Relationship between autonomic neuropathy, 24-hr blood pressure and retinopathy in normoalbuminuric and normotensive type 1 diabetic patients.

In order to investigate factors related to the development of retinopathy in 122 normotensive and normoalbuminuric patients 24 hr-blood pressure (BP) measurement and autonomic tests based on standard, vector and spectral analysis of heart rate variation (HRV) were performed. Retinopathy was found in 47 patients with significantly longer duration of diabetes and prevalence of autonomic neuropathy (9.5 +/- 5.5; 59.6%) in comparison with 75 patients without retinopathy (5.29 +/- 4.9; 16%), (p < 0.05). Patients were matched according to age, gender, HbA1c and 24-hr urinary albumin excretion rate. Maximal night systolic, mean night and day diastolic BPs were significantly higher in patients with retinopathy (118.94 +/- 11; 62.94 +/- 8.1; 74.3 +/- 7.2 mmHg) as compared to patients without it (115.03 +/- 8.9; 59.65 +/- 7.1; 71.75 +/- 5.7) (p = 0.03). Maximal night systolic BP was inversely related to power high frequency (HF; r = -0.28, p = 0.05) and deep breathing CV (r = -0.23, p = 0.02). Mean night diastolic BP was inversely related to power mid frequency (r = -0.21, p = 0.03), HF (r = -0.32, p = 0.005), CV deep breathing (r = -0.27, p = 0.005) and mean circular resultant deep breathing (r = -0.24, p = 0.003); mean day diastolic BP to power HF (r = -0.22, p = 0.02). In multiple regression analysis retinopathy was associated with the duration of diabetes (beta = 0.53) and autonomic neuropathy (beta = 0.28) (p < 0.001). Autonomic neuropathy was related to BP elevation and retinopathy in normotensive and normoalbuminuric Type 1 diabetic patients.