Project description:The 'obesity paradox' refers to the fact that obese patients have better outcomes than normal weight patients. This has been observed in multiple cardiovascular conditions, but evidence for obesity paradox in pulmonary hypertension (PH) remains sparse.We categorized 267 patients from the National Institute of Health-PH registry into five groups based on body mass index (BMI): underweight, normal weight, overweight, obese and morbidly obese. Mortality was compared in BMI groups using the χ2 statistic. Five-year probability of death using the PH connection (PHC) risk equation was calculated, and the model was compared with BMI groups using Cox proportional hazards regression and Kaplan-Meier (KM) survival curves.Patients had a median age of 39 years (interquartile range 30-50 years), a median BMI of 23.4 kg m-2 (21.0-26.8 kg m-2) and an overall mortality at 5 years of 50.2%. We found a U-shaped relationship between survival and 1-year mortality with the best 1-year survival in overweight patients. KM curves showed the best survival in the overweight, followed by obese and morbidly obese patients, and the worst survival in normal weight and underweight patients (log-rank P=0.0008). In a Cox proportional hazards analysis, increasing BMI was a highly significant predictor of improved survival even after adjustment for the PHC risk equation with a hazard ratio for death of 0.921 per kg m-2 (95% confidence interval: 0.886-0.954) (P<0.0001).We observed that the best survival was in the overweight patients, making this more of an 'overweight paradox' than an 'obesity paradox'. This has implications for risk stratification and prognosis in group 1 PH patients.
Project description:During transition at birth with ventilation of the lungs, pulmonary vascular resistance (PVR) decreases from high fetal values, leading to an 8 to 10-fold increase in pulmonary blood flow (Qp). In some infants, this transition does not occur, resulting in pulmonary hypertension (PH). In infants, PH can present as: (a) primary PH in term neonates (idiopathic), (b) PH secondary to lung disease or hypoplasia in term infants, (c) acute PH in preterm infants with respiratory distress syndrome (RDS), (d) chronic PH with bronchopulmonary dysplasia (BPD) in preterm infants and (e) post-neonatal PH. A hemodynamically significant patent ductus arteriosus (PDA) can exacerbate PH in preterm infants due to increased Qp. Pulmonary vein stenosis (PVS) can complicate BPD with PH. Diagnosis of PH is based on clinical features, echocardiography and, in some intractable cases, cardiac catheterization. Therapy of PH includes oxygen, invasive or non-invasive ventilation, correction of acidosis, surfactant and selective and non-selective pulmonary vasodilators such as inhaled nitric oxide and sildenafil, respectively. Early closure of a hemodynamically significant PDA has the potential to limit pulmonary vascular remodeling associated with BPD and PH. The role of thiamine in pathogenesis of PH is also discussed with the recent increase in thiamine-responsive acute pulmonary hypertension in early infancy. Recognition and prompt therapy of PH can prevent right ventricular dysfunction, uncoupling and failure.
Project description:This study consists of 10 whole genome RNA-seq profiles which have been generated from blood samples collected from ten different volunteers in the Personal Genome Project UK
Project description:Mechanisms underlying pulmonary arterial hypertension (PAH) remain elusive. Pulmonary arterial hypertension and exercise PH share similar physiologic consequences; it is debated whether they share biologic mechanisms and if exercise PH represents an early phase of pulmonary arterial hypertension. We conducted an observational study to test if there is a graded metabolic disturbance along the severity of PH, which may indicate shared or disparate pathophysiology. Individuals referred to an academic medical dyspnea center with unexplained exertional intolerance underwent invasive cardiopulmonary exercise testing. We identified controls with no hemodynamic exercise limitation, individuals with exercise PH (mean pulmonary arterial pressure (mPAP) < 25 mmHg at rest but ≥ 30 mmHg during exercise without pulmonary venous hypertension) and pulmonary arterial hypertension (mPAP > 25 mmHg at rest without pulmonary venous hypertension) (n = 26 in each group). Unbiased metabolomics with chromatography mass spectrometry was performed on pulmonary arterial blood at rest and peak exercise. Random forest analysis and hierarchical clustering were used to quantify metabolite prediction of group membership and rank metabolites which were significantly different between groups. Compared to controls, pulmonary arterial hypertension subjects exhibited perturbations in pathways involving glycolysis, TCA cycle, fatty acid and complex lipid oxidation, collagen deposition and fibrosis, nucleotide metabolism, and others. The metabolic signature of exercise PH was uniquely between that of control and pulmonary arterial hypertension subjects. Accuracy predicting control, exercise PH, and pulmonary arterial hypertension group was 96%, 90%, and 88%, respectively, using paired rest-exercise metabolic changes. Our data suggest the metabolic profile of exercise PH is between that of controls and patients with pulmonary arterial hypertension.
Project description:The aim of the present study was to determine contemporary survival in pulmonary arterial hypertension (PAH), and to investigate whether or not the National Institutes of Health (NIH) equation remains an accurate predictor of survival. In 576 patients with PAH referred during 1991-2007, observed survival was described using the Kaplan-Meier method. In patients with idiopathic, familial and anorexigen-associated PAH (n = 247), observed versus NIH equation predicted survival was compared. A new survival prediction equation was developed using exponential regression analysis. The observed 1-, 3- and 5-yr survival in the total cohort were 86, 69 and 61%, respectively. In patients with idiopathic, familial and anorexigen-associated PAH, the observed 1-, 3- and 5-yr survival (92, 75 and 66%, respectively) were significantly higher than the predicted survival (65, 43 and 32%, respectively). The new equation (P(t) = e(-A(x,y,z)t), where P(t) is probability of survival, t the time interval in years, A(x,y,z) = e((-1.270-0.0148x+0.0402y-0.361z)), x the mean pulmonary artery pressure, y the mean right atrial pressure and z the cardiac index) performed well when applied to published contemporary studies of survival in PAH. Contemporary survival in the PAH cohort was better than that predicted by the NIH registry equation. The NIH equation underestimated survival in idiopathic, familial and anorexigen-associated PAH. Once prospectively validated, the new equation may be used to determine prognosis.
Project description:Serotonin (5-HT) contributes to the pathogenesis of experimental neonatal pulmonary hypertension (PH) associated with bronchopulmonary dysplasia (BPD). Platelets are the primary source of circulating 5-HT and is released upon platelet activation. Platelet transfusions are associated with neonatal mortality and increased rates of BPD. As BPD is often complicated by PH, we tested the hypothesis that circulating platelets are activated and also increased in the lungs of neonatal mice with bleomycin-induced PH associated with BPD. Newborn wild-type mice received intraperitoneal bleomycin (3 units/kg) three times weekly for 3 weeks. Platelets from mice with experimental PH exhibited increased adhesion to collagen under flow (at 300 s-1 and 1,500 s-1 ) and increased expression of the ?IIb?3 integrin and phosphatidylserine, markers of platelet activation. Platelet-derived factors 5-HT and platelet factor 4 were increased in plasma from mice with experimental PH. Pharmacologic blockade of the 5-HT 2A receptor (5-HT 2A R) prevents bleomycin-induced PH and pulmonary vascular remodeling. Here, platelets from mice with bleomycin-induced PH demonstrate increased 5-HT 2A R expression providing further evidence of both platelet activation and increased 5-HT signaling in this model. In addition, bleomycin treatment increased lung platelet accumulation. In summary, platelets are activated, granule factors are released, and are increased in numbers in the lungs of mice with experimental neonatal PH. These results suggest platelet activation and release of platelet-derived factors may increase vascular tone, promote aberrant angiogenesis, and contribute to the development of neonatal PH.
Project description:Hypoglycemia in neonates is associated with long-term neurodevelopmental effects. Hyperinsulinemic hypoglycemia (HH) is the most common cause of persistent hypoglycemia in neonatal intensive care units. Diazoxide is the only medication that is currently recommended for treatment of HH in neonates. However, the use of diazoxide in neonates is associated with pulmonary hypertension as an adverse effect. In this article, we review the literature on the mechanism of action and adverse effects with the use of diazoxide in neonatal hyperinsulinism. We then present a case series of neonates treated with diazoxide in our neonatal intensive care unit over a 5-year period. Among 23 neonates who received diazoxide, 4 developed pulmonary hypertension and 1 died. All infants who developed pulmonary hypertension were born preterm at less than 36 weeks gestation and had pre-existing risk factors for pulmonary hypertension. HH in preterm neonates, with pre-existing pulmonary hypertension or with risk factors for pulmonary hypertension requires thoughtful management.
Project description:Pulmonary hypertension in the neonate is associated with multiple underlying problems such as respiratory distress syndrome, meconium aspiration syndrome, congenital diaphragmatic hernia, bronchopulmonary dysplasia, sepsis, or congenital heart disease. Because of the heterogeneous group of disorders, the therapeutic approach and response often depends on the underlying disease. In many of these conditions, there is evidence that cyclic nucleotide signaling and specifically phosphodiesterases (PDEs) are disrupted. PDE inhibitors represent an emerging class of pulmonary vasodilators in adults. Studies are now under way to evaluate the utility, efficacy, and safety of such therapies in infants with pulmonary hypertension.
Project description:We aimed to characterize metabolites during tuberculosis (TB) disease and identify new pathophysiologic pathways involved in infection as well as biomarkers of TB onset, progression and resolution. Such data may inform development of new anti-tuberculosis drugs. Plasma samples from adults with newly diagnosed pulmonary TB disease and their matched, asymptomatic, sputum culture-negative household contacts were analyzed using liquid chromatography high-resolution mass spectrometry (LC-MS) to identify metabolites. Statistical and bioinformatics methods were used to select accurate mass/charge (m/z) ions that were significantly different between the two groups at a false discovery rate (FDR) of q<0.05. Two-way hierarchical cluster analysis (HCA) was used to identify clusters of ions contributing to separation of cases and controls, and metabolomics databases were used to match these ions to known metabolites. Identity of specific D-series resolvins, glutamate and Mycobacterium tuberculosis (Mtb)-derived trehalose-6-mycolate was confirmed using LC-MS/MS analysis. Over 23,000 metabolites were detected in untargeted metabolomic analysis and 61 metabolites were significantly different between the two groups. HCA revealed 8 metabolite clusters containing metabolites largely upregulated in patients with TB disease, including anti-TB drugs, glutamate, choline derivatives, Mycobacterium tuberculosis-derived cell wall glycolipids (trehalose-6-mycolate and phosphatidylinositol) and pro-resolving lipid mediators of inflammation, known to stimulate resolution, efferocytosis and microbial killing. The resolvins were confirmed to be RvD1, aspirin-triggered RvD1, and RvD2. This study shows that high-resolution metabolomic analysis can differentiate patients with active TB disease from their asymptomatic household contacts. Specific metabolites upregulated in the plasma of patients with active TB disease, including Mtb-derived glycolipids and resolvins, have potential as biomarkers and may reveal pathways involved in TB disease pathogenesis and resolution.