RESUMO
BACKGROUND: Hypertensive patients with reduced blood pressure fall (BPF) at night are at higher risk of cardiovascular events (CVE). METHODS: We evaluated in hypertensive diabetic patients, if a reduced nocturnal BPF can precedes the development of diabetic nephropathy (DN). We followed 70 patients with normal urinary albumin excretion (UAE) for two years. We performed 24-hours ambulatory BP monitoring in baseline and at the end of the study. RESULTS: Fourteen (20%) patients (GI) developed DN (N = 11) and/or CVE (n = 4). Compared to the remaining 56 patients (GII) in baseline, GI had similar diurnal systolic (SBP) and diastolic BP (DBP), but higher nocturnal SBP (138 +/- 15 vs 129 +/- 16 mmHg; p < 0.05) and DBP (83 +/- 12 vs 75 +/- 11 mmHg; p < 0,05). Basal nocturnal SBP correlated with occurrence of DN and CVE (R = 0.26; P < 0.05) and with UAE at the end of the study (r = 0.3; p < 0.05). Basal BPF (%) correlated with final UAE (r = -0.31; p < 0.05). In patients who developed DN, reductions occurred in nocturnal systolic BPF (12 +/- 5 vs 3 +/- 6%, p < 0,01) and diastolic BPF (15 +/- 8 vs 4 +/- 10%, p < 0,01) while no changes were observed in diurnal SBP (153 +/- 17 vs 156 +/- 16 mmHg, NS) and DBP (91 +/- 9 vs 90 +/- 7 mmHg, NS). Patients with final UAE < 20 microg/min, had no changes in nocturnal and diurnal BP. CONCLUSIONS: Our results suggests that elevations in nocturnal BP precedes DN and increases the risk to develop CVE in hypertensive patients with T2DM.