Insulin exposure mitigates the increase of arterial stiffness in patients with type 2 diabetes and albuminuria: an exploratory analysis

Aims Insulin possesses both vasodilatory and sympathomimetic activities. The aim was to examine the relationship between changes in insulin exposure and arterial stiffness in type 2 diabetes (T2D). Methods Patients with T2D with (n = 22) or without (n = 24) albuminuria, and non-diabetic controls (n = 25) were randomized to a crossover study having a breakfast with or without pre-meal rapid-acting insulin. Pulse wave velocity (PWV) was measured at 30 min before and at 60-min intervals up to 240 min after the breakfast. Results At baseline, both postprandial aortic (p = 0.022) and brachial (p = 0.011) PWV were higher in individuals with T2D than in healthy controls irrespective of the presence of albuminuria. In patients with albuminuria, weight-adjusted insulin dose correlated inversely with the excursion of the aortic (r = - 0.412, p = 0.006) and brachial (r = - 0.372; p = 0.014) PWV. Similarly, circulating endogenous insulin concentrations correlated inversely with the aortic (r = - 0.347, p = 0.026) and brachial (r = - 0.622, p =Peer reviewe

Influence of Postprandial Hyperglycemic Conditions on Arterial Stiffness in Patients With Type 2 Diabetes

Context: Patients with type 2 diabetes (T2D) are at an increased risk of cardiovascular disease. Objective: The objective of the study was to determine whether postprandial hyperglycemia affects arterial function in T2D. Design: Asingle-center, open-label study of three groups of men were studied: 1) T2D patients with albuminuria (n = 22), 2) T2D patients without albuminuria (n = 24), and 3) nondiabetic controls (n = 25). Patients were randomized to a two-period crossover study schedule, ingesting breakfast, with or without insulin lispro (to induce low or high postprandial glycemia). Main Outcome Measures: Arterial stiffness was assessed by calculating pulse wave velocity (PWV) and augmentation index using applanation tonometry, and endothelial dysfunction was assessed using peripheral arterial tonometry, 30 minutes before breakfast and up to 240 minutes after breakfast. Results: At baseline, arterial stiffness was increased in patients. When adjusted for age and body mass index, in a combined group of patients with and without albuminuria, brachial PWV was higher during low (P = .032) and high (P = .038) postprandial glycemia vs controls. These differences were driven by the albuminuria group vs controls during low (P = .014) and high (P = .018) postprandial glycemia. No differences were observed in aortic PWV, augmentation index, or peripheral arterial tonometry ratio between patients and controls. Endothelin-1 and IL-6 were higher, and superoxide dismutase was lower, during postprandial hyperglycemia in T2D patients vs controls. Conclusions: In patients with T2D and albuminuria, brachial PWV was higher under postprandial hyperglycemic conditions, relative to controls. These data suggest that hyperglycemia induces an increase in stiffness of intermediate-sized arteries. We found no changes in other parts of the arterial bed.Peer reviewe

VEGF-C–induced lymphangiogenesis in sentinel lymph nodes promotes tumor metastasis to distant sites

The mechanisms by which tumors metastasize to sentinel and distant lymph nodes, and beyond, are poorly understood. We developed transgenic mice that overexpress vascular endothelial growth factor-C (VEGF-C) and green fluorescent protein specifically in the skin and studied the effects of chemically-induced skin carcinogenesis in this model. We found that in contrast to VEGF-A, VEGF-C does not increase the growth of primary tumors, but instead induces expansion of lymphatic networks within sentinel lymph nodes, even before the onset of metastasis. Once the metastatic cells arrived at the sentinel lymph nodes, the extent of lymphangiogenesis at these sites increased. Of importance, in mice with metastasis-containing sentinel lymph nodes, tumors that expressed VEGF-C were more likely to metastasize to additional organs, such as distal lymph nodes and lungs. No metastases were observed in distant organs in the absence of lymph node metastases. These findings indicate an important role of VEGF-C–induced lymph node lymphangiogenesis in the promotion of cancer metastasis beyond the sentinel lymph nodes. VEGF-C is therefore a good target to slow or even prevent the onset of metastasis