Reduction In Airflow Research Articles

Obstructive sleep apnea syndrome and sleep quality in hypertensive patients.

Obstructive sleep apnea and hypopnea syndrome (OSAHS) is one of the developmental factors of high blood pressure (HBP), a relevant global public health problem. OSAHS is characterized by the reduction or complete cessation of respiratory airflow due to intermittent airway collapse. Additionally, significant changes in sleep rhythm and pattern are observed in these patients. To evaluate the association between OSAHS and sleep quality in essential and resistant hypertensives. A cross-sectional, observational study evaluated 43 hypertensive patients treated at the outpatient clinics of the Faculdade de Medicina do ABC (FMABC) who were medicated with two or more antihypertensive drugs and divided into nonresistant or resistant to treatment. Group I (using up to two antihypertensive agents - 60.47% of the sample) presented mean systolic blood pressure (SBP) of 127.5±6.4 mmHg, mean diastolic blood pressure (DBP) of 79.6±5.2 mmHg, mean body mass index (BMI) of 27.2±5.3 kg/m2 and mean age of 51.2±15.1 years. Group II (using more than two antihypertensive drugs - 37.2% of the sample) presented mean SBP of 132.1±9.3 mmHg, mean DBP of 84.5±5.8 mmHg, mean BMI of 27.2±7.2 kg/m2 and mean age of 55.5±13.4 years. The patients presented low quality of sleep/sleep disorder evaluated by the Pittsburgh Sleep Quality Index (PSQI), which represents a preponderant factor for OSAHS. Patients at high risk for OSAHS had poor sleep quality and high levels of DBP, suggesting a causal relation between these parameters. However, they did not present a higher prevalence of resistant high blood pressure (RHBP).

Relationship between degree of obstruction and airflow limitation in subglottic stenosis.

Subglottic stenosis (SGS) is one of the most common airway disorders in pediatric patients. Currently, treatment decisions rely primarily on the Cotton-Myer scale, which classifies SGS severity based on percentage reduction in airspace cross-sectional area (CSA). However, the precise relationship between upper airway resistance and subglottic CSA is unknown. We hypothesize that airway resistance can be described by the Bernoulli Obstruction Theory, which predicts that airway resistance is inversely proportional to airspace CSA ( R∝A-1) in cases of severe constriction. Computed tomography (CT) scans of six healthy subjects and five SGS patients were used to create three-dimensional models of the respiratory tract from nostrils to carina. Cylindrical segments of varying lengths and varying diameters were digitally inserted in the subglottis of the healthy subjects to create simulated SGS models. Computational fluid dynamics simulations were run, and airway resistance was computed in the simulated SGS models and actual SGS models. Constriction diameter had a greater impact in airway resistance than constriction length. In agreement with the Bernoulli Obstruction Theory, airway resistance in the simulated SGS models was well represented by the power law R=aAb, where a is a constant and the exponent b ranged from -0.85 to -1.07. The percentage reduction in airflow (QOBSTRUCTIONQHEALTHY) at a constant pressure drop was found to be directly proportional to the percentage reduction in CSA (AOBSTRUCTIONAHEALTHY) in the limit of severe constrictions, namely QOBSTRUCTIONQHEALTHY=kAOBSTRUCTIONAHEALTHY, where k=2.25±0.15. Airway resistances in the simulated SGS models were similar to resistances in models based on CT scans of actual SGS patients, suggesting that our simulated SGS models were representative of airway resistance in actual SGS patients. Our computer simulations suggest that the degree of airflow limitation in SGS patients may be estimated based on anatomic measurements alone. Future studies are recommended to test these predictions in larger cohorts. 4. Laryngoscope, 128:1551-1557, 2018.

Distinct Patterns of Hyperpnea During Cheyne-Stokes Respiration: Implication for Cardiac Function in Patients With Heart Failure.

In heart failure (HF), we observed two patterns of hyperpnea during Cheyne-Stokes respiration with central sleep apnea (CSR-CSA): a positive pattern where end-expiratory lung volume remains at or above functional residual capacity, and a negative pattern where it falls below functional residual capacity. We hypothesized the negative pattern is associated with worse HF. Patients with HF underwent polysomnography. During CSR-CSA, hyperpnea, apnea-hyperpnea cycle, and lung to finger circulation times (LFCT) were measured. Plasma N-terminal prohormone of brain natriuretic peptide (NT-proBNP) concentration and left ventricular ejection fraction (LVEF) were assessed. Of 33 patients with CSR-CSA (31 men, mean age 68 years), 9 had a negative hyperpnea pattern. There was no difference in age, body mass index, and apnea-hypopnea index between groups. Patients with a negative pattern had longer hyperpnea time (39.5 ± 6.4 versus 25.8 ± 5.9 seconds, P < .01), longer cycle time (67.8 ± 15.9 versus 51.7 ± 9.9 seconds, P < .01), higher NT-proBNP concentrations (2740 [6769] versus 570 [864] pg/ml, P = .01), and worse New York Heart Association class (P = .02) than those with a positive pattern. LFCT and LVEF did not differ between groups. Patients with HF and a negative CSR-CSA pattern have evidence of worse cardiac function than those with a positive pattern. Greater positive expiratory pressure during hyperpnea is likely generated during the negative pattern and might support stroke volume in patients with worse cardiac function. A commentary on this article appears in this issue on page 1227. The trial is registered with Current Controlled Trials (www.controlled-trials.com; ISRCTN67500535) and Clinical Trials (www.clinicaltrials.gov; NCT01128816).

Reducing Diesel Engine Drive Cycle Fuel Consumption through Use of Cylinder Deactivation to Maintain Aftertreatment Component Temperature during Idle and Low Load Operating Conditions

Modern on-road diesel engine systems incorporate flexible fuel injection, variable geometry turbocharging, high pressure exhaust gas recirculation, oxidation catalysts, particulate filters and selective catalytic reduction systems in order to comply with strict tailpipe-out NOx and soot limits. Fuel consuming strategies, including late injections and turbine-based engine exhaust throttling are typically used to increase turbine outlet temperature and flow rate in order to reach the aftertreatment component temperatures required for efficient reduction of NOx and soot. The same strategies are used at low load operating conditions to maintain aftertreatment temperatures. This paper demonstrates that cylinder deactivation (CDA) can be used to maintain aftertreatment temperatures in a more fuel efficient manner through reductions in airflow and pumping work. The incorporation of CDA to maintain desired aftertreatment temperatures during idle conditions is experimentally demonstrated to result in fuel savings of 3.0% over the HD-FTP drive cycle. Implementation of CDA at non-idle portions of the HD-FTP where BMEP is below 3 bar is demonstrated to reduce fuel consumption further by an additional 0.4%, thereby resulting in 3.4% fuel savings over the drive cycle.

The long-term effects of mandibular advancement splint on cardiovascular fitness and psychomotor performance in patients with mild to moderate obstructive sleep apnea: a prospective study.

Obstructive sleep apnea (OSA) manifests as a reduction or complete cessation of airflow despite an ongoing inspiratory effort, leading to hypoxemia and hypercapnia. The inability to maintain normal breathing reduces the oxygen saturation in blood leading to a cycle of various systemic implications. Hence, a prospective single arm study was planned to evaluate the long-term (2years) effect of oral appliance on cardiovascular fitness and psychomotor performance in patients with mild to moderate obstructive sleep apnea. Thirty dentulous OSA patients (25 males; 5 females; age 41±4years; BMI 22±5; AHI 5-30) were included in the study. All the patients were assessed for systolic blood pressure (SBP), diastolic blood pressure (DBP), apnea/hypopnea index (AHI), lipid peroxidation, and psychomotor vigilance test at baseline, 6months, 1year, and 2years after wearing mandibular advancement splint (MAS). A significant reduction in AHI, blood pressure, and lipid peroxidation was observed following MAS use. Psychomotor vigilance test showed marked improvement in response time with almost 0 count of lapses after 2years of MAS use. The present study suggested that MAS can be helpful in improving cardiovascular fitness and cognitive response in patients with mild to moderate OSA.

Effects of application of variable valve timing on the exhaust gas temperature improvement in a low-loaded diesel engine

Engine manufacturers generally use aftertreatment systems to meet the strict emission criteria on automotive diesel engines. However, those systems operate inefficiently particularly at low-loaded cases of diesel engines since exhaust gas temperatures at aftertreatment inlet remain below 250°C. For those cases, variable valve timing (VVT) method can be applied to elevate exhaust temperatures and improve aftertreatment emission conversion efficiency. Therefore, in this study, intake valve closing (IVC) timing is advanced and retarded sufficiently from the base condition on a low-loaded diesel engine to increase aftertreatment inlet exhaust temperature above 250°C. A specially designed computer program, Lotus Engine Simulation (LES), is utilized to model the diesel engine. Experimental data of a similar study is used for the validation of the simulation. Engine loading (taken as brake mean effective pressure (BMEP)) is kept constant at 2.5bar by adjusting the fuel injection rate. The results show that there is a considerable exhaust temperature rise (up to 65°C) at aftertreatment inlet with the method and it is adequate for effective aftertreatment performance (Texhaust>250°C). It is also seen that the increase on exhaust temperature is due to the sudden reduction on volumetric efficiency (from 94% to 65%). Therefore, there is lower air induction into the cylinders and hence lower pumping losses which result in fuel-efficiency in the system. However, air flow reduction also causes a sharp decrease on the exhaust flow rate which affects the heat capacity of exhaust gases negatively in the system.

Effect of windbreaks on wind speed reduction and soil protection against wind erosion

Windbreaks form efficient soil protection against wind erosion particularly at the time when soil cover is not protected by the cultivated plant vegetation cover. The objective of this research was to evaluate windbreaks efficiency in terms of wind speed reduction. Wind speed along the windbreaks was measured in the cadastral areas of Dobrovíz and Středokluky (Czech Republic, Central Europe). The measurement was carried out by 4 stations placed at windward side (1 station at the distance of 3 times the height of the windbreak) and at leeward side of the windbreak (3 stations at the distance of 3, 6, and 9 times the height of the windbreak). Each station contained 2 anemometers situated 0.5 and 1 m above surface. The character of windbreak was described by terrestrial photogrammetry method as the value of optical porosity from the photo documentation of the windbreak at the time of field measurement. A significant dependence between the value of optical porosity and efficiency of windbreak emerged from the results. The correlation coefficient between optical porosity and wind speed reduction was in the range of 0.842 to 0.936 (statistical significance more than 95%). A significant effect of windbreak on airflow reduction was proven on the leeward side of windbreak in a belt corresponding to approximately six times the height of the windbreaks depending on the optical porosity and it was expressed by a polynomial equation.

Real-time sleep apnea detection using wavelet packet transform and support vector machines

Sleep apnea events as obstructive, central, mixed, or hypopnea are characterized by frequent breathing cessations or reduction in upper airflow during sleep. An advanced method for analyzing the patterning of biomedical signals to recognize obstructive sleep apnea and hypopnea is presented. In the aim to extract characteristic parameters, which will be used for classifying the above-stated (obstructive, central, mixed) sleep apnea and hypopnea, the proposed method is based, first, on the analysis of polysomnopraphy signals such as electrocardiogram signal (ECG) and electromyogram (EMG) and then classification of (obstructive, central, mixed) sleep apnea and hypopnea. The analysis is carried out using the wavelet transform technique in order to extract characteristic parameters, whereas classification is carried out by applying the SVM (support vector machine) technique. The obtained results show good recognition rates using characteristic parameters.

Utilizing low airflow strategies, including cylinder deactivation, to improve fuel efficiency and aftertreatment thermal management

Approximately 30% of the fuel consumed during typical heavy-duty vehicle operation occurs at elevated speeds with low-to-moderate loads below 6.5 bar brake mean effective pressure. The fuel economy and aftertreatment thermal management of the engine at these conditions can be improved using conventional means as well as cylinder deactivation and intake valve closure modulation. Airflow reductions result in higher exhaust gas temperatures, which are beneficial for aftertreatment thermal management, and reduced pumping work, which improves fuel efficiency. Airflow reductions can be achieved through a reduction of displaced cylinder volume by using cylinder deactivation and through reduction of volumetric efficiency by using intake valve closure modulation. This paper shows that, depending on load, cylinder deactivation and intake valve closure modulation can be used to reduce the fuel consumption between 5% and 25%, increase the rate of warm-up of aftertreatment, maintain higher temperatures, or achieve active diesel particulate filter regeneration without requiring dosing of the diesel oxidation catalyst.

Dynamic hyperinflation in patients with asthma and exercise-induced bronchoconstriction

BackgroundLittle is known about the behavior of operative lung volumes during exercise in patients with asthma and exercise-induced bronchoconstriction (EIB). ObjectiveTo compare the presence of dynamic hyperinflation (DH) in patients with mild asthma with and without EIB and in healthy individuals and to relate the changes in end-expiratory lung volume (EELV) with postexercise airflow reduction. MethodsA total of 122 consecutive stable patients (>12 years of age) with mild asthma and 38 controls were studied. Baseline lung volumes were measured, and all patients performed an exercise bronchial challenge. At each minute of exercise, EELV and end-inspiratory lung volume (EILV) were estimated from inspiratory capacity measurements to align the tidal breathing flow-volume loops to within the maximal expiratory curve. ResultsDH was more frequent in patients with asthma and EIB (76%) than in patients with asthma but without EIB (11%) or controls (18%). The EELV increased in patients with asthma and EIB and decreased in patients with asthma without EIB and controls during exercise. In the patients with asthma, the decrease in forced expiratory volume in 1 second after the exercise challenge correlated with age (r = −0.179, P = .05), baseline forced vital capacity (r = 0.255, P = .005), EELV increase (r = 0.447, P < .001), and EILV increase (r = 0.246, P = .007). Age, baseline forced vital capacity, and magnitude of DH were retained as independent predictors of EIB intensity. ConclusionIn patients with asthma and EIB, the development of DH is very frequent and related to the intensity of postexercise bronchoconstriction. This finding could implicate DH in the development of EIB.

Quantitative EEG in obstructive sleep apnea syndrome: a review of the literature

Obstructive sleep apnea syndrome (OSAS) is characterized by the recurrent cessation (apnea) or reduction (hypopnea) of airflow due to the partial or complete upper airway collapse during sleep. Respiratory disturbances causing sleep fragmentation and repetitive nocturnal hypoxia are responsible for a variety of nocturnal and daytime complaints of sleep apnea patients, such as snoring, daytime sleepiness, fatigue, or impaired cognitive functions. Different techniques, such as magnetic resonance imaging, magnetic resonance spectroscopy, and positron emission tomography, are used to evaluate the structural and functional changes in OSAS patients. With quantitative electroencephalographic (qEEG) analysis, the possible existence of alterations in the brain electrical activity of OSAS patients can be investigated. We review the articles on qEEG results of sleep apnea patients and summarize the possible explanations of these qEEG measures. Finally, we review the impact of continuous positive airway pressure (CPAP) treatment on these alterations to assess whether CPAP use can eliminate alterations in the brain activity of OSAS patients.

Obstructive Sleep-Disordered Breathing Is More Common than Central in Mild Familial Dysautonomia.

In familial dysautonomia (FD) patients, sleep-disordered breathing (SDB) might contribute to their high risk of sleep-related sudden death. Prevalence of central versus obstructive sleep apneas is controversial but may be therapeutically relevant. We, therefore, assessed sleep structure and SDB in FD-patients with no history of SDB. 11 mildly affected FD-patients (28 ± 11 years) without clinically overt SDB and 13 controls (28 ± 10 years) underwent polysomnographic recording during one night. We assessed sleep stages, obstructive and central apneas (≥ 90% air flow reduction) and hypopneas (> 30% decrease in airflow with ≥ 4% oxygen-desaturation), and determined obstructive (oAI) and central (cAI) apnea indices and the hypopnea index (HI) as count of respective apneas/hypopneas divided by sleep time. We obtained the apnea-hypopnea index (AHI4%) from the total of apneas and hypopneas divided by sleep time. We determined differences between FD-patients and controls using the U-test and within-group differences between oAIs, cAIs, and HIs using the Friedman test and Wilcoxon test. Sleep structure was similar in FD-patients and controls. AHI4% and HI were significantly higher in patients than controls. In patients, HIs were higher than oAIs and oAIs were higher than cAIs. In controls, there was no difference between HIs, oAIs, and cAIs. Only patients had apneas and hypopneas during slow wave sleep. In our FD-patients, obstructive apneas were more common than central apneas. These findings may be related to FD-specific pathophysiology. The potential ramifications of SDB in FD-patients suggest the utility of polysomnography to unveil SDB and initiate treatment. A commentary on this article appears in this issue on page 1583.

Exercise-induced laryngeal obstruction: a common and overlooked cause of exertional breathlessness.

A commonly-encountered clinical scenario in primary care involves an adolescent or young adult, with no past medical history, presenting with wheeze and breathlessness, occurring in association with exercise.1 However, the differential diagnosis for this presentation is broad. Such patients are often diagnosed with exercise-induced asthma and prescribed a short-acting bronchodilator.1 Recently there has been increasing recognition that an alternative diagnosis should be considered,2 specifically a condition termed exercise-induced laryngeal obstruction (EILO), a phenomenon in which closure of the larynx occurs during high-intensity exercise. This narrowing causes a significant reduction in airflow, thereby precipitating breathlessness and wheeze. Some have termed this condition exercise-induced vocal cord dysfunction (VCD), although the narrowing most frequently occurs at a level above the vocal cords (that is, involves supra-glottic structures) and thus EILO is an appropriate descriptor. The reason EILO develops in some individuals is currently unclear. A primary function of the glottis is to defend the airway, and thus the larynx resides in a primed status that favours closure. The larynx is richly innervated and may become hypersensitive upon repeated exposure to laryngeal irritants. Moreover, the forces and pressure change that are manifest across the larynx during intense exercise appear to play a role in precipitating laryngeal closure. Distinguishing between exercise-induced bronchoconstriction and EILO can be diagnostically challenging, particularly in a primary care setting. The aim of this short article is thus not to provide a complete review of EILO, but to highlight pertinent features for focus in a clinic-based assessment, and …

Hungarian Society for Sleep Medicine guideline for detecting drivers with obstructive sleep apnea syndrome

Obstructive sleep apnea is the most frequent sleep-disordered breathing. The prevalence of sleep apnea in the general population is 2-4% and the main characteristics of the disease are the intermittent cessation or substantial reduction of airflow during sleep, which is caused by complete, or near complete upper airway obstruction. Decreased airflow is followed by oxygen desaturation and intermittent arousals. Untreated patients are 4-6 times more likely to cause traffic accidents than their healthy counterparts. The aims of the obstructive sleep apnea screening are to prevent and reduce the incidence of serious car accidents, which are often caused by one of the most dangerous sleep disorders. Since April 1, 2015 a modification of the 13/1992 regulation has been in force in Hungary which orders screening of obstructive sleep apnea during medical checkup of drivers. The Hungarian Society for Sleep Medicine made a guideline according to the regulation which was adapted to national circumstances and family doctors, occupational health specialists can more easily screen obstructive sleep apnea in suspected patients. In sleep ambulances the disease can be diagnosed and effective treatment can be started. Patients receiving appropriate treatment and with appropriate compliance can get their driving licence under regular care and control.

In-situ diagnostic tools for hydrogen transfer leak characterization in PEM fuel cell stacks part II: Operational applications

This paper describes a diagnostic tool for in-situ characterization of the rate and distribution of hydrogen transfer leaks in Polymer Electrolyte Membrane (PEM) fuel cell stacks. The method is based on reducing the air flow rate from a high to low value at a fixed current, while maintaining an anode overpressure. At high air flow rates, the reduction in air flow results in lower oxygen concentration in the cathode and therefore reduction in cell voltages. Once the air flow rate in each cell reaches a low value at which the cell oxygen-starves, the voltage of the corresponding cell drops to zero. However, oxygen starvation results from two processes: 1) the electrochemical oxygen reduction reaction which produces current; and 2) the chemical reaction between oxygen and the crossed over hydrogen. In this work, a diagnostic technique has been developed that accounts for the effect of the electrochemical reaction on cell voltage to identify the hydrogen leak rate and number of leaky cells in a fuel cell stack. This technique is suitable for leak characterization during fuel cell operation, as it only requires stack air flow and voltage measurements, which are readily available in an operational fuel cell system.

Nasal airway responses to nasal continuous positive airway pressure breathing: An in-vivo pilot study

The nasal cycle, through variation in nasal airflow partitioning, allows the upper airway to accommodate the contrasting demands of air conditioning and removal of entrapped air contaminants. The purpose of this study was to investigate the influence of nasal continuous positive airway pressure (nCPAP) breathing has on both nasal airflow partitioning and nasal geometry. Using a custom-made nasal mask, twenty healthy participants had the airflow in each naris measured during normal nasal breathing followed by nCPAP breathing. Eight participants also underwent magnetic resonance imaging (MRI) of the nasal region during spontaneous nasal breathing, and then nCPAP breathing over a range of air pressures. During nCPAP breathing, a simultaneous reduction in airflow through the patent airway together with a corresponding increase in airway flow within the congested nasal airway were observed in sixteen of the twenty participants. Nasal airflow resistance is inversely proportional to airway cross-sectional area. MRI data analysis during nCPAP breathing confirmed airway cross-sectional area reduced along the patent airway while the congested airway experienced an increase in this parameter. During awake breathing, nCPAP disturbs the normal inter-nasal airflow partitioning. This could partially explain the adverse nasal drying symptoms frequently reported by many users of this therapy.

Lung Function in Childhood and Adolescence: Influence of Prematurity and Bronchopulmonary Dysplasia

The introduction of prenatal steroids, surfactant replacement therapy and gentle ventilation modes has reduced short term respiratory morbidity and increased survival of very preterm infants. However, there is some evidence that prenatal factors, the extend of prematurity and bronchopulmonary dysplasia (BPD) may affect pulmonary function in childhood and adolescence. We have performed a comprehensive review on the outcome of pulmonary function after premature birth before 32 weeks of gestation in the era of surfactant replacement therapy and tried to evaluate the influence of chorioamnionitis, intrauterine growth retardation (IUGR), maternal metabolic syndrome, prematurity and BPD on long term pulmonary function. Some children and adolescents born very preterm may experience significant airflow reduction. The bronchial obstruction in these patients is not entirely reversible by inhalative ß2-mimetics. The degree of pulmonary function impairment is partly correlated with the degree of BPD. Abnormalities in pulmonary diffusion capacity may occur after extreme prematurity, but also in patients with moderate and severe BPD. IUGR may have a negative impact on later pulmonary function in very children. There is insufficient data to assess the preterm impact of chorioamnionitis or maternal metabolic syndrome on later lung function. Infants born before 32 weeks of gestational age in the surfactant era still carry an increased risk to suffer an impaired pulmonary function in childhood and adolescence, particularly if they survived with BPD. Long term pulmonary care for these patients should take place in specialized centers.

The Prevalence and Characteristics of REM Sleep without Atonia (RSWA) in Patients Taking Antidepressants.

The association of REM sleep without atonia (RSWA) as well as REM sleep behavior disorder (RBD) with the intake of selective serotonin reuptake inhibitors (SSRI) and selective norepinephrine reuptake inhibitors (SNRI) is well established. Our study objective was to determine the prevalence of RSWA and RBD among a group of sleep center patients taking SSRI and SNRI. A retrospective chart review was done at our tertiary sleep center, and 10,746 consecutive records from October 1, 2007, through October 31, 2013, were searched for SSRI and SNRI names using the Sleep Cataloguer Software. The search resulted in 1,444 records, which were then reviewed for keywords of RSWA and RBD. The AASM scoring criteria were used to determine RSWA. Reports of 41 patients with known narcolepsy or α-synucleinopathies were excluded. The remaining records were mined for age, sex, presence of obstructive sleep apnea (OSA), type of antidepressant (SSRI or SNRI), and diagnosis for which antidepressant was prescribed. We used logistic regression analysis to adjust for age, OSA, and sex. Of the 1,444 participants on antidepressants, 176 (12.2%) had RSWA (all confirmed by the investigators) compared to 226 of the entire sleep lab population of 10,746 (2.1%), risk ratio (95% CI) 9.978 (8.149, 12.22). Seven of the 176 patients on antidepressants had RBD (0.48%) compared to 108 of 10,746 (1%), p = 0.005. SSRI and SNRI are associated with a higher prevalence of RSWA but not of RBD. This is independent of medication type.

Relationship of airflow limitation severity with work productivity reduction and sick leave in a Japanese working population.

BackgroundThe aim of this study was to reveal the association between airflow limitation (AL) severity and reduction with work productivity as well as use of sick leave among Japanese workers.MethodsThis cross-sectional study included 1,378 workers who underwent a lung function test during a health checkup at the Japanese Red Cross Kumamoto Health Care Center. AL was defined as forced expiratory volume in 1 second/forced vital capacity of <0.7. Workers completed a questionnaire on productivity loss at work and sick leave. The quality and quantity of productivity loss at work were measured on a ten-point scale indicating how much work was actually performed on the previous workday. Participants were asked how many days in the past 12 months they were unable to work because of health problems. Logistic regression analysis was used to assess the associations between AL severity and the quality and quantity of productivity loss at work as well as use of sick leave.ResultsCompared with workers without AL, workers with moderate-to-severe AL showed a significant productivity loss (quality: odds ratio [OR] =2.04, 95% confidence interval [CI]: 1.12–3.71, P=0.02 and quantity: OR =2.19, 95% CI: 1.20–4.00, P=0.011) and use of sick leave (OR =2.69, 95% CI: 1.33–5.44, P=0.006) after adjusting for sex, age, body mass index, smoking status, hypertension, hyperglycemia, dyslipidemia, sleep duration, work hours per day, and workplace smoking environment.ConclusionAL severity was significantly associated with work productivity loss and use of sick leave. Our findings suggested that early intervention in the subjects with AL at the workforce might be beneficial for promoting work ability.

Is there a correlation between nasal septum deviation and maxillary transversal deficiency? A retrospective study on prepubertal subjects

IntroductionDeviated nasal septum may cause a reduction of the nasal airflow, thus, during the craniofacial development, a reduced nasal airflow could originate a chronic mouth-breathing pattern, related with moderate to severe maxillary constriction. The aim of this retrospective study is to analyze the correlation between maxillary transverse deficiency and nasal septum deviation. MethodsFrontal cephalograms were performed on 66 posterior–anterior radiographs of subjects (34M, 32F; mean age 9.95±2.50 years) with maxillary transverse deficiency and on a control group of 31 posterior–anterior radiographs of subjects (13M, 18F; 9.29±2.08 years). Angular parameters of the nasal cavities were recorded and compared between the two groups using a Student's t-test. ResultsGenerally all the parameters are very similar between the two groups except for the ASY angle that differs for about the 27%; anyway the Student's t-test showed no statistically significant differences between the two groups (mostly p>0.20). ConclusionsThis study failed to show an association between transverse maxillary deficiencies and nasal septum deviations. Moreover, no significant differences were found between the mean nasal cavities dimensions in subjects with transverse maxillary deficiency and the control group.