The clinicopathological findings in non-diabetic ckd patients with cardiovascular autonomic neuropathy

Background: Cardiovascular autonomic neuropathy (CAN) is common as the process of kidney injury. Coefficient of variation of R-R interval (CVR-R) is one of the most convenient, noninvasive tests of heart rate variability, and is widely used to assess cardiac autonomic nerve function. However, the clinical and pathological findings in non-diabetic CKD patients with CAN has not been fully elucidated. This current study investigated the characteristics of non-diabetic CKD patients with CAN diagnosed by CVR-R. Method: Subjects who underwent percutaneous kidney biopsy and performed CVR-R test at the Jikei University School of Medicine Hospital, Tokyo, Japan were retrospectively examined. Patients with arrhythmia, diabetes, and post transplantation were excluded. CAN was defined using the reference values of CVR-R based on age and sex. The proportion of glomerulosclerosis (GS) and interstitial fibrosis/tubular atrophy (IF/TA) were assessed. The severity of arteriosclerosis was determined by the extent of thickening of the intima: grade0 = intimal thickening< thickness of media grade1 = intimal thickening> thickness of media. Results: Ninety subjects were identified (Age 45.7 ± 14.9 (mean ± SD) years old; Male 56%; heart rate 69 ± 11 /min; eGFR 60.0 ± 29.5 mL/min/1.73m2; 24h-urinary protein excretion 0.55 [0.24–1.30] (median [IQR]) g/day; CVR-R rest 3.7 ± 1.7%; GS 11.6 [3.6–24.8] %, IFTA 20 [10–30] %.) Eleven patients were diagnosed as CAN, with nephrosclerosis [n = 4], acute tubulointerstitial nephritis [n = 2], IgA nephropathy [n = 1], IgA vasculitis [n = 1], membranous nephropathy [n = 1], lupus nephritis [n = 1], and focal segmental glomerular sclerosis [n = 1]. Patients with CAN had a higher triglyceride (P = 0.030) and higher IF/TA(P = 0.005) than those without CAN. The severity of arteriosclerosis increased in patients with CAN. (P = 0.017) Conclusion: These results indicated that that arteriosclerosis and IF/TA were associated with CAN in non-diabetic CKD patients.