GCG and Insulin resistance: Third, increased levels of pro-inflammatory cytokines can lead to chronic inflammation, insulin resistance, and impaired glucose metabolism.[28] In a mouse and human study, clozapine administration resulted in decreased glucagon levels and elevated expression of interleukin-1β (IL-1β), IL-6, and tumor necrosis factor-α (TNF-α).[29] IL-1β binds to IL-1 receptors on pancreatic beta cells, potentially leading to cell apoptosis and impaired insulin secretion.