Basal Brachial Artery Diameter Research Articles

P142 Effect of Atorvastatin on vascular endothelial function in early Systemic Sclerosis: An open label Randomized Controlled trial

Abstract Background/Aims Systemic Sclerosis (SSc) is driven by early endothelial dysfunction, leading to loss of endothelium-dependent vasodilatation. This predisposes to increased stiffness of large arteries. Prospective studies have found a conflicting role of statins in improving vascular function in established SSc. We undertook this study to explore if statins influence endothelium dependent vasodilation in early SSc Methods In this single center open label randomized controlled trial between July 2021 to January 2022, SSc patients (ACR-EULAR 2013) between 18-65 years, with duration < 3 years from the first non-Raynaud’s symptom were included. Those with complicated Raynaud’s, overlap syndromes and cardiovascular comorbidities were excluded. Participants were randomized into statin (atorvastatin 40 mg/day/A40) or no -statin arm. Both groups received stable doses of immunosuppression, during the study period. The primary outcome of flow-mediated dilation (FMD %) of brachial artery, measured by single assessor and secondary outcomes of common carotid intima medial thickness (CIMT), modified Rodnan Skin score (mRSS), Raynaud’s visual analogue scale (RayVAS:0-10), hs CRP, von Willebrand factor and oxidized low-density lipoproteins were measured at baseline and 16 weeks. All patients provided written informed consent; study protocol was approved by IEC(JIP/IEC/2020/026). Considering a change in FMD of 1% between arms as clinically meaningful, sample size was calculated to be 144. Analysis was performed using SPSS v.19.CTRI registration no: REF/2020/07/03495 Results Total 71 eligible patients were randomized into statin(n = 36) and no-statin(n = 35) arms. Baseline parameters were comparable between arms. Baseline mRSS was 14.25. On per-protocol analysis of statin (n = 28) and no-statin (n = 32) arms, there was no significant difference in FMD either at baseline or at 16 weeks (table 1). At week 16, basal brachial artery diameter increased (p = 0.008) in statin arm. Ray VAS scores improved in the statin arm,not achieving significance(p = 0.15). An increase in mRSS from 14 to 16 was noted in no-statin arm , whereas it remained stable in the statin arm (14.5). Secondary endpoints were not met. No adverse events were noted. Conclusion In early SSc, atorvastatin 40 mg/day, added to background immunosuppression, failed to improve endothelial function, assessed using brachial FMD, at 16 weeks. Stabilization of skin tightening was noted in the statin arm. Disclosure A.C. Das: None. M.M. Thabah: None. C. Mariaselvam: None. R. Vijayan: None. A. Anantharaj: None. V. Negi: None.

Effects of nifedipine on endothelial function, assessed by flow-mediated vasodilatation in pregnant patients

Objectives To evaluate the endothelial function, through flow-mediated vasodilation parameters from brachial artery test in women receiving nifedipine for acute tocolysis with threatened preterm delivery. Methods In a prospective study in a university-affiliated hospital, each participant served as herself control. We evaluated various parameters of endothelial function in 22 patients between 27 and 33 weeks of gestation with a diagnosis of threatened preterm delivery (TPTD) before and after 48 h of nifedipine treatment. Each patient received 80 mg nifedipine per day. The assessment tool was Brachial artery reactivity test (BART). Primary outcome was flow mediated vasodilation (FMD). Results The average participant's age was 27 ± 4.5 years, median gestational age of 28.5 weeks, BMI, kg/m2 (mean ± SD) 28.4 ± 3.3. Systolic blood pressure (mmHg) and diastolic blood pressure (mmHg) decreased from 108 ± 6 to 104 ± 5, p < .001 and from 66 ± 4 to 63 ± 4, p < .001, respectively. FMD (%) significantly decrease from 10.8 ± 6.1 to 7.2 ± 4.7, p = .03 prior to and after nifedipine treatment. The basal brachial artery diameter (mm) at rest was (3.19 ± 0.38 versus 3.39 ± 0.49, p = .28) before versus after nifedipine. The largest brachial artery diameter (mm) was (3.54 ± 0.35 versus 3.58 ± 0.44, p = .76) before versus after nifedipine. Conclusions Our results suggest unfavorable changes in FMD probably as a result of nifedipine used for acute tocolysis. Future prospective studies should try to evaluate the safety of acute and maintenance tocolytic therapy with nifedipine on endothelial function in pregnant women.

Carotid Extra-Media Thickness in Children: Relationships With Cardiometabolic Risk Factors and Endothelial Function

Background: Emerging evidence suggests that structural adventitial modifications and perivascular adipose tissue (PAT) may have a role in early atherogenesis. In a cohort of children and adolescents, we explored (1) the association of carotid extra-media thickness (cEMT), an ultrasound measure whose main determinants are arterial adventitia and PAT, with obesity and its cardiometabolic complications; and (2) the interplay between cEMT and endothelial function.Methods: The study participants included 286 youths (age, 6–16 years; 154 boys, and 132 girls). Anthropometric and laboratory parameters, liver ultrasound, vascular structure measures [cEMT and carotid intima-media thickness (cIMT)], endothelial function [brachial artery flow-mediated dilation (FMD)] were obtained in all subjects. Non-alcoholic fatty liver disease (NAFLD) was diagnosed in the presence of hepatic fat on ultrasonography, in the absence of other causes of liver disease. Diagnosis of metabolic syndrome (MetS) was established on the basis of three or more of the following cardiovascular disease (CVD) risk variables: abdominal obesity, high triglycerides, low high-density lipoprotein cholesterol, elevated blood pressure (BP), and impaired fasting glucose.Results: cEMT demonstrated significant associations with body-mass index (BMI) and waist circumference (WC), BP, insulin resistance, NAFLD, and inflammation. No association was found between cEMT and lipid values, and between cEMT and MetS. A stepwise multivariate linear regression analysis indicated that WC (β coefficient, 0.35; P < 0.0001) was the only determinant of cEMT, independently of other major cardiometabolic risk factors. Further adjustment for cIMT did not significantly alter this association. FMD was correlated to age, Tanner stage, total and abdominal obesity, BP, NAFLD, and cEMT. The association between FMD and cEMT was independent of age, sex, Tanner stage, WC, and BMI (β coefficient, −0.14; P = 0.027). After controlling for CVD risk factors and basal brachial artery diameter, cEMT remained associated with FMD (β coefficient, −0.11; P = 0.049).Conclusions: In youths, cEMT is associated with abdominal fat, a well-established body fat depot with important implications for cardiovascular diseases. Furthermore, cEMT is related to FMD, suggesting that arterial adventitia and PAT may be involved in the early changes in endothelial function.

Particularities of endothelial dysfunction in hypothyroid patients.

It is well known that hypothyroidism promotes the premature onset of subclinical atherosclerosis. This condition is defined by endothelial dysfunction (ED) and increased arterial stiffness (AS) and leads to augmentation of peripheral vascular resistance. To assess the presence and severity of ED and to follow its evolution under therapy in three groups of hypothyroid patients, we used three different noninvasive methods: carotidian intima-media thickness (IMT), flow mediated vasodilatation (FMD), and AS. The study group consisted of 56 young, hypothyroid women without associated cardiovascular pathology or risk factors for atherosclerosis. We selected our patients in order to have normal IMT (< 0.9 mm) and assessed the basal diameter of the brachial artery and the alterations of FMD and of AS parameters: pulse wave velocity (PWV) and augmentation index (AIx). We found, in all patients, a reduced basal diameter of brachial artery, pathological patterns of FMD, and increased values of PWV and AIx, compared to controls, in relation with the severity of thyroid dysfunction. We documented an improvement of ED after therapy with L-thyroxin. ED, documented in hypothyroid patients by means of three noninvasively methods, was strongly related to the severity of thyroid disease. We detected, in all three subgroups, significant alterations of FMD and AS, even in the absence of structural changes, documented by a normal IMT. ED improved consistently after restoring the euthyroid state.

Evaluation of endothelium functions by flow-mediated dilatation in pediatric patients with Crimean-Congo hemorrhagic fever.

Crimean-Congo hemorrhagic fever (CCHF) is a systemic viral disease that also affects the endothelium. Thrombocytopenia and hemorrhage are seen in this disease. But, the cause of thrombocytopenia is not clear. We hypothesized that endothelium dysfunction may be the cause of thrombocytopenia. We evaluated the endothelium functions by flow-mediated dilatation (FMD) in CCHF. Consecutive children with suspected CCHF who applied to our hospital were evaluated for recruitment into the study. FMD analysis was done in the active and healing period of the disease. Diagnosis was confirmed or ruled out by polymerase chain reaction and/or ELISA test. Basal brachial artery diameter (BBAD) and dilated brachial artery diameter (DBAD) after ischemic period were measured and percent dilatations [(DBAD-BBAD)/BBAD, FMD%] were computed from all subjects. Fifty-four children (40 male, mean age 12.4 ± 4.4 years) were recruited into the study. CCHF diagnosis was confirmed in 28 children and ruled out in 26 children. Groups were similar for age and gender. FMD% was significantly decreased in CCHF patients when comparing this with the control patients in the active period (2.65 ± 2.76 vs. 13.76 ± 7.95, P < 0.001). FMD% was correlated with platelet count in the active period of the disease (r = 0.599, P = 0.004). FMD% was recovered in the healing period (2.65 ± 2.76 vs. 14.72 ± 2.66, P < 0.001) and was not significantly different from basal values of control patients (P > 0.05). FMD is significantly decreased in CCHF and recovers in the healing period. So, endothelium functions are disturbed, and disturbance is correlated with thrombocytopenia in CCHF.

EFFICACY OF NEBIVOLOL IN TREATMENT OF WOMEN WITH CORONARY HEART DISEASE

Aim. Evaluation of clinical efficacy and tolerability of beta-blockers in premenopausal women with stable angina. Material and methods. The anaysis of 43-55 years old premenopausal 50 women with stable angina was performed. Therapy included enalapril 2,5-10 mg daily, betaadrenoblocker in 1 group (23 persons) – 5-10 mg of bisoprolol daily, and in 2 group (27 pers.) nebivolol 2,5-5 mg daily (Nebilet®, “Berlin-Chemie/A. Menarini”, Germany), acetylsalycilic acid 100 mg daily during 6 months. The studies done were veloergometry, long-lasting ECG monitoring, echocardiography and also the test with reactive hyperemia on brachial artery. Severity of anxiety-depressive syndrome was evaluated usin hospital scale of anxiety and depression, and the severity of climacteric disorders – by the M. Kuppermann index. Results. With the therapy all patients self-reported improvement of their condition: in 80% there was a decrease of angina functional class, more significant in the second group. Also there was decrease of climacteric symptoms salience as anxiety-depressive disorders, especially in nebivolol group. By the results of ECG monitoring, i. e. frequency of rhythm dosirders (supraventricular and ventricular arrhythmias) there was lower quantity of episodes, more significant in nebivolol group. All groups showed an increase of basal brachial artery diameter, more significant in the 2nd group. Also we marked the changes in central hemodynamics parameters and sctructure-functional parameters of the left ventricle in both groups. Conclusion. Nebilet® in saily dose as 2,5-5 mg is an effective antianginal drug in women with CHD and stable angina pectoris. Under Nebilet® action there is improvement of systolic and diastolic functions of the left ventricle myocardium. With Nebilet® women with stable angina significantly increase exercise tolerance and there is a decrease of climacteric and anxiety-depressive syndrome.

Plasma lactoferrin level as a predictor to endothelial dysfunction in patients with obstructive sleep apnea

Abstract Background Obstructive sleep apnea (OSA) syndrome is associated with cardiovascular complications attributed to endothelial dysfunction. There are contradictory reports on whether lactoferrin is protective or injurious to the blood vessels. Objectives To determine circulating plasma lactoferrin level in OSA patients in relation to endothelial dysfunction and to assess its relation to other criteria of OSA. Patients and methods In a cross-sectional study, 40 OSA patients were recruited after an established diagnosis in the sleep laboratory of the pulmonary medicine department. Doppler flow-mediated dilatation percentage (FMD%) was tested as an indicator of endothelial function. Anthropometric measurements, systolic and diastolic blood pressure, lipid profile, plasma lactoferrin level, fasting, and 2 h postprandial plasma glucose (PPG) were estimated in the patients and the control groups. Moreover, the apnea–hypopnea index, and the mean and nadir nocturnal oxygen saturation of OSA patients were determined. Results OSA patients were found to have significantly higher BMI, waist circumference (WC), neck circumference, fasting plasma glucose (FPG), 2h PPG, low-density lipoprotein-cholesterol, and lower plasma lactoferrin, FMD%, and high-density lipoprotein (HDL)-cholesterol compared with the control group. There was a significant direct correlation between FMD%, as an indicator of endothelial function, and plasma lactoferrin level as well as HDL-cholesterol, and an inverse correlation between FMD% and BMI, WC, FPG, 2h PPG, and basal brachial artery diameter. Multiple regression analysis showed that lactoferrin was the only independent predictor for FMD% among OSA patients. However, plasma lactoferrin level was inversely correlated with BMI, WC, FPG, and 2h PPG, and was directly correlated with HDL-cholesterol and FMD%. Multiple regression analysis selected BMI and FMD% as the independent predictors for lactoferrin level. Conclusion The present study showed that low circulating plasma lactoferrin levels in OSA patients independently predict endothelial dysfunction as assessed by FMD%. High BMI in OSA patients negatively influences plasma lactoferrin levels unrelated to other OSA severity predictors.

Study of endothelial dysfunction and its correlation with disease activity in systemic lupus erythematosus patients without conventional cardiovascular risk factors

Background Endothelial dysfunction is an important cause of cardiovascular morbidity and mortality in patients of systemic lupus erythematosus (SLE), causing atherosclerosis and its related complications, even in the absence of conventional cardiovascular risk factors. Objective The present study was aimed at finding the prevalence of endothelial dysfunction in SLE and its relation with disease activity. Methods Fifty SLE patients without traditional cardiovascular risk factors, and equal number of age and sex matched controls were chosen. Endothelial function was assessed by flow mediated vasodilatation (FMV) on brachial artery using B-mode ultrasonography. Results Mean age of SLE patients was 26.06 ± 6.231 years. Thirty-seven (74%) of the patients were having severe disease activity, defined as systemic lupus erythematosus disease activity index (SLEDAI) >8. We found significantly lower levels of basal brachial artery diameter in SLE patients (0.3499±0.075 cm) compared to controls (0.3826 ± 0.0002cm), as also impaired FMV (2.57 ± 2.32% and 8.7082 ± 1.5776%, respectively). Flow mediated vasodilatation significantly correlated with SLEDAI ( r=-0.52) and complement (C3) levels ( r=0.33). Conclusion Endothelial dysfunction in SLE correlates with disease activity.

Responses of Flow-Mediated Vasodilation to Taking Meal Could Supply Valuable Information of Endothelial Function

Backgroud: It has been recognized that flow-mediated vasodilation (FMD) is influenced by various factors. However, effects of taking meal on FMD remain unknown. Methods: FMD of the brachial artery (BA) was determined in 70 patients with coronary artery disease (CAD) or patients at risk for CAD (66.1±14.5 years) using UNEXEF18G. In 53 of these 70 patients, FMD was re-evaluated 2 hours after meal. Results: FMD before meal was negatively correlated with the basal BA diameter (r=-0.33, p<0.01). There was a trend toward higher HbA1c in patients with lower FMD (≤6%), as compared to those with FMD>6%, but ages or plasma glucose and lipid levels were not different between 2 groups.

Postprandial Endothelial Function: The Effect of Various Types of Fat and of Red Wine Intake on Flow- Mediated Dilation in Healthy Volunteers

Background : Current evidence suggests that postprandial lipid composition may have either atherogenic or anti-atherogenic properties. This study investigated the acute postprandial effect of three different types of fat (saturated, mono-unsaturated, poly-unsaturated) and of red wine upon endothelial function of healthy subjects. Methods: We fed 21 healthy young subjects four meals containing 1000 kcal and 50 g fat each. Three of the meals contained different fat sources: yellow cheese (saturated fat-meal A), olive oil (monounsaturated fat-meal B) and margarine (polyunsaturated fat-meal C). The fourth meal contained the same amount of saturated fat as the first one together with 250 cc of red wine (meal D). We measured serum lipoproteins, with the use of standard laboratory techniques. Β rachial artery flow-mediated vasodilation (FMD), an index of endothelial function, was also assessed with B-Mode vascular ultrasound. All measurements were performed before, 2 and 4 h after each meal Results: All four meals significantly raised plasma triglycerides. Meal A was associated with a decrease in FMD 2 and 4 hours after its intake ( 16.5 ± 5% vs. 13 ± 4% vs. 12.3 ± 6% , p= 0.030) while with meal D FMD profoundly decreased 2 hours postprandially with a rapid return to baseline levels at 4 hours (14.3 ± 9.5 vs. 8.6 ± 5.5 vs. 12.6 ± 7.5 , p=0.214) . This type of response was associated with a concomitant increase of basal brachial artery diameter at 2 hours postpandially ( 3.7±0.6 mm vs 4.2±0.7 mm vs 3.9±0.7mm at 0, 2 and 4 hours respectively , p=0.000 ). Meals B and C did not significantly affect FMD. Conclusions. Saturated fat acutely decreases FMD while mono-unsaturated and poly-unsaturated fat do not have any harmful effect on endothelium. The concomitant intake of red wine with saturated fat is associated with a delayed counteracting effect on lipid-induced postprandial endothelial dysfunction.

ARTERIAL FUNCTION IN YOUNG ADULTS AFTER CHEMOTHERAPY DUE TO ACUTE LYMPHOBLASTIC LEUKEMIA- PILOT STUDY: PP.6.235

Objective: Survivors of childhood cancer have increased cardiovascular (CV) morbidity and mortality possibly related to anticancer treatment. Therefore, we assessed CV risk profile and arterial function in the young adults with acute lymphoblastic leukemia (ALL) in whom chemotherapy was completed at least five years ago. Methods: Young (age: 18–30 years) survivors of ALL were invited for assessment of CV risk factors and arterial function. Medical history, physical examination with anthropological measurements, ambulatory blood pressure monitoring; levels of fasting glucose (FG), cholesterol, fibrinogen, hsCRP were measured. Arterial function was assessed using endothelium dependent flow-mediated dilatation (FMD%) of right brachial artery and carotid -femoral pulse wave velocity (PWV). Results: We present preliminary results of 14 subjects (7 men, age: 21,4 ± 3,08) years) who agreed to participate in the study. Mean BMI was 22(2,01) and WHR 0,79(0,06). 24-hour mean BP was 116,8(7,2)/68,3(4,7) mmHg. The values of laboratory findings were: FG: 4,6(0,3) mmol/l, hsCRP: 0,83(1,2) mg/l, TC: 4,28(0,8) mmol/l, LDL: 2,28(0,7) mmol/l, HDL: 1,57(0,4) mmol/l, TG: 0,97(0,48) mmol/l, fibrinogen: 3,1(0,5) g/l. Five subjects presented with 1 or more CV risk factors such as smoking (4), positive family history of CVD (2), hypercholesterolemia (2), masked hypertension (1). Patients had a mean basal brachial artery diameter of 3,40 ± 0,67 mm. Mean FMD response was 5,74 ± 5,99 % and reactive hyperemia: 51,66 ± 28,25%, the percent change in nitrogliceryne mediated dilatation was 23,36 ± 10,12%. 9 (64%) participants had FMD < 10% and 7 < 7%. When 9 subjects without CV risk factors were analysed in 6 of them FMD was found to be below 10% and in 5 < 7%. Mean PWV was 8,03(0,81) m/s and in 9 subjects exceeded 8 m/s. Moreover, PWV was increased in 4 out of 9 subjects without CV risk factors. Conclusions: These preliminary results indicate that even in the absence of major cardiovascular risk factors young adult survivors of ALL demonstrate impaired endothelial function and increased arterial stiffness.

Endothelial dysfunction in Turkish patients with non‐alcoholic fatty liver disease

The components of the metabolic syndrome are closely related with endothelial dysfunction, which is a pathophysiological issue of cardiovascular diseases. Non-alcoholic fatty liver disease (NAFLD) is considered as one of the components of the metabolic syndrome. The aim of this study was to evaluate the endothelial-dependent dilatation (EDD) and endothelial-independent dilatation (EID) of the brachial artery in NAFLD. Fifteen non-alcoholic steatohepatitis (NASH), 17 patients with simple steatosis and 16 healthy subjects formed the study group. Non-alcoholic fatty liver disease group was composed of patients admitted to the gastroenterology outpatient clinic because of increased liver enzymes. Endothelial functions of the brachial artery were evaluated by vascular ultrasound. EDD was assessed by establishing reactive hyperaemia, and EID was determined by using sublingual nitrate. No statistical difference for the basal diameter of brachial artery was found between the groups (P = 0.49). The values for EDD and EID were significantly different across all three groups (P < 0.0001 and P < 0.0001, respectively). EDD and EID were significantly lower in NASH compared with simple steatosis (P = 0.01 and P < 0.01, respectively). However, there was no statistical significance for EDD and EID in simple steatosis groups compared with controls (P = 0.58 and P = 0.98, respectively). Our study showed that patients with NASH had significantly worse endothelial dysfunction compared with patients with simple steatosis and healthy subjects. The treatment strategies with ameliorative effects for endothelial dysfunction might be effective for delaying the development of cardiovascular complications in NAFLD.

Black Tea Improves Endothelial Function in Renal Transplant Recipients

Background Endothelial damage and dysfunction are commonplace in renal transplant recipients. Impaired endothelial function is an important contributor to cardiovascular diseases. We hypothesized that short-term black tea consumption may improve endothelium-dependent arterial dilation in kidney recipients. Methods Fifteen recipients were studied on an outpatient basis in a single, university-affiliated clinic. Inclusion criteria were stable and good allograft function. The main exclusion criteria were uncontrolled hypertension, smoking, alcohol consumption, coffee drinking, diabetes mellitus, and coronary artery disease, or a history of upper limb vascular manipulations. After overnight fasting, the brachial artery diameter (BAD) was measured at the end of diastole using an ultrasound machine before (basal BAD) and 1 minute after temporary (∼3 minutes) external occlusion (posthyperemia BAD). Flow-mediated vasodilation (FMV) and percent of FMV (FMV%) were calculated by appropriate formula. FMV and FMV% were determined at baseline and 2 hours after consuming 0.5 L freshly brewed black tea. For control, the study was repeated for each patient the next day and FMV and FMV% were determined before and 2 hours after consuming 0.5 L of water. Results The men age of patients was 37.2 ± 9.7 years (range, 25 to 50) with a male:female ratio of 3:2. Patients were 26.8 ± 10.6 months postrenal transplantation. Black tea consumption significantly increased posthyperemia BAD, FMV, and FMV% ( P < .05). However, water consumption did not alter the basal or posthyperemia BAD, FMV, or FMV% ( P > .05). Conclusion Based on our study, short-term consumption of black tea may improve endothelial function and endothelium-dependent arterial vasodilation in renal transplant recipients.

Measurement of Flow-Mediated Vasodilation of the Brachial Artery A Comparison of Measurements in the Seated and Supine Positions

Measurement of flow-mediated vasodilation (FMD) is used to assess endothelial function in humans and according to the guidelines, subjects must remain supine during the study. However, measurement of FMD while seated would be more comfortable and convenient for patients, so the purpose of this study was to determine the effect of the patient's position on FMD results. High-resolution ultrasonography, a linear array transducer (13 MHz) and an arm-holding device were used to measure arterial diameter in response to reactive hyperemia (FMD, cuff inflated to 50 mmHg above systolic blood pressure for 5 min) and in response to sublingual nitroglycerine (NTG, 75 microg) in 31 subjects, which included those with cardiovascular diseases. There was no significant difference between basal or peak hyperemic blood flow in the seated or supine position. Basal brachial artery diameter, FMD and vascular response to NTG were similar in both positions (basal diameter: 3.8+/-0.4 vs 3.9+/-0.4 mm, FMD: 7.3+/-4.3% vs 7.2+/-4.5%, NTG: 13.1+/-5.1% vs 12.8+/-5.6%). The findings suggest that measurement of FMD in the seated position is as useful as measuring it in the supine position for assessing endothelial function. This flexibility of position is better for patients and physicians, and should lead to more widespread measurement of FMD.

Effects of Personal Exposure to Particulate Air Pollution on Diabetic Patients-Changes in Cardiovascular System and Biomarkers of Inflammation and Oxidative Stress

P-036 Abstract: Daily variations in exposure to particulate air pollution have been associated with cardiovascular morbidity and mortality. Some studies have suggested that people with diabetes mellitus are vulnerable to cardiovascular health effects associated with exposure to air pollution. We hypothesized that a short-term exposure of diabetic patients in Windsor Ontario Canada to elevated levels of particulate matter (PM10) was associated with impaired cardiovascular function, and increased blood pro-inflammatory cytokines and oxidative stress markers. Non-smoking diabetics (n = 25, twenty one of them were type II diabetics, and 15 were females), age 27–67 years (mean 46.2) were recruited for the study. Patients were followed for 7 weeks, total of 171 visits. One day before each visit, patients were given a personal PM10 monitor to wear for approximately 24 hours. Upon visiting the clinic, brachial artery diameter, flow-mediated vasodilation (FMD), heart rate and blood pressure were measured, and blood samples were drawn to determine the concentrations of C-reactive protein (CRP), thiobarbituric acid reactive substances (TBARS, an oxidative stress marker), tumor necrosis factor-α (TNF-α), and interleukin-6. To analyze the associations between personal exposure to PM10 and health outcomes, mixed-effects models were used assuming random slopes and random intercepts. Ambient temperature, glucose, and study time were adjusted when needed. Subjects were also stratified into groups of body mass index (BMI) <29 and ≥29 (the 50th percentile), with and without cardiovascular medication use, and with and without high blood pressure and/or high cholesterol. The 24-hour median concentration of PM10 was 25.5 μg/m3 (5th–95th percentile 9.8–133 μg/m3). FMD was negatively associated with high BMI (p = 0.022) and high blood pressure and/or high cholesterol (p = 0.078), indicating a relationship between the brachial artery narrowness and these cardiovascular risk factors. PM10 was significantly associated with a decrease in basal brachial artery diameter (p = 0.006), and an increase in CRP (p = 0.086) and TBARS (p = 0.001), the latter two having been linked to reduced endothelial relaxation factor nitric oxide. These changes occurred only in subjects not taking cardiovascular medication. In this sub-group, PM10 was also associated with elevated diastolic blood pressure (p = 0.027). PM10 did not have an adverse impact on FMD, heart rate, TNF-α, or interleukin-6. In conclusion, our results suggest that daily exposure to particulate air pollution may be linked to an impaired basal arterial dilatation in diabetic patients, possibly attributable to a reduced nitric oxide-mediated vasodilation associated with oxidative stress and an influx of CRP.

Insulin resistance and vascular dysfunction in nondiabetic Asian Indians.

Asian Indians are at higher risk for diabetes and cardiovascular disease than European Caucasians. To examine the pathophysiology of this increased risk, we measured insulin sensitivity, cardiovascular risk factors, fat distribution, and endothelium-dependent (reactive hyperemia) and -independent (nitroglycerin) vasodilation before and after a 2-h hyperinsulinemic clamp (40 mU/m(2).min) in 25 nondiabetic Asian Indians and 15 Caucasians with similar age and body mass index. Asian Indians had higher fasting insulin than Caucasians (6.7 +/- 0.8 vs. 3.7 +/- 0.3 microU/ml, P = 0.007) but similar FPG (90 +/- 2 vs. 88 +/- 2 mg/dl). Glucose uptake during the clamp was markedly reduced in Asian Indians vs. Caucasians (4.5 +/- 0.3 vs. 7.5 +/- 0.4 mg/kg x min, P < 0.0001). During the clamp, basal brachial artery diameter increased less in Asian Indians vs. Caucasians (2.6 +/- 1.0 vs. 5.7 +/- 1.0%, P = 0.04), and the reduction was correlated with the impairment in insulin sensitivity (r = 0.38, P = 0.04). In contrast, vasodilatory responses to reactive hyperemia and nitroglycerin were similar in Asian Indians and Caucasians both before and during hyperinsulinemia. Plasminogen activator inhibitor-1 and FFA were significantly elevated and adiponectin was significantly lower in Asian Indians vs. Caucasians, and there were trends toward higher low-density lipoprotein and triglycerides, lower high-density lipoprotein, and increased total, sc, and visceral fat. These risk factors were all significantly correlated with insulin sensitivity. Thus, apparently healthy Asian Indians have severe insulin resistance, dyslipidemia, elevated plasminogen activator inhibitor-1, impaired insulin-mediated vasodilation, and trends toward altered body fat distribution. These abnormalities may contribute to the increased risk of diabetes and cardiovascular disease in this population.

Vascular function correlates with risk factors for cardiovascular disease in a healthy population of 35-year-old subjects.

To investigate whether, in a healthy, randomly selected population of 35-year-old men and women, there is a relation between vascular function and conventional risk factors for cardiovascular disease such as gender, smoking, elevated blood-lipids, high blood pressure and heredity for cardiovascular disease, and to blood glucose. Basal brachial artery diameter was measured. Endothelial function was measured as flow mediated dilation (FMD) in response to reactive hyperaemia. The nonendothelial dependent dilation was measured after sublingual nitro-glycerine (NTG). A research centre of general medicine and a university hospital. One hundred men and 100 women all 35 years old, were invited by letter. Sixty-six of the 92 men (72%) living in the community and 74 of the 88 women (84%) participated. Gender had the largest influence on FMD and NTG induced arterial dilation, probably reflecting the larger vessel diameters in the men as FMD and NTG induced dilation is inversely related to basal vessel size (r = -0.55, P < 0.001 and r = -0.40, P < 0.001). In women basal vessel diameter was positively correlated to blood glucose (r = 0.35, P = 0.009) and BMI (r = 0.34, P = 0.012) and negatively correlated to HDL cholesterol (r = -0.43, P = 0.001). FMD and NTG induced arterial dilation correlated with a combined risk factor score (r = -0.32, P = 0.019 and r = -0.31, P = 0.024). The men with the highest risk factor scores had larger vessel size and higher blood flow at rest compared to men without risk factors (4.8 +/- 0.6 mm, 240 +/- 84 mL min-1 and 4.0 +/- 0.8 mm, 139 +/- 72 mL min-1, respectively, P = 0.014 and P = 0.016). FMD or NTG induced dilation did not correlate to any of the risk factors in men. There are correlations between vascular reactivity and risk factors for IHD in women and correlations between vessel diameter and risk factors for IHD in both men and women already in a healthy population 35-year-old subjects. Further studies are needed to determine if the vessel diameter in itself, in a healthy population, is a sign of attenuated endothelial function.