3,019 research outputs found
Urinary proteomics pilot study for biomarker discovery and diagnosis in heart failure with reduced ejection fraction
Background
Biomarker discovery and new insights into the pathophysiology of heart failure with reduced ejection fraction (HFrEF) may emerge from recent advances in high-throughput urinary proteomics. This could lead to improved diagnosis, risk stratification and management of HFrEF.
Methods and Results
Urine samples were analyzed by on-line capillary electrophoresis coupled to electrospray ionization micro time-of-flight mass spectrometry (CE-MS) to generate individual urinary proteome profiles. In an initial biomarker discovery cohort, analysis of urinary proteome profiles from 33 HFrEF patients and 29 age- and sex-matched individuals without HFrEF resulted in identification of 103 peptides that were significantly differentially excreted in HFrEF. These 103 peptides were used to establish the support vector machine-based HFrEF classifier HFrEF103. In a subsequent validation cohort, HFrEF103 very accurately (area under the curve, AUC = 0.972) discriminated between HFrEF patients (N = 94, sensitivity = 93.6%) and control individuals with and without impaired renal function and hypertension (N = 552, specificity = 92.9%). Interestingly, HFrEF103 showed low sensitivity (12.6%) in individuals with diastolic left ventricular dysfunction (N = 176). The HFrEF-related peptide biomarkers mainly included fragments of fibrillar type I and III collagen but also, e.g., of fibrinogen beta and alpha-1-antitrypsin.
Conclusion
CE-MS based urine proteome analysis served as a sensitive tool to determine a vast array of HFrEF-related urinary peptide biomarkers which might help improving our understanding and diagnosis of heart failure
Ethnic differences in proximal and distal tubular sodium reabsorption are heritable in black and white populations.
BACKGROUND: Segmental handling of sodium along the proximal and distal nephron might be heritable and different between black and white participants.
METHODS: We randomly recruited 95 nuclear families of black South African ancestry and 103 nuclear families of white Belgian ancestry. We measured the (FENa) and estimated the fractional renal sodium reabsorption in the proximal (RNaprox) and distal (RNadist) tubules from the clearances of endogenous lithium and creatinine. In multivariable analyses, we studied the relation of RNaprox and RNadist with FENa and estimated the heritability (h) of RNaprox and RNadist.
RESULTS: Independent of urinary sodium excretion, South Africans (n = 240) had higher RNaprox (unadjusted median, 93.9% vs. 81.0%; P < 0.001) than Belgians (n = 737), but lower RNadist (91.2% vs. 95.1%; P < 0.001). The slope of RNaprox on FENa was steeper in Belgians than in South Africans (-5.40 +/- 0.58 vs. -0.78 +/- 0.58 units; P < 0.001), whereas the opposite was true for the slope of RNadist on FENa (-3.84 +/- 0.19 vs. -13.71 +/- 1.30 units; P < 0.001). h of RNaprox and RNadist was high and significant (P < 0.001) in both countries. h was higher in South Africans than in Belgians for RNaprox (0.82 vs. 0.56; P < 0.001), but was similar for RNadist (0.68 vs. 0.50; P = 0.17). Of the filtered sodium load, black participants reabsorb more than white participants in the proximal nephron and less postproximally.
CONCLUSION: Segmental sodium reabsorption along the nephron is highly heritable, but the capacity for regulation in the proximal and postproximal tubules differs between whites and blacks
Peripheral blood mitochondrial DNA content in relation to circulating metabolites and inflammatory markers: a population study
Mitochondrial DNA (mtDNA) content might undergo significant changes caused by metabolic derangements, oxidative stress and inflammation that lead to development and progression of cardiovascular diseases. We, therefore, investigated in a general population the association of peripheral blood mtDNA content with circulating metabolites and inflammatory markers. We examined 310 subjects (50.6% women; mean age, 53.3 years) randomly selected from a Flemish population. Relative mtDNA content was measured by quantitative real-time PCR in peripheral blood cells. Peak circulating metabolites were quantified using nuclear magnetic resonance spectroscopy. The level of inflammation was assessed via established inflammatory markers. Using Partial Least Squares analysis, we constructed 3 latent factors from the 44 measured metabolites that explained 62.5% and 8.5% of the variance in the contributing metabolites and the mtDNA content, respectively. With adjustments applied, mtDNA content was positively associated with the first latent factor (P = 0.002). We identified 6 metabolites with a major impact on the construction of this latent factor including HDL3 apolipoproteins, tyrosine, fatty acid with αCH2, creatinine, β-glucose and valine. We summarized them into a single composite metabolite score. We observed a negative association between the composite metabolic score and mtDNA content (P = 0.001). We also found that mtDNA content was inversely associated with inflammatory markers including hs-CRP, hs-IL6, white blood cell and neutrophil counts as well as neutrophil-to-lymphocyte ratio (P≤0.0024). We demonstrated that in a general population relative peripheral blood mtDNA content was associated with circulating metabolites indicative of perturbed lipid metabolism and with inflammatory biomarkers
Blood pressure response to renal denervation is correlated with baseline blood pressure variability: a patient-level meta-analysis
Background: Sympathetic tone is one of the main
determinants of blood pressure (BP) variability and
treatment-resistant hypertension. The aim of our study was
to assess changes in BP variability after renal denervation
(RDN). In addition, on an exploratory basis, we investigated
whether baseline BP variability predicted the BP changes
after RDN.
Methods: We analyzed 24-h BP recordings obtained at
baseline and 6 months after RDN in 167 treatmentresistant
hypertension patients (40% women; age, 56.7
years; mean 24-h BP, 152/90 mmHg) recruited at 11 expert
centers. BP variability was assessed by weighted SD [SD
over time weighted for the time interval between
consecutive readings (SDiw)], average real variability (ARV),
coefficient of variation, and variability independent of the
mean (VIM).
Results: Mean office and 24-h BP fell by 15.4/6.6 and 5.5/
3.7 mmHg, respectively (P < 0.001). In multivariable-adjusted
analyses, systolic/diastolic SDiw and VIM for 24-h
SBP/DBP decreased by 1.18/0.63 mmHg (P 0.01) and
0.86/0.42 mmHg (P 0.05), respectively, whereas no
significant changes in ARV or coefficient of variation
occurred. Furthermore, baseline SDiw (P ¼ 0.0006), ARV
(P ¼ 0.01), and VIM (P ¼ 0.04) predicted the decrease in
24-h DBP but not 24-h SBP after RDN.
Conclusion: RDN was associated with a decrease in BP
variability independent of the BP level, suggesting that
responders may derive benefits from the reduction in BP
variability as well. Furthermore, baseline DBP variability
estimates significantly correlated with mean DBP decrease
after RDN. If confirmed in younger patients with less
arterial damage, in the absence of the confounding effect
of drugs and drug adherence, baseline BP variability may
prove a good predictor of BP response to RDN
Epidemiologic observations guiding clinical application of a urinary peptidomic marker of diastolic left ventricular dysfunction
Hypertension, obesity, and old age are major risk factors for left ventricular (LV) diastolic dysfunction (LVDD), but easily applicable screening tools for people at risk are lacking. We investigated whether HF1, a urinary biomarker consisting of 85 peptides, can predict over a 5-year time span mildly impaired diastolic LV function as assessed by echocardiography. In 645 white Flemish (50.5% women; 50.9 years [mean]), we measured HF1 by capillary electrophoresis coupled with mass spectrometry in 2005-2010. We measured early (E) and late (A) peak velocities of the transmitral blood flow and early (e') and late (a') mitral annular peak velocities and their ratios in 2009-2013. In multivariable-adjusted analyses, per 1-standard deviation increment in HF1, e' was -0.193 cm/s lower (95% confidence interval: -0.352 to -0.033; P = .018) and E/e' 0.174 units higher (0.005-0.342; P = .043). Of 645 participants, 179 (27.8%) had LVDD at follow-up, based on impaired relaxation in 69 patients (38.5%) or an elevated filling pressure in the presence of a normal (74 [43.8%]) or low (36 [20.1%]) age-specific E/A ratio. For a 1-standard deviation increment in HF1, the adjusted odds ratio was 1.37 (confidence interval, 1.07-1.76; P = .013). The integrated discrimination (+1.14%) and net reclassification (+31.7%) improvement of the optimized HF1 threshold (-0.350) in discriminating normal from abnormal diastolic LV function at follow-up over and beyond other risk factors was significant (P ≤ .024). In conclusion, HF1 may allow screening for LVDD over a 5-year horizon in asymptomatic people
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 (P0.03 for all). In 47 patients with 3- and 6-month ambulatory measurements, systolic BP did not change between these two time points (P0.08). 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
Arterial Properties in Relation to Genetic Variations in the Adducin Subunits in a White Population
Background Adducin is a membrane skeleton protein, which consists of either α- and β- or α- and γ-subunits. We investigated whether arterial characteristics might be related to the genes encoding ADD1 (Gly460Trp-rs4961), ADD2 (C1797T-rs4984), and ADD3 (IVS11+386A>G-rs3731566). Methods We randomly recruited 1,126 Flemish subjects (mean age, 43.8 years; 50.3% women). Using a wall-tracking ultrasound system, we measured the properties of the carotid, femoral, and brachial arteries. We studied multivariate-adjusted phenotype-genotype associations, using a population- and family-based approach. Results In single-gene analyses, brachial diameter was 0.15 mm (P = 0.0022) larger, and brachial distensibility and cross-sectional compliance were 1.55 × 10-3/kPa (P = 0.013) and 0.017 mm2/kPa (P = 0.0029) lower in ADD3 AA than ADD3 GG homozygotes with an additive effect of the G allele. In multiple-gene analyses, the association of brachial diameter and distensibility with the ADD3 G allele occurred only in ADD1 GlyGly homozygotes. Otherwise, the associations between the arterial phenotypes in the three vascular beds and the ADD1 or ADD2 polymorphisms were not significant. In family-based analyses, the multivariate-adjusted heritability was 0.52, 0.38, and 0.30 for brachial diameter, distensibility, and cross-sectional compliance, respectively (P < 0.001). There was no evidence for population stratification (0.07 ≤ P ≤ 0.96). Transmission of the mutated ADD3 G allele was associated with smaller brachial diameter in 342 informative offspring (-0.12 ± 0.04 mm; P = 0.0085) and in 209 offspring, who were ADD1 GlyGly homozygotes (-0.14 ± 0.06 mm; P = 0.018). Conclusions In ADD1 GlyGly homozygotes, the properties of the brachial artery are related to the ADD3 (A386G) polymorphism, but the underlying mechanism needs further clarification. American Journal of Hypertension (2009). doi: 10.1038/ajh.2008.26
Biomarkers to assess right heart pressures in recipients of a heart transplant: a proof-of-concept study
Background: This proof-of-concept study investigated the feasibility of using biomarkers to monitor right heart pressures (RHP) in heart transplanted (HTx) patients.
Methods: In 298 patients, we measured 7.6 years post-HTx mean pressures in the right atrium (mRAP) and pulmonary artery (mPAP) and capillaries (mPCWP) along with plasma high-sensitivity troponin T (hsTnT), a marker of cardiomyocyte injury, and the multidimensional urinary classifiers HF1 and HF2, mainly consisting of dysregulated collagen fragments.
Results: In multivariable models, mRAP and mPAP increased with hsTnT (per 1-SD, +0.91 and +1.26 mm Hg; P < 0.0001) and with HF2 (+0.42 and +0.62 mm Hg; P ≤ 0.035), but not with HF1. mPCWP increased with hsTnT (+1.16 mm Hg; P < 0.0001), but not with HF1 or HF2. The adjusted odds ratios for having elevated RHP (mRAP, mPAP or mPCWP ≥10, ≥24, ≥17 mm Hg, respectively) were 1.99 for hsTnT and 1.56 for HF2 (P ≤ 0.005). In detecting elevated RHPs, areas under the curve were similar for hsTnT and HF2 (0.63 vs 0.65; P = 0.66). Adding hsTnT continuous or per threshold or HF2 continuous to a basic model including all covariables did not increase diagnostic accuracy (P ≥ 0.11), whereas adding HF2 per optimized threshold increased both the integrated discrimination (+1.92%; P = 0.023) and net reclassification (+30.3%; P = 0.010) improvement.
Conclusions: Correlating RHPs with noninvasive biomarkers in HTx patients is feasible. However, further refinement and validation of such biomarkers is required before their clinical application can be considered
Antihypertensive treatment decreases arterial stiffness at night but not during the day. Results from the Hypertension in the Very Elderly Trial
The main Hypertension in the Very Elderly Trial (HYVET) demonstrated a very marked reduction in cardiovascular events by treating hypertensive participants 80 years or older with a low dose, sustained release prescription of indapamide (indapamide SR, 1.5 mg) to which was added a low dose of an angiotensin converting enzyme inhibitor in two-thirds of cases (perindopril 2–4 mg). This report from the ambulatory blood pressure sub-study investigates whether changes in arterial stiffness and ambulatory blood pressure (BP) could both explain the benefits observed in the main trial. A total of 139 participants were randomized to placebo [67] and to active treatment [72] and had both day and night observations of BP and arterial stiffness as determined from the Q wave Korotkoff diastolic (QKD) interval. The QKD interval was 5.6 ms longer (p = 0.017) in the actively treated group at night than in the placebo group. This was not true for the more numerous daytime readings so that 24-h results were similar in the two groups. The QKD interval remained longer at night in the actively treated group even when adjusted for systolic pressure, heart rate and height. The reduced arterial stiffness at night may partly explain the marked benefits observed in the main trial
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