The role of heart rate variability and heart rate turbulence in diabetic retinopathy

BACKGROUND: The aim of this study was to evaluate the cardiac autonomic functions of individuals with asymp-tomatic diabetic retinopathy (DR) and no obvious heart disease by heart rate turbulence (HRT) and heart rate variability (HRV) analysis. METHODS: A total of 72 patients with type 2 diabetes mellitus: 20 non-retinopathic (NRDM), 26 non-proliferative retinopathic patients (NPDR) and 26 proliferative retinopathic patients (PDR) were enrolled in this cross-sectional study. RESULTS: The HRV parameters of Standard deviation of NN intervals (SDNN) (119.8 perpendicular to 11.7, 101.1 perpendicular to 20.2, 100.6 perpendicular to 17.04), standard deviation of the average NN intervals (108.3 +/- 10.8, 91.2 +/- 17.5, 93.6 +/- 18.4), SDNN Index (49.5 +/- 5.1, 40.1 +/- 13.4, 38.6 +/- 12.7), Root mean square of successive RR interval differences (28.3 +/- 5.1, 22.3 +/- 7.5, 26 +/- 9.2) and Triangular index (34.4 +/- 4.3, 29.7 +/- 8.8, 27.3 +/- 6.7) were significantly lower in the NPDR and PDR groups than in the NRDM group (for all P<0.05). Also, there was a statistically significant higher Turbulence Onset (-1.80 +/- 0.7,-1.1 +/- 0.9,-0.43 +/- 0.81) and lower Turbulence Slope (8.05 +/- 2.59, 5.82 +/- 3.39, 4.53 +/- 2.07) in HRT parameters in patients in the NPDR and PDR groups than in the NRDM group (P<0.001). CONCLUSIONS: We found that HRV and HRT parameters had a significant deterioration in retinopathic individuals compared to the group without retinopathy. We think that HRV and HRT analysis can have an important role in the evalu-ation of these patients.