Cardiac autonomic neuropathy in patients with uraemia is not related to pre-diabetes.

Introduction: It has been proposed that pre-diabetes may cause neuropathy. The aim of this study was to investigate whether cardiac autonomic neuropathy (CAN) in uraemic patients was related to the presence of pre-diabetes.

Material and methods: The study included 66 non-diabetic uraemic patients selected from a waiting list for kidney transplantation. They were on average 43 ± 12 years old, with a duration of uraemia of 32 ± 27 months in the pre-dialytic stage, or receiving either haemo-, or peritoneal dialysis. A control group of 14 healthy people matched by sex, age and body mass index were enrolled. Beat-to-beat variability was determined from the echocardiographic recording during deep inspiration and expiration. CAN was defined as a beat-to-beat value below 10 beats/min. Pre-diabetes was defined as presence of impaired fasting glucose and/or impaired glucose tolerance measured by oral glucose tolerance test (WHO/American Diabetes Association criteria 2007).

Results: The prevalence of CAN was 38% in uraemic patients compared with 8% in the controls (p < 0.005). Twenty-seven (41%) out of the 66 uraemic patients were pre-diabetic, while the remaining 39 had a normal glucose tolerance. The prevalence of CAN was comparable in uraemic patients with (44%) and without (33%) pre-diabetes. Uraemic patients with CAN were characterised by higher systolic blood pressure (p < 0.05) and higher age (p < 0.005) compared with uraemic patients without CAN.

Conclusion: The prevalence of CAN and impaired glucose tolerance is high in uraemic patients, but impaired glucose tolerance seems to play no significant role in the aetiology of CAN in uraemic patients.