Early microvascular changes with loss of the glycocalyx in children with type 1 diabetes.

OBJECTIVE: To evaluate the microcirculation of children with type 1 diabetes mellitus who demonstrate no clinical signs of diabetic microangiopathy for the presence of microvascular alterations and glycocalyx perturbation. STUDY DESIGN: Images of sublingual vessels were obtained in 14 children with diabetes (ages 12.8 ± 2.8 years, diabetes duration 6.7 ± 4.3 years) and 14 control patients (ages 11.8 ± 2.8 years) by the use of sidestream dark field imaging and analyzed for total vessel density, vessel surface coverage, vessel diameter distribution, mean flow index, and glycocalyx thickness. Wilcoxon rank sum test and Pearson correlation were used for statistical analysis. RESULTS: We observed profound microcirculatory changes in children with diabetes compared with control patients, with a significant reduction of glycocalyx thickness (0.38 µm vs 0.60 µm; P = .013), which was inversely correlated with blood glucose levels (r = -0.55; P = .003). Furthermore, the percentage of large vessels (>20 µm diameter) was significantly increased (11% vs 6%; P = .023) at the expense of capillaries (<10 µm diameter) with consequent increase in total vessel surface coverage (30% vs 26.0%; P = .041). No differences were seen in total vessel density and mean flow index. CONCLUSIONS: Microvascular alterations, including changes in microvessel distribution and loss of the glycocalyx, can be detected in children with type 1 diabetes mellitus before clinically apparent vascular complications. Our results disclose the glycocalyx as a possible monitoring measurement for earlier detection of diabetic microangiopathy and may provide a basis for new therapeutic strategies aiming at protection or restoration of the glycocalyx.

Microcirculation in preterm infants: profound effects of patent ductus arteriosus.

OBJECTIVES: To assess potential effects of a hemodynamically significant persistent ductus arteriosus (sPDA) in the skin microcirculation in preterm neonates. STUDY DESIGN: In 25 patients (<32 weeks of gestation; birth weight <1250 g) with sPDA (n = 13) or no significant PDA (non-sPDA; n = 12) functional vessel density and vessel diameters were investigated prospectively. Sidestream dark field imaging was performed in the skin of both arms from the third day of life until PDA closure or until day 7 or 8 for the non-sPDA group. RESULTS: Before PDA treatment, functional vessel density was significantly lower in the sPDA group compared with the non-sPDA group. In the sPDA group, there were significantly fewer large vessels (diameter >20 microm) and significantly more small vessels (diameter <10 microm). After successful PDA treatment, these differences disappeared. In both groups, functional vessel density differed significantly between the left and right arm, persisting even after successful treatment. Regression analysis showed an inverse linear correlation between the hemodynamic echocardiographic findings and functional vessel density (P <.005). CONCLUSION: sPDA causes major changes in the microcirculation of premature neonates; functional vessel density is reduced, with a shift in perfusion from larger toward smaller vessels. The redistribution of flow might be a compensatory mechanism to preserve physiologic metabolism.