Search Results (6)

Background/Objectives: Childhood obesity represents a growing public health concern. It is closely associated with obstructive sleep apnoea (OSA), which impairs nocturnal breathing and significantly affects neurocognitive and cardiovascular health. This review aims to analyse differences in fat distribution, anthropometric parameters, and instrumental assessments of paediatric OSA compared to adult OSA to improve the diagnostic characterisation of obese children. Methods: narrative review. Results: While adenotonsillar hypertrophy (ATH) remains a primary cause of paediatric OSA, the increasing prevalence of obesity has introduced distinct pathophysiological mechanisms, including fat accumulation around the pharynx, reduced respiratory muscle tone, and systemic inflammation. Children exhibit different fat distribution patterns compared to adults, with a greater proportion of subcutaneous fat relative to visceral fat. Nevertheless, cervical and abdominal adiposity are crucial in increasing upper airway collapsibility. Recent evidence highlights the predictive value of anthropometric and body composition indicators such as neck circumference (NC), neck-to-height ratio (NHR), neck-to-waist ratio (NWR), fat-to-muscle ratio (FMR), and the neck-to-abdominal-fat percentage ratio (NAF%). In addition, ultrasound assessment of lateral pharyngeal wall (LPW) thickness and abdominal fat distribution provides clinically relevant information regarding anatomical contributions to OSA severity. Among imaging modalities, dual-energy X-ray absorptiometry (DXA), bioelectrical impedance analysis (BIA), and air displacement plethysmography (ADP) have proven valuable tools for evaluating body fat distribution. Conclusions: Despite advances in the topic, a validated predictive model that integrates these parameters is still lacking in clinical practice. Polysomnography (PSG) remains the gold standard for diagnosis; however, its limited accessibility underscores the need for complementary tools to prioritise the identification of children at high risk. A multimodal approach integrating clinical, anthropometric, and imaging data could support the early identification and personalised management of paediatric OSA in obesity. Full article

The present study used the adult earthworm Aporrectodea trapezoides as a bioindicator species to look into the possible dangers of ammonium sulfate (AS) fertilizer. Two complementary toxicity tests were conducted to determine the LC50values, growth rate inhibition, morphological alterations, and histopathological texture of worms. The lethality test included four increasing concentrations of AS fertilizer (ranging from 2500 to 7500 mg/kg of dry soil weight (d.w.)), while sub-lethal concentrations were based on 10%, 30%, 40%, and 50% of the 14-day median lethal concentration (LC50), with a control group included for both tests. The LC₍₅₀₎ values for AS fertilizer were significantly higher at 7 days (4831.13 mg/kg d.w.) than at 14 days (2698.67 mg/kg d.w.) of exposure. Notably, earthworms exhibited significant growth rate inhibition under exposure to various concentrations and time durations (14/28 exposure days). Morphological alterations such as clitellar swelling, bloody lesions, whole body coiling and constriction, body strangulation, and fragmentation were accentuated steadily, with higher concentrations. Histopathological manifestations included severe injuries to the circular and longitudinal muscular layers, vacuolation, muscle layer atrophy, degradation of the chloragogenous tissue in the intestine, collapsed digestive epithelium of the pharynx with weak reserve inclusion, and fibrosis of blood vessels. These effects were primarily influenced by increasing concentrations of fertilizer and time exposure. The study highlights the strong relationship between concentration and exposure time responses and underscores the potential of A. trapezoides earthworms as valuable biological control agents against acidic ammonium sulfate fertilizer. Importantly, this research contributes to the use of such biomarkers in evaluating soil toxicity and the biological control of environmental risk assessment associated with chemical fertilizers. Full article

This study presents a data-driven approach to identifying anomaly-sensitive parameters through a multiscale, multifaceted analysis of simulated respiratory flows. The anomalies under consideration include a pharyngeal model with three levels of constriction (M1, M2, M3) and a flapping uvula with two types of kinematics (K1, K2). Direct numerical simulations (DNS) were implemented to solve the wake flows induced by a flapping uvula; instantaneous vortex images, as well as pressures and velocities at seven probes, were recorded for twelve cycles. Principal component analysis (PCA), wavelet-based multifractal spectrum and scalogram, and Poincaré mapping were implemented to identify anomaly-sensitive parameters. The PCA results demonstrated a reasonable periodicity of instantaneous vortex images in the leading vector space and revealed distinct patterns between models with varying uvula kinematics (K1, K2). At higher PCA ranks, the periodicity gradually decays, eventually transitioning to a random pattern. The multifractal spectra and scalograms of pressures in the pharynx (P6, P7) show high sensitivity to uvula kinematics, with the pitching mode (K2) having a wider spectrum and a left-skewed peak than the heaving mode (K1). Conversely, the Poincaré maps of velocities and pressures in the pharynx (Vel6, Vel7, P6, P7) exhibit high sensitivity to pharyngeal constriction levels (M1–M3), but not to uvula kinematics. The parameter sensitivity to anomaly also differs with the probe site; thus, synergizing measurements from multiple probes with properly extracted anomaly-sensitive parameters holds the potential to localize the source of snoring and estimate the collapsibility of the pharynx. Full article

Obstructive sleep apnea (OSA) is a highly prevalent sleep breathing disorder characterized by the collapse of the pharyngeal walls that entails recurrent episodes of cessation of breathing or decrease in airflow while sleeping. This results in sleep fragmentation, decreased oxygen saturation and an increase in the partial pressure of carbon dioxide, causing excessive daytime sleepiness, hypertension and increased prevalence of cardiovascular morbidity and mortality. Mandibular advancement devices (MAD) represent a valid alternative therapy to Continuous Positive Airway Pressure, thrusting the mandible forward, increasing the lateral diameter of the pharynx and reducing the collapsibility of the airway. Several investigations have focused on the detection of the best mandibular advancement amount in terms of effectiveness and tolerance, but few and contrasting data are available on the role of occlusal bite raise in reducing the apnea/hypopnea index (AHI). The aim of this systematic review with meta-regression analysis was to investigate the effect of the bite raise of MAD on AHI values in adult patients affected by OSA. An electronic search was performed in MEDLINE, the Cochrane Database, Scopus, Web of Science and LILACS. Randomized controlled trials (RCT) investigating the effectiveness of MAD in OSA patients were included. The quality of evidence was evaluated with the Grading of Recommendations Assessment, Development and Evaluation (GRADE) and the risk of bias with the Cochrane risk-of-bias tool for randomized trials (RoB2). Six RCT were included. The success rate of each study was computed: (mean baseline AHI − mean post treatment AHI)/mean baseline AHI. The GRADE scores indicated that the quality of evidence was very low. The meta-regression analysis showed that there was no correlation between the occlusal bite raise and the AHI improvement. Full article

This paper presents a computational and experimental study of steady inhalation in a realistic human pharyngeal airway model. To investigate the intricate fluid dynamics inside the pharyngeal airway, the numerical predicted flow patterns are compared with in vitro measurements using Particle Image Velocimetry (PIV) approach. A structured mesh with 1.4 million cells is used with a laminar constant flow rate of 10 L/min. PIV measurements are taken in three sagittal planes which showed flow acceleration after the pharynx bend with high velocities in the posterior pharyngeal wall. Computed velocity profiles are compared with the measurements which showed generally good agreements with over-predicted velocity distributions on the anterior wall side. Secondary flow patterns on cross-sectional slices in the transverse plane revealed vortices posterior of pharynx and a pair of secondary flow vortexes due to the abrupt cross-sectional area increase. Finally, pressure and flow resistance analysis demonstrate that greatest pressure occurs in the superior half of the airway and maximum in-plane pressure variation is observed at the velo-oropharynx junction, which expects to induce a high tendency of airway collapse during inhalation. This study provides insights of the complex fluid dynamics in human pharyngeal airway and can contribute to a reliable approach to assess the probability of flow-induced airway collapse and improve the treatment of obstructive sleep apnea. Full article

Obstructive sleep apnea (OSA) is a highly prevalent disease characterized by recurrent closure of the upper airway during sleep. It has a complex pathophysiology involving four main phenotypes. An abnormal upper airway anatomy is the key factor that predisposes to sleep-related collapse of the pharynx, but it may not be sufficient for OSA development. Non-anatomical traits, including (1) a compromised neuromuscular response of the upper airway to obstruction, (2) an unstable respiratory control (high loop gain), and (3) a low arousal threshold, predict the development of OSA in association with anatomical abnormalities. Current therapies for OSA, such as continuous positive airway pressure (CPAP) and oral appliances, have poor adherence or variable efficacy among patients. The search for novel therapeutic approaches for OSA, including pharmacological agents, has been pursued over the past years. New insights into OSA pharmacotherapy have been provided by preclinical studies, which highlight the importance of appropriate use of animal models of OSA, their applicability, and limitations. In the present review, we discuss potential pharmacological targets for OSA discovered using animal models. Full article