Decreased glomerular filtration rate and increased albuminuria for identification of cardiovascular autonomic neuropathy in subjects with and without diabetes

Objective: The purpose of this study was to determine the relationship between chronic kidney disease (CKD) and cardiovascular autonomic neumpathy (CAN). Research design and methods: From October 2008 to May 2011, we enrolled 218 patients with diabetes and 62 nondiabetic subjects. Heart rate variability was represented as the maximal heart rate minus the minimal heart rate (HRmax-min) during a one-minute deep breathing test. Normal, impaired cardiovascular autonomic function and CAN were defined ass HRmax-min > 15 beats/min, HRmax-min of 10-15 beats/min and HRmax-min < 10 beats/min, respectively. CKD was diagnosed if the estimated glomerular filtration rate (eGFR) was <60/min/1.73 m(2) or albuminuria. Results: In our sample, 19.4% of nondiabetic subjects and 49.5% of diabetic subjects had CKD. The prevalence of CAN was higher among patients with diabetes than among nondiabetic subjects (26.4 vs. 4.9%). A significant association was observed between eGFR and HRmax-min. CAN was independently associated with CKD with an adjusted odds ratio of 2.77 (95% CI, 1.15-6.68) in diabetic patients. A positive linear trend was observed for the odds of CAN with increasing CKD severity in diabetes. The areas under the curve (AUCs) for the predictive ability of eGFR for the risk of impaired cardiovascular autonomic function for nondiabetic group and CAN for the diabetic group were 0.734 and 0.703, respectively. Adding age, sex, body mass index, and albuminuria to the prediction model increased the AUCs to 0.852 and 0.791, respectively. Conclusion: CKD is associated with the risk of CAN in both nondiabetic and diabetic subjects. eGFR and albuminuria improve the prediction of CAN.