Forced expiratory flows' contribution to lung function interpretation in schoolchildren.

Forced expiratory flow (FEF) at low lung volumes are supposed to be better at detecting lung-function impairment in asthmatic children than a forced volume. The aim of this study was to examine whether FEF results could modify the interpretation of baseline and post-bronchodilator spirometry in asthmatic schoolchildren in whom forced expiratory volumes are within the normal range. Spirometry, with post-bronchodilator vital capacity within 10% of that of baseline in healthy and asthmatic children, was recorded prospectively. We defined abnormal baseline values expressed as z-scores <-1.645, forced expiratory volume in 1 s (FEV1) reversibility as a baseline increase >12%, FEF reversibility as an increase larger than the 2.5th percentile of post-bronchodilator changes in healthy children. Among 66 healthy and 50 asthmatic schoolchildren, only two (1.7%) children with normal vital capacity and no airways obstruction had abnormal baseline forced expiratory flow at 25-75% of forced vital capacity (FEF25-75%). After bronchodilation, among the 45 asthmatic children without FEV1 reversibility, 5 (11.1%) had an FEF25-75% increase that exceeded the reference interval. Isolated abnormal baseline values or significant post-bronchodilator changes in FEF are rare situations in asthmatic schoolchildren with good spirometry quality.

Carbon dioxide levels during polygraphy in children with sleep-disordered breathing.

PURPOSE: The recent scoring rules of the American Academy of Sleep Medicine (AASM) define hypoventilation in children as a carbon dioxide (CO2) level of >50 mmHg for >25 % of total sleep time (partial pressure of CO2 (PCO2) > 50[>25 %]). As there is no validated level of nocturnal hypoventilation with regard to end-organ damage in children, we evaluated the prevalence of hypoventilation with the AASM definition but also with a lesser degree of elevated CO2 in children with sleep-disordered breathing (SDB). METHODS: Transcutaneous CO2 (PtcCO2) was recorded during overnight polygraphy (PG). Hypoventilation was defined according to four definitions: the AASM score (PCO2 > 50[>25 %]), the peak value of PtcCO2 > 50 mmHg (PtcCO2 > 50[peak]), a percentage of PtcCO2 > 50 mmHg > 2 % of nighttime recording (PtcCO2 > 50[>2 %]) or a nocturnal PtcCO2 > 10 mmHg above waking baseline level (PtcCO2[>10 mmHg]). PtcCO2 indices were correlated to the apnoea-hypopnoea index (AHI) and oxygenation indices. RESULTS: PGs from 221 children with suspicion of obstructive sleep apnoea (72 %), neuromuscular diseases (21 %), and lung diseases (7 %) were analysed. The prevalence of hypoventilation according to PCO2 > 50[>25 %], PtcCO2 > 50[peak], PtcCO2 > 50[>2 %] and PtcCO2[>10 mmHg] were 16, 27, 31 and 52 %, respectively, and did not differ between the three diagnostic groups. Significant but weak correlations were observed between hypoventilation and AHI and oxygenation indices. CONCLUSIONS: Nocturnal hypoventilation occurs in a large number of children referred for SDB, independent of the underlying disease, when more stringent criteria than those of the AASM are used. The poor correlation between hypoventilation and AHI or oxygenation indices is in favour of CO2 being a supplemental index of SDB.

Primary ciliary dyskinesia presentation in 60 children according to ciliary ultrastructure.

Primary ciliary dyskinesia (PCD) is an inherited disease related to ciliary dysfunction, with heterogeneity in clinical presentation and in ciliary ultrastructural defect. Our study intended to determine if there are phenotypic differences in patients with PCD based on ciliary ultrastructural abnormality. In this retrospective study carried out among 60 children with a definitive diagnosis of PCD, we analyzed clinical, radiological, and functional features at diagnosis and at last recorded visit, according to cilia defect (absence of dynein arms: DAD group, n = 36; abnormalities of the central complex: CCA group, n = 24). Onset of respiratory symptoms occurred later in the CCA than in the DAD group (9.5 versus 0.5 months, p = 0.03). Situs inversus was only observed in the DAD group, while respiratory disease in siblings were more frequent in the CCA group (p = 0.003). At diagnosis, clinical presentation was more severe in the CCA group: frequency of respiratory tract infections (p = 0.008), rhinosinusitis (p = 0.02), otitis complications (p = 0.0001), bilateral bronchiectasis (p = 0.04), and number of hypoxemic patients (p = 0.03). Pulmonary function remained stable in both groups, but outcome was better in the CCA than in the DAD group: less antibiotic therapy and hypoxemic patients (p = 0.004). In conclusion, our results underlined the relationship between the severity of clinical presentation and the ultrastructural ciliary defect.

Nocturnal hypoxaemia and hypercapnia in children with neuromuscular disorders.

The aim of the study was to identify daytime predictors of nocturnal gas exchange anomalies in children with neuromuscular disease (NMD) and normal daytime gas exchange. Lung function tests, respiratory muscle evaluation and nocturnal gas exchange were obtained as part of routine evaluation. We included 52 consecutive children with Duchenne muscular dystrophy (n = 20), spinal muscular atrophy (n = 10) and other NMD (n = 22). 20 patients had nocturnal hypoxaemia, defined as minimal arterial oxygen saturation measured by pulse oximetry (S(p,O(2))) <90% for ≥ 2% of night time, and 22 had nocturnal hypercapnia, defined as maximal transcutaneous carbon dioxide tension (P(tc,CO(2))) >50 mmHg for ≥ 2% of night time. Forced vital capacity and helium functional residual capacity correlated with minimal nocturnal S(p,O(2)) (p = 0.009 and p = 0.01, respectively). Daytime pH correlated negatively with maximal nocturnal P(tc,CO(2)) (p=0.005) and daytime arterial carbon dioxide tension (P(a,CO(2))) correlated with the percentage of time with a P(tc,CO(2)) >50 mmHg (p = 0.02). Sniff nasal inspiratory pressure correlated with minimal nocturnal S(p,O(2)) (p = 0.02). Daytime P(a,CO(2)) was a weak predictor of nocturnal hypercapnia (sensitivity 80%; specificity 57%). Daytime lung function and respiratory muscle parameters correlate poorly with nocturnal hypoxaemia and hypercapnia in children with NMD and normal daytime gas exchange, which necessitates more systematic sleep studies in these children.

Lung function, diagnosis, and treatment of sleep-disordered breathing in children with achondroplasia.

Children with achondroplasia are at risk of sleep-disordered breathing. The aim of the study was to evaluate lung function and sleep-disordered breathing in children with achondroplasia. An interview, clinical examination, lung function tests with blood gases, and a polygraphic sleep study were obtained as part of routine annual evaluation in consecutive children with achondroplasia. We included 30 children (median age 3.0 years, range: 0.4-17.1) over a period of 21 months. Habitual snoring and witnessed apneas were observed in 77% and 33% of the patients, respectively. Prior to the sleep study, 10/29 (34%) patients had undergone upper airway surgery and 5/29 (17%) craniocervical decompression operation. Arterial blood gases were abnormal in two (7%) patients. Sleep findings were abnormal in 28/30 (93%) patients. Eleven (37%) patients had an apnea index≥1 event/hr and 26 (87%) had an apnea-hypopnea index≥5 events/hr. The ≥3% desaturation index was >5/hr in 22 (73%) patients. Sixteen (53%) patients had a minimal pulse oximetry<90% but only two (7%) patients had a maximal transcutaneous carbon dioxide pressure>50 mmHg during sleep. As a consequence, the following therapeutic interventions were performed: upper airway surgery in four patients and noninvasive positive pressure ventilation (NPPV) in five other patients, resulting in an improvement in sleep studies in all nine patients. Systematic sleep studies are recommended in children with achondroplasia because of the high prevalence of sleep-disordered breathing. Upper airway surgery and NPPV are effective treatments of sleep-disordered breathing.

Whole pulmonary assessment 1 year after paediatric acute respiratory distress syndrome: prospective multicentre study.

BACKGROUND: Long-term pulmonary sequelae, including 1-year thoracic computed tomography (CT) sequelae of paediatric acute respiratory distress syndrome (ARDS) remain unknown. The purpose of the study was to determine pulmonary abnormalities in child survivors of pulmonary (p-ARDS) and extra-pulmonary ARDS (ep-ARDS) 1 year after paediatric intensive care unit discharge (PICUD). METHODS: Prospective multicentre study in four paediatric academic centres between 2005 and 2014. Patients with ARDS were assessed 1 year after PICUD with respiratory symptom questionnaire, thoracic CT and pulmonary function tests (PFT). RESULTS: 39 patients (31 p-ARDS) aged 1.1-16.2 years were assessed. Respiratory symptoms at rest or exercise and/or respiratory maintenance treatment were reported in 23 (74%) of children with p-ARDS but in 1 (13%) of those with ep-ARDS. Thoracic CT abnormalities were observed in 18 (60%) of children with p-ARDS and 4 (50%) of those with ep-ARDS. Diffuse and more important CT abnormalities, such as ground glass opacities or mosaic perfusion patterns, were observed in 5 (13%) of children, all with p-ARDS. PFT abnormalities were observed in 30 (86%) of patients: lung hyperinflation and/or obstructive pattern in 12 (34%) children, restrictive abnormalities in 6 (50%), mild decrease in diffusing capacity in 2 (38%) and 6-min walking distance decrease in 11 (73%). Important PFT abnormalities were observed in 7 (20%) children, all with p-ARDS. Increasing driving pressure (max plateau pressure-max positive end-expiratory pressure) was correlated with increasing CT-scan abnormalities and increasing functional residual capacity (more hyperinflation) (p < 0.005). CONCLUSIONS: Children surviving ARDS requiring mechanical ventilation present frequent respiratory symptoms, significant CT-scan and PFT abnormalities 1 year after PICUD. This highlights the need for a systematic pulmonary assessment of these children. Trial registration The study was registered on Clinical Trials.gov PRS (ID NCT01435889).

Sleep disordered breathing in Silver-Russell syndrome patients: a new outcome.

OBJECTIVE: Imprinting disorders (ID), such as Prader-Willi syndrome (PWS), are associated with sleep-disordered breathing (SDB). No data are available for Silver-Russell syndrome (SRS), another ID that shares clinical features with PWS, although many patients describe excessive daytime sleepiness, disturbed sleep, and snoring. The aim of this study was to characterize sleep in children with SRS and to evaluate the impact of recombinant growth hormone (rGH) therapy. METHODS: We performed a retrospective analysis of sleep recordings in 40 patients with molecularly proven SRS (methylation anomaly in 11p15 [n = 32] or maternal uniparental disomy of chromosome 7 [n = 16]). Sleep recordings were either by means of polygraphy or polysomnography (PSG) (n = 16). A total of 34 patients received rGH therapy. RESULTS: We collected 61 sleep recordings. The mean apnea-hypopnea index (AHI) was 3.4 events/h (0-12.4), with a mean central AHI of 0.5 events/h (0-2.4). SDB was identified in 73.8% (n = 45) of the recordings and was severe in 4.9%. SDB was present in 86.4% of patients before rGH therapy and was severe in 13.6%. AHI worsened for 5 of 12 patients with sleep recordings before and after rGH therapy initiation, reaching mild impairment. The mean rGH dose was 32.3 µg/kg/(12.9-51.4), with a mean insulin-like growth factor 1 plasma level of 1.7 SDS (-1.9 to 6.6). CONCLUSION: Most patients with SRS present with SDB with an obstructive profile, possibly explained by narrowing of the airways and lymphoid organ hypertrophy. We recommend systematic ear-nose-throat evaluation of SRS patients and PSG if there are clinical anomalies, preferably before initiating rGH therapy, to monitor and adapt the management of patients with SDB.

Diagnosis, follow-up and management of sleep-disordered breathing in children with osteogenesis imperfecta.

OBJECTIVES: Osteogenesis imperfecta (OI) is the most common genetic skeletal disorder. Extraskeletal findings are common but an association with sleep-disordered breathing (SDB) has never been described. The aim of this study was to investigate clinical features of children with OI and suspected SDB. METHODS: A retrospective study of clinical records, signs of SDB and polysomnographic recordings of children with OI was performed. We paid particular attention to symptoms that could be associated with SDB in this population - scoliosis, kyphosis, vertebral arthrodesis, chest wall deformities, basilar impression, autonomy - as well as data already known to be associated with obstructive sleep apnea such as body mass index and upper-airway impairment. RESULTS: We reviewed the clinical charts of 188 patients referred to our genetic skeletal disorders reference center for OI. Among the 15 patients (8%) with polysomnographic recordings, 12 (6.4%) had sleep-disordered breathing. We found a negative correlation between the Brief Assessment of Motor Function score and Apnea Hypopnea Index (r=-0.68; p=0.01) and Desaturation Index (r=-0.62; p=0.02). The Apnea Hypopnea Index was higher for non-walkers than walkers (mean [SD]: 6.5 [3.6] vs. 2.4 [1.5]; p=0.02) and with type III versus IV OI. Two patients were started on continuous positive airway pressure ventilation, with clinical improvement. CONCLUSION: For OI children, symptoms suggesting obstructive sleep disorders should be searched for systematically, especially in children with compromised autonomy, high body mass index, trunk deformations, and severe OI type.

Respiratory muscle testing: a valuable tool for children with neuromuscular disorders.

RATIONALE: Data on respiratory muscle performance in children with neuromuscular disorders are limited. OBJECTIVES: The aim of this study was to assess respiratory muscle strength by volitional and nonvolitional tests and to compare these tests with forced vital capacity. METHODS: Inspiratory muscle strength was assessed by measuring transdiaphragmatic and esophageal pressures generated during volitional and nonvolitional maneuvers, whereas expiratory muscle strength was assessed by measuring the gastric pressure generated during a cough maneuver. Lung volumes were assessed by measuring forced vital capacity. MEASUREMENTS AND MAIN RESULTS: Forty-one patients with Duchenne muscular dystrophy (n = 20), spinal amyotrophy (n = 8), and congenital myopathy (n = 13) were included, aged 2 to 18 yr. All the patients were able to perform the sniff and the cough maneuver. Sniff transdiaphragmatic pressure decreased with age in Duchenne patients, whereas it increased with age in patients with spinal amyotrophy and congenital myopathy. Magnetic stimulation of the phrenic nerves was obtained in all patients. Twenty-five (61%) patients were able to perform forced vital capacity. In the three groups of patients, a positive correlation was observed between volitional, assessed by the sniff maneuver, and nonvolitional respiratory muscle tests, assessed by the magnetic stimulation of the phrenic nerves. Also, forced vital capacity correlated with sniff transdiaphragmatic pressure and cough gastric pressure. CONCLUSIONS: Volitional respiratory muscle tests correlated with nonvolitional tests and with forced vital capacity. Simple volitional respiratory muscle tests constitute a valuable tool for the assessment of respiratory muscle strength in young patients with neuromuscular disorders.

Pulmonary function and sleep-related breathing disorders in severely obese children.

BACKGROUND & AIMS: To evaluate the frequency of pulmonary function and sleep-breathing disorders in severely obese children and to search for their association with obesity phenotypes. METHODS: Sleep studies and spirometry were performed for 54 severely obese children. RESULTS: Upper airway resistances (RAWs) were increased with RAW>200% and forced 25s expiratory volume<80% in 83% and 60% of individuals, respectively. A decrease in functional residual capacity (FRC)<80% was found in 43%. Fifty-two percent of the children had a desaturation index>10 during sleep, and 41% of children presented at least one of three severity criteria (snoring index>300 per hour, respiratory events index (REI)>10 and arousal index>10). Univariate analyses showed a positive correlation between snoring index and BMI Z-score and neck/height ratio (P=0.01 and 0.04, respectively) as between REI and the same parameters (P=0.01 and 0.03, respectively). In a multivariate model with BMI Z-score, NHR still correlated with the snoring index (P=0.02) and REI (P=0.01). CONCLUSIONS: In our cohort, obese children showed frequent pulmonary function and sleep-breathing disorders. The later were associated with impaired upper airway respiratory conductance.

Mechanical limitation during CO2 rebreathing in young patients with cystic fibrosis.

The aim of the study was to determine whether a decrease in the ventilatory response to carbon dioxide (CO2) in children with cystic fibrosis (CF) is related to a mechanical limitation of the respiratory muscle capacity. The ventilatory response during CO2 rebreathing was performed in 15 patients (mean forced expiratory volume in 1 s (FEV1): 37 +/- 21% predicted, mean arterial CO2: 41+/- 5 mmHg). The slope of the minute ventilation normalised for weight per mmHg CO2 increment correlated negatively with respiratory muscle output, assessed by the oesophageal (p = 0.002), the diaphragmatic pressure time product (p = 0.01), and the tension time index (p = 0.005). In addition, this slope was correlated with dynamic lung compliance (p < 0.0001) and FEV1 (p = 0.03) but not with airway resistance and maximal transdiaphragmatic pressure. Therefore, an excessive load imposed on the respiratory muscles explains the blunting of the ventilatory response to CO2 in young patients with CF.

Sleep disordered breathing in patients with Prader-Willi syndrome: A multicenter study.

OBJECTIVES: Sleep disordered breathing (SDB) is common in patients with Prader-Willi syndrome (PWS) and systematic screening is recommended, especially before growth hormone treatment. The aim of the study was to describe the baseline SDB and therapeutic interventions in a large cohort of patients. STUDY DESIGN: Retrospective study. SUBJECT SELECTION: Eighty-eight patients with PWS, median [interquartile range] age of 5.1 [1.0-14.5] years old (range 0.3-44.3), who were followed in three centers (France, Italy). METHODOLOGY: Anthropometrics, polygraphy (PG), and gas exchange data were analyzed. RESULTS: Median body mass index (BMI) was 20 [16-34] kg/m(2), BMI z-score for patients aged 2-20 years old was 2.1 [1.2-2.8] SD, mixed-obstructive apnea-hypopnea index (MOAHI) 1.8 [0.6-5.0] events/hr, and central apnea index (CAI) 0.1 [0.0-0.6] events/hr. Minimum pulse oximetry (SpO2) was 88 [84-91]%, percentage of time with SpO2 <90% 0.1 [0.0-1.0]%, and oxygen desaturation index 2 [1-4]/hr. An apnea-hypopnea index (AHI) ≥ 1.5 and ≥ 5 events/hr was observed in 53% of children and 41% of adults, respectively. No correlations were observed between MOAHI and anthropometrics data (age, BMI, BMI z-score), while MOAHI significantly correlated with SpO2 indexes. Age and BMI only weakly correlated with SpO2 indexes. Growth hormone could be initiated in 48 patients. Regarding post-PG therapy, 9 patients had upper airway surgery, and noninvasive CPAP/bilevel ventilation was started in 16 patients. CONCLUSIONS: Patients with PWS exhibit a high prevalence of SDB. The lack of association between obesity and SDB leads to hypothesize that hypotonia and/or facial dysmorphic features may play a major role in the occurrence of SDB.

Glutathione-S-transferase M1, M3, P1 and T1 polymorphisms and severity of lung disease in children with cystic fibrosis.

OBJECTIVES: Progression and severity of lung disease differs markedly and early between patients with cystic fibrosis (CF). We investigated the hypothesis that polymorphisms in the detoxifying enzymes glutathione-S-transferase (GST) could influence phenotypic presentation of lung disease in CF. METHODS: Genotypes for GSTM1, GSTM3, GSTP1 and GSTT1 were determined in a cohort of 146 children with CF by PCR-based methods. Pulmonary function, assessed by spirometric measures of forced expiratory volume in one second (FEV1) and forced vital capacity (FVC), was analysed in children at the age of 9. RESULTS: No association between spirometric measurements, and GSTM1, GSTP1 or GSTT1 genotypes was found. As compared with patients homozygous for GSTM3*A allele, CF children carrying the GSTM3*B allele displayed a significant better lung function, assessed by both mean values of FEV1 and of FVC (respectively P = 0.01 and P = 0.002). These correlations remained significant after adjustment for potential confounding factors (respectively adjusted P = 0.008 and P = 0.002) and also in subgroups of CF patients who carry the deltaF508 CFTR mutation. Haplotype analysis of GSTM3 in combination with GSTM1 indicated that the positive impact of GSTM3*B allele on pulmonary performances was barely influenced by the GSTM1 genotypes of CF children. CONCLUSIONS: These data provide the first evidence suggesting that polymorphism of the GSTM3 gene contributes to clinical severity in CF, which may have prognostic significance and could prompt to start a more targeted therapy in young patients with CF.

Nutritional status is an important predictor of diaphragm strength in young patients with cystic fibrosis.

BACKGROUND: The effect of nutritional status and lung disease progression on diaphragm strength in young patients with cystic fibrosis remains unclear. OBJECTIVE: The aim of this study was to investigate the effect of nutritional status and airway obstruction on diaphragm strength. DESIGN: Twitch transdiaphragmatic pressure (Tw Pdi) obtained by bilateral anterior magnetic phrenic nerve stimulation, body mass index (BMI) z score, fat mass, fat-free mass (FFM), arm muscle circumference (AMC), forced expiratory volume in 1 s (FEV(1)), and functional residual capacity (FRC) were measured in 20 patients aged 15.1 +/- 2.8 y (x +/- SD). Values were expressed as a percentage of predicted values. RESULTS: Mean (+/-SD) Tw Pdi was 24.3 +/- 5.5 cm H(2)O. Univariate regression analysis showed positive correlations between Tw Pdi and nutrition scores (BMI z score: r = 0.63, P = 0.003; FFM: r = 0.47, P = 0.04; AMC: r = 0.45, P = 0.04), airway obstruction (FEV(1): r = 0.68, P = 0.001), and arterial oxygen partial pressure (r = 0.68, P = 0.001). Negative correlations were observed between Tw Pdi and dynamic hyperinflation (FRC: r = -0.65, P = 0.005) and arterial carbon dioxide pressure (r = -0.50, P = 0.03). Furthermore, stepwise regression analysis showed that Tw Pdi correlated with BMI z score (r = 0.75, P = 0.0002) and FEV(1) (r = 0.69, P = 0.001). CONCLUSIONS: Diaphragm strength is relatively well preserved in young patients with cystic fibrosis. However, the strength of the diaphragm decreases with the progression of malnutrition and airway obstruction.

Respiratory muscle decline in Duchenne muscular dystrophy.

OBJECTIVES: Duchenne muscular dystrophy (DMD) causes progressive respiratory muscle weakness. The aim of the study was to analyze the trend of a large number of respiratory parameters to gain further information on the course of the disease. STUDY DESIGN: Retrospective study. SUBJECT SELECTION: 48 boys with DMD, age range between 6 and 19 year old, who were followed in our multidisciplinary neuromuscular clinic between 2001 and 2011. METHODOLOGY: Lung function, blood gases, respiratory mechanics, and muscle strength were measured during routine follow-up over a 10-year period. Only data from patients with at least two measurements were retained. RESULTS: The data of 28 patients were considered for analysis. Four parameters showed an important decline with age. Gastric pressure during cough (Pgas cough) was below normal in all patients with a mean decline of 5.7 ± 3.8 cmH2 O/year. Sniff nasal inspiratory pressure (SNIP) tended to increase first followed by a rapid decline (mean decrease 4.8 ± 4.9 cmH2 O; 5.2 ± 4.4% predicted/year). Absolute forced vital capacity (FVC) values peaked around the age of 13-14 years and remained mainly over 1 L but predicted values showed a mean 4.1 ± 4.4% decline/year. Diaphragmatic tension-time index (TTdi) increased above normal values after the age of 14 years with a mean increase of 0.04 ± 0.04 point/year. CONCLUSIONS: This study confirms the previous findings that FVC and SNIP are among the most important parameters to monitor the evolution of DMD. Expiratory muscle strength, assessed by Pgas cough, and the endurance index, TTdi, which are reported for the first time in a large cohort, appeared to be informative too, even though measured through an invasive method.

Longitudinal course of lung function and respiratory muscle strength in spinal muscular atrophy type 2 and 3.

BACKGROUND: Spinal muscular atrophy (SMA) is a common genetic disorder that causes severe hypotonia and weakness, and often fatal restrictive lung disease. The aim of the study was to describe the natural history of the respiratory involvement in patients with SMA type 2 and 3 in order to assess the relevance of the clinical classification and identify the parameters associated with the earliest and most rapid decline over time. METHODS: Thirty-one patients aged 3-21 years were followed over a 10-year period. Lung function, blood gases, respiratory mechanics and muscle strength with recording of oesogastric pressures were measured during routine follow-up. RESULTS: At least two measurements were available in 16 patients (seven type 2 and nine type 3). Among all the volitional and non-volitional, invasive and non-invasive tests, forced vital capacity (FVC) and sniff nasal inspiratory pressure (SNIP) were shown to be the most informative parameters, showing lower values in SMA type 2, with however a similar rate of decline in patients with SMA type 2 and 3. CONCLUSION: Our results confirm an earlier decline in lung and respiratory muscle function in patients classified as SMA type 2 as compared with patients classified as type 3. This decline can be assessed by two simple non-invasive tests, FVC and SNIP, with the last maneuver being feasible and reliable in the youngest children, underlying its interest for the monitoring of children with SMA.

Arterial alterations in severely obese children with obstructive sleep apnoea.

BACKGROUND: Obstructive sleep apnoea (OSA) in obese adults is associated with cardiovascular disease independently of obesity. Vascular alterations exist in children with obesity and may constitute the first stage in the development of adulthood cardiovascular disease. OBJECTIVE: To investigate the relationship between OSA and early arterial alterations in obese children. DESIGN: Cross-sectional study of a prospective cohort. PATIENTS: A total of 51 children with severe obesity managed at a teaching hospital outpatient clinic. MEASUREMENTS: Polysomnography was performed. We measured the intima-media thickness and incremental elastic modulus (Einc) to assess the mechanical characteristics of the common carotid artery. Arterial endothelial function was evaluated by measuring flow-mediated dilation and glyceryl trinitrate-mediated dilation (GTNMD) of the brachial artery. RESULTS: A total of 24 (47%) children had a desaturation index (DI) >10/h and 7 (14%) had a respiratory event index >10/h. DI >10/h was associated with significantly higher values of Einc (4.0 + or - 0.5 vs. 2.4 + or - 0.4 mm Hg(-1) x 10(3), p=0.003) and GTNMD (18.0 + or - 1.1 vs. 14.1 + or - 1.0 %, p=0.02) after adjustment for age, sex, body mass index, fasting insulin, and leptin. In the univariate analysis, GTNMD correlated positively with DI (r=0.14, p=0.02) after adjustment for age, sex, fasting insulin and leptin. By multivariate analysis with BMI as an additional independent variable, both GTNMD and Einc correlated significantly with DI (beta=0.4, p=0.02 and beta=0.27, p=0.04, respectively). CONCLUSIONS: OSA in children is associated with arterial alterations independently from obesity. The increased vasodilation in response to glyceryl trinitrate reflects pre-existing vasoconstriction probably induced by intermittent hypoxia. OSA should be detected early in children with severe obesity.

Genetic variations in inflammatory mediators influence lung disease progression in cystic fibrosis.

The clinical course of cystic fibrosis (CF) varies considerably among patients carrying the same CF-causing gene mutation. Additional genetic modifiers may contribute to this variability. As airway inflammation is a key component of CF pathophysiology, we investigated whether major cytokine variants represent such modifiers in young CF patients. We tested 13 polymorphisms in 8 genes that play a key role in the inflammatory response: tumor necrosis factor, lymphotoxin alpha, interleukin (IL) 1B, IL1 receptor antagonist, IL6, IL8, IL10 and transforming growth factor beta 1 (TGFB1), for an association with lung disease progression and nutritional status in 329 CF patients. Variants in the TGFB1 gene at position +869T/C demonstrated a significant association with lung function decline. A less pronounced rate of decline in forced expiratory volume in 1 sec (FEV(1)) and forced vital capacity (FVC) were observed in patients heterozygous for TGFB1 +869 (+869CT), when compared to patients carrying either TGFB1 +869TT or +869CC genotypes. These findings support the concept that TGFB1 gene variants appear to be important genetic modifiers of lung disease progression in CF.

Influence of interleukin-10 on Aspergillus fumigatus infection in patients with cystic fibrosis.

Recent evidence suggests that genetic polymorphisms that affect the production of interleukin (IL)-10 may play a role in the response to pathogens in cystic fibrosis (CF). The present study was designed to investigate a possible association between alleles carried at position -1082 in the promoter region of the IL-10 gene and clinical data on 378 patients with CF. After adjustment for potential confounding variables, a significant relationship was found between the -1082GG genotype and both colonization with Aspergillus fumigatus and allergic bronchopulmonary aspergillosis. In addition, higher serum levels of IL-10 were observed in patients colonized with A. fumigatus. These results suggest that polymorphisms in the promoter region of the IL-10 gene may influence the host response to A. fumigatus in the context of CF.