RESUMEN
BACKGROUND: In the blood vessels the impaired hemorheological parameters in patients with type 2 diabetes mellitus (T2DM) could lead to elevated flow resistance, increased forces at the endothelial wall and to microvascular disturbances. OBJECTIVE: The aim of the study is to investigate the hemorheological variables and the changes of the skin blood flow responses to cold stress in T2DM patients. METHODS: The basic hemorheological parameters: hematocrit (Ht), fibrinogen (Fib), whole blood viscosity (WBV) and plasma viscosity (PV) were examined in 20 patients with T2DM and a control group of 10 healthy age and sex matched controls. The mechanisms of vascular tone regulation were investigated using the wavelet analysis of the skin temperature oscillations (WAST). The degrees of the microvascular tone changes were determined during a cold test in the endothelial (0.02-0.0095âHz), neurogenic (0.05- 0.02âHz) and myogenic (0.05- 0.14âHz) frequency ranges. RESULTS: Significant increase of Fib and WBV in the patients in comparison to controls was found. The mean values of the amplitudes of the skin temperature (ST) pulsations decreased significantly during the cold stress only in the endothelial frequency range for the diabetic patients. CONCLUSIONS: The results of our study reveal parallel impairment of the blood rheological parameters and the cutaneous microcirculation in T2DM patients.
Asunto(s)
Diabetes Mellitus Tipo 2 , Viscosidad Sanguínea/fisiología , Agregación Eritrocitaria , Deformación Eritrocítica , Fibrinógeno , Hematócrito , Hemorreología , Humanos , MicrocirculaciónRESUMEN
The focus of this paper is the determination of endothelial dysfunction in patients with metabolic syndrome (MetS) and the establishment of a relationship between the traditional biomarkers of endothelial dysfunction and the vascular tone regulation indices obtained from indirect cold tests in MetS patients. Our investigation was conducted on 30 patients aged 45.5±9 years. The control group comprised 14 healthy subjects aged 48.2±2.4 years. The mechanism of vascular tone regulation was investigated using the wavelet analysis of skin temperature oscillations (WAST). The degrees of microvascular vasoconstriction and vasodilatation were determined during contralateral cold tests in the endothelial (0.02-0.0095âHz), neurogenic (0.05-0.02âHz) and myogenic (0.05-0.14âHz) frequency ranges. In MetS patients, vasoconstriction indices were higher and vasodilatation indices were lower than in the subjects of the control group, which is indicative of disorders in the mechanisms of microvascular tone regulation. These indices correlate with the metabolic parameters and VEGF (vascular endothelial growth factor) levels. The correlation of vasoconstriction and vasodilatation indices with the main factors of the metabolic syndrome testifies that the biological and functional aspects of the endothelial dysfunction are closely related.
Asunto(s)
Biomarcadores/sangre , Síndrome Metabólico/sangre , Temperatura Cutánea/fisiología , Piel/irrigación sanguínea , Factor A de Crecimiento Endotelial Vascular/fisiología , Adulto , Estudios de Casos y Controles , Femenino , Hemodinámica , Humanos , Masculino , Persona de Mediana EdadRESUMEN
There is a great need for early verification of the severity of acute pancreatitis (AP). The early stage of pathogenesis of AP is characterized by endothelial dysfunction which could be determined by wavelet analysis of skin temperature (WAST) technique. The aim is to investigate whether the dysregulation of microvascular tone caused by endothelial dysfunction and detected by WAST can be a significant indicator in early differential diagnosis of AP severity. The WAST performed in the frequency range of 0.0095-0.02 Hz during the contralateral cold test. Forty nine patients with AP aged 19-65 participated in this study. The control group included 12 healthy volunteers aged 20-65. Dysregulation of vascular tone during the contralateral cold test was observed in all patients with AP. The basal amplitudes of skin temperature oscillations in patients with AP were much lower than in healthy volunteers and progressively decreased as the disease severity increased. In patients with mild and moderate AP only the vasodilator component is destroyed, but vasoconstriction still operates. In patients with severe AP both mechanisms of endothelial vascular tone regulation are destroyed. Patients with AP have abnormal microvascular reactions related to the endothelial mechanism of vascular tone regulation. Based on the initial values of amplitudes and the indices of vasoconstriction and postcold vasodilatation, the WAST method makes it possible to evaluate two related but different characteristics of the endothelial dysfunction in patients with AP on admission which can be a significant indicator in early differential diagnosis of AP severity.
Asunto(s)
Diagnóstico Diferencial , Endotelio Vascular/fisiopatología , Pancreatitis/diagnóstico , Enfermedad Aguda , Adulto , Anciano , Diagnóstico Precoz , Femenino , Voluntarios Sanos , Humanos , Masculino , Microcirculación , Persona de Mediana Edad , Monitoreo Fisiológico , Reproducibilidad de los Resultados , Índice de Severidad de la Enfermedad , Temperatura Cutánea , Programas Informáticos , Vasoconstricción , Análisis de Ondículas , Adulto JovenRESUMEN
The aim of the study is to investigate the changes of the skin blood flow responses to cold stress in patients with diabetes mellitus type 2 through wavelet analysis of the peripheral skin temperature oscillations and to estimate their relationship with the blood viscosity values. The amplitudes of the skin temperature pulsations (ASTP) were monitored by "Microtest" device ("FM-Diagnostics", Russia); the whole blood viscosity and the shear stresses were measured by Contraves LS30 viscometer (Switzerland) at a steady flow in 9 healthy subjects and in 30 patients with type 2 diabetes mellitus. Power law and Herschel-Bulkley (HB) equations were applied to describe the blood rheology. Both models include consistency (k) and flow index (m), and the HB also gives the yield stress (τ0). The Spearman rank correlations between these parameters and the ASTP in the frequency ranges, corresponding to the myogenic, neurogenic and endothelial mechanisms of the microcirculation tone regulation were calculated. The ASTP values decreased when the blood viscosity increased. The correlation analysis revealed good ASTP-m (râ>â0.5) and ASTP-k (râ<â-0.5) relationships in the endothelial range, while the ASTP-τ0 correlation was weaker (r≈-0.4). These correlations became lower for the ASTP during the cold stress. The results prompt manifestation of endothelial dysfunction in patients with type 2 diabetes.
Asunto(s)
Viscosidad Sanguínea/fisiología , Diabetes Mellitus Tipo 2/fisiopatología , Reología , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Microcirculación , Persona de Mediana EdadRESUMEN
OBJECTIVE: The purpose of this study was to examine correlations between laboratory markers of ED and the degree of endothelium-dependent vasodilation using WAST during a local heating test in patients with PAD. MATERIALS AND METHODS: The study population consisted of 17 healthy subjects and 38 patients with PAD. The ST on the plantar surface of the first toe was measured during the test, and the inverse wavelet transform was applied to reconstruct the ST signals in three frequency bands corresponding to myogenic, neurogenic, and endothelial mechanisms of vascular tone regulation. RESULTS: In healthy subjects, a local increase in temperature of up to 42°C caused a greater than threefold increase in the amplitudes of foot ST oscillations. Among patients with PAD, the response to the test was much weaker in all frequency ranges. The level of vasodilation dysfunction correlated with the level of artery stenosis in the lower extremities and with laboratory markers of ED (endothelin, homocysteine, and von Willebrand factor). CONCLUSION: WAST can be considered as a low cost, portable, and easy to use technique for the noninvasive assessment of ED.