistance. According to the hypothesis proposed in this paper, all of these factors could cause insulin resistance by the same mechanism. The first step in the cascade of events leading to insulin resistance is increased production of interleukin-2. This is followed by secretion of other cytokines, activation of macrophages and increased production of nitric oxide from L-arginine. The reduced amount of plasma L-arginine leads to decreased secretion of growth hormone and insulin-like growth factor-1 during exercise. The decreased secretion of insulin-like growth factor-1 is the basic reason for insulin resistance. Tumour necrotizing factor may also be involved in the pathogenesis of insulin resistance directly by binding in beta-adrenergic receptors. High plasma interleukin-2 also causes decreased bioavailability of insulin-like growth factor-1 by reducing the production of androgenic hormones.