Cardiovascular autonomic neuropathy and risk of kidney function decline in type 1 and type 2 diabetes: findings from the PERL and ACCORD cohorts

Previous studies have suggested that cardiovascular autonomic neuropathy (CAN) may predict rapid kidney function decline among persons with diabetes. We analyzed the association between baseline CAN and subsequent glomerular filtration rate (GFR) decline among individuals with type 1 diabetes (T1D) from the Preventing Early Renal Loss in Diabetes (PERL) study (N=469) and with type 2 diabetes (T2D) from the Action to Control Cardiovascular Risk in Diabetes (ACCORD) study (N=7,973). Baseline CAN was ascertained using ECG-derived heart rate variability indices. Its association with GFR slopes, rapid kidney function decline (GFR loss ≥-5 ml/min/1.73 m²/year), and ≥40% GFR loss was evaluated by linear mixed effect, logistic, and Cox regression, respectively. Participants with CAN experienced more rapid GFR decline, by an excess 1.15 (95%CI [-1.93, -0.37], P= 4.0×10^-3) ml/min/1.73m²/year in PERL and 0.34 (95%CI [-0.49, -0.19], P= 6.3×10^-6) ml/min/1.73m²/year in ACCORD. This translated in 2.11 (95% CI [1.23-3.63], P=6.9×10^-3) and 1.39 (95% CI [1.20-1.61], P=1.1×10^-5) odds ratios of rapid kidney function decline in PERL and ACCORD, respectively. Baseline CAN was also associated with a greater risk of ≥40% GFR loss events during follow-up (HR=2.60, 95%CI [1.15-5.45], p=0.02 in PERL and HR=1.54, 95%CI [1.28-1.84], P=3.8×10^-6 in ACCORD). These associations remained significant after adjustment for potential confounders, including baseline GFR and albuminuria. Our findings indicate that CAN is a strong, independent predictor of rapid kidney function decline in both T1D and T2D. Further studies of the link between these two complications may help develop new therapies to prevent kidney function decline in patients with diabetes.