INS and Abnormal autonomic nervous system physiology: Laitinen et al demonstrated that insulin infusion during a euglycemic clamp increased the LF:HF ratio and decreased the HF spectral component in individuals with insulin resistance (assessed by high C-peptide levels) but did not change the values in normal subjects with deficient insulin secretion capacity.10 These results suggest that cardiac autonomic dysfunction plays an important role in the progression of insulin resistance to type 2 diabetes.