The aim of this study was to evaluate the relationship between early blood pressure (BP) changes (detected using ambulatory BP monitoring; ABPM) with different markers of inflammation and endothelial dysfunction in patients with type 1 diabetes mellitus (T1DM). The study design was observational cross-sectional in 85 T1DM patients, clinically normotensive and with normo-albuminuria. We analyzed the relationships between ABPM-measured BP alterations over 24 h with the inflammatory cytokines (interleukin-6 (IL-6), tumor necrosis factor-α and vascular endothelial growth factor (VEGF)) and the markers of endothelial damage (vascular adhesion molecule, intercellular adhesion molecule and plasminogen activator inhibitor-1 (PAI)). Despite being recorded as normotensive, 27 (31.8%) subjects presented with an average of pathological BP. VEGF levels were significantly elevated in the patients with an altered mean diurnal values compared with normotensives (112.33 (72.87-213.53) pg ml-1 vs 71.03 (37.71-107.92) pg ml-1; P = 0.007). Further, VEGF levels correlated significantly with the parameters of diurnal BP and of 24 h values. IL-6 concentration was a risk factor in the patients with hypertension (OR = 1.406; P = 0.027). There were no modifications in the levels of markers of endothelial damage. Summarizing, there is an increase in pro-inflammatory cytokines, but not the endothelial adhesion molecules, in early stages of arterial hypertension in patients with T1DM.