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Biomedical subjects

A J Smit

Publications and source records attributed to A J Smit.

At least 19 recordsLinked to original sources

Treatment with intramuscular vascular endothelial growth factor gene compared with placebo for patients with diabetes mellitus and critical limb ischemia: a double-blind randomized trial.

Despite advances in revascularization techniques, limb salvage and relief of pain cannot be achieved in many diabetic patients with diffuse peripheral vascular disease. Our objective was to determine the effect of intramuscular administration of phVEGF165 (vascular endothelial growth factor gene-carrying plasmid) on critical limb ischemia (CLI) compared with placebo (0.9% NaCl). A double-blind, placebo-controlled study was performed in 54 adult diabetic patients with CLI. The primary end point was the amputation rate at 100 days. Secondary end points were a 15% increase in pressure indices (ankle-to-brachial index and toe-to-brachial index), clinical improvement (skin, pain, and Quality of Life score), and safety. In patients (n=27) treated with placebo versus phVEGF165-treated patients (n=27) the following results were found: 6 amputations versus 3 (p=not significant [NS]); hemodynamic improvement in 1 versus 7 (p=0.05); improvement in skin ulcers, 0 versus 7 (p=0.01); decrease in pain, 2 versus 5 (p=NS); and overall, 3 versus 14 responding patients (p=0.003). No grade 3 or 4 adverse effects were seen in these patients. We conclude that this small, randomized gene therapy study failed to meet the primary objective of significant amputation reduction. However, significant and meaningful improvement was found in patients treated with a VEGF165-containing plasmid. There were no substantial adverse events.

Adult↗

Traditional and non-traditional risk factors contribute to the development of accelerated atherosclerosis in patients with systemic lupus erythematosus.

To determine risk factors of accelerated atherosclerosis in patients with systemic lupus erythematosus (SLE), 72 patients with inactive disease and 36 age- and sex-matched controls were included. The intima-media thickness (IMT) of the common carotid artery was determined by ultrasound. Traditional risk factors and disease-related factors were recorded. Cardiovascular risk was estimated using SCORE (systematic coronary risk evaluation). Markers of inflammation, endothelial activation and vascular remodelling (matrix metalloproteinases (MMP-3, MMP-9) and tissue inhibitor of metalloproteinase- 1 (TIMP- 1)) were determined. IMT was increased in patients (0.67 mm+/-0.13 versus 0.61 mm+/-0.11, P < 0.05). Prevalence of hypertension (33% versus 6%, P < 0.001), SCORE (2.2 (1.7-4.2) versus 1.7 (1.3-2.1), P < 0.001), as well as parameters of inflammation (CRP 1.8 (0.6-5.8) mg/L versus 0.6 (0.2-1.0) mg/L, P < 0.001) and endothelial activation (VCAM-1 505 (389-683) ng/mL versus 374 (322-427) ng/mL, P < 0.001) and von Willebrand factor (138 (59-208)% versus 48 (24-92)%, P < 0.001), were increased in patients. Vascular remodelling was altered: MMP-3 and TIMP-1 were increased (18 (10-29) ng/mL versus 8 (5-11) ng/mL, P < 0.001, and 275 (216-352) ng/mL versus 230 (197-268) ng/mL, P < 0.001, respectively), and MMP-9 was decreased in SLE (266 (147-412) ng/mL versus 348 (226-530) ng/mL, P < 0.05). Univariate analyses revealed that in patients IMT was associated with age, systolic blood pressure, SCORE and disease duration. In multivariate analysis, age and SCORE were independent predictors of IMT. In conclusion, SLE patients have an increased IMT, which is associated with traditional risk factors. Non-traditional risk factors, such as endothelial activation, altered vascular remodelling and disease duration, might play an additional role.

Atherosclerosis↗

A young man with nonhealing venous ulcers.

A 35-year-old man presented with nonhealing ulcers at an atypical location on his left foot, caused by a combination of venous insufficiency (after deep venous thrombosis) and arterial insufficiency. The underlying cause was Buerger's disease.

Adult↗

Elevated plasma phospholipid transfer protein activity is a determinant of carotid intima-media thickness in type 2 diabetes mellitus.

AIM/HYPOTHESIS: The plasma activity of phospholipid transfer protein (PLTP), which has putative pro- and anti-atherogenic roles in lipoprotein metabolism, is increased in type 2 diabetes mellitus. We analysed the relationship between carotid artery intima-media thickness (IMT), an established marker of atherosclerosis, and PLTP activity in diabetic patients and control subjects. METHODS: The IMT (mean of three segments in both carotid arteries by ultrasonography), clinical variables, plasma PLTP activity (phospholipid vesicle-HDL system), lipoproteins, C-reactive protein and insulin were measured in 87 non-smoking men and women, who had type 2 diabetes mellitus, no cardiovascular disease, and were not on insulin or lipid-lowering medication, and in 83 age-matched control subjects. RESULTS: In diabetic patients, carotid IMT (p=0.02), pulse pressure (p=0.003), plasma PLTP activity (p<0.001), triglycerides (p=0.01), C-reactive protein (p<0.01) and insulin (p<0.001) were higher, whereas HDL cholesterol was lower (p<0.001) than in control subjects. Multiple stepwise linear regression analysis demonstrated that in type 2 diabetic patients IMT was independently associated with age (p<0.001), sex (p=0.001), pulse pressure (p=0.003), plasma PLTP activity (p=0.03) and HDL cholesterol (p=0.03), but not with very low density lipoprotein+LDL cholesterol, triglycerides, C-reactive protein and insulin (all p>0.20). The relationship between plasma PLTP activity and IMT was not significant in control subjects. CONCLUSIONS/INTERPRETATION: Plasma PLTP activity is a positive determinant of IMT in type 2 diabetes mellitus, suggesting that high PLTP activity is involved in accelerated atherosclerosis in this disease.

Aged↗

Increased accumulation of skin advanced glycation end-products precedes and correlates with clinical manifestation of diabetic neuropathy.

AIMS/HYPOTHESIS: The accumulation of AGE is related to the progression of the renal, retinal and vascular complications of diabetes. However, the relationship with diabetic neuropathy remains unclear. We recently showed that skin autofluorescence, measured non-invasively with an AutoFluorescence Reader (AFR), could be used to assess skin AGE accumulation. We evaluated the relationship between skin autofluorescence and the severity of diabetic neuropathy. MATERIALS AND METHODS: Skin autofluorescence in arbitrary units (AU) was assessed in 24 diabetic patients with a history of neuropathic foot ulceration (NP(+)), 23 diabetic patients without clinical neuropathy (NP(-)) and 21 control subjects, using the AFR. Arterial occlusive disease was excluded in all. The severity of foot ulceration was assessed by the Wagner score. Peripheral nerve function was assessed by neurography, measuring motor and sensory nerve conduction velocity and amplitude of the median, peroneal and sural nerves. Heart rate variability (HRV) and baroreflex sensitivity (BRS) were measured by Finapres to assess autonomic nervous function. RESULTS: Autofluorescence was increased in NP(-) compared with control subjects. In NP(+) patients, autofluorescence was further increased and correlated with the Wagner score. Autofluorescence correlated negatively with nerve conduction velocity and amplitude, HRV and BRS in both NP(+) and NP(-) groups. Autofluorescence correlated with age, diabetes duration, mean HbA(1)c of the previous year, serum creatinine level, presence of microalbuminuria and severity of diabetic retinopathy. CONCLUSIONS/INTERPRETATION: Skin autofluorescence correlates with the severity of peripheral and autonomic nerve abnormalities in diabetes, even before being clinically manifest. The AFR may be a convenient and rapid clinical tool for assessing risk of progression of long-term diabetic complications.

Aged↗

Comparison of randomization techniques for clinical trials with data from the HOMERUS-trial.

BACKGROUND: Several methods of randomization are available to create comparable intervention groups in a study. In the HOMERUS-trial, we compared the minimization procedure with a stratified and a non-stratified method of randomization in order to test which one is most appropriate for use in clinical hypertension trials. A second objective of this article was to describe the baseline characteristics of the HOMERUS-trial. METHODS: The HOMERUS population consisted of 459 mild-to-moderate hypertensive subjects (54% males) with a mean age of 55 years. These patients were prospectively randomized with the minimization method to either the office pressure (OP) group, where antihypertensive treatment was based on office blood pressure (BP) values, or to the self-pressure (SP) group, where treatment was based on self-measured BP values. Minimization was compared with two other randomization methods, which were performed post-hoc: (i) non-stratified randomization with four permuted blocks, and (ii) stratified randomization with four permuted blocks and 16 strata. In addition, several factors that could influence outcome were investigated for their effect on BP by 24-h ambulatory blood pressure monitoring (ABPM). RESULTS: Minimization and stratified randomization did not lead to significant differences in 24-h ABPM values between the two treatment groups. Non-stratified randomization resulted in a significant difference in 24-h diastolic ABPM between the groups. Factors that caused significant differences in 24-h ABPM values were: region, centre of patient recruitment, age, gender, microalbuminuria, left ventricular hypertrophy and obesity. CONCLUSION: Minimization and stratified randomization are appropriate methods for use in clinical trials. Many outcome factors should be taken into account for their potential influence on BP levels. Recommendation. Due to the large number of potential outcome factors that can influence BP levels, minimization should be the preferred method for use in clinical hypertension trials, as it has the potential to randomize more outcome factors than stratified randomization.

Adult↗

Left ventricular and cardiac autonomic function in survivors of testicular cancer.

BACKGROUND: Following cisplatin-based chemotherapy, survivors of testicular cancer have a high prevalence of cardiovascular risk factors and an increased risk of cardiovascular disease. Cardiac function has not been extensively studied and no comparisons have been made with men from the general population. DESIGN: Left ventricular and cardiac autonomic function were evaluated in chemotherapy-treated testicular cancer patients, in stage I patients after orchidectomy only, and in healthy men using Doppler echocardiography [wall motion score index, peak early (E) and atrial filling (A) velocities across the mitral valve, E/A-ratio, isovolumetric relaxation time, and deceleration time of the early peak flow] and measurements of N-terminal pro-brain natriuretic peptide and baroreflex sensitivity. Furthermore, 24-h ambulatory blood pressure was measured. RESULTS: Ninety chemotherapy-treated patients (median age 37 years, range 20-65; median follow up of 7 years, range 3-13) were compared with 44 stage I patients (median age 36 years, range 24-63) and 47 healthy controls (median age 37 years, range 22-55). Wall motion score index was less than 1.5 in all participants. Chemotherapy-treated patients had a higher peak A-wave and a lower E/A-ratio than stage I patients and controls. Isovolumetric relaxation and deceleration times did not differ between groups. Age, 24-h diastolic blood pressure and treatment with chemotherapy were significantly associated with E/A-ratio. Natriuretic peptide levels were normal. Baroreflex sensitivity was similar in the three groups. CONCLUSIONS: Chemotherapy-treated testicular cancer survivors have a lower E/A-ratio than healthy subjects from the general population, which may indicate impaired relaxation of the left ventricle and reflect the high prevalence of cardiovascular risk factors previously reported in these men.

Adult↗

Human plasma phospholipid transfer protein activity is decreased by acute hyperglycaemia: studies without and with hyperinsulinaemia in Type 1 diabetes mellitus.

AIMS: Little is known about the regulation of phospholipid transfer protein (PLTP), that plays a key role in lipoprotein metabolism. PLTP secretion may be up-regulated by glucose in vitro, whereas plasma PLTP activity is decreased by exogenous hyperinsulinaemia and glucose-induced hyperinsulinaemia in vivo. In the present study, we evaluated the separate effects of hyperglycaemia and hyperinsulinaemia in C-peptide-negative Type 1 diabetic patients. METHODS: The protocol was carried out in 16 patients (eight females). In each individual, plasma PLTP mass and activity (measured by enzyme-linked immuno-sorbent assay and liposome-high density lipoprotein system, respectively) as well as plasma cholesteryl ester transfer protein (CETP) activity, lipids and apolipoprotein levels were determined at the end of four different glucose clamps, each lasting 210 min: standard insulin (30 mU/kg/h) and standard glucose (glucose 5.0 mmol/l) (SI-SG), standard insulin and high glucose (glucose 12 mmol/l) (SI-HG), high insulin (150 mU/kg/h) and standard glucose (HI-SG), and high insulin and high glucose (HI-HG). RESULTS: Plasma lipids and (apo)lipoproteins, measured at the end of the SI-HG, HI-SG and HI-HG clamps, were not significantly different compared with the levels obtained at the end of the SI-SG clamp. Median plasma PLTP mass and activity at the end of the SI-SG clamp were 12.8 mg/l and 13.2 micromol/ml/h, respectively. Median plasma PLTP mass decreased by 9.1% at the end of the HI-HG clamp (P < 0.01), whereas the changes at the end of the SI-HG and HI-SG clamps were not significant. Median plasma PLTP activity decreased by 5.7, 4.6 and 8.6% at the end of the SI-HG, HI-SG and HI-HG clamps, respectively (all P < 0.05). Median plasma CETP activity was 177 nmol/ml/h at the end of the SI-SG clamp, and decreased by 4.9% (P < 0.05) and by 8.3% (P < 0.05) at the end of the HI-SG and the HI-HG clamps, respectively. Plasma CETP activity did not change significantly at the end of the SI-HG clamp. CONCLUSIONS: The present study demonstrates that plasma PLTP activity is independently decreased by acute hyperglycaemia and hyperinsulinaemia in humans in vivo. These data do not support a direct role of short-term hyperglycaemia in up-regulating plasma PLTP levels.

Adult↗

Data density curves of B-mode ultrasound arterial wall thickness measurements in unaffected control and at-risk populations.

AIM: Atherosclerosis is a slow disease process of arterial walls with onset decades prior to its clinical manifestations. Lifelong follow-up data may help to identify and understand the pathophysiology of this process. These longitudinal data are scarce. Using a standardized imaging and image analysis protocol, we acquired cross-sectional data of carotid and femoral arterial wall segments in populations at different cardiovascular disease risk. METHODS: B-mode ultrasound intima-media thickness (IMT) data of carotid and femoral arteries were acquired in individuals at high cardiovascular disease risk: 44 young adolescents with familial hypercholesterolemia (FH), 248 adult FH patients and 184 patients with coronary artery disease (CAD), as well as in disease free unaffected individuals, 44 young adolescents, 26 middle-aged adults and 48 senior adults. RESULTS: Per patient combined average IMT (SD) and % of lesions in the high risk populations were 0.55 (0.05) mm, 0.1%, 0.86 (0.18) mm, 15%, and 0.9 (0.18) mm, 18%, respectively. In the unaffected groups these values were 0.53 (0.03) mm, 0%, 0.59 (0.07) mm, 0%, and 0.77 (0.12) mm, 8%. Of all arterial segments, the far wall of the common femoral artery (CFA) of the FH patients exhibited the highest absolute IMT (1.12 [0.61] mm), the most rapid estimated IMT increase since adolescence (+0.58 mm) and the highest percentage of lesions (39% of CFA measurements). CONCLUSIONS: Regardless of location, carotid and femoral arterial walls increase in thickness with age and cardiovascular disease risk. This increase in thickness and prevalence of lesions is not similarly distributed among anatomical segments. The strong preponderance in arterial wall segments with the highest estimated atherosclerosis progression indicates the existence of a threshold value beyond which plaque formation is greatly increased. In the set of arterial locations we studied, this process might be best represented by the far wall of the CFA.

Adolescent↗

Simple non-invasive assessment of advanced glycation endproduct accumulation.

AIMS/HYPOTHESIS: The accumulation of AGE is thought to play a role in the pathogenesis of chronic complications of diabetes mellitus and renal failure. All current measurements of AGE accumulation require invasive sampling. We exploited the fact that several AGE exhibit autofluorescence to develop a non-invasive tool for measuring skin AGE accumulation, the Autofluorescence Reader (AFR). We validated its use by comparing the values obtained using the AFR with the AGE content measured in extracts from skin biopsies of diabetic and control subjects. METHODS: Using the AFR with an excitation light source of 300-420 nm, fluorescence of the skin was measured at the arm and lower leg in 46 patients with diabetes (Type 1 and 2) and in 46 age- and sex-matched control subjects, the majority of whom were Caucasian. Autofluorescence was defined as the average fluorescence per nm over the entire emission spectrum (420-600 nm) as ratio of the average fluorescence per nm over the 300-420-nm range. Skin biopsies were obtained from the same site of the arm, and analysed for collagen-linked fluorescence (CLF) and specific AGE: pentosidine, N(epsilon)-(carboxymethyl)lysine (CML) and N(epsilon)-(carboxyethyl)lysine (CEL). RESULTS: Autofluorescence correlated with CLF, pentosidine, CML, and CEL ( r=0.47-0.62, p</=0.002). In 32 of 46 diabetic patients (70%), autofluorescence values were above the 95% CI of the mean value in control subjects, and correlated with age, diabetes duration, mean HbA(1)c of the previous year and creatinine levels. CONCLUSIONS/INTERPRETATION: The AFR offers a simple alternative to invasive measurement of AGE accumulation and, to date, has been validated in non-pigmented skin. The AFR may prove to be a useful clinical tool for rapid risk assessment of AGE-related long-term complications in diabetes mellitus and in other conditions associated with AGE accumulation.

Adult↗

Microalbuminuria, decreased fibrinolysis, and inflammation as early signs of atherosclerosis in long-term survivors of disseminated testicular cancer.

Testicular cancer patients have an increased risk for coronary artery disease more than ten years after cisplatin-based chemotherapy. We investigated whether vascular changes, including endothelial dysfunction, are present earlier. Ninety chemotherapy-treated testicular cancer patients (median follow-up of seven years) were compared with 44 patients after orchidectomy only and 47 healthy men. Microalbuminuria was present in 10 (12%) chemotherapy patients, one stage I patient and none of the controls. Chemotherapy patients had higher levels of fibrinogen, C-reactive protein (hs-CRP), von Willebrand factor (vWF), plasminogen activator inhibitor (PAI-1), and tissue-type plasminogen activator (t-PA). Chemotherapy patients with elevated PAI-1 (25/90) showed clustering of cardiovascular risk factors resembling the metabolic syndrome. In conclusion, cured testicular cancer patients showed a high prevalence of microalbuminuria and increased plasma levels of endothelial and inflammatory marker proteins, which might progress to more severe endothelial dysfunction and overt atherosclerosis.

Adult↗

Increased alpha-linolenic acid intake lowers C-reactive protein, but has no effect on markers of atherosclerosis.

OBJECTIVE: To investigate the effects of increased alpha-linolenic acid (ALA)-intake on intima-media thickness (IMT), oxidized low-density lipoprotein (LDL) antibodies, soluble intercellular adhesion molecule-1 (sICAM-1), C-reactive protein (CRP), and interleukins 6 and 10. DESIGN: Randomized double-blind placebo-controlled trial. SUBJECTS: Moderately hypercholesterolaemic men and women (55 +/- 10 y) with two other cardiovascular risk factors (n = 103). INTERVENTION: Participants were assigned to a margarine enriched with ALA (fatty acid composition 46% LA, 15% ALA) or linoleic acid (LA) (58% LA, 0.3% ALA) for 2 y. RESULTS: Dietary ALA intake was 2.3 en% among ALA users, and 0.4 en% among LA users. The 2-y progression rate of the mean carotid IMT (ALA and LA: +0.05 mm) and femoral IMT (ALA:+0.05 mm; LA:+0.04 mm) was similar, when adjusted for confounding variables. After 1 and 2 y, ALA users had a lower CRP level than LA users (net differences -0.53 and -0.56 mg/l, respectively, P < 0.05). No significant effects were observed in oxidized LDL antibodies, and levels of sICAM-1, interleukins 6 and 10. CONCLUSIONS: A six-fold increased ALA intake lowers CRP, when compared to a control diet high in LA. The present study found no effects on markers for atherosclerosis. SPONSORSHIP: The Dutch 'Praeventiefonds'.

Adult↗

No effects of acute hyperglycaemia and hyperinsulinaemia on skin microcirculation and endothelial markers in Type II diabetes mellitus.

BACKGROUND: Increased microvascular permeability is a hallmark of microangiopathy in Type I diabetes mellitus and is associated with endothelial dysfunction and haemodynamic alterations. Type II diabetes mellitus is characterized by insulin resistance and hyperinsulinaemia. The purpose of this study was to determine whether acute hyperinsulinaemia, under both normoglycaemic and hyperglycaemic conditions, increases skin capillary permeability through its effect on skin haemodynamics, capillary recruitment or circulating markers of endothelial dysfunction in Type II diabetes. METHODS: Nine Type II diabetic patients without microalbuminuria, (pre-) proliferative retinopathy or clinical neuropathy underwent three glucose clamps of 210 min., in random order, on separate days. A "standard" clamp (insulin-infusion rate 30 mU kg(-1) h(-1), glucose-target 5.0 mmol/L) was compared with a hyperinsulinaemic (insulin-infusion rate 150 mU kg(-1) h(-1), glucose-target 5.0 mmol/L) and a hyperinsulinaemic, hyperglycaemic (insulin-infusion rate 150 mU kg(-1) h(-1), glucose-target 12.0 mmol/L) clamp. Skin capillary permeability and density were measured using large-window sodium fluorescein videodensitometry, and skin blood flow by laser Doppler flowmetry. Endothelial dysfunction was estimated from increases in soluble intercellular adhesion molecule-1 (sICAM-1) and von Willebrand factor antigen (vWF). RESULTS: No differences were found in skin capillary permeability, skin haemodynamics and capillary density at the end of the three glucose clamp periods. sICAM-1 and vWF did not increase as compared to the standard glucose clamp. sICAM-1 (r=-0.76, p<0.05) and vWF (r=-0.71, p<0.05) correlated negatively with insulin sensitivity, but not with skin microcirculatory parameters. CONCLUSIONS: Acute hyperinsulinaemia, both with and without concomitant hyperglycaemia, does not increase skin microvascular permeability, haemodynamics or parameters of endothelial dysfunction in Type II diabetic patients. Furthermore, these data suggest that the coexistence of hyperinsulinaemia and endothelial dysfunction in Type II diabetes does not indicate a causal relationship, but may rather indicate decreased insulin sensitivity as a common underlying cause.

Antigens↗

The clinical relevance of advanced glycation endproducts (AGE) and recent developments in pharmaceutics to reduce AGE accumulation.

Advanced glycation endproducts (AGE) are a class of compounds resulting from glycation and oxidation of proteins, lipids or nucleic acids. Glycation is the non-enzymatic addition or insertion of saccharide derivatives to these molecules. This leads to the formation of intermediary Schiff bases and Amadori products and finally to irreversible AGE. This classical view has been modified in recent years with recognition of the importance of oxidative and carbonyl stress in endogenous AGE formation. AGE may also have exogenous sources, in certain foods and tobacco smoke. A whole class of specific and non-specific receptors binding AGE has been characterized. Apart from cross-linking of proteins by AGE, the effects of receptor stimulation contribute to the development of chronic complications of conditions like diabetes mellitus, renal failure, and atherosclerosis. Possible interventions to reduce the effects of AGE accumulation include AGE formation inhibitors or breakers, or receptor blockers, but possibly also dietary interventions. Some of the problems with current assay or diagnostic techniques, and several unresolved issues on the role of AGE in disease will be discussed. Our review will focus on the clinical and pharmaceutical implications of these developments.

Animals↗

Sympathetic mediated vasomotion and skin capillary permeability in diabetic patients with peripheral neuropathy.

AIMS/HYPOTHESIS: A loss of sympathetic function could lead to changes in capillary fluid filtration in diabetic patients. We investigated whether a decreased sympathetically mediated vasomotion in the skin in diabetic patients with peripheral neuropathy is associated with an abnormal capillary leakage. METHODS: Three matched groups were studied: 18 diabetic patients with documented peripheral neuropathy (DN), 18 diabetic patients without peripheral neuropathy (D), and 18 healthy control subjects (C). Sensory and motor nerve function of the distal extremities were assessed by standard neurography, and expressed in a sensory-motor nerve function score. Sympathetic vasomotion of the skin microcirculation was assessed by determining the power of blood flow variability in the low-frequency (0.02-0.14 Hz) band by spectral analysis of laser Doppler flowmetry at the median ankle. Skin capillary leakage was evaluated by sodium fluorescein videodensitometry at the same site of the foot. RESULTS: Sympathetically mediated vasomotion of the foot skin microcirculation was lower in diabetic patients with documented peripheral neuropathy compared with diabetic patients without peripheral neuropathy and control subjects (p<0.001). Capillary sodium fluorescein leakage was larger in 18 diabetic patients with documented peripheral neuropathy than in diabetic patients without peripheral neuropathy (p<0.02) and C (p<0.005). Multiple regression analysis disclosed that a reduced sympathetically mediated vasomotion, together with a lower sensory-motor nerve function score, independently contributed to the variance in sodium fluorescein leakage, for 30% (p<0.001) and 17% (p<0.01), respectively. CONCLUSIONS: A loss of sympathetic tone, apart from sensory-motor nerve dysfunction, seems to be a major determinant of an increased capillary permeability in diabetic patients with neuropathy.

Capillary Permeability↗

Home versus Office blood pressure MEasurements: Reduction of Unnecessary treatment Study: rationale and study design of the HOMERUS trial.

The Home versus Office MEasurements, Reduction of Unnecessary treatment Study (HOMERUS) is a multicentre prospective study, primarily designed to examine in subjects with mild to moderate hypertension whether treatment decisions based on home blood pressure measurements can lead to reduction in the use of antihypertensive drugs and the associated costs, compared to office blood pressure measurements. After inclusion, 360 patients are randomized to two groups. In one group, antihypertensive therapy is based on blood pressure measured in the outpatient clinic: the office pressure (OP) group. In the other group, antihypertensive therapy is based on home blood pressure measurements: the self-pressure (SP) group. All readings, both in OP and in SP, are obtained with the same validated oscillometric device, the Omron 705 CP. Treatment decisions are taken by an independent physician at the coordinating centre, who is unaware whether the patient belongs to the SP or OP group. Following a standardized treatment schedule, blood pressure is targeted at 120-139 mmHg for systolic and 80-89 mmHg for diastolic pressure. Patients are followed for 1 year. At the start and at the end of the study, ambulatory blood pressure measurements are obtained as a reference. Microalbuminuria and echocardiography are assessed to evaluate the possible development of target organ damage. It is expected that, at the end of the trial, patients in both groups will have the same blood pressure, at the expense of more medication in the OP group. Therefore, a cost-minimization analysis will be performed first. If short-term effects appear not to be comparable for OP and SP, a cost-effectiveness analysis will be performed to assess the value of the SP strategy in comparison to standard practice. In addition, medication compliance is recorded within random subgroups of the SP and OP groups by means of Medication Event Monitoring System (MEMS) V TrackCaps.

Algorithms↗

Acute hyperglycemia and hyperinsulinemia enhance vasodilatation in Type 1 diabetes mellitus without increasing capillary permeability and inducing endothelial dysfunction.

Uncomplicated Type 1 (insulin-dependent) diabetes mellitus is characterized by generalized vasodilatation. Its possible correlates, increased microvascular permeability and endothelial dysfunction, have been associated with long-term complications. The objective was to study the effects of acute hyperglycemia and hyperinsulinemia, both separately and in combination, on skin microvascular flow, capillary permeability, capillary recruitment, and endothelial dysfunction in Type 1 diabetes mellitus. Sixteen Type 1 diabetic patients (all normoalbuminuric, no (pre-)proliferative retinopathy) underwent a euglycemic (glucose target 5.0 mmol/L, insulin infused at 30 mU x kg(-1) x h(-1)), a hyperglycemic (glucose target 12.0 mmol/L, insulin 30 mU x kg(-1) x h(-1)), a hyperinsulinemic (glucose target 5.0 mmol/L, insulin 150 mU x kg(-1) x h(-1)), and a hyperglycemic-hyperinsulinemic (glucose target 12.0 mmol/L, insulin 150 mU x kg(-1) x h(-1)) clamp on separate days, in random order. Skin microvascular flow was measured by laser Doppler flowmetry. Capillary permeability and density were determined by large-window sodium-fluorescein videodensitometry. Increases in serum soluble intercellular adhesion molecule-1 (sICAM-1) and plasma von Willebrand factor antigen (vWF-Ag) were considered to represent abnormal endothelial function. Hyperglycemia (P < 0.01) and hyperinsulinemia (P < 0.05) as well as both interventions combined (P < 0.001) induced an increase in laser Doppler flow, without capillary recruitment. Transcapillary leakage of sodium-fluorescein and sICAM-1 and vWF-Ag levels were unaffected by hyperglycemia or hyperinsulinemia. Microvascular permeability appears to be determined primarily by properties of the capillary wall and not by acute changes in local hemodynamics. The acute hyperglycemia- and hyperinsulinemia-induced vasodilatation is not accompanied by changes in microvascular permeability or endothelial markers.

Acute Disease↗