Lower limb ischemia and microrheological alterations in patients with diabetic retinopathy

Biró, Katalin T.; Sandor, Barbara; Kovács, D; Csiszar, Beata; Vékási, Judit; Totsimon, Kinga; Tóth, András; Koltai, Katalin; Endrei, D.; Tóth, Kálmán; Késmárky, Gábor

doi:10.3233/ch-189103

Cited by 13 publications

(12 citation statements)

References 33 publications

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“…Overall, predicting the consequences of increased RBC aggregation in vivo appears to be complex. However, clinical works performed to study aggregation in cardiovascular, metabolic, or inflammatory diseases consistently show that people with these diseases generally have higher RBC aggregation levels than healthy individuals, and the elevated aggregation contributes to the development of adverse disease outcomes (Totsimon et al, 2017; Biro et al, 2018; Brun et al, 2018; Ko et al, 2018; Lapoumeroulie et al, 2019; Piecuch et al, 2019; Sheremet’ev et al, 2019).…”

Section: Blood Is Not a Simple Fluidmentioning

confidence: 99%

Blood Rheology: Key Parameters, Impact on Blood Flow, Role in Sickle Cell Disease and Effects of Exercise

et al. 2019

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Blood viscosity is an important determinant of local flow characteristics, which exhibits shear thinning behavior: it decreases exponentially with increasing shear rates. Both hematocrit and plasma viscosity influence blood viscosity. The shear thinning property of blood is mainly attributed to red blood cell (RBC) rheological properties. RBC aggregation occurs at low shear rates, and increases blood viscosity and depends on both cellular (RBC aggregability) and plasma factors. Blood flow in the microcirculation is highly dependent on the ability of RBC to deform, but RBC deformability also affects blood flow in the macrocirculation since a loss of deformability causes a rise in blood viscosity. Indeed, any changes in one or several of these parameters may affect blood viscosity differently. Poiseuille’s Law predicts that any increase in blood viscosity should cause a rise in vascular resistance. However, blood viscosity, through its effects on wall shear stress, is a key modulator of nitric oxide (NO) production by the endothelial NO-synthase. Indeed, any increase in blood viscosity should promote vasodilation. This is the case in healthy individuals when vascular function is intact and able to adapt to blood rheological strains. However, in sickle cell disease (SCD) vascular function is impaired. In this context, any increase in blood viscosity can promote vaso-occlusive like events. We previously showed that sickle cell patients with high blood viscosity usually have more frequent vaso-occlusive crises than those with low blood viscosity. However, while the deformability of RBC decreases during acute vaso-occlusive events in SCD, patients with the highest RBC deformability at steady-state have a higher risk of developing frequent painful vaso-occlusive crises. This paradox seems to be due to the fact that in SCD RBC with the highest deformability are also the most adherent, which would trigger vaso-occlusion. While acute, intense exercise may increase blood viscosity in healthy individuals, recent works conducted in sickle cell patients have shown that light cycling exercise did not cause dramatic changes in blood rheology. Moreover, regular physical exercise has been shown to decrease blood viscosity in sickle cell mice, which could be beneficial for adequate blood flow and tissue perfusion.

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Section: Blood Is Not a Simple Fluidmentioning

confidence: 99%

Blood Rheology: Key Parameters, Impact on Blood Flow, Role in Sickle Cell Disease and Effects of Exercise

et al. 2019

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“… 13 TcPO2 directly reflects tissue oxygenation and microvascular ischemia, which can distinguish between asymptomatic ischemic and non-ischemic states. 14 The Neuropad is a non-invasive and convenient POCDs that evaluates the sweat gland secretion function. 15 The sudomotor function can be evaluated qualitatively and quantitatively by using Neuropad.…”

Section: Introductionmentioning

confidence: 99%

Lower Limb Arterial Ischemia: An Independent Risk Factor of Sudomotor Dysfunction in Type 2 Diabetes

Lv¹,

Zheng²,

Xiang³

et al. 2023

DMSO

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Background As an early manifestation of diabetic peripheral neuropathy (DPN), sudomotor dysfunction significantly increases the risk of diabetic foot ulcer. The pathogenesis of sudomotor dysfunction is still unclear. Lower limb ischemia may be related to sudomotor dysfunction, but few studies have explored it. The purpose of this study is to explore the relationship between sudomotor function and comprehensive lower limb arterial ischemia including large arteries, small arteries and microvascular in type 2 diabetes mellitus (T2DM). Patients and Methods 511 T2DM patients were enrolled in this cross-sectional study. Sudomotor function was assessed qualitatively and quantitatively by Neuropad. Lower limb arterial ischemia was defined as any abnormality of the ankle brachial index (ABI), toe brachial index (TBI) or transcutaneous oxygen tension (TcPO2). Results In this study, 75.1% of patients had sudomotor dysfunction. Compared with normal sudomotor function, patients with sudomotor dysfunction had a higher incidence of lower limb arterial ischemia (51.2% vs 36.2%, p = 0.004). Similarly, compared with the non-arterial ischemia group, the proportion of sudomotor disorders was higher in the arterial ischemia group ( p = 0.004). Low TBI and low TcPO2 groups also had a higher proportion of sudomotor disorders (all p < 0.05).Compare with normal groups, low ABI, low TBI, and low TcPO2 groups had lower Slop4 which quantitatively reflecting Neuropad discoloration. Arterial ischemia was an independent risk factor for sudomotor dysfunction [OR = 1.754, p = 0.024]. Low TcPO2 also independently increased the risk of sudomotor disorders [OR = 2.231, p = 0.026]. Conclusion Lower limb arterial ischemia is an independent risk factor of sudomotor dysfunction. Especially below the ankle (BTA) small arteries and microvascular ischemia may also be involved in the occurrence of sudomotor disorders.

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“…Besides many clinical states (e.g., ischemic heart disease, diabetes, and venous thrombosis), heart failure is known to be associated with increased RBC aggregation, which has a negative influence on the in vivo flow dynamics of blood. The reduction of RBC aggregation may have a positive effect on the flow properties of blood, which can be beneficial in cardiovascular diseases [ 7 – 10 ]. Furthermore, when the vascular autoregulatory reserve is exhausted in heart failure, the hemorheological disturbances—which can be easily compensated in healthy individuals—will have deleterious effects.…”

Section: Introductionmentioning

confidence: 99%

Hemorheological Alterations in Patients with Heart Failure with Reduced Ejection Fraction Treated by Resveratrol

Gal

Praksch

Kenyeres

et al. 2020

Cardiovascular Therapeutics

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Objectives. Several beneficial effects of resveratrol have already been published. This study evaluated the effect of resveratrol on the hemorheological parameters in patients with heart failure with reduced ejection fraction. Methods. In our double-blind, placebo-controlled human clinical trial, we enrolled 60 outpatients with heart failure. Patients were randomized into two groups: receiving either 100 mg resveratrol capsule daily or placebo for 3 months. Hematocrit was determined by microhematocrit centrifuge. Plasma and whole blood viscosity was evaluated by capillary viscometer. Erythrocyte aggregation was measured by both LORCA and Myrenne aggregometers. LORCA ektacytometer was used for measuring erythrocyte deformability. Exercise capacity was assessed by a 6-minute walk test. Results. Resveratrol treatment did not have any significant effect on hematocrit and viscosity. The erythrocyte deformability also remained unchanged. However, significant improvement of red blood cell aggregation was observed in the resveratrol group compared to baseline after 3 months. Furthermore, positive correlation was found between the exercise capacity and the hemorheological properties (Hct, WBV, and RBC aggregation and deformability) as well. Conclusion. These findings indicate that resveratrol can significantly reduce red blood cell aggregation, which may positively influence microcirculation, which may contribute to the improvement of tissue perfusion and oxygen supply in heart failure.

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Lower limb ischemia and microrheological alterations in patients with diabetic retinopathy

Abstract: Macro- and microcirculatory lower limb disorders could be revealed at high prevalence in diabetic patients with retinopathy. Measurement of tcpO2 and hemorheological variables could be useful to discover patients at higher risk for diabetic foot complications.

Cited by 13 publications

References 33 publications

Blood Rheology: Key Parameters, Impact on Blood Flow, Role in Sickle Cell Disease and Effects of Exercise

Blood Rheology: Key Parameters, Impact on Blood Flow, Role in Sickle Cell Disease and Effects of Exercise

Lower Limb Arterial Ischemia: An Independent Risk Factor of Sudomotor Dysfunction in Type 2 Diabetes

Hemorheological Alterations in Patients with Heart Failure with Reduced Ejection Fraction Treated by Resveratrol

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