Dysfunction of pre- and post-operative cardiac autonomic nervous system in elderly patients with diabetes mellitus

The pre- and post-operative cardiac autonomic nervous functions were compared in elderly, non-cardiac surgery patients with diabetes mellitus (DM) and without diabetes mellitus (NDM). A group of 30 unpremedicated elderly patients scheduled to undergo elective non-cardiac surgery were studied, including 15 DM patients and 15 NDM patients. Each component of heart rate variability (HRV) analysis in the frequency domain was monitored with Holter during the nights of the day before and on 1st and 2nd day after operation. After surgery, total power (TP), high frequency (HF), low frequency (LF) and very low frequency (VLF) significantly decreased as compared to the baseline values before operation in both groups (p < 0.05). The LF/HF ratio was significantly changed in DM group but did not change in NDM group. On the 2nd postoperative day, TP, HF, LF and VLF in DM group were further decreased as compared to those on the 1st postoperative day and were significantly lower than those in NDM group (p < 0.01 or 0.05), but these indices in NDM group did not show significant decreases. Surgery induced the cardiac autonomic nervous dysfunction in elderly patients not only with DM but also without diabetes. On the 2nd postoperative day, the disturbances of cardiac autonomic nervous activity were more sever in DM patients, compared to the 1st postoperative day, but was not significantly more sever than in the NDM patients.