Arterial stiffness is increased in asthmatic children.

UNLABELLED: Altered arterial stiffness is a recognized risk factor of poor cardiovascular health. Chronic inflammation may increase arterial stiffness. We tested whether arterial stiffness is increased children with asthma, a chronic disease characterized by fluctuating airway and systemic inflammation. Arterial stiffness, expressed as carotid-femoral pulse wave velocity (PWVcf), was measured in 37 mild-to-moderate asthmatic children: 11 girls, median (range) age 11.1 years (6-15). PWVcf in asthma was compared to PWVcf in 65 healthy controls matched for age, height, and gender previously studied in Germany and was correlated with airway inflammation and obstruction. PWVcf was higher in asthmatic children compared to controls: PWVcf median (interquartile range) was 4.7 m/s (4.5-4.9) vs. 4.3 m/s (4.1-4.7), p < 0.0001. In asthmatic children, PWVcf was inversely associated (r (2) = 0.20, p = 0.004) with forced expiratory volume in 1 s (FEV1). This association remained significant after adjusting for possible confounders including body mass index, blood pressure, steroid use, and FeNO. CONCLUSION: Arterial stiffness is increased in children with mild-to-moderate asthma. The association between impaired lung function and increased arterial stiffness suggests that severity of disease translates into detrimental effects on the cardiovascular system.

Abnormal small airways function in children with mild asthma.

BACKGROUND: Small airways disease is a hallmark in adults with persistent asthma, but little is known about small airways function in children with mild asthma and normal spirometry. We assessed ventilation heterogeneity, a marker of small airways function, with an easy tidal breath single-breath washout (SBW) technique in school-aged children with mild asthma and normal FEV1 and healthy age-matched control subjects. METHODS: The primary outcome was the double-tracer gas phase III slope (SDTG), an index of ventilation heterogeneity in acinar airways derived from the tidal double-tracer gas SBW test. The second outcome was the nitrogen phase III slope (SN2), an index of global ventilation heterogeneity derived from the tidal nitrogen SBW test using pure oxygen. Triplicate SBW and spirometry tests were performed in healthy children (n=35) and children with asthma (n=31) at baseline and in children with asthma after bronchodilation. RESULTS: Acinar (SDTG) but not global (SN2) ventilation heterogeneity was significantly increased in asthma despite normal FEV1. Of the 31 children with asthma, abnormal results were found for SDTG (≤-2 z scores) in 11; forced expiratory flow, midexpiratory phase (FEF25%-75%) in three; and FEV1 in zero. After bronchodilation, SDTG, SN2, FEF25%-75%, and FEV1 significantly changed (mean [95% CI] change from baseline, 36% [15%-56%], 38% [18%-58%], 17% [9-25%], and 6% [3%-9%], respectively). CONCLUSIONS: Abnormal acinar ventilation heterogeneity in one-third of the children suggests that small airways disease may be present despite rare and mild asthma symptoms and normal spirometry. The easy tidal SBW technique has considerable potential as a clinical and research outcome in children with asthma.

Treatment response of airway clearance assessed by single-breath washout in children with cystic fibrosis.

BACKGROUND: We studied the ability of 4 single-breath gas washout (SBW) tests to measure immediate effects of airway clearance in children with CF. METHODS: 25 children aged 4-16 years with CF performed pulmonary function tests to assess short-term variability at baseline and response to routine airway clearance. Tidal helium and sulfur hexafluoride (double-tracer gas: DTG) SBW, tidal capnography, tidal and vital capacity nitrogen (N2) SBW and spirometry were applied. We analyzed the gasses' phase III slope (SnIII--normalized for tidal volume) and FEV1 from spirometry. RESULTS: SnIII from tidal DTG-SBW, SnIII from vital capacity N2-SBW, and FEV1 improved significantly after airway clearance. From these tests, individual change of SnIII from tidal DTG-SBW and FEV1 exceeded short-term variability in 10 and 6 children. CONCLUSIONS: With the tidal DTG-SBW, an easy and promising test for peripheral gas mixing efficiency, immediate pulmonary function response to airway clearance can be assessed in CF children.

Multiple-breath washout measurements can be significantly shortened in children.

Multiple-breath washout (MBW)-derived lung clearance index (LCI) is a sensitive measure of ventilation inhomogeneity in patients with cystic fibrosis (CF), but LCI measurement is time consuming. We systematically assessed ways to shorten LCI measurements. In 68 school-aged children (44 with mild CF lung disease) three standard nitrogen (N2) MBWs were applied. We assessed repeatability and diagnostic performance of (1) LCI measured earlier from three MBW runs and (2) LCI measured at complete MBW (1/40th of starting N2 concentration) from two runs only. Compared with the standard LCI from three complete MBW runs, the new LCI based on three N2MBW runs until 1/20th, or two complete runs until 1/40th, provided similar or better repeatability as well as sensitivity and specificity for CF lung disease. Alternative ways to measure LCI reduced test duration in children with CF by 30% and 41%, respectively. LCI measurements can be reliably shortened in children. These new MBW protocols may advance the transition of LCI from research into clinical settings.

Practicability of nitrogen multiple-breath washout measurements in a pediatric cystic fibrosis outpatient setting.

BACKGROUND: Although lung clearance index (LCI) is a sensitive indicator of mild cystic fibrosis (CF) lung disease, it is rarely measured due to lengthy protocols and the commercial unavailability of multiple-breath washout (MBW) setups and tracer gases. We used a newly validated, commercially available nitrogen (N2 ) MBW setup to assess success rate, duration, and variability of LCI within a 20 min timeframe, during clinical routine. We also evaluated the relationship between LCI and other clinical markers of CF lung disease. METHODS: One hundred thirty six children (83 with CF) between 4 and 16 years were studied in a pediatric CF outpatient setting. One hundred eighteen out of 136 children were naïve to MBW. Within 20 min, each child was trained, N2 MBW was performed, and LCI was analyzed. We assessed intra- and between-test reproducibility in a subgroup of children. RESULTS: At least one LCI was feasible in 123 (90%) children, with a mean (range) of 3.3 (1.2-6.4) min per test. Two or more measurements were feasible in 56 (41%) children. Comparing LCI in CF versus controls, LCI mean (SD) was 12.0 (3.9) versus 6.1 (0.9), and the intra- and inter-test coefficient of repeatability was 1.00 versus 0.81 and 0.96 versus 0.62, respectively. LCI was correlated with spirometry, blood gases, and Pseudomonas aeruginosa infection. CONCLUSIONS: Using available N2 MBW equipment, LCI measurements are practical and fast in children. LCI is correlated with markers of CF lung disease. Longer timeframes would be required for triplicate N2 MBW tests in inexperienced children.

A new double-tracer gas single-breath washout to assess early cystic fibrosis lung disease.

In cystic fibrosis (CF), tests for ventilation inhomogeneity are sensitive but not established for clinical routine. We assessed feasibility of a new double-tracer gas single-breath washout (SBW) in school-aged children with CF and control subjects, and compared SBW between groups and with multiple-breath nitrogen washout (MBNW). Three SBW and MBNW were performed in 118 children (66 with CF) using a side-stream ultrasonic flowmeter setup. The double-tracer gas containing 5% sulfur hexafluoride and 26.3% helium was applied during one tidal breath. Outcomes were SBW phase III slope (SIII(DTG)), MBNW-derived lung clearance index (LCI), and indices of acinar (S(acin)) and conductive (S(cond)) ventilation inhomogeneity. SBW took significantly less time to perform than MBNW. SBW and MBNW were feasible in 109 (92.4%) and 98 (83.0%) children, respectively. SIII(DTG) differed between children with CF and controls, mean±sd was -456.7±492.8 and -88.4±129.1 mg·mol·L(-1), respectively. Abnormal SIII(DTG) was present in 36 (59%) children with CF. SIII(DTG) was associated with LCI (r= -0.58) and S(acin) (r= -0.58), but not with S(cond). In CF, steeply sloping SIII(DTG) potentially reflects ventilation inhomogeneity near the acinus entrance. This tidal SBW is a promising test to assess ventilation inhomogeneity in an easy and fast way.

Long-term course of lung clearance index between infancy and school-age in cystic fibrosis subjects.

Multiple breath washout (MBW) measurements have recently been shown to be sensitive for detection of early cystic fibrosis (CF) lung disease, with the lung clearance index (LCI) being the most common measure for ventilation inhomogeneity. The aim of this observational study was to describe the longitudinal course of LCI from time of clinical diagnosis during infancy to school-age in eleven children with CF. Elevated LCI during infancy was present in seven subjects, especially in those with later clinical diagnosis. Tracking of LCI at follow-up was evident only in the four most severe cases. We provide the first longitudinal data describing the long-term course of LCI in a small group of infants with CF. Our findings support the clinical usefulness of MBW measurements to detect and monitor early lung disease in children with CF already present shortly after clinical diagnosis.

Posttraumatic stress disorder and soluble cellular adhesion molecules at rest and in response to a trauma-specific interview in patients after myocardial infarction.

Posttraumatic stress disorder (PTSD) and circulating cellular adhesion molecules (CAMs) predict cardiovascular risk. We hypothesized a positive relationship between PTSD caused by myocardial infarction (MI) and soluble CAMs. We enrolled 22 post-MI patients with interviewer-rated PTSD and 22 post-MI patients with no PTSD. At 32±6months after index MI, all patients were re-scheduled to undergo the Clinician-Administered PTSD Scale (CAPS) interview and had blood collected to assess soluble CAMs at rest and after the CAPS interview. Relative to patients with no PTSD, those with PTSD had significantly higher levels of soluble vascular cellular adhesion molecule (sVCAM)-1 and intercellular adhesion molecule (sICAM)-1 at rest and, controlling for resting CAM levels, significantly higher sVCAM-1 and sICAM-1 after the interview. Greater severity of PTSD predicted significantly higher resting levels of sVCAM-1 and soluble P-selectin in patients with PTSD. At follow-up, patients with persistent PTSD (n=15) and those who had remitted (n=7) did not significantly differ in CAM levels at rest and after the interview; however, both these groups had significantly higher sVCAM-1 and sICAM-1 at rest and also after the interview compared to patients with no PTSD. Elevated levels of circulating CAMs might help explain the psychophysiologic link of PTSD with cardiovascular risk.

Momentary stress moderates procoagulant reactivity to a trauma-specific interview in patients with posttraumatic stress disorder caused by myocardial infarction.

Hypercoagulability of the blood might partially explain the increased cardiovascular disease risk in posttraumatic stress disorder (PTSD) and is also triggered by anticipatory stress. We hypothesized exaggerated procoagulant reactivity in patients with PTSD in response to a trauma-specific interview that would be moderated by momentary stress levels. We examined 23 patients with interviewer-diagnosed PTSD caused by myocardial infarction (MI) and 21 post-MI patients without PTSD. A second diagnostic (i.e., trauma-specific) interview to assess posttraumatic stress severity was performed after a median follow-up of 26 months (range 12-36). Before that interview patients rated levels of momentary stress (Likert scale 0-10) and had blood collected before and after the interview. The interaction between PTSD diagnostic status at study entry and level of momentary stress before the follow-up interview predicted reactivity of fibrinogen (P=0.036) and d-dimer (P=0.002) to the PTSD interview. Among patients with high momentary stress levels, PTSD patients had greater fibrinogen (P=0.023) and d-dimer (P=0.035) reactivity than non-PTSD patients. Among patients with low momentary stress levels, PTSD patients had less d-dimer reactivity than non-PTSD patients (P=0.024); fibrinogen reactivity did not significantly differ between groups. Momentary stress levels, but not severity of posttraumatic stress, correlated with d-dimer reactivity in PTSD patients (r=0.46, P=0.029). We conclude that momentary stress levels moderated the relationship between PTSD and procoagulant reactivity to a trauma-specific interview. Procoagulant reactivity in post-MI patients with PTSD confronted with their traumatically experienced MI was observed if patients perceived high levels of momentary stress before the interview.

Posttraumatic stress disorder and dyslipidemia: previous research and novel findings from patients with PTSD caused by myocardial infarction.

OBJECTIVES: Based on a brief systematic review suggesting dyslipidemia in posttraumatic stress disorder (PTSD), we studied, for the first time, levels of blood lipids in patients with a DSM-IV diagnosis of PTSD caused by myocardial infarction (MI). METHODS: Study participants were eight patients with full PTSD, eight patients with subsyndromal PTSD, and 31 patients with no PTSD who were diagnosed using the Clinician-Administered PTSD Scale (CAPS) interview after a mean of 32+/-8 months after MI. Levels of total cholesterol, low-density lipoprotein-cholesterol, triglycerides, and high-density lipoprotein-cholesterol (HDL-C) were determined in plasma. RESULTS: Patients with full PTSD had lower HDL-C than patients with subsyndromal PTSD (P = 0.044) and those with no PTSD (P = 0.014) controlling for sex, body mass index, and statin equivalent dosage. Moreover, HDL-C levels were inversely associated with PTSD total symptoms (r = -0.33, P = 0.027), re-experiencing symptoms (r = -0.32, P = 0.036), and avoidance symptoms (r = -0.34, P = 0.025). There were no significant associations of PTSD diagnostic status and symptomatology with the three other lipid measures. CONCLUSION: Chronic PTSD caused by MI was associated with lower plasma levels of HDL-C. The finding concurs with the notion of dyslipidemia partially underlying the atherosclerotic risk in individuals with PTSD caused by different types of trauma.

Inflammatory biomarkers in patients with posttraumatic stress disorder caused by myocardial infarction and the role of depressive symptoms.

OBJECTIVE: Inflammation might link posttraumatic stress disorder (PTSD) with an increased risk of cardiovascular events. We explored the association between PTSD and inflammatory biomarkers related to cardiovascular morbidity and the role of co-morbid depressive symptoms in this relationship. METHODS: We investigated 15 patients with interviewer-rated PTSD caused by myocardial infarction (MI) and 29 post-MI patients with no PTSD. All patients completed the depression subscale of the Hospital Anxiety and Depression Scale and had blood collected to determine inflammatory markers of increased cardiovascular risk. RESULTS: Controlling for demographic and medical covariates, patients with PTSD had higher leptin levels than patients with no PTSD (p = 0.038, explained variance 10.4%); this difference became nonsignificant when controlling for depressive symptoms. After controlling for depressive symptoms, PTSD patients had higher interleukin-6 (p = 0.041; explained variance 10%), lower C-reactive protein (p = 0.022, explained variance 12.1%), and lower soluble CD40 ligand (p = 0.016, explained variance 13.4%) than patients without PTSD. After controlling for PTSD status, depressive symptoms correlated with soluble CD40 ligand (r = 0.45, p = 0.002) and with C-reactive protein (r = 0.29, p < 0.07). CONCLUSIONS: The findings provide further evidence for altered inflammation in PTSD. Comorbid depressive symptoms ought to be considered to disentangle the unique associations of PTSD caused by MI and systemic inflammation.

Stress hormones in patients with posttraumatic stress disorder caused by myocardial infarction and role of comorbid depression.

BACKGROUND: Chronic posttraumatic stress disorder (PTSD) has been associated with perturbed hypothalamic-pituitary-adrenal (HPA) axis function and a hyperadrenergic state. We hypothesized that patients with PTSD attributable to myocardial infarction (MI) would show peripheral hypocortisolemia and increased norepinephrine levels, whereby taking into account that depressive symptoms would affect this relationship. METHODS: We investigated 15 patients with interviewer-rated PTSD caused by myocardial infarction (MI) and 29 post-MI patients with no PTSD. Patients also completed the depression subscale of the Hospital Anxiety and Depression Scale and had blood collected to determine plasma cortisol and norepinephrine levels. RESULTS: In bivariate correlation analysis PTSD and depressive symptoms were not significantly associated with cortisol levels. However, patients with PTSD had lower mean+/-SEM cortisol levels than patients with no PTSD when controlling for depressive symptoms (77+/-11 vs. 110+/-7 ng/ml, p=.035). In turn, depressive symptoms correlated with cortisol levels when taking PTSD into account (r=.36, p=.019). In all patients cortisol levels correlated with total PTSD symptoms (r=-.43, p=.005) and hyperarousal symptoms (r=-.45, p=.002) after controlling for depressive symptoms. Depression correlated with cortisol levels after controlling for total PTSD symptoms (r=.45, p=.002). Posttraumatic stress disorder and depressive symptoms were not significantly associated with norepinephrine levels. CONCLUSIONS: In post-MI patients we found peripheral hypocortisolemia related to PTSD, respectively hypercortisolemia related to depressive symptoms, when taking joint effects of PTSD and depression into account. No evidence was found for a hyperadrenergic state. Comorbid depressive symptoms ought to be considered to disentangle the unique associations of PTSD with HPA axis dysfunction in cardiac patients.

Association between posttraumatic stress disorder following myocardial infarction and liver enzyme levels: a prospective study.

BACKGROUND: Research in rodents demonstrated that psychological stress increases circulating levels of alanine transaminase, aspartate transaminase, and alkaline phosphatase reflecting liver injury. Moreover, chronic posttraumatic stress disorder and transaminases predicted coronary heart disease. AIMS: To investigate the hypothesis that severity of posttraumatic stress disorder following myocardial infarction would prospectively relate to liver enzymes. METHODS: Study participants were 24 patients (mean 59+/-7 years, 79% men) with an interviewer-rated diagnosis of posttraumatic stress disorder caused by an index myocardial infarction 3+/-3 months before. After a mean follow-up of 26+/-6 months, patients had a clinical interview to reassess posttraumatic stress disorder severity, a medical history, and blood collected to determine liver enzymes. RESULTS: Total posttraumatic stress disorder symptoms assessed at study entry prospectively predicted plasma levels of alanine transaminase (r=.47, p=.031) and alkaline phosphatase (r=.57, p=.004), but not of aspartate transaminase (p=.15), controlling for follow-up duration and antidepressant use. Total posttraumatic stress disorder symptoms assessed at follow-up were associated with alanine transaminase (r=.72, p=.004), aspartate transaminase (r=.60, p=.018), and alkaline phosphatase (r=.64, p=.001) in the 16 patients who had maintained diagnostic posttraumatic stress disorder, but not in all 24 patients. CONCLUSIONS: The severity of posttraumatic stress disorder following myocardial infarction was associated with mild increase in liver enzyme levels, suggesting that chronic psychological stress relates to hepatic damage in humans. This might help to explain the previously observed increased cardiovascular risk in chronically traumatized individuals.

Trajectory of posttraumatic stress disorder caused by myocardial infarction: a two-year follow-up study.

OBJECTIVE: A substantial proportion of patients develop posttraumatic stress disorder (PTSD) following myocardial infarction (MI). Previous research on the trajectory over time of PTSD in post-MI patients is scant and refers to self-rated posttraumatic symptoms. The aim of this study was to investigate the longitudinal course of an interviewer-rated diagnosis of PTSD and PTSD symptom severity following MI. METHODS: Study participants were 40 patients (78% men, mean age 54 +/- 8 years) who were diagnosed with PTSD using the Clinician-administered PTSD Scale (CAPS) after an average of 5 +/- 4 months (range 2-16 months) following an index MI. After a mean follow-up of 26 +/- 6 months (range 12-36 months), 24 patients underwent a second diagnostic interview. RESULTS: Two-thirds of patients (n = 16) still qualified for a diagnosis of PTSD at follow-up. In all 24 patients, total PTSD symptoms (p = 0.001), re-experiencing symptoms (p < 0.001), avoidance symptoms (p = 0.015), and, with borderline significance, hyperarousal symptoms (p < 0.06) had all decreased over time. However, in the subgroup of the 16 patients who had retained PTSD diagnostic status at follow-up, symptoms of avoidance (p = 0.23) and of hyperarousal (p = 0.48) showed no longitudinal decline. Longer duration of follow-up was associated with a greater decrease in avoidance symptoms (p = 0.029) and, with borderline significance, in re-experiencing symptoms (p < 0.07) across all patients. CONCLUSION: Although PTSD symptomatology waned over time and in relation to longer follow-up, two-thirds of patients still qualified for a diagnosis of PTSD 2 years after the initial diagnosis. In post-MI patients, clinical PTSD is a considerably persistent condition.