Early stage detection of conduit artery endothelial dysfunction in patients with type 1 diabetes

Abstract

Flow-mediated dilatation evaluation using hand skin heating may possibly be more accurate than post-ischaemic hyperaemia to detect conduit artery endothelial dysfunction in type 1 diabetes. We measured in 24 type 1 diabetic patients (n=16 without microangiopathy) and 24 healthy matched subjects radial artery diameter (echotracking), blood flow and mean wall shear stress during heating and post-ischaemic hyperaemia. Compared with controls, flow-mediated dilatation was lower in diabetic patients during post-ischaemic hyperaemia and heating. However, in the subgroup of uncomplicated patients, a decreased flow-mediated dilatation was only apparent during heating (17.1±1.6% vs. 24.3±0.7%, p<0.05) but not during post-ischaemic hyperaemia (10.1±1.1% vs. 10.5±0.6%, NS). This was confirmed by the lower slope of the diameter-mean wall shear stress relationship in these patients in the absence of modification in endotheliumindependent dilatation. We conclude that hand skin heating permits the early detection of conduit artery endothelial dysfunction in type 1 diabetic patients with normal response to post-ischaemic hyperaemia. This procedure could be useful to investigate the prognostic role of vascular dysfunction and the impact of vasculoprotective treatments in this patient population.

Impact of repeated increases in shear stress via reactive hyperemia and handgrip exercise: no evidence of systematic changes in brachial artery FMD

“…This eliminates the need for post hoc normalization procedures. While the mechanisms responsible for FMD in response to a sustained stimulus versus a transient RH stimulus may vary (29), there is growing evidence that FMD resulting from non-RH increases in shear stress is impaired in individuals with cardiovascular disease risk factors (2,12,17). Indeed, in studies by Bellian et al (2) and Grzelak et al (17), heating and handgrip exercise (HGEX)-induced increases in shear stress, respectively, resulted in larger FMD differences between control and interest groups (type I diabetic and healthy older subjects) than did FMD after RH-induced increases in shear stress.…”

Neurovascular microcirculatory vasodilation mediated by C-fibers and Transient receptor potential vanilloid-type-1 channels (TRPV 1) is impaired in type 1 diabetes

“…Moreover, macroangiopathy related to atherosclerosis is a major cause of morbidity and mortality in diabetic patients5. Endothelial dysfunction, while discussed in terms of vascular beds (conductance artery vs resistance artery) and the stage of the disease67, may appear early on in the disease process and contributes to the induction and development of atherosclerotic plaques. Indeed, the endothelium plays a major role in blood flow regulation by producing several substances, such as nitric oxide (NO), prostacyclin, and endothelium-derived hyperpolarizing factor (EDHF), and participates in the control of many vascular functions: modulation of vasomotor tone, coagulation, cell adhesion mechanisms and migration, inflammatory processes, remodeling mechanisms, and vascular permeability8.…”

“…Cutaneous microcirculation is considered as a mirror of generalized vascular function and is a useful translational model for investigating mechanisms of cutaneous physiology and cutaneous pathophysiology due either to skin disease or to other diseases such as diabetes10. Various microvascular tests for some of these, though not validated, have been used to assess both neurovascular abnormalities and endothelial dysfunction in T1D patients4671112131415161718. The heterogeneity of both tests used and groups of patients studied does not allow us to understand the changes to the microvascular mechanisms involved in T1D or the time course over which microvascular abnormalities develop.…”

The impact of a cold pressor test on brachial artery handgrip exercise-induced flow-mediated dilation

“…perfusion may be compromised if EX-FMD is impaired). 2,13,14 Existing evidence indicates that RH-FMD and EX-FMD may have differing vulnerabilities to impairment, [15][16][17][18] although similar vulnerability has also been found. 19,20 As a whole, findings suggest that the impact of a stimulus or condition on RH-FMD cannot be generalized to EX-FMD.…”

“…10,11 EX-FMD is understudied; however, a small body of evidence indicates that it provides information that is relevant to arterial health. First, FMD in response to exercise or other sustained, modest increases in shear stress has been shown to be impaired in some populations at increased risk for cardiovascular disease (patients with type 1 diabetes 18 and smokers 15,19 ). However, this has not always been found (patients with hypercholesterolemia 8 ).…”