INS and heart failure: Finally, higher HbA<sub>1c</sub> ([Formula: see text]<sub>per SD</sub> -0.094, [- 0.171;-0.017], P = 0.017) and C-peptide ([Formula: see text]<sub>per SD</sub> -0.076, [- 0.159;0.007], P = 0.075) were more strongly associated with a lower HRR<sub>60</sub> after two years of follow-up.<h4>Conclusions</h4>This study demonstrates the relevance of insulin status for vagal activity of cardiac autonomic function, particularly in heart failure.