The purpose of the study was to examine the geometry of the left ventricle (LV) in patients with type 1 diabetes mellitus (DM) in relation to the 24-hour profile of blood pressure (BP) and urinary albumin excretion. The study covered 60 patients with type 1 DM and normal creatinine clearance, including 20 patients with normal albuminuria, 23 with microalbuminuria, and 17 with proteinuria. 24-hour BP monitoring was performed oscillometrically; myocardial structural parameters were studied by echoCG. LV hypertrophy (LVH) was found in 1 patient with normal albuminuria and in 8 with proteinuria (5, 30.4, and 47%, respectively; chi2 = 9.3; p = 0.09). The frequency of concentric and eccentric types of LVH was equal. In patients with a lower nocturnal BP decrease, the LV myocardial mass index (LVMMI) and relative posterior wall thickness (RPWT) were higher than those in other patients (LVMMI, 120.8 +/- 24.6 and 95.0 +/- 23.1 g/m2, respectively; p < 0.001; RPWT, 0.35 +/- 0.06 and 0.31 +/- 0.06, respectively, p = 0.013). Multifactorial stepwise regression analysis has indicated that age, male sex, and proneinuria directly affected LVMMI (R2 = 0.70; p < 0.001). Diastolic BP, autonomic neuropathy, and hemoglobin levels were found to be independent predictors of RPWT (R2 = 0.70; p < 0.009). The findings suggest that there is a close relationship between diabetic neuropathy and LV remodeling in patients with type 1 DM. This relationship may be operative via factors, such as arterial hypertension, altered diurnal BP profile, autonomic neuropathy, and anemia.