We hypothesize that real-time in vivo microvascular abnormalities should correlate with biochemical markers of inflammation/endothelial dysfunction in T1DM. Real-time quantification of T1DM and healthy non-diabetic control microcirculation was conducted utilizing computer-assisted intravital microscopy. Selected biochemical markers (high sensitivity C-reactive protein (hsCRP), soluble vascular cell adhesion molecules (sVCAM), soluble intercellular adhesion molecules (sICAM), soluble E-selectin (sE-selectin), nitrotyrosine, superoxide anion (O2-), interleukin-1beta (IL-1beta) and tumor necrosis factor-alpha (TNF-alpha)) were used for correlation. The severity of microvascular abnormalities, as reflected by the arithmetic severity index (SI), was significantly increased in T1DM vs. controls (5.89 +/- 1.47 vs. 2.34 +/- 1.48; P<0.001). In addition several of the specific microvascular abnormalities (related to flow and morphometry) were significantly more prevalent in the T1DM patients. Finally, the following significant positive correlations existed between the inflammatory/endothelial dysfunction markers and specific microvascular abnormalities: sVCAM and abnormal vessel diameter (P=0.004, OR =1.033, 95% CI for OR =(1.01, 1.056)), superoxide (O2-) release and abnormal vessel distribution (P=0.032, OR =1.798, 95% CI for OR =(1.051, 3.075)), and sE-selectin and abnormal vessel distribution (P=0.036, OR =1.118, 95% CI for OR =(1.007, 1.241)). In view of such significant correlations, we conclude that these specific microvascular abnormalities can serve as unique physiologic markers of endothelial dysfunction to correlate with the biochemical markers of inflammatory/endothelial dysfunction in disease progression and therapeutic efficacy studies.