Lotte Jacobs

Blood pressure changes after renal denervation at 10 European expert centers

We did a subject-level meta-analysis of the changes (Δ) in blood pressure (BP) observed 3 and 6 months after renal denervation (RDN) at 10 European centers. Recruited patients (n=109; 46.8% women; mean age 58.2 years) had essential hypertension confirmed by ambulatory BP. From baseline to 6 months, treatment score declined slightly from 4.7 to 4.4 drugs per day. Systolic/diastolic BP fell by 17.6/7.1 mm Hg for office BP, and by 5.9/3.5, 6.2/3.4, and 4.4/2.5 mm Hg for 24-h, daytime and nighttime BP (P⩽0.03 for all). In 47 patients with 3- and 6-month ambulatory measurements, systolic BP did not change between these two time points (P⩾0.08). Normalization was a systolic BP of <140 mm Hg on office measurement or <130 mm Hg on 24-h monitoring and improvement was a fall of ⩾10 mm Hg, irrespective of measurement technique. For office BP, at 6 months, normalization, improvement or no decrease occurred in 22.9, 59.6 and 22.9% of patients, respectively; for 24-h BP, these proportions were 14.7, 31.2 and 34.9%, respectively. Higher baseline BP predicted greater BP fall at follow-up; higher baseline serum creatinine was associated with lower probability of improvement of 24-h BP (odds ratio for 20-μmol l−1 increase, 0.60; P=0.05) and higher probability of experiencing no BP decrease (OR, 1.66; P=0.01). In conclusion, BP responses to RDN include regression-to-the-mean and remain to be consolidated in randomized trials based on ambulatory BP monitoring. For now, RDN should remain the last resort in patients in whom all other ways to control BP failed, and it must be cautiously used in patients with renal impairment.

Subclinical responses in healthy cyclists briefly exposed to traffic-related air pollution: an intervention study

BackgroundNumerous epidemiological studies have demonstrated adverse health effects of a sedentary life style, on the one hand, and of acute and chronic exposure to traffic-related air pollution, on the other. Because physical exercise augments the amount of inhaled pollutants, it is not clear whether cycling to work in a polluted urban environment should be encouraged or not. To address this conundrum we investigated if a bicycle journey along a busy commuting road would induce changes in biomarkers of pulmonary and systematic inflammation in a group of healthy subjects.Methods38 volunteers (mean age: 43 ± 8.6 years, 26% women) cycled for about 20 minutes in real traffic near a major bypass road (road test; mean UFP exposure: 28,867 particles per cm3) in Antwerp and in a laboratory with filtered air (clean room; mean UFP exposure: 496 particles per cm3). The exercise intensity (heart rate) and duration of cycling were similar for each volunteer in both experiments. Exhaled nitric oxide (NO), plasma interleukin-6 (IL-6), platelet function, Clara cell protein in serum and blood cell counts were measured before and 30 minutes after exercise.ResultsPercentage of blood neutrophils increased significantly more (p = 0.004) after exercise in the road test (3.9%; 95% CI: 1.5 to 6.2%; p = 0.003) than after exercise in the clean room (0.2%; 95% CI: -1.8 to 2.2%, p = 0.83). The pre/post-cycling changes in exhaled NO, plasma IL-6, platelet function, serum levels of Clara cell protein and number of total blood leukocytes did not differ significantly between the two scenarios.ConclusionsTraffic-related exposure to particles during exercise caused a small increase in the distribution of inflammatory blood cells in healthy subjects. The health significance of this isolated change is unclear.

Air Pollution–Related Prothrombotic Changes in Persons with Diabetes

Background Population studies suggest that persons with diabetes are more sensitive to the effects of particulate matter (PM) air pollution. However, the biological mechanisms of a possible prothrombotic effect underlying this enhanced susceptibility remain largely unknown. Objective We hypothesized that exposure to PM causes prothrombotic changes in persons with diabetes, possibly via systemic inflammation. Methods Our study included 137 nonsmoking adults with diabetes who were outpatients at the University Hospital Leuven. Recent exposure (2 hr before examination) to ambient PM was measured at the entrance of the hospital. Individual chronic exposure to PM was assessed by measuring the area occupied by carbon in airway macrophages obtained by sputum induction. Platelet function was measured ex vivo with the PFA-100 platelet function analyzer, which simulates a damaged blood vessel; we analyzed the function of platelets in primary hemostasis under high shear conditions. Total and differential blood leukocytes were counted. Results Independent of antiplatelet medication, an interquartile range (IQR) increase of 39.2 μg/m3 in PM10 (PM with aerodynamic diameter ≤ 10 μm) concentration measured 2 hr before the clinical examination (recent exposure) was associated with a decrease of 21.1 sec [95% confidence interval (CI), − 35.3 to − 6.8] in the PFA-100 closure time (i.e., increased platelet activation) and an increase in blood leukocytes of 512 per microliter of blood (95% CI, 45.2–979). Each area increase of 0.25 μm2 (IQR) in carbon load of airway macrophages (chronic exposure) was associated with an increase of 687 leukocytes per microliter of blood (95% CI, 224–1,150). Conclusions A relevant increase in recent PM exposure was associated with a change in platelet function toward a greater prothrombotic tendency. The magnitude of the change was about two-thirds (in the opposite direction) of the average effect of antiplatelet medication. Diabetic patients showed evidence of proinflammatory response to both recent and chronic exposure to PM air pollution.

Within-Subject Blood Pressure Level—Not Variability—Predicts Fatal and Nonfatal Outcomes in a General Population

To assess the prognostic significance of blood pressure (BP) variability, we followed health outcomes in a family-based random population sample representative of the general population (n=2944; mean age: 44.9 years; 50.7% women). At baseline, BP was measured 5 times consecutively at each of 2 home visits 2 to 4 weeks apart. We assessed within-subject overall (10 readings), within- and between-visit systolic BP variability from variability independent of the mean, the difference between maximum and minimum BP, and average real variability. Over a median follow-up of 12 years, 401 deaths occurred and 311 participants experienced a fatal or nonfatal cardiovascular event. Overall systolic BP variability averaged (SD) 5.45 (2.82) units, 15.87 (8.36) mmHg, and 4.08 (2.05) mmHg for variability independent of the mean, difference between maximum and minimum BP, and average real variability, respectively. Female sex, older age, higher-mean systolic BP, lower body mass index, a history of peripheral arterial disease, and use of &bgr;-blockers were the main correlates of systolic BP variability. In multivariable-adjusted analyses, overall and within- and between-visit BP variability did not predict total or cardiovascular mortality or the composite of any fatal plus nonfatal cardiovascular end point. For instance, the hazard ratios for all cardiovascular events combined in relation to overall variability independent of the mean, difference between maximum and minimum BP, and average real variability were 1.05 (0.96–1.15), 1.06 (0.96–1.16), and 1.08 (0.98–1.19), respectively. By contrast, mean systolic BP was a significant predictor of all end points under study, independent of BP variability. In conclusion, in an unbiased population sample, BP variability did not contribute to risk stratification over and beyond mean systolic BP.

No exercise-induced increase in serum BDNF after cycling near a major traffic road.

Commuting by bike has a clear health enhancing effect. Moreover, regular exercise is known to improve brain plasticity, which results in enhanced cognition and memory performance. Animal research has clearly shown that exercise upregulates brain-derived neurotrophic factor (BDNF - a neurotrophine) enhancing brain plasticity. Studies in humans found an increase in serum BDNF concentration in response to an acute exercise bout. Recently, more evidence is emerging suggesting that exposure to air pollution (such as particulate matter (PM)) is higher in commuter cyclists compared to car drivers. Furthermore, exposure to PM is linked to negative neurological effects, such as neuroinflammation and cognitive decline. We carried-out a cross-over experiment to examine the acute effect of exercise on serum BDNF, and the potential effect-modification by exposure to traffic-related air pollution. Thirty eight physically fit, non-asthmatic volunteers (mean age: 43, 26% women) performed two cycling trials, one near a major traffic road (Antwerp Ring, R1, up to 260,000 vehicles per day) and one in an air-filtered room. The air-filtered room was created by reducing fine particles as well as ultrafine particles (UFP). PM10, PM2.5 and UFP were measured. The duration (∼20min) and intensity of cycling were kept the same for each volunteer for both cycling trials. Serum BDNF concentrations were measured before and 30min after each cycling trial. Average concentrations of PM10 and PM2.5 were 64.9μg/m(3) and 24.6μg/m(3) in cycling near a major ring way, in contrast to 7.7μg/m(3) and 2.0μg/m(3) in the air-filtered room. Average concentrations of UFP were 28,180 particles/cm(3) along the road in contrast to 496 particles/cm(3) in the air-filtered room. As expected, exercise significantly increased serum BDNF concentration after cycling in the air-filtered room (+14.4%; p=0.02). In contrast, serum BDNF concentrations did not increase after cycling near the major traffic route (+0.5%; p=0.42). Although active commuting is considered to be beneficial for health, this health enhancing effect could be negatively influenced by exercising in an environment with high concentrations of PM. Whether this effect is also present with chronic exercise and chronic exposure must be further elucidated.

Eligibility for Renal Denervation: Experience at 11 European Expert Centers

Based on the SYMPLICITY studies and CE (Conformité Européenne) certification, renal denervation is currently applied as a novel treatment of resistant hypertension in Europe. However, information on the proportion of patients with resistant hypertension qualifying for renal denervation after a thorough work-up and treatment adjustment remains scarce. The aim of this study was to investigate the proportion of patients eligible for renal denervation and the reasons for noneligibility at 11 expert centers participating in the European Network COordinating Research on renal Denervation in treatment-resistant hypertension (ENCOReD). The analysis included 731 patients. Age averaged 61.6 years, office blood pressure at screening was 177/96 mm Hg, and the number of blood pressure–lowering drugs taken was 4.1. Specialists referred 75.6% of patients. The proportion of patients eligible for renal denervation according to the SYMPLICITY HTN-2 criteria and each center’s criteria was 42.5% (95% confidence interval, 38.0%–47.0%) and 39.7% (36.2%–43.2%), respectively. The main reasons of noneligibility were normalization of blood pressure after treatment adjustment (46.9%), unsuitable renal arterial anatomy (17.0%), and previously undetected secondary causes of hypertension (11.1%). In conclusion, after careful screening and treatment adjustment at hypertension expert centers, only ≈40% of patients referred for renal denervation, mostly by specialists, were eligible for the procedure. The most frequent cause of ineligibility (approximately half of cases) was blood pressure normalization after treatment adjustment by a hypertension specialist. Our findings highlight that hypertension centers with a record in clinical experience and research should remain the gatekeepers before renal denervation is considered.Based on the SYMPLICITY studies and CE (Conformite Europeenne) certification, renal denervation is currently applied as a novel treatment of resistant hypertension in Europe. However, information on the proportion of patients with resistant hypertension qualifying for renal denervation after a thorough work-up and treatment adjustment remains scarce. The aim of this study was to investigate the proportion of patients eligible for renal denervation and the reasons for noneligibility at 11 expert centers participating in the European Network COordinating Research on renal Denervation in treatment-resistant hypertension (ENCOReD). The analysis included 731 patients. Age averaged 61.6 years, office blood pressure at screening was 177/96 mm Hg, and the number of blood pressure–lowering drugs taken was 4.1. Specialists referred 75.6% of patients. The proportion of patients eligible for renal denervation according to the SYMPLICITY HTN-2 criteria and each center’s criteria was 42.5% (95% confidence interval, 38.0%–47.0%) and 39.7% (36.2%–43.2%), respectively. The main reasons of noneligibility were normalization of blood pressure after treatment adjustment (46.9%), unsuitable renal arterial anatomy (17.0%), and previously undetected secondary causes of hypertension (11.1%). In conclusion, after careful screening and treatment adjustment at hypertension expert centers, only ≈40% of patients referred for renal denervation, mostly by specialists, were eligible for the procedure. The most frequent cause of ineligibility (approximately half of cases) was blood pressure normalization after treatment adjustment by a hypertension specialist. Our findings highlight that hypertension centers with a record in clinical experience and research should remain the gatekeepers before renal denervation is considered. # Novelty and Significance {#article-title-32}

Traffic air pollution and oxidized LDL.

Background Epidemiologic studies indirectly suggest that air pollution accelerates atherosclerosis. We hypothesized that individual exposure to particulate matter (PM) derived from fossil fuel would correlate with plasma concentrations of oxidized low-density lipoprotein (LDL), taken as a marker of atherosclerosis. We tested this hypothesis in patients with diabetes, who are at high risk for atherosclerosis. Methodology/Principal Findings In a cross-sectional study of non-smoking adult outpatients with diabetes we assessed individual chronic exposure to PM by measuring the area occupied by carbon in airway macrophages, collected by sputum induction and by determining the distance from the patients residence to a major road, through geocoding. These exposure indices were regressed against plasma concentrations of oxidized LDL, von Willebrand factor and plasminogen activator inhibitor 1 (PAI-1). We could assess the carbon load of airway macrophages in 79 subjects (58 percent). Each doubling in the distance of residence from major roads was associated with a 0.027 µm2 decrease (95% confidence interval (CI): −0.048 to −0.0051) in the carbon load of airway macrophages. Independently from other covariates, we found that each increase of 0.25 µm2 [interquartile range (IQR)] in carbon load was associated with an increase of 7.3 U/L (95% CI: 1.3 to 13.3) in plasma oxidized LDL. Each doubling in distance of residence from major roads was associated with a decrease of −2.9 U/L (95% CI: −5.2 to −0.72) in oxidized LDL. Neither the carbon load of macrophages nor the distance from residence to major roads, were associated with plasma von Willebrand factor or PAI-1. Conclusions The observed positive association, in a susceptible group of the general population, between plasma oxidized LDL levels and either the carbon load of airway macrophages or the proximity of the subjects residence to busy roads suggests a proatherogenic effect of traffic air pollution.

Meta-analysis of randomized controlled trials of renal denervation in treatment-resistant hypertension

Abstract Objective. The blood pressure (BP)-lowering effect of renal sympathetic nervous denervation (RDN) in resistant hypertension (rHT) shows large variation among studies. Methods. We meta-analyzed summary statistics of randomized clinical trials on RDN in rHT. For continuous outcomes, we assessed heterogeneity by Cochrans Q test and used random-effect models weighted for the inverse of the variance. We assessed safety by assessing the risk of major adverse events from stratified contingency tables. Results. Of 5652 patients screened in seven trials, 985 (17.4%) qualified and were randomized to control (n = 397) or RDN with SYMPLICITY™ catheters (n = 588). Follow-up was 6 months. In both control and RDN patients, antihypertensive treatment was continued or optimized. At enrolment, age averaged 58.1 years, systolic/diastolic office and 24 h BP 168.5/93.3 mmHg and 151.8/86.1 mmHg, respectively, and estimated glomerular filtration rate (eGFR) 79.3 ml/min/1.73 m². For BP outcomes, there was heterogeneity among trials. Pooled effects (control minus RDN) were −4.9/−3.5 mmHg (95% confidence interval, −20.9 to 11.1/−8.9 to 1.9) for office BP, −2.8/−1.5 mmHg (−6.5 to 0.8/−3.3 to 0.4) for 24 h BP and 0.81 ml/min/1.73 m² (−1.69 to 3.30) for eGFR. Removing one trial at a time produced confirmatory results. Adverse events occurred in 7.4% and 9.9% of control and RDN patients, respectively (p = 0.24). Conclusion. In selected rHT patients maintained on antihypertensive drugs, RDN with the SYMPLICITY systems does not significantly decrease BP but is safe. Future trials with next-generation catheters should aim at identifying responders in patients with evidence of sympathetic nervous overactivity.

Acute changes in pulse pressure in relation to constituents of particulate air pollution in elderly persons

An increased pulse pressure (difference between systolic and diastolic blood pressure) suggests aortic stiffening. The objective of this study was to examine the acute effects of both particulate matter (PM) mass and composition on blood pressure, among elderly persons. We carried out a panel study in persons living in elderly homes in Antwerp, Belgium. We recruited 88 non-smoking persons, 70% women with a mean age of 83 years (standard deviation: 5.2). Blood pressure was measured and a blood sample was collected on two time points, which were chosen so that there was an exposure contrast in ambient PM exposure. The elemental content of the collected indoor and outdoor PM(2.5) (particulate matter with an aerodynamic diameter <2.5 μm) mass concentration was measured. Oxygenated polycyclic aromatic hydrocarbons (oxy-PAHs) on outdoor PM(10) (particulate matter with an aerodynamic diameter <10 μm) were measured. Each interquartile range increase of 20.8 μg/m³ in 24-h mean outdoor PM(2.5) was associated with an increase in pulse pressure of 4.0 mm Hg (95% confidence interval: 1.8-6.2), in persons taking antihypertensive medication (n=57), but not in persons not using antihypertensive medication (n=31) (p for interaction: 0.02). Vanadium, iron and nickel contents of PM(2.5) were significantly associated with systolic blood pressure and pulse pressure, among persons on antihypertensive medication. Similar results were found for indoor concentrations. Of the oxy-PAHs, chrysene-5,6-dione and benzo[a]pyrene-3,6-dione were significantly associated with increases in systolic blood pressure and pulse pressure. In elderly, pulse pressure was positively associated with acute increases in outdoor and indoor air pollution, among persons taking antihypertensive medication. These results might form a mechanistic pathway linking air pollution as a trigger of cardiovascular events.

The urinary proteome as correlate and predictor of renal function in a population study.

BACKGROUND We investigate whether the urinary proteome refines the diagnosis of renal dysfunction, which affects over 10% of the adult population. METHODS We measured serum creatinine, estimated glomerular filtration rate (eGFR) and 24-h albuminuria in 797 people randomly recruited from a population. We applied capillary electrophoresis coupled with mass spectrometry to measure multi-dimensional urinary proteomic classifiers developed for renal dysfunction (CKD273) or left ventricular dysfunction (HF1 and HF2). Renal function was followed up in 621 participants and the incidence of cardiovascular events in the whole study population. RESULTS In multivariable-adjusted cross-sectional analyses, higher biomarker levels analysed separately or combined by principal component analysis into a single factor (SF), correlated (P ≤ 0.010) with worse renal function. Over 4.8 years, higher HF1 and SF predicted (P ≤ 0.014) lowering of eGFR; higher HF2 predicted (P ≤ 0.049) increase in serum creatinine and decrease eGFR. HF1, HF2 and SF predicted progression from CKD Stages 2 or ≤2 to Stage ≥3, with risk estimates for a 1-SD increment in the urinary biomarkers ranging from 38 to 71% (P ≤ 0.039). HF1, HF2 and SF yielded a net reclassification improvement of 31-51% (P ≤ 0.029). Over 6.1 years, 47 cardiovascular events occurred. HF2 and SF, independent of baseline eGFR, 24-h albuminuria and other covariables were significant predictors of cardiovascular complications with risk estimates for 1-SD increases ranging from 32 to 41% (P ≤ 0.047). CONCLUSIONS The urinary proteome refines the diagnosis of existing or progressing renal dysfunction and predicts cardiovascular complications.