Skin Microcirculation in Patients with Type I Diabetes with and without Neuropathy after Neurovascular Stimulation

1998 ◽  
Vol 94 (3) ◽  
pp. 255-261 ◽  
Author(s):  
Thomas Forst ◽  
Andreas Pfützner ◽  
Thomas Kunt ◽  
Thomas Pohlmann ◽  
Ulrike Schenk ◽  
...  
Keyword(s):  
Blood Flow ◽  
Diabetic Neuropathy ◽  
Type I Diabetes ◽  
Capillary Blood ◽  
Capillary Blood Flow ◽  
Diabetic Patients ◽  
Type I ◽  
Skin Microcirculation ◽  
Skin Perfusion ◽  
Diabetes Patients

1. Neurovascular inflammation is impaired in patients suffering from diabetic neuropathy. The aim of our study was to evaluate the distribution of nutritive and total skin blood flow in diabetic patients with and without neuropathy after neurovascular stimulation with acetylcholine. 2. Twenty patients with Type I diabetes, 10 with and 10 without neuropathy, and 10 age-matched non-diabetic control subjects, underwent microvascular investigations before and after neurovascular stimulation by intracutaneous application of acetylcholine. The capillary blood cell velocity in the nailfold of the hallux was measured by videophotometric capillaroscopy, and the total skin microcirculation in the same area by laser Doppler flowmetry. 3. The increase in total skin blood flow was significantly impaired in the group of neuropathic diabetic patients compared with the non-neuropathic diabetic patients (17.5 ± 83 versus 51.0 ± 16.2; P < 0.05) and the non-diabetic subjects (17.5 ± 8.3 versus 67.8 ± 19.7; P < 0.01). The increase in capillary blood flow was not significantly impaired in Type 1 diabetes patients with neuropathy. 4. The ratio between capillary blood flow and total skin perfusion decreased significantly in the control group (from 0.82 ± 0.15 to 0.47 ± 0.11; P < 0.005) and in the Type I diabetes patients without neuropathy (from 0.79 ± 0.12 to 0.43 ± 0.12; P < 0.05), whereas the decrease in the neuropathic group was statistically insignificant (from 1.05 ± 0.19 to 0.72 ±0.16). 5. Diminished total skin perfusion in the foot after intracutaneous stimulation with acetylcholine in Type I diabetes patients is associated with diabetic neuropathy, indicating a disturbance in the neurovascular reflex arc. This impaired neurovascular response is caused by a diminished total and sub-papillary blood flow and not by a diminished nutritive capillary flow. There is no evidence of a diminished nutritive capillary blood flow during neurogenic inflammation in Type I diabetes patients suffering from diabetic neuropathy.

Diminished skin blood flow in Type I diabetes: evidence for non-endothelium-dependent dysfunction

2001 ◽  
Vol 101 (1) ◽  
pp. 59-64 ◽  
Author(s):  
Abram KATZ ◽  
Karin EKBERG ◽  
Bo-Lennart JOHANSSON ◽  
John WAHREN
Keyword(s):  
Blood Flow ◽  
Sodium Nitroprusside ◽  
Skin Blood Flow ◽  
Perfusion Imaging ◽  
Healthy Subjects ◽  
Type I Diabetes ◽  
Diabetic Patients ◽  
Type I ◽  
Laser Doppler Perfusion Imaging ◽  
Before And After

The purpose of this study was to quantify the extent to which skin blood flow (SBF) responses to application of endothelium-dependent and -independent vasodilating agents differ between Type I diabetic patients and healthy subjects. Patients and matched controls were studied after an overnight fast. SBF was determined with laser Doppler perfusion imaging before and after iontophoresis of acetylcholine (Ach; endothelium-dependent) and sodium nitroprusside (SNP; endothelium-independent). Basal SBF did not differ significantly between groups. Iontophoresis of ACh and SNP increased SBF 20-fold in controls. In the patients, the increases in SBF following iontophoresis of ACh and SNP were reduced by 18% and 19%, respectively, versus controls (P < 0.05 for both). These data demonstrate that Type I diabetic patients have similar diminished SBF responses to iontophoresis of ACh and SNP, which suggests that non-endothelial-dependent factors are primarily responsible for the diminished SBF responses.

The increase in sympathetic nerve activity after glucose ingestion is reduced in type I diabetes

2000 ◽  
Vol 98 (5) ◽  
pp. 627-632 ◽  
Author(s):  
Jan FAGIUS ◽  
Christian BERNE
Keyword(s):  
Sympathetic Activity ◽  
Type I Diabetes ◽  
Diabetic Patients ◽  
Type I ◽  
Sympathetic Outflow ◽  
Control Subjects ◽  
Glucose Ingestion ◽  
Muscle Nerve ◽  
Normal Strength ◽  
Diabetes Patients

Food intake is followed by an increase in baroreflex-governed sympathetic outflow to muscle vessels. It is established that insulin contributes to this stimulation; however, the increase occurs (to a lesser degree) even in the absence of enhanced insulin secretion. To further elucidate the role of insulin, muscle nerve sympathetic activity was recorded by microneurography, and the increase after an oral 100-g glucose load in eight C-peptide-negative patients with type I diabetes without any signs of neuropathy was compared with that in 16 healthy control subjects. The level of sympathetic activity at rest was similar in the two groups (type I diabetes patients, 19.5±2.4 bursts/min; controls, 20.4±4.8 bursts/min; means±S.D.). Following glucose intake there was a significant increase in activity in both groups, with maximum values at 30 min of 24.3±3.7 bursts/min for type I diabetes patients and 34.4±9.1 bursts/min for controls. The summarized response (during 90 min) of the diabetic patients was less than half that of the control subjects (P = 0.0003). It is concluded that the response of muscle nerve sympathetic activity to glucose ingestion is reduced to about half of its normal strength in the absence of insulin, and that there is no difference in sympathetic outflow at rest between healthy subjects and diabetic patients without polyneuropathy.

Terminal Synergetic Control for Blood Glucose Regulation in Diabetes Patients

2018 ◽  
Vol 140 (10) ◽  
Author(s):  
A. Hachana ◽  
M. N. Harmas
Keyword(s):  
Blood Glucose ◽  
Sliding Mode ◽  
Type I Diabetes ◽  
System Stability ◽  
Diabetic Patients ◽  
Type I ◽  
Continuous Control ◽  
Control Scheme ◽  
Synergetic Control ◽  
Diabetes Patients

In this paper, a new robust terminal synergetic control scheme is proposed to regulate blood glucose level in diabetic patients (type I diabetes), based on recently developed synergetic control and a terminal attractor technique. The technique presented has the advantage of using a continuous control law. Moreover, the proposed control scheme, besides being chattering free, has the characteristics of finite time convergence. Lyapunov synthesis is adopted to ensure controlled system stability. Simulation results of terminal synergetic control are compared to classic synergetic and second-order sliding mode control (SMC) performance, demonstrating that the proposed control method allows for rapidly achieving normoglycemia in type I diabetes patients.

Effects of nisoldipine and lisinopril on microvascular dysfunction in hypertensive Type I diabetes patients with nephropathy

1998 ◽  
Vol 95 (6) ◽  
pp. 709-717 ◽  
Author(s):  
V. B. SØRENSEN ◽  
P. ROSSING ◽  
L. TARNOW ◽  
H.-H. PARVING ◽  
T. NØRGAARD ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Diabetic Nephropathy ◽  
Vascular Resistance ◽  
Antihypertensive Treatment ◽  
Type I Diabetes ◽  
Diabetic Patients ◽  
Type I ◽  
Once Daily ◽  
Control Subjects ◽  
Diabetes Patients

1. Our objective was to compare the effect of a long-acting calcium antagonist (nisoldipine) compared with an angiotensin-converting enzyme inhibitor (lisinopril) on the non-neurogenic regulation of the microvascular blood flow in hypertensive Type I diabetes patients with diabetic nephropathy. 2. We performed a 1-year double-blind, double-dummy randomized controlled study comparing nisoldipine (20–40 mg once daily) with lisinopril (10–20 mg once daily) in 48 hypertensive Type I diabetes patients with diabetic nephropathy. For comparison, 22 age-matched normotensive healthy control subjects were included. Measurements were performed at baseline and after 1 year of antihypertensive treatment. The minimal vascular resistance and distensibility (stiffness) of resistance vessels in skin and skeletal muscle were measured using the local isotope washout method. 3. Mean arterial pressure was reduced to the same extent in both groups: nisoldipine, 113±2.1 to 105±1.6 mmHg (P< 0.001); lisinopril, 110±2.7 to 101±2.1 mmHg (P< 0.002) (controls, 88±2.2 mmHg; P< 0.0001 compared with diabetic patients). Nisoldipine improved the skin vascular distensibility from 28±3.3 to 43±3.8% (P< 0.005) and decreased skin minimal vascular resistance from 16.9±1.0 to 13.6±0.8 mmHg·ml-1·min·100 g (P< 0.02). Lisinopril had no significant effect on skin vascular distensibility (40±4.0% and 41±4.4%), but minimal vascular resistance tended to diminish (18.1±0.9 to 15.8±1.3 mmHg·ml-1·min·100 g (P =0.09). Nisoldipine significantly increased the skin distensibility (P = 0.05) after 1 year of antihypertensive treatment compared with lisinopril. 4. The control group had a skin vascular distensibility of 54±3.2% and a minimal vascular resistance of 10.8±0.7 mmHg·ml-1·min·100 g, both significantly different from the values in the diabetic groups (P< 0.0001 for all). Skeletal muscle vascular distensibility was unaltered after 1 year of treatment with both nisoldipine (22±3.3% and 19±2.7%) and lisinopril (19±2.1% and 24±2.5%), but was reduced compared with a control value of 43±3.7% (P< 0.0001 for diabetes patients versus controls). However, neither nisoldipine nor lisinopril had any effect on the increased minimal vascular resistance or the reduced skeletal muscle distensibility. 5. Enhanced thickening of the basement membranes of the terminal arteriolar wall was found in skin biopsy specimens in 91% of diabetic patients and 38% only in control subjects (P< 0.000001 both before and after treatment for diabetic patients versus controls). There was no significant effect of antihypertensive treatment on arteriolar hyalinosis. 6. The reduction in systemic blood pressure was identical during 1 year of treatment with nisoldipine or lisinopril. The abnormal arteriolar stiffness was more pronounced in the group treated with nisoldipine than with lisinopril and only nisoldipine compared with lisinopril improved the abnormal arteriolar stiffness and minimal vascular resistance in the skin. This suggests that nisoldipine can reverse the peripheral skin perfusion and thereby improve the local protection against development of ischaemic skin lesions in Type I diabetes patients with clinical diabetic nephropathy.

Lutein Complex Supplementation Increases Ocular Blood Flow Biomarkers in Healthy Subjects

2019 ◽  
Vol 89 (1-2) ◽  
pp. 5-12
Author(s):  
Alon Harris ◽  
Brent Siesky ◽  
Amelia Huang ◽  
Thai Do ◽  
Sunu Mathew ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Blood Flow ◽  
Diastolic Blood Pressure ◽  
Healthy Subjects ◽  
Ocular Blood Flow ◽  
Capillary Blood ◽  
Post Treatment ◽  
Capillary Blood Flow ◽  
Doppler Imaging ◽  
Retinal Capillary

Abstract. Introduction: To investigate the effects of a lutein complex supplementation on ocular blood flow in healthy subjects. Materials and Methods: Sixteen healthy female patients (mean age 36.8 ± 12.1 years) were enrolled in this randomized, placebo-controlled, double-blinded, two-period crossover study. Subjects received daily an oral dose of the lutein with synergistic phytochemicals complex (lutein (10 mg), ascorbic acid (500 mg), tocopherols (364 mg), carnosic acid (2.5 mg), zeaxanthin (2 mg), copper (2 mg), with synergistic effects in reducing pro-inflammatory mediators and cytokines when administered together in combination) and placebo during administration periods. Measurements were taken before and after three-week supplementation periods, with crossover visits separated by a three-week washout period. Data analysis included blood pressure, heart rate, intraocular pressure, visual acuity, contrast sensitivity detection, ocular perfusion pressure, confocal scanning laser Doppler imaging of retinal capillary blood flow, and Doppler imaging of the retrobulbar blood vessels. Results: Lutein complex supplementation produced a statistically significant increase in mean superior retinal capillary blood flow, measured in arbitrary units (60, p = 0.0466) and a decrease in the percentage of avascular area in the superior (−0.029, p = 0.0491) and inferior (−0.023, p = 0.0477) retina, as well as reduced systolic (−4.06, p = 0.0295) and diastolic (−3.69, p = 0.0441) blood pressure measured in mmHg from baseline. Data comparison between the two supplement groups revealed a significant decrease in systemic diastolic blood pressure (change from pre- to post-treatment with lutein supplement (mean (SE)): −3.69 (1.68); change from pre- to post-treatment with placebo: 0.31 (2.57); p = 0.0357) and a significant increase in the peak systolic velocity (measured in cm/sec) in the central retinal artery (change from pre- to post-treatment with lutein supplement: 0.36 (0.19); change from pre- to post-treatment with placebo: −0.33 (0.21); p = 0.0384) with lutein complex supplement; data analyses from the placebo group were all non-significant. Discussion: In healthy participants, oral administration of a lutein phytochemicals complex for three weeks produced increased ocular blood flow biomarkers within retinal vascular beds and reduced diastolic blood pressure compared to placebo.

Stem Cell-Based Therapies: A New Ray of Hope for Diabetic Patients

2019 ◽  
Vol 14 (2) ◽  
pp. 146-151 ◽  
Author(s):  
Junaid Khan ◽  
Amit Alexander ◽  
Mukta Agrawal ◽  
Ajazuddin ◽  
Sunil Kumar Dubey ◽  
...  
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Drug Therapy ◽  
Type I Diabetes ◽  
Embryonic Stem ◽  
Health Concern ◽  
Future Research ◽  
Diabetic Patients ◽  
Successful Implementation ◽  
Type I

Diabetes and its complications are a significant health concern throughout the globe. There are physiological differences in the mechanism of type-I and type-II diabetes and the conventional drug therapy as well as insulin administration seem to be insufficient to address the problem at large successfully. Hypoglycemic swings, frequent dose adjustments and resistance to the drug are major problems associated with drug therapy. Cellular approaches through stem cell based therapeutic interventions offer a promising solution to the problem. The need for pancreatic transplants in case of Type- I diabetes can also be by-passed/reduced due to the formation of insulin producing β cells via stem cells. Embryonic Stem Cells (ESCs) and induced Pluripotent Stem Cells (iPSCs), successfully used for generating insulin producing &#946; cells. Although many experiments have shown promising results with stem cells in vitro, their clinical testing still needs more exploration. The review attempts to bring into light the clinical studies favoring the transplantation of stem cells in diabetic patients with an objective of improving insulin secretion and improving degeneration of different tissues in response to diabetes. It also focuses on the problems associated with successful implementation of the technique and possible directions for future research.

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