High Prevalence Of Vascular Disease Research Articles

Vascular injury markers associated with cognitive impairment in people with HIV on suppressive antiretroviral therapy.

Human immunodeficiency virus (HIV)-associated neurocognitive disorders (HAND) remain prevalent despite viral suppression on antiretroviral therapy (ART). Vascular disease contributes to HAND, but peripheral markers that distinguish vascular cognitive impairment (VCI) from HIV-related etiologies remain unclear. Cross-sectional study of vascular injury, inflammation, and central nervous system (CNS) injury markers in relation to HAND. Vascular injury (VCAM-1, ICAM-1, CRP), inflammation (IFN-γ, IL-1β, IL-6, IL-8, IL-15, IP-10, MCP-1, VEGF-A), and CNS injury (NFL, total Tau, GFAP, YKL-40) markers were measured in plasma and CSF from 248 individuals (143 HIV+ on suppressive ART and 105 HIV- controls). Median age was 53 years, median CD4 + cell count, and duration of HIV infection were 505 cells/μl and 16 years, respectively. Vascular injury, inflammation, and CNS injury markers were increased in HIV+ compared with HIV- individuals ( P < 0.05). HAND was associated with increased plasma VCAM-1, ICAM-1, and YKL-40 ( P < 0.01) and vascular disease ( P = 0.004). In contrast, inflammation markers had no significant association with HAND. Vascular injury markers were associated with lower neurocognitive T scores in age-adjusted models ( P < 0.01). Furthermore, plasma VCAM-1 correlated with NFL ( r = 0.29, P = 0.003). Biomarker clustering separated HAND into three clusters: two clusters with high prevalence of vascular disease, elevated VCAM-1 and NFL, and distinctive inflammation profiles (CRP/ICAM-1/YKL-40 or IL-6/IL-8/IL-15/MCP-1), and one cluster with no distinctive biomarker elevations. Vascular injury markers are more closely related to HAND and CNS injury in PWH on suppressive ART than inflammation markers and may help to distinguish relative contributions of VCI to HAND.

Expanding the criteria for targeted muscle reinnervation: A national assessment of eligibility

This study represents an effort to examine the national eligibility of patients who would benefit from lower extremity (LE) targeted muscle reinnervation (TMR) in the United States. The objective of this study is to quantify and characterize the patient population eligible for LE TMR. Using the National Inpatient Sample database from 2008 to 2015, patients undergoing lower extremity amputations were identified by ICD-9 diagnosis code. Differences in patient-level demographic parameters and hospital-level factors were compared using descriptive statistics. Over the study period, a weighted total of 369,717 patients met inclusion criteria, representing an annual mean of 46,214 patients per year. 214,756 patients underwent below-knee amputation, and 150,634 underwent above-knee amputation. Patients were predominantly male (63%), from the south (47.4%), and of the lowest income quartile (38.8%). Younger patients were more likely to be privately insured (44.1%) or on Medicaid (44.1%), while older patients were predominantly on Medicare (89.4%). Peripheral vascular disease affected 45.5%, 51.3%, and 52.0% of patients in the sixth, seventh, and eighth decades of life respectively. Black patients also made up 26% of amputations despite only composing 13% of the overall population. At least 46,214 patients per year present a population that would possibly benefit from TMR, with about half of those with peripheral vascular disease. In addition to the high prevalence of vascular disease, low-income, minority individuals are disproportionately affected by LE amputation. • A total of 46,214 patients per year undergo lower extremity amputation. • Almost half of patients with lower extremity amputation have comorbid peripheral vascular disease. • Eligibility for targeted muscle reinnervation must consider the comorbidities of the population.

Self-Identified Female Patients Experience Worse Outcomes After Carotid Endarterectomy, Endovascular Abdominal Aortic Aneurysm Repair, and Lower Extremity Amputation: Gender Disparities in Vascular Surgery

Carotid endarterectomy (CEA), endovascular abdominal aortic aneurysm repair (EVAR), and below-the-knee amputation (BKA) are frequently performed procedures in vascular surgery. Controlling for a naturally occurring higher prevalence of vascular disease in the biologically male population, we sought to determine whether gender disparities exist in the outcomes of these commonly performed procedures.

High prevalence of obstructive sleep apnea syndrome in Spain's Stroke Belt.

ObjectiveSpain’s so-called Stroke Belt is an area with high prevalence of vascular disease. We aimed to determine the prevalence of undetected obstructive sleep apnea–hypopnea syndrome (OSAHS) among patients with acute ischemic stroke (AIS) in southern Spain.MethodsWe conducted a cross-sectional study at the Virgen Macarena University Hospital Stroke Unit during 2018 to 2019. We included patients <72 hours after AIS with a neuroimaging lesion and performed sleep tests.ResultsSeventy-two patients were included. The median participant age was 72 years. Mean body mass index was 27.07 kg/m2, and 40.28% were daily alcohol drinkers. Hypertension, atrial fibrillation, ischemic cardiomyopathy, and previous stroke were detected in 63.9%, 11.1%, 15.3%, and 17.6% of patients, respectively. Polygraphy was feasible in 91.38% of patients. The prevalence of OSAHS was 84.72% (apnea–hypopnea index ≥5). Patients with moderate and severe OSAHS were more likely to be obese and to have a larger neck circumference and facial palsy. The diagnostic criteria of central sleep apnea syndrome were met in only 1.38% of patients.ConclusionsThe high prevalence of OSAHS found in the Spanish Stroke Belt justifies further investigation and development of a screening program as a strategy to identify patients with undetected OSAHS.

Intraventricular Thrombus Formation and Embolism in Takotsubo Syndrome: Insights From the International Takotsubo Registry.

Takotsubo syndrome (TTS) is characterized by acute left ventricular dysfunction, which can contribute to intraventricular thrombus and embolism. Still, prevalence and clinical impact of thrombus formation and embolic events on outcome of TTS patients remain unclear. This study aimed to investigate clinical features and outcomes of patients with and without intraventricular thrombus or embolism. Additionally, factors associated with thrombus formation or embolism, as well as predictors for mortality, were identified. Approach and Results: TTS patients enrolled in the International Takotsubo Registry at 28 centers in Australia, Europe, and the United States were dichotomized according to the occurrence/absence of intraventricular thrombus or embolism. Patients with intraventricular thrombus or embolism were defined as the ThrombEmb group. Of 1676 TTS patients, 56 (3.3%) patients developed intraventricular thrombus and/or embolism following TTS diagnosis (median time interval, 2.0 days [range, 0-38 days]). Patients in the ThrombEmb group had a different clinical profile including lower left ventricular ejection fraction, higher prevalence of the apical type, elevated levels of troponin and inflammatory markers, and higher prevalence of vascular disease. In a Firth bias-reduced penalized-likelihood logistic regression model apical type, left ventricular ejection fraction ≤30%, previous vascular disease, and a white blood cell count on admission >10×103 cells/μL emerged as independent predictors for thrombus formation or embolism. Intraventricular thrombus or embolism occur in 3.3% of patients in the acute phase of TTS. A simple risk score including clinical parameters associated with intraventricular thrombus formation or embolism identifies patients at increased risk. URL: http://www.clinicaltrials.gov. Unique identifier: NCT01947621.

Analytic Approaches for the Treatment of Hyperhomocysteinemia and Its Impact on Vascular Disease.

Homocysteine is an intermediary metabolite in the methionine cycle. Accumulation of homocysteine is caused either by mutation of relevant genes or by nutritional depletion of related vitamin(s). This review covers the historical background of hyperhomocysteinemia in which indispensable subjects in relation to underlying pathophysiological processes are discussed with the view of metabolism and genetics of folate and methionine cycles. This review emphasizes the unique role of homocysteine that is clearly distinct from other risk factors, particularly cholesterol in the development of vascular disease. The critical issue in understanding the role of homocysteine is the relation with plasma folic acid. The majority of subjects with homocysteine > 15μmol/L exhibit plasma folate < 9nmol/ L, indicating that depletion of folate is the main cause of hyperhomocysteinemia irrespective of the presence or absence of vascular disease. Furthermore, only the group of subjects with homocysteine levels > 15μmol/L demonstrated a higher prevalence of vascular disease. Analytic approaches to treat hyperhomocysteinemia are discussed in which stepwise administration with nutritional doses of folic acid, 5-methyitetrahydrofolate (5-MTHF), and betaine is provided singly or by combined manner based on clinical and laboratory evaluations. Whether correction of hyperhomocysteinemia is able to prevent the development of homocysteine-associated vascular disease remains an unresolved issue. The review discussed a biochemical and mechanistic approach to resolve questions involved in the relation between homocysteine and the development of atherosclerotic vascular disease.

Circulation : Clinical Summaries

<i>Circulation</i> : Clinical Summaries

Quality of care provided to people with dementia: utilisation and quality of the annual dementia review in general practice

Primary care services are often the main healthcare service for people with dementia; as such, good-quality care at this level is important. To measure the quality of care provided to people with dementia in general practice using routinely collected data, and to explore associated patient and practice factors. Observational, cross-sectional review of medical records from general practices (n = 52) in five primary care trusts. A total of 994 people with dementia were identified from dementia registers. An unweighted quality-of-care score was constructed using information collected in the annual dementia review, together with pharmacological management of cognitive and non-cognitive symptoms. Multilevel modelling was carried out to identify factors associated with quality-of-care scores. In total, 599 out of 745 (80%) patients with dementia had received an annual dementia review; however, a social care review or discussion with carers was evident in just 305 (51%) and 367 (61%) of those 599 cases, respectively. Despite high prevalence of vascular disease, over a quarter (n = 259, 26%) of all patients with dementia were prescribed antipsychotics; only 57% (n = 148) of these had undergone medication review in the previous 6 months. Those with vascular dementia who were registered with single-handed practices received poorer quality of care than those registered with practices that had more than one GP. Although the number of people with dementia with a record of an annual dementia review is high, the quality of these reviews is suboptimal. The quality score developed in this study could be used as one source of data to identify weaknesses in practice activity that need to be corrected, and so would be of value to commissioners and regulators, as well as practices themselves.

Protecting the endothelium: A new focus for management of chronic kidney disease

It is being increasingly recognized that cardiovascular disease (CVD) and its complications are the most important cause of morbidity and mortality in patients with chronic kidney disease (CKD) and dialysis patients. If outcomes for these patients are to be improved, therapeutic strategies at all stages of CKD will have to target the etiologies and mechanisms that lead to CVD. In this review, we focus on the central role of endothelial dysfunction as the critical precursor of CVD. We argue that a better understanding of endothelial dysfunction by nephrologists and dialysis physicians is necessary if there is to be success in limiting the CVD epidemic that kills and maims our patients. The extensive studies to explain the high prevalence of vascular disease in patients with CKD have shown the close relationship among endothelial dysfunction, inflammation, and atherosclerosis. The pathogenesis starts with endothelial cell injury from any of many possible causes, and strategies to reduce the burden of CVD in uremic and dialysis patients must be directed at restoring normal endothelial function or, at the least, preventing aggravation of endothelial damage. At the center of the exploration of endothelial dysfunction and atherosclerosis are oxidative stress and inflammation. Of these, which is the chicken and which is the egg is unknown, but in the setting of uremia, endothelial injury because of free radical, oxidative stress is likely to precede inflammation. The issues raised here are highly complex and most renal practitioners may not have been adequately exposed to the background research underlying current thinking of the pathogenesis of vascular disease. Clearly, progress in management of CVD in patients with CKD will require collaboration with experts in the research and treatment of vascular disease. Nephrologists seeking optimum outcomes for patients with CKD will need to become "endotheliologists" or, at the least, subscribe to a mission "to protect the endothelium."

Gene Polymorphism Association Studies in Dialysis: The Nutrition‐Inflammation Axis

Although traditional risk factors for cardiovascular disease are common in dialysis patients, they alone cannot explain the unacceptably high prevalence of vascular disease in this patient group. Much recent interest has therefore focused on the role of various nontraditional cardiovascular risk factors, such as inflammation, wasting, obesity, vascular calcification, and oxidative stress. In addition, genetic factors such as single nucleotide polymorphisms (SNPs) may significantly influence the immune response, the levels of inflammatory markers and body composition, as well as the prevalence of vascular calcification in this patient group. While genetic variations in the tumor necrosis factor (TNF)-alpha-308 and interleukin (IL)-10 -1082 SNPs seem to be consistently associated with adverse clinical outcome in end-stage renal disease (ESRD) patients, the results regarding genetic variations in the IL-6 gene have been conflicting. To elucidate the respective role of DNA polymorphisms in the IL-6 and C-reactive protein (CRP) genes, as well as genes that encode vascular calcification inhibitors (such as fetuin-A, matrix Gla protein, and osteoprotegerin), sufficiently powered studies are needed in which both the protein product and the specific phenotype are determined. In addition, polymorphisms in genes related to body composition may be excellent candidates for analysis in the ESRD population, since nutritional parameters are strongly associated with adverse events in these patients. It seems conceivable that in the future, prognostic or predictive multigene DNA assays (which allow a simultaneous and rapid assessment of multiple genetic variants) will provide nephrologists with a more precise approach for the identification of "high-risk" ESRD patients and the development of accurate individualized treatment strategies.

Activation of mesangial cell MAPK in responseto homocysteine

Alteration in mesangial cell function is central to the progression of glomerular disease in numerous models of chronic renal failure (CRF). Animal models of chronic glomerular disease are characterized by mesangial cell proliferation and elaboration of extracellular matrix protein (ECM), resulting in glomerulosclerosis. Elevated plasma levels of homocysteine (Hcy) are seen in both animal models and humans with CRF, and have been proposed to contribute to the high prevalence of vascular disease in this group. Some of the pathogenetic effects of Hcy are thought to be mediated via the induction of endoplasmic reticulum stress. Thus, Hcy effects on mesangial cells could contribute to the progression of CRF. Previous work has shown Hcy- mediated induction of Erk mitogen-activated protein kinase (MAPK) in vascular smooth muscle cells (VSMCs). Erk induces increases in activator protein-1 (AP-1) transcription factor activity which may augment mesangial cell proliferation and ECM protein production. Consequently, we studied the effect of Hcy on mesangial cell Erk signaling. Mesangial cells were exposed to Hcy after 24 hours of serum starvation and Erk activity assessed. Nuclear translocation of phospho-Erk was visualized by confocal microscopy. AP-1 nuclear protein binding was measured in response to Hcy by mobility shift assay. Hcy-induced mesangial cell calcium flux was measured in Fura-2 loaded cells. Mesangial cell DNA synthesis in response to Hcy was assessed by [3H]-thymidine incorporation and proliferation by Western blotting for proliferating cell nuclear antigen (PCNA). Expression of endoplasmic reticulum stress response genes were determined by Northern and Western analysis. Hcy led to an increase in Erk activity that was maximal at 50 micromol/L and 20 minutes of treatment. Subsequent experiments used this concentration and time point. Erk activity in response to Hcy was insensitive to n-acetylcysteine and catalase, indicating oxidative stress did not play a role. However, Hcy50 micromol/L induced a brief increase in intracellular mesangial cell calcium within 5 minutes, and the calcium ionophores A23187 and ionomycin increased Erk activity while chelation of intracellular calcium with BAPTA-AM abrogated the Erk response to Hcy. Confocal microscopy of activated Erk nuclear translocation mirrored these results as did mesangial cell nuclear protein binding to AP-1 consensus sequences. Hcy- induced increases in thymidine incorporation and PCNA expression at 24 hours were Erk dependent. The expression of endoplasmic reticulum stress response genes was significantly elevated by Hcy in an Erk-dependent manner. Hcy increases Erk activity in mesangial cells via a calcium-dependent mechanism, resulting in increased AP-1 nuclear protein binding, cell DNA synthesis and proliferation and induction of endoplasmic reticulum stress. These observations suggest potential mechanisms by which Hcy may contribute to progressive glomerular injury.

Associations between insulin resistance and thrombotic risk factors in high-risk South Asian subjects.

There is recognized association of thrombotic factors to insulin resistance in White Europeans. South Asians are more insulin resistant compared with white Europeans and express increased metabolic features of insulin resistance. The aim of the study was to determine whether there was any relationship between insulin resistance and thrombotic risk factors in healthy South Asian subjects. Healthy South Asians (n = 185) clinically free from ischaemic heart disease, ischaemic stroke or peripheral vascular disease were randomly recruited. Partial correlations of homeostasis model assessment (HOMA) (surrogate of insulin resistance) were analysed with two fibrinolytic and five coagulation factors. Age and gender-adjusted HOMA was significantly correlated to plasminogen activator inhibitor-1 (0.51, P = 0.0001), tissue plasminogen activator antigen (r = 0.40, P = 0.0001), fibrinogen (r = 0.28, P = 0.0001), von Willebrand factor (r = 0.17, P = 0.03), factor XIIa (r = 0.22, P = 0.006) factor VII antigen (r = 0.19, P = 0.02) and factor XIII B subunit (r = 0.30, P = 0.001). Insulin resistance significantly clusters with fibrinolytic and coagulation factors in South Asians, which may contribute to high prevalence of vascular disease in this population.

Risk factor management in stable, insulin-treated patients with Type 2 diabetes: The Diabetes Outcomes in Veterans Study

Objectives: Describe the methodologies and study population of the Diabetes Outcomes in Veterans Study (DOVES). Research Design and Methods: Prospective, multicenter, observational study of Southwestern veterans with stable, insulin-treated Type 2 diabetes. Subjects were randomly selected from pharmacy records and were required to be using at least one long-acting insulin preparation daily. Baseline psychosocial evaluations included psychological status, social and cultural barriers to care, self-care behaviors, and vascular disease risk factors. Clinical measurements included self-reported vascular disease, hemoglobin A1c (HbA1c), blood pressure, blood lipids, and body mass index (BMI). A subset of subjects completed a protocol of four times daily self-monitored blood glucose testing for 8 weeks. Subjects were followed for 12 months. Principal endpoints included glycemic control, the occurrence of hypoglycemia, and control of vascular disease risk factors. Results: We enrolled 338 subjects. The mean (±S.D.) age was 65.1±9.7 years and 3.8% were women. At baseline, over two-thirds of subjects reported vascular disease complications. Nearly three-quarters had limited physical activity. Among subjects younger than 65 years, 53% considered themselves disabled for work. Despite the high prevalence of vascular disease, 43.8% had an HbA1c ≥8.0%. Many subjects were sedentary, 62.1% had a BMI of 30 kg/m 2 or above, and 22.2% were still smoking. Conclusions: Detailed measurements of psychological status, self-care behaviors, and risk factor control are feasible in this elderly, debilitated population. Although the prevalence of complications and self-rated disability was high, vascular disease risk factors were poorly controlled in a substantial proportion of subjects.

Clustering of Thrombotic Factors with Insulin Resistance in South Asian Patients with Ischaemic Stroke

We aimed to investigate significant correlations of insulin resistance with thrombotic factors in South Asians with stroke. Correlations of Homeostasis Model Assessment (HOMA)(as a surrogate of insulin resistance) were analysed with 6 thrombotic factors in 140 South Asian patients with a history of confirmed (by computerised tomography) ischaemic stroke. Age and sex adjusted HOMA was correlated to waist-hip ratio (r = 0.38, p = 0.0001), triglycerides (r = 0.22, p = 0.03), systolic blood pressure (r = 0.21, p = 0.04), tissue plasminogen activator (t-PA) (r = 0.22, p = 0.04); plasminogen activator inhibitor 1(PAI-1) (r = 0.26, p = 0.02); fibrinogen (r = 0.25, p = 0.02); and factor VII antigen (r = 0.21, p = 0.06). On regression analysis, with HOMA as dependent variable and significant correlates as independent variables in the model, HOMA was independently associated with PAI-1 antigen. There is extensive clustering of metabolic and thrombotic factors with insulin resistance in South Asian patients with ischaemic stroke, which may contribute to high prevalence of vascular disease in this population.

Adverse endothelial function and the insulin resistance syndrome.

Type 2 diabetes is characterized by impaired endothelial dependent vasodilatation which may contribute to the high prevalence of vascular disease in such patients. Although hyperglycaemia, dyslipidaemia and hypertension can all independently cause a similar defect, recent data suggest that endothelial dysfunction may be intrinsic to the insulin resistance syndrome that commonly precedes type 2 diabetes. Such abnormalities in endothelial function could represent the impact of subclinical disturbance of metabolism or alternatively the presence of a common cellular defect that influences both nitric oxide bioavailability and insulin mediated glucose disposal. Resolution of this puzzle is likely to lead to important advances in our knowledge and ultimately treatment of vascular disease.

A cholesteryl ester transfer protein gene mutation and vascular disease in dialysis patients.

Among patients undergoing maintenance hemodialysis, a decreased high-density lipoprotein cholesterol (HDL-C) concentration is among the most common abnormalities of lipid metabolism and apparently is an independent risk factor for vascular disease. A common missense mutation of cholesteryl ester transfer protein gene, D442G (Asp 442 to Gly), increases HDL-C levels through the reduced activity of cholesteryl ester transfer from HDL to VLDL, but the mutation also may lead to reduced activity of reverse cholesterol transport. To investigate the effect of the D442G polymorphism on atherosclerotic complications in dialysis patients, the genotype and allele frequency of the polymorphism were determined in 414 unselected dialysis patients and 220 control subjects, and postprandial serum lipid levels were measured in the dialysis patients. A similar genotype distribution was found between hemodialysis patients and healthy control subjects, and in dialysis patients with and without vascular disease. Serum levels of total cholesterol and HDL-C did not differ between patients with and without the mutation and in patients with and without vascular disease. However, patients with sub-median HDL-C levels (<45 mg/dl) had an independent odds ratio of 1.8 for vascular disease (95% confidence interval, 1.04 to 3.2; P < 0.05). In this low-HDL-C subgroup, patients with the D442G mutation had a significantly higher prevalence of vascular disease than those with no mutation (54.5% versus 24.4%; P < 0.05), and an independent odds ratio of 4.9 (95% confidence interval, 1.05 to 22.65; P < 0.05). In conclusion, the D442G mutation is an independent risk factor for atherosclerotic complications in dialysis patients with HDL-C levels below 45 mg/dl.

Impaired nitric oxide-mediated vasodilation in patients with non-insulin-dependent diabetes mellitus

Objectives. This study sought to determine whether nitric oxide-mediated vasodilation is abnormal in patients with non-insulin-dependent diabetes mellitus.Background. Multiple investigations, both in experimental models and in patients with insulin-dependent diabetes mellitus, demonstrate impaired endothelium-dependent vasodilation. Decreased availability of endothelium-derived nitric oxide may contribute to the high prevalence of vascular disease in diabetes.Methods. Vascular reactivity was measured in the forearm resistance vessels of 21 patients with non-insulin-dependent diabetes mellitus and 23 matched healthy control subjects. No patient had hypertension or hypercholesterolemia. Each subject was protreated with aspirin to inhibit endogenous production of vasoactive prostanoids. Methacholine chloride (0.3 to 10 μg/min) was administered through a brachial artery cannula to assess vasodilation to endothelium-derived nitric oxide. Sodium nitroprusside (0.3 to 10 μg/min) was infused to evaluate vasodilation to an exogenous nitric oxide donor. Verapamil (10 to 300 μg/min) was administered to distinguish impaired nitric oxide-mediated vasodilation from general dysfunction of vascular smooth muscle. Forearm blood flow was determined by venous occlusion plethysmography, and dose-response curves were generated for each agent. To assess the role of vasoconstrictor prostanoids, a subset of eight diabetic subjects were reexamined in the absence of aspirin treatment.Results. Basal forearm blood flow in diabetic and nondiabetic subjects was comparable. The forearm blood flow responses to both methacholine chloride and nitroprasside were significantly attenuated in diabetic compared with nondiabetic subjects (p < 0.005 by analysis of variance for both agents). In contrast, the response to verapamil was not significantly different between the groups (p > 0.50). The forearm blood flow responses to these agents were not significantly affected by cyclooxygenase inhibition.Conclusion. Nitric oxide-mediated vasodilation is impaired in non-insulin-dependent diabetes mellitus. Vasoconstrictor prostanoids do not contribute significantly to vascular dysfunction. The attenuated response to exogenous as well as endogenous nitric oxide donors suggests that the abnormality is due to increased inactivation of nitric oxide or to decreased reactivity of the vascular smooth muscle to nitric oxide.

Impaired endothelium-dependent vasodilation in patients with insulin-dependent diabetes mellitus.

Endothelium-dependent vasodilation is abnormal in experimental models of diabetes mellitus. We postulated that abnormalities of endothelial function are also present in patients with insulin-dependent diabetes mellitus and may contribute to the pathogenesis of vascular disease in these individuals. Vascular reactivity was measured in the forearm resistance vessels of 15 patients with insulin-dependent diabetes mellitus and 16 age-matched normal subjects. No patient had hypertension or dyslipidemia. Each subject was pretreated with aspirin to inhibit endogenous production of prostanoids. Methacholine chloride (0.3 to 10 micrograms/min) was administered via the brachial artery to assess endothelium-dependent vasodilation. Sodium nitroprusside (0.3 to 10 micrograms/min) and verapamil (10 to 300 micrograms/min) were infused intra-arterially to assess endothelium-independent vasodilation; phenylephrine (0.3 to 3 micrograms/min) was administered to examine vasoconstrictor responsiveness. Forearm blood flow was determined by venous occlusion plethysmography, and dose-response curves were generated for each drug. Basal forearm blood flow in diabetic and normal subjects was comparable (2.6 +/- 0.2 versus 2.1 +/- 0.3 mL x 100 mL-1 x min-1, respectively; P = NS). The forearm vasodilative response to methacholine was less in diabetic than in normal subjects. At the highest dose of methacholine, the forearm blood flow increased 9.5 +/- 1.1 mL x 100 mL-1 x min-1 in diabetic subjects and 15.3 +/- 1.4 mL.100 mL-1 x min-1 in normal subjects (P < .01). The forearm blood flow responses to nitroprusside and verapamil and the forearm vasoconstrictor responses to phenylephrine were similar in diabetic and healthy subjects. In diabetic subjects, endothelium-dependent vasodilation correlated inversely with serum insulin concentration but not with glucose concentration, glycosylated hemoglobin, or duration of diabetes. Endothelium-dependent vasodilation is abnormal in forearm resistance vessels of patients with insulin-dependent diabetes mellitus. This abnormality may be relevant to the high prevalence of vascular disease that occurs in these individuals.

Association of autoimmunity to vascular heparan sulfate proteoglycan and vascular disease in the aged.

In the very old, there is an increased prevalence of immunologically mediated vascular disease. Vascular heparan sulfate proteoglycan (vHSPG) is a molecule which plays an important structural and functional role in the vasculature. Autoimmunity to vHSPG may play a role in the pathogenesis of vascular disease. The presence of autoantibodies to vHSPG was investigated in sera from aged nursing home patients who have a high prevalence of vascular disease. The results showed an association of the presence of autoantibodies to vHSPG in the sera from patients in this aged population with vascular disease, particularly cerebrovascular disease, renal disease and diabetes. In addition, autoantibodies to vHSPG protein core were associated with cerebrovascular disease in this frail elderly population. These studies support the hypothesis that autoimmunity may play a role in vascular disease in the aged.

THE RELATIONSHIP OF CARDIOVASCULAR DISEASE TO HYPERGLYCEMIA.

Excerpt The high prevalence of vascular disease among diabetics has long been recognized and has become increasingly important since the acute complications of diabetes, acidosis, and infection hav...