Change In Flow-mediated Dilation Research Articles

Abstract P157: Assessment of Vascular Endothelial Function in Postural Tachycardia Syndrome and Healthy Controls

Postural tachycardia syndrome (POTS) is a heterogeneous disorder characterized by an excessive rise in HR and symptoms consistent with cerebral hypoperfusion while upright. Increased sympathetic activity may contribute to this condition and may also impair nitric oxide (NO)-function. We evaluated NO function using flow-mediated dilation (FMD) and Peripheral Artery Tonometry (PAT) in POTS patients and age-matched controls. We studied 16 POTS patients (30±2 years, BMI 22.3±1 kg/m 2 ) and 7 healthy control subjects (HC; 31±2 years, BMI 22.1±1 kg/m 2 ). Medications affecting BP, blood volume, the immune system, and autonomic function, were withheld for ≥5 half-lives. All subjects followed the same low-monoamine, caffeine-free diet for ≥3 days before testing. Endothelial function was measured as the percentage change in FMD (%FMD) and using the reactive hyperemic index (RHI) for PAT. We also measured autonomic function, plasma levels of catecholamines, renin activity (PRA) and aldosterone. We found that POTS patients had a significantly blunted FMD (6.11±0.8 vs. 9.67±1.6 %, P=0.049, figure), compared to healthy controls. This blunted FMD response was similar as what our group has reported in obese hypertensive females (N=13, 5.7±0.9%, figure). Also, as expected they had higher upright HR (121±6 vs. 90±6 bpm, for POTS and HC, P=0.020). There were no differences in PAT (2.08±0.12, vs. 1.8±0.13 RHI, for POTS and HC, P=0.168). There were no differences in norepinephrine (765±150 vs. 545±39 pg/mL, P=0.955), renin activity (5.3±1.3 vs. 5.2±1.6 ng/mL/hr, P=0.735) or aldosterone (19.6±3.8 vs. 15.9±5.5 ng/dL, P=0.129).

Effect of breaking up sedentary time with callisthenics on endothelial function

ABSTRACTPeriods of prolonged sitting impairs endothelial function in lower limb conduit arteries, which is attenuated with physical activity breaks. The effect of activity breaks on upper limb arteries has not been examined. This study assessed changes in brachial artery endothelial function following either a prolonged sitting period or breaking up this sedentary time by performing sets of callisthenics exercises. Ten healthy participants (6 men) completed 2 conditions in a counterbalanced order: (a) 1-h 26-min sitting, or (b) breaking up this period every 20 min by performing a set of 5 callisthenics exercises. Brachial artery endothelial function was assessed via ultrasound using the flow-mediated dilation (FMD) technique prior to and following each condition, while brachial shear rate (SR) was acquired after each set of callisthenics. There was no significant change in FMD over time (P = 0.09) or between conditions (P = 0.12). Compared to sitting, brachial SR increased following each set of callisthenics, with a significant difference after the third break (Sit: 33.94 ± 12.79 s−1; Callisthenics: 57.16 ± 30.48 s−1, P = 0.02). Alterations in SR in the upper limbs suggest callisthenics may be an effective intervention to break up sedentary time and attenuate the potentially deleterious effects of prolonged sitting on cardiovascular health.

Acute Effect of High-Intensity Eccentric Exercise on Vascular Endothelial Function in Young Men.

Choi, Y, Akazawa, N, Zempo-Miyaki, A, Ra, S-G, Shiraki, H, Ajisaka, R, and Maeda, S. Acute effect of high-intensity eccentric exercise on vascular endothelial function in young men. J Strength Cond Res 30(8): 2279-2285, 2016-Increased central arterial stiffness is as an independent risk factor for cardiovascular disease. Evidence regarding the effects of high-intensity resistance exercise on vascular endothelial function and central arterial stiffness is conflicting. The purpose of this study was to examine the effects of acute high-intensity eccentric exercise on vascular endothelial function and central arterial stiffness. We evaluated the acute changes in endothelium-dependent flow-mediated dilation (FMD), low-flow-mediated constriction (L-FMC), and arterial stiffness after high-intensity eccentric exercise. Seven healthy, sedentary men (age, 24 ± 1 year) performed maximal eccentric elbow flexor exercise using their nondominant arm. Before and 45 minutes after eccentric exercise, carotid arterial compliance and brachial artery FMD and L-FMC in the nonexercised arm were measured. Carotid arterial compliance was significantly decreased, and β-stiffness index significantly increased after eccentric exercise. Brachial FMD was significantly reduced after eccentric exercise, whereas there was no significant difference in brachial L-FMC before and after eccentric exercise. A positive correlation was detected between change in arterial compliance and change in FMD (r = 0.779; p ≤ 0.05), and a negative correlation was detected between change in β-stiffness index and change in FMD (r = -0.891; p < 0.01) with eccentric exercise. In this study, acute high-intensity eccentric exercise increased central arterial stiffness; this increase was accompanied by a decrease in endothelial function caused by reduced endothelium-dependent vasodilation but not by a change in endothelium-dependent vasoconstriction.

Effects of estradiol on measurements of conduit artery endothelial function after ischemia and reperfusion in premenopausal women.

In premenopausal women, ovarian steroids are felt to play a role in the prevention of cardiovascular disease. We aimed to assess whether menstrual cycle variations in estrogen can modify the response to ischemia-reperfusion (IR) injury in humans. In an investigator-blinded crossover study, 10 healthy premenopausal women with regular menstrual cycles were studied. They had flow-mediated dilatation (FMD) measured by ultrasound in the radial artery before and after IR (15 min of brachial artery ischemia, 15 min of reperfusion) during both the early and late follicular phases of the menstrual cycle. The order of these visits was not randomized. IR significantly blunted FMD in the early follicular phase (pre-IR: 7.1% ± 1.0%; post-IR: 3.6% ± 1.0%, P = 0.01) when estradiol levels were low (148.4 ± 19.8 pmol/L). Conversely, FMD was preserved after IR during the late follicular phase (pre-IR: 7.2% ± 0.9%; post-IR: 7.0% ± 0.8%, P = NS, P = 0.03 compared with early follicular) when estradiol levels were high (825.7 ± 85.8 pmol/L, P < 0.001 compared with early follicular). There was a significant inverse relationship between estradiol concentration and IR-induced endothelial dysfunction (i.e., change in FMD after IR) (r = 0.59, r2 = 0.36, P < 0.01). These findings demonstrate, for the first time in humans, a clear relationship between the cyclical changes in serum concentrations of estradiol and the endothelium's response to IR.

Effect of teriparatide treatment on endothelial function, glucose metabolism and inflammation markers in patients with postmenopausal osteoporosis.

Teriparatide, an anabolic agent used in the treatment of postmenopausal osteoporosis, can induce effects similar to primary hyperparathyroidism. Our objective was to evaluate the effects of teriparatide on endothelial functions, glucose metabolism and inflammation markers in patients diagnosed with postmenopausal osteoporosis. This was a single-centre, single-arm, 6-month prospective study. Twenty-three postmenopausal women over 65years old with a lumbar spine or femoral neck T-score of -4·0 or lower and having at least two compression fractures in thoracic or lumbar spine were studied. Low-dose intermittent teriparatide (20μg/day) was supplemented with calcium carbonate (1000mg elemental calcium) and 880 IU cholecalciferol for 6months. The biochemical parameters for glucose metabolism, inflammation and atherosclerosis were determined. For the assessment of vascular endothelial function, carotid intima-media thickness (CIMT), brachial artery intima-media thickness (BIMT), per cent change in flow-mediated dilation (FMD%) and nitroglycerine-induced dilations (NID%) were measured on ultrasonography. The fasting plasma glucose, homoeostatic model assessment of insulin resistance, fibrinogen, homocysteine and high-density lipoprotein cholesterol increased significantly with teriparatide treatment (P<0·05 for all). Baseline CIMT and BIMT did not change significantly with 6 months of teriparatide treatment (P>0·05); however, FMD% and NID% showed significant decrease after treatment (P<0·01 for both). Intermittent teriparatide treatment may adversely affect some parameters of glucose metabolism, inflammation and endothelial function. On the basis of our findings, further large-scale and controlled studies are needed to clarify the exact effect of teriparatide treatment on glucose metabolism, inflammation and endothelial function.

Maraviroc Intensification Improves Endothelial Function in Abacavir-Treated Patients, an Open-Label Randomized Cross-Over Pilot Study

BackgroundThe increased risk of abacavir in cardiovascular disease (CVD) in HIV-infected patients is still being debated. Maraviroc, a CCR5 blocker, has been shown to decrease immune activation and monocyte infiltration in atherosclerotic plaques in murine experiments. Therefore, we examined the effect of maraviroc intensification on flow-mediated dilatation (FMD) in abacavir-treated HIV-infected patients and its effect on immunological and inflammatory parameters.MethodsA open-label prospective crossover study with a duration of 16 weeks: 8 weeks of intervention (maraviroc intensification) and 8 weeks of control (unchanged cART regimen). FMD, HIV-specific variables, expression of HIV co-receptors, markers of inflammation and coagulation and cellular markers of immune activation were measured at weeks 0, 8 and 16. The changes (Δ) in these variables were compared between intervention and control periods using non-parametric tests. To evaluate the relation with the change in FMD, linear regression modeling was used.ResultsTwenty-one male patients with suppressed plasma HIV-RNA, on cART, had a known HIV infection for 9.2 years (IQR 6.9–13.5) with abacavir use for 6.5 years (2.8–9.3). A significantly increased FMD of 0.73% (IQR −0.25 to 1.70) was seen after maraviroc intensification compared to a decrease of −0.42% (IQR −1.89 to 0.25; p = 0.049) in the control period. There was a negative relation between ΔFMD with ΔD-dimer (β −22.70, 95% CI −39.27; −6.13, p = 0.011) and ΔCD95+ CD4+ T cells (β −0.16, 95% CI −0.28; −0.04, p = 0.013), adjusted for age and duration of HIV.ConclusionMaraviroc intensification modestly improves endothelial function in HIV-infected patients on an abacavir-containing regimen.Trial registrationNCT01389063.Electronic supplementary materialThe online version of this article (doi:10.1007/s40121-016-0115-0) contains supplementary material, which is available to authorized users.

Shiftwork and decline in endothelial function among police officers

Our objective was to assess the influence of shiftwork on change in endothelial function. This longitudinal study was conducted in 188 police officers (78.2% men). Shiftwork status (day, afternoon, night) was assessed objectively using daily Buffalo, NY payroll work history records. Brachial artery flow-mediated dilation (FMD) was assessed using ultrasound. Mean change in FMD% between 2004-2009 and 2010-2015 was compared across shiftwork using analysis of variance/covariance. Overall, mean FMD% decreased from 5.74 ± 2.83 to 3.88 ± 2.11 over an average of 7 years among all officers; P < 0.0001. Effect modification by gender was significant. Among men (but not women), those who worked day shifts had a smaller mean (±SE) decrease in FMD% (-0.89 ± 0.35) compared with those who worked the afternoon (-2.69 ± 0.39; P = 0.001) or night shifts (-2.31 ± 0.45; P = 0.020) after risk factor adjustment. Larger declines in endothelial function were observed among men who worked afternoon or night shifts. Further investigation is warranted. Am. J. Ind. Med. 59:1001-1008, 2016. Published 2016. This article is a U.S. Government work and is in the public domain in the USA.

The Effectiveness Of Ischemic Preconditioning In Older Physically (in)active Males

Reperfusion is critical for the survival of ischemic tissue, but causes significant additional damage to the endothelium (ischemia-reperfusion [IR]). Ischemic preconditioning (IPC) refers to short repetitive episodes of ischemia, which has demonstrated to reduce IR injury. The protective effects of IPC against endothelial IR injury are attenuated with aging. Possibly, regular physical activity is able to 1) attenuate endothelial IR, and 2) restore effectiveness of IPC in older humans. PURPOSE: To compare endothelial IR-injury and the effectiveness of IPC to protect against endothelial IR-injury between older lifelong physically active versus inactive males. METHODS: We included 11 older athletes (63±4 years, >5 exercise hours/week) and 3 inactive controls (69±6 years, <1 exercise hours/week). We measured brachial artery endothelial function before and after IR injury using flow-mediated dilation (FMD). IR-injury was induced by 20-minute ischemia followed by 20 minutes of reperfusion. Prior to IR-injury, subjects underwent SHAM (35-minute rest) or IPC (3 cycles of 5-minute cuff inflation to 220 mmHg). The order of SHAM and IPC was randomly assigned to the participants. RESULTS: FMD% did not differ between athletes and inactive controls at baseline for SHAM (4.5±4.4% vs. 4.1±2.4%, p=0.87) or IPC (5.1±3.1% vs. 3.3±1.1%, p=0.37). IR-injury showed no significant decrease in FMD% in athletes (FMDpre 4.5±4.4% vs. FMDpost 3.0±2.0%, p=0.32), whereas FMD% markedly decreased in inactive controls (FMDpre 4.1±2.3% vs. FMDpost 0.5±2.5%, p=0.036). Applying IPC before IR-injury did not alter the change in %FMD in both athletes (FMDpre 5.1±3.2% vs. FMDpost 2.8±3.3%, p=0.17) and controls (FMDpre 3.3±1.1% vs. FMDpost 1.5±2.2%, p=0.19). No differences were observed in %FMD change between SHAM and IPC in athletes and inactive controls. CONCLUSIONS: Athletes demonstrate smaller endothelial IR-injury compared to their physically inactive peers. The cardio-protective effects of regular exercise training may, in part, relate to attenuating endothelial IR-injury. Finally, lifelong regular exercise training seems unable to alter the age-related attenuated efficacy of IPC against endothelial IR-injury.

TCF7L2 polymorphism is associated with low nitric oxide release, endothelial dysfunction and enhanced inflammatory response after myocardial infarction

BackgoundThe favorable effects of insulin during myocardial infarction (MI) remain unclear due to the divergence between mechanistic studies and clinical trials of exogenous insulin administration. The rs7903146 polymorphism of the transcription factor 7-like 2 (TCF7L2) gene is associated with attenuated insulin secretion. MethodsIn non-diabetic patients with ST-elevation MI (STEMI), using such a model of genetically determined down-regulation of endogenous insulin secretion we investigated the change in plasma insulin, C-peptide, interleukin-2 (IL-2), C-reactive protein (CRP), and nitric oxide (NOx) levels between admission (D1) and the fifth day after MI (D5). Coronary angiography and flow-mediated dilation (FMD) were performed at admission and 30days after MI, respectively. Homeostasis Model Assessment estimated insulin secretion (HOMA2%β) and insulin sensitivity (HOMA2%S). ResultsAlthough glycemia did not differ between genotypes, carriers of the T-allele had lower HOMA2%β and higher HOMA2%S at both D1 and D5. As compared with non-carriers, T-allele carriers had higher plasma IL-2 and CRP at D5, higher intracoronary thrombus grade, lower FMD and NOx change between D1 and D5 and higher 30-day mortality. ConclusionIn non-diabetic STEMI patients, the rs7903146 TCF7L2 gene polymorphism is associated with lower insulin secretion, worse endothelial function, higher coronary thrombotic burden, and higher short-term mortality. General significanceDuring the acute phase of MI, a lower capacity of insulin secretion may influence clinical outcome.

Aerobic exercise improves measures of vascular health in diabetic peripheral neuropathy

Aims: Aerobic exercise improves vascular endothelial function in people with Type 2 diabetes mellitus (T2DM). There is minimal information available regarding vascular health in people with T2DM and diabetic peripheral neuropathy (DPN). Thus, the primary aim of this secondary analysis was to determine whether a 16-week aerobic exercise intervention could improve vascular health in people with T2DM and DPN. A secondary aim was to explore the relationship between changes in flow-mediated dilation (FMD) and the number of years since diagnosis of DPN. Methods: We examined whether a 16-week aerobic exercise intervention would improve vascular health in people with T2DM and DPN. We used Doppler ultrasound to assess brachial artery diameter and peak shear at baseline and post-exercise. Paired t-tests were used to determine whether the outcome measures improved from baseline to post-intervention. Pearson correlation assessed the relationship between DPN (years) and the percent change score (pre- to post-intervention) for FMD. Results: Seventeen individuals were included in the data analysis. After the intervention, peak diameter increased (3.9 (0.5) to 4.0 (0.5) mm; p = 0.07). Time to peak shear occurred at 60.5 (24.6) seconds when compared to baseline at 68.2 (22.7) seconds; p = 0.17. We found that a longer duration (in years) of DPN demonstrated a fair, negative relationship (r = −0.41, p = 0.19) with the percent change in FMD. Conclusion: Aerobic exercise was beneficial for improving measures of vascular health but these were not statistically significant. The magnitude of change may be affected by the duration of DPN.

Serial assessment of arterial structure and function in patients with coarctation of the aorta undergoing stenting

Stenting for CoA has become an acceptable treatment modality in the last 20years. However little is known about arterial changes after this procedure. To assess arterial structure and function including peripheral reactivity and stiffness and intima-media thickness (IMT) pre and post stenting for coarctation of the aorta (CoA). Twenty-one patients [median age: 15years (8-39)] were studied at baseline, 1day, 6months and 1year after stenting. Twenty-one healthy subjects (1:1 matched) were used as controls. Left ventricular (LV) mass, ejection fraction, flow-mediated dilation (FMD) and nitrate-mediated dilation (NMD) of left brachial artery, common carotid (CC) and right subclavian artery (RSCA) IMT and pulse wave velocity (PWV) were assessed by echocardiography and vascular ultrasound. CoA patients had higher LV indexed mass (p<0.0001), impaired FMD (p<0.0001) and NMD (p<0.0001), increased PWV (p<0.0001), carotid and RSCA IMT (both p<0.0001). All procedures were successful and resulted in significant gradient reduction (p<0.001). One year after stenting there was improvement in LV function (p=0.034) and although there was significant reduction of LV mass (103.29±24.77 vs. 74.39±22.07g/m(2), p<0.0001) values did not normalize. There was no significant change in FMD, NMD, PWV and CC or RSCA IMT. In patients with CoA, arterial reactivity is impaired and LV mass, arterial stiffness and thickness are increased. Although stenting is successful to relieve the obstruction resulting in better LV function and mass reduction, arterial structure and function remains abnormal after 1year of follow-up.

Influence of beta-blockers on endothelial function: A meta-analysis of randomized controlled trials.

Endothelial dysfunction (ED) frequently precedes cardiovascular diseases (CVD) and is a well-established risk factor of major adverse cardiac events. Beta-blockers are the fundamental drugs used in CVD treatment. A systematic literature search for randomized controlled trials investigating influence of beta-blockers on endothelial function assessed by flow-mediated dilation (FMD) was performed in the PubMed and Cochrane Databases. Sixteen full-text studies involving a total of 1,273 patients were included in the final analysis. The mean age of participating patients ranged from 44.9 to 63.2 years, the follow-up duration from 1 to 12 months. The comparison of FMD change between the beta-blockers and placebo groups showed a statistically significant effect of beta-blockers on endothelial function (mean difference [MD] 0.83; 95% confidence interval [CI] 0.11-1.55; p = 0.02). Third generation beta-blockers improved FMD in a statistically significant manner compared with second generation beta-blockers (MD 1.65; 95% CI 0.17-3.11; p = 0.03). Beta-blockers gave an FMD change similar to that obtained with angiotensin receptor blockers (ARB), calcium channel blockers (CCB) or hydrochlorothiazide. The FMD value in the beta-blocker group was significantly lower compared with the group treated with angiotensin converting enzyme inhibitors (ACEI) (MD -0.79; 95% CI -1.37-(-0.21); p = 0.008) and higher than in the ivabradine group (1.6 ± 3.61 vs -0.3 ± 1.66; p = 0.02). Beta-blockers improve the endothelial function compared with placebo. More-over, third generation beta-blockers improve FMD values significantly better than the second generation ones. Beta-blockers had similar effect on endothelial function as did ARB, CCB or diuretics. However, the beneficial effect of beta-blockers was lower when confronted with ACEI.

Vasculoprotective Effects of Dietary Cocoa Flavanols in Patients on Hemodialysis: A Double-Blind, Randomized, Placebo-Controlled Trial.

Hemodialysis (HD) per se entails vascular dysfunction in patients with ESRD. Endothelial dysfunction is a key step in atherosclerosis and is characterized by impaired flow-mediated dilation (FMD). Interventional studies have shown that cocoa flavanol (CF)-rich supplements improve vascular function. Aim of this study was to investigate the effect of flavanol-rich bioactive food ingredients on acute and chronic HD-induced vascular dysfunction in ESRD. We conducted a randomized, double-blind, placebo-controlled trial from 2012 to 2013. Fifty-seven participants were enrolled, ingested CF-rich beverages (900 mg CF per study day), and were compared with those ingesting CF-free placebo. This included (1) a baseline cross-over acute study to determine safety and efficacy of CF and (2) a subsequent chronic parallel group study with a 30-day follow-up period to study effects of CF on HD-mediated vascular dysfunction entailing (3) an acute substudy during HD in flavanol-naive patients and (4) an acute on chronic study during HD. Primary and secondary outcome measures included changes in FMD and hemodynamics. CF ingestion was well tolerated. Acute ingestion improved FMD by 53% (3.2±0.6% to 4.8±0.9% versus placebo, 3.2±0.7% to 3.3±0.8%; P<0.001), with no effects on BP or heart rate. A 30-day ingestion of CF led to an increase in baseline FMD by 18% (3.4±0.9% to 3.9±0.8% versus placebo, 3.5±0.7% to 3.5±0.7%; P<0.001), with reduced diastolic BP (73±12 to 69±11 mmHg versus placebo, 70±11 to 73±13 mmHg; P=0.03) and increased heart rate (70±12 to 74±13 bpm versus placebo, 75±15 to 74±13 bpm; P=0.01). No effects were observed for placebo. Acute ingestion of CF during HD alleviated HD-induced vascular dysfunction (3.4±0.9% to 2.7±0.6% versus placebo, 3.5±0.7% to 2.0±0.6%; P<0.001). This effect was sustained throughout the study (acute on chronic, 3.9±0.9% to 3.0±0.7% versus placebo, 3.5±0.7% to 2.2±0.6; P=0.01). Dietary CF ingestion mitigates acute HD-induced and chronic endothelial dysfunction in patients with ESRD and thus, improves vascular function in this high-risk population. Larger clinical trials are warranted to test whether this translates into an improved cardiovascular prognosis in patients with ESRD.

The Acute Effect of Exercise Intensity on Vascular Function in Adolescents.

Impairments in vascular function are present in asymptomatic youths with risk factors for cardiovascular disease. Exercise can promote vascular health in youth, but the effects of exercise intensity and the time course in response to acute exercise are unknown. Twenty adolescents (10 male, 14.1 ± 0.3 yr) performed the following on separate days in a counterbalanced order: 1) cycling at 90% of the gas exchange threshold (moderate-intensity exercise (MIE)) and 2) 8 × 1-min cycling at 90% peak power with 75-s recovery (high-intensity interval exercise (HIIE)). The duration of MIE (25.8 ± 2.1 min) was work-matched to HIIE (23.0 min). Macro- and microvascular functions were assessed before, immediately after, and 1 and 2 h after exercise by flow-mediated dilation (FMD) and laser Doppler imaging (total reactive hyperemia). FMD was attenuated immediately after HIIE (P < 0.001, effect size (ES) = 1.20) but not after MIE (P = 0.28, ES = 0.26). Compared with that before exercise, FMD was elevated 1 and 2 h after HIIE (P < 0.001, ES = 1.33; P < 0.001, ES = 1.36) but unchanged in MIE (P = 0.67, ES = 0.10; P = 0.72, ES = 0.08). Changes in FMD were unrelated to shear or baseline arterial diameter. Compared with that in preexercise, total reactive hyperemia was always greater after MIE (P < 0.02, ES > 0.60 for all) and HIIE (P < 0.001, ES > 1.18 for all). Total reactive hyperemia was greater in HIIE compared with that in MIE immediately after (P = 0.03, ES = 0.67) and 1 h after (P = 0.01, ES = 0.62) exercise, with a trend to be greater 2 h after (P = 0.06, ES = 0.45). Exercise intensity is positively associated with macro- and microvascular function 1 and 2 h after exercise. Performing HIIE may provide superior vascular benefits than MIE in adolescents.

Evaluation of sit-stand workstations in an office setting: a randomised controlled trial.

BackgroundExcessive sitting time is a risk factor for cardiovascular disease mortality and morbidity independent of physical activity. This aim of this study was to evaluate the impact of a sit-stand workstation on sitting time, and vascular, metabolic and musculoskeletal outcomes in office workers, and to investigate workstation acceptability and feasibility.MethodsA two-arm, parallel-group, individually randomised controlled trial was conducted in one organisation. Participants were asymptomatic full-time office workers aged ≥18 years. Each participant in the intervention arm had a sit-stand workstation installed on their workplace desk for 8 weeks. Participants in the control arm received no intervention. The primary outcome was workplace sitting time, assessed at 0, 4 and 8 weeks by an ecological momentary assessment diary. Secondary behavioural, cardiometabolic and musculoskeletal outcomes were assessed. Acceptability and feasibility were assessed via questionnaire and interview. ANCOVA and magnitude-based inferences examined intervention effects relative to controls at 4 and 8 weeks. Participants and researchers were not blind to group allocation.ResultsForty-seven participants were randomised (intervention n = 26; control n = 21). Relative to the control group at 8 weeks, the intervention group had a beneficial decrease in sitting time (−80.2 min/8-h workday (95 % CI = −129.0, −31.4); p = 0.002), increase in standing time (72.9 min/8-h workday (21.2, 124.6); p = 0.007) and decrease in total cholesterol (−0.40 mmol/L (−0.79, −0.003); p = 0.049). No harmful changes in musculoskeletal discomfort/pain were observed relative to controls, and beneficial changes in flow-mediated dilation and diastolic blood pressure were observed. Most participants self-reported that the workstation was easy to use and their work-related productivity did not decrease when using the device. Factors that negatively influenced workstation use were workstation design, the social environment, work tasks and habits.ConclusionShort-term use of a feasible sit-stand workstation reduced daily sitting time and led to beneficial improvements in cardiometabolic risk parameters in asymptomatic office workers. These findings imply that if the observed use of the sit-stand workstations continued over a longer duration, sit-stand workstations may have important ramifications for the prevention and reduction of cardiometabolic risk in a large proportion of the working population.Trial registrationClinicalTrials.gov NCT02496507.

Abstract 19288: Acute and Chronic Affects of Indoor Air Pollution on Endothelial Function

Objective: Pollution exposure has been linked to accelerated atherosclerosis. Endothelial dysfunction is a reversible indicator for early atherosclerosis, but it is unknown if indoor air pollution from biomass fuel cookstoves is associated with acute and chronic endothelial dysfunction. Methods: We enrolled 76 adults in Puno, Peru (3825 m above sea level); 56 from a rural community that almost exclusively use biomass fuels for cooking (biomass fuel users) and 20 from urban communities that use clean fuels for cooking (clean fuel users). We measured flow-mediated dilatation (FMD) of the brachial artery before and after cooking. We compared baseline FMD in biomass vs. clean fuel users and evaluated for acute effects of cooking by looking and changes in FMD before and after cooking with biomass vs. clean fuels Results: Mean age was 53 ± 9.1 years with 54% male. Biomass fuel users had similar age, blood pressure, and BMI but had lower LDL-cholesterol compared to clean fuel users (p&lt;0.05). Mean baseline FMD was 5.2 ± 2.3% vs. 6.3 ± 3.2% in clean vs. biomass fuel users respectively (p=0.22). Adjusting for age, sex, blood pressure, BMI, and LDL-cholesterol demonstrated no difference in baseline FMD between biomass and clean fuel users (p=0.92). Among biomass fuel users, mean FMD dropped to 3.8 ± 3.0% after one hour of biomass fuel smoke exposure from cooking (p&lt;0.001). This did not occur when FMD was repeated in clean fuel users one hour after baseline exam (FMD: 4.9 ± 2.9%, p=0.29). Conclusion: Biomass fuel smoke exposure causes acute decrease in endothelial function in this population with already abnormal function. However, we found no differences in baseline endothelial function in these two heterogeneous populations. Larger studies are needed to determine if biomass fuel exposure is associated with chronic endothelial dysfunction and if interventions aimed to decrease biomass fuel smoke exposure can improve endothelial function and thus cardiovascular mortality.

Antihypertensive therapy increases natural immunity response in hypertensive patients.

The aim of this work was to evaluate the effects of treatment of hypertension on the autoantibodies to apolipoprotein B-derived peptides (anti-ApoB-D peptide Abs) response, inflammation markers and vascular function. Eighty-eight patients with hypertension (stage 1 or 2) were recruited and advised to receive perindopril (4mg), hydrochlorothiazide (25mg), or indapamide (1.5mg) for 12weeks in a blinded fashion. Office and 24-h ambulatory blood pressure monitoring (24h ABPM), flow-mediated dilatation (FMD), nitrate-induced dilatation (NID), titers of IgG and IgM anti-ApoB-D peptide Abs, hsCRP, and interleukins (IL-8 and IL-10) were evaluated at baseline and 12weeks after therapies. All treatments reduced office BP, and improved FMD (P<0.05 vs. baseline). The NID was improved only in the perindopril arm (P<0.05 vs. baseline). The 24h-ABPM was reduced with perindopril and hydrochlorothiazide therapies (P<0.05 vs. baseline), but not with indapamide, and this effect was followed by increase in titers of IgM Anti-ApoB-D peptide Abs (P<0.05 vs. baseline), without modifications in titers IgG Anti-ApoB-D peptide Abs and interleukins. Multivariable regression analysis has shown that change in the titers of IgM anti-ApoB-D peptide was associated with the changes in FMD (β -0.347; P<0.05). These findings shed light to a possible modulator effect of the antihypertensive therapy on the natural immunity responses and vascular function.

The effects of acute garlic supplementation on the fibrinolytic and vasoreactive response to exercise.

BackgroundThe purpose of this project was to examine the effects of acute garlic supplementation on fibrinolysis and vasoreactivity both at rest and following maximal exercise.MethodsEighteen healthy trained males (20.9 ± 2.2 years, 178 ± 7.7 cm, 75.5 ± 9.6 kg, VO2max = 59.8 ± 6.7 ml • kg−1 • min−1) performed a graded treadmill test to volitional exhaustion. Blood samples were taken at rest, within two minutes post-exercise, and one hour post-exercise. Eleven of the subjects also had a brachial vasoreactivity test performed immediately after the blood sample to assess flow-mediated dilation (FMD) of the brachial artery. Participants were randomly assigned to ingest either 900 mg of powdered garlic or a placebo three hours before the exercise session. The supplement was distributed in a double-blind, crossover fashion. Participants repeated the protocol with the other treatment after a 14-day washout period. Paired t-tests were used to compare VO2max between the two trials. A two-factor (treatment and time) repeated measures analysis of variance (ANOVA) was used to assess changes in FMD, tPA activity, tPA antigen, and PAI-1 activity. A priori statistical significance was set at P <0.05.ResultsVO2max was greater for the garlic treatment trial vs. placebo (Placebo = 59.8 ± 6.7 ml • kg−1 • min−1; Garlic = 61.4 ± 6.6 ml • kg−1 • min−1). There was no main effect for treatment and no treatment x time interaction for FMD or any fibrinolytic variables examined.ConclusionAcute garlic supplementation does not alter vasoreactivity, fibrinolytic potential or the fibrinolytic response to exercise in young healthy trained males. Acute garlic supplementation does, however, cause a small but statistically significant increase in VO2max. It remains unclear if this increase in VO2max is of functional importance.

Brachial artery endothelial function is stable across the morning in young men.

BackgroundThe morning hours are associated with increased cardiovascular (CV) risk, and vascular endothelial function (VEF) is a strong predictor of CV disease. A diurnal rhythm in VEF has been established but the morning variation in VEF is not well-documented. Thus, we tested if VEF is impaired across the vulnerable morning period.MethodsAfter overnight fasts, eight healthy men (age 26.3 ± 3 yr) underwent assessments of VEF under standardized testing conditions every 2 h from 0700 to 1300 h on two separate days. VEF was estimated following 5 min brachial artery occlusions by hyperemic flow-mediated dilation (FMD).ResultsThere was no significant change in FMD or hyperemic shear stimulus across the 6 h vulnerable period on either day, despite changes in physical activity and meals across these periods.ConclusionIn this healthy group of young men, VEF is stable across the vulnerable morning period when typical behaviors occurred (breakfast and physical activity). Future research should focus on the roles of sleep, physical inactivity during sleep and endogenous circadian rhythm in VEF.

Effects of bariatric surgery on markers of subclinical atherosclerosis and endothelial function: a meta-analysis of literature studies.

Several studies confirmed a significantly increased carotid intima-media thickness (IMT) and impaired flow-mediated dilation (FMD) and nitrate-mediated dilation (NMD) in obese subjects, but few data are available on the effects of bariatric surgery on these markers of cardiovascular (CV) risk. We performed a meta-analysis of studies evaluating changes in IMT, FMD and NMD in obese patients after bariatric surgery. A systematic search was performed in the PubMed, Web of Science, Scopus and EMBASE databases without any language or publication year restriction. The last search was performed in January 2015. In addition, the reference lists of all retrieved articles were manually reviewed. Prospective studies evaluating the impact of bariatric surgery on the markers of CV risk were included. Changes in IMT, FMD and NMD after bariatric surgery were expressed as mean differences (MD) with pertinent 95% confidence intervals (95% CIs). IMT has been expressed in millimeters (mm); FMD and NMD as percentage (%). Impact of clinical and demographic features on effect size was assessed by meta-regression. Ten articles (314 obese patients) were included in the analysis. Six studies contained data on IMT (7 data sets; 206 patients), 8 studies on FMD (9 data sets; 269 patients) and 4 on NMD (4 data sets; 149 patients). After bariatric surgery, there was a significant reduction of IMT (MD: -0.17 mm; 95% CI: -0.290, -0.049; P=0.006) and a significant improvement in FMD (MD: 5.65%; 95% CI: 2.87, 8.03; P<0.001), whereas NMD did not change (MD: 2.173%; 95% CI: -0.796, 5.142; P=0.151). Interestingly, percentage of changes in the body mass index were associated with changes in IMT (Z=11.52, P<0.001), FMD (Z=-4.26, P<0.001) and NMD (Z=-3.81, P<0.001). Despite heterogeneity among studies, bariatric surgery is associated with improvement of subclinical atherosclerosis and endothelial function. These effects may significantly contribute to the reduction of the CV risk after bariatric surgery.