Analysis of a Screening System for Diabetic Cardiovascular Autonomic Neuropathy in China

Abstract

BACKGROUND The aim of this study was to create a screening system for diabetic cardiovascular autonomic neuropathy (DCAN) in diabetic patients. MATERIAL AND METHODS A Chinese cohort of 455 diabetic participants was recruited between 2011 and 2013. Short-term heart rate variability testing was used to evaluate cardiovascular autonomic function. A simple model was developed using multiple variable regression to include only significant risk factors that were simple and easily assessed. A DCAN score was determined based on the coefficients of the multiple variable model. This score was tested on the entire cohort of 455 diabetic patients and another independent, external cohort of 115 diabetic patients. RESULTS The screening system consisted of age, body mass index, duration of diabetes mellitus, and resting heart rate, and these factors were significantly (P<0.05) associated with DCAN. Receiver operating characteristic (ROC) curve analysis was done. The areas under the ROC curve were 0.798, 0.756, and 0.729 for the total sample, validation cohort, and external set, respectively. A cutoff DCAN score of 12 out of 25 produced optimal results for sensitivity (80.36%), specificity (58.27%), and percentage of patients that needed subsequent testing (43.55%) for the validation set. CONCLUSIONS The study concludes that a simple and practical DCAN screening can be applied for early intervention to delay or prevent the disease in the Chinese population.

Figure 1

Comparison of prevalence of diabetic cardiovascular autonomic neuropathy (DCAN) according to risk factors. (A) Comparison of DCAN prevalence according to age. DCAN prevalence was 20.83%, 24.71% and 36.36% in the 3 groups, respectively. Additionally, there were significant differences among the 3 groups (P for difference <0.001 and P for a trend <0.001). (B) Comparison of DCAN prevalence according to body mass index (BMI). DCAN prevalence was 27.79%, and 44.12% between BMI ≤30 kg/cm² and BMI >30 kg/cm² group, respectively. There was a significant difference between the 2 groups (P=0.004). (C) Comparison of DCAN prevalence according to heart rate (HR). DCAN prevalence was 07.01%, 18.75%, 36.67% and 64.29% in the 4 groups, respectively. There were significant differences among the 4 groups (P for difference <0.001 and P for a trend <0.001). (D) Comparison of DCAN prevalence according to duration of diabetes (DM duration). DCAN prevalence was 18.18%, 26.35%, 36.25% and 51.72% in the 4 groups, respectively. There were significant differences among the 4 groups (P for difference <0.001 and P for a trend <0.001).

Figure 2

Receiver operating characteristic curves showed the performance of each cardiovascular autonomic neuropathy risk score (CRS) in predicting prevalence of diabetic cardiovascular autonomic neuropathy (DCAN) in the exploratory set, total sample, validation set and external dataset. The 95% confidence interval (CI) is given in parentheses. AUC – area under the curve. In exploratory set, AUC=0.779, 95%CI: 0.744–0.813, P<0.001; in total sample, AUC=0.798, 95%CI: 0.752–0.844, P<0.001; in validation set, AUC=0.756, 95%CI: 0.705–0.808, P<0.001; and in external dataset, AUC=0.729, 95%CI: 0.601–0.857, P=0.002.

Figure 3

Distribution of diabetic cardiovascular autonomic dysfunction (CAN) risk score (bottom bars) and DCAN prevalence (upper bars) against DCAN risk score in the modeling dataset.