Association of heart rate variability with progression of retinopathy among adults with type 2 diabetes

AIM: We evaluated the associations of heart rate variability (HRV) with incident vision‐threatening retinopathy and retinopathy progression among adults with type 2 diabetes. METHODS: Participants recruited to the ACCORD (Action to Control Cardiovascular Risk in Diabetes) study with HRV measures at baseline were analysed. HRV measures included standard deviation of all normal‐to‐normal intervals (SDNN) and root mean square of successive differences between normal‐to‐normal intervals (rMSSD). Low SDNN was defined as SDNN <8.2 ms; low rMSSD as rMSSD <8.0 ms. We used multivariable adjusted Cox proportional hazards and modified Poisson regression models to generate risk estimates for incident vision‐threatening retinopathy and retinopathy progression, respectively. RESULTS: A total of 5810 participants without incident vision‐threatening retinopathy at baseline (mean age 62 years, 40.5% women, 63.5% White) were included. Over a median of 4.7 years, 280 incident vision‐threatening retinopathy cases requiring treatment occurred. Low HRV (vs. normal HRV) was associated with higher risk of incident vision‐threatening retinopathy (adjusted hazard ratio 1.32 [95%CI 1.03–1.71] and 1.14 [95%CI 1.01–1.28] for low SDNN and rMSSD, respectively). In the subset of 2184 participants with complete eye examinations at baseline and 4 years, 191 experienced retinopathy progression, and low HRV (vs. normal HRV) was associated with a higher risk of retinopathy progression (adjusted relative risks 1.36 [95%CI 1.01–1.83] and 1.36 [95%CI 1.01–1.84] for low SDNN and rMSSD, respectively). CONCLUSIONS: Cardiac autonomic neuropathy, as assessed by low HRV, was independently associated with increased risks of incident vision‐threatening retinopathy and overall retinopathy progression in a large cohort of adults with type 2 diabetes.