Figure 1: Reciprocity between the autonomic nervous system (ANS) and diabetes. Metabolic shift can increase blood glucose levels, insulin resistance and lipotoxicity. Increased blood glucose and increased insulin resistance lead to elevated insulin levels and insulin sensitivity, thus activating the SNS. As a result, norepinephrine release and lipolysis increase, further exacerbating metabolic shift and lowering insulin sensitivity. In retrospect, vagal impairment can lead to sympathetic overactivity as well as hyperglycemia.