Sex differences in polysomnographic findings in patients with obstructive sleep apnea.

BACKGROUND AND PURPOSE: Sex differences in the clinical findings and the polysomnographic presentation of patients with obstructive sleep apnea (OSA) are compelling current research issues. For example, patients suffering from obstructive sleep apnea are predominantly male. While women are older than men and tend to have a higher body mass index, men typically present with a more severe form of obstructive sleep apnea. Using polysomnography, we investigated a German cohort, subdivided per severity levels of obstructive sleep apnea (apnea-hypopnea index: ≥5 to < 15/h (mild), ≥15 to < 30/h (moderate), and ≥30/h (severe)) to provide a detailed analysis of breathing and sleep parameters, accounting for body position effects and severity of illness. A deeper understanding of sex differences may allow targeted diagnosis and treatment adjustment. PATIENTS AND METHODS: This retrospective study included a cohort of 1242 German patients (940 male, 302 female) who underwent overnight polysomnography at the private sleep laboratory "Intersom Köln", Center for Sleep Medicine and Sleep Research. In 1125 subjects (878 male, 247 female), obstructive sleep apnea was diagnosed. All patients were examined between January 01, 2018 and December 31, 2020, comparing anthropometric, sleep morphological, and respiratory polysomnographic findings. RESULTS: Female patients with obstructive sleep apnea were significantly older than male patients (60.9 ± 12.3 vs. 56.9 ± 12.5 years, P < .001), also among OSA subgroups per OSA severity. The body mass index was similar in male and female patients (29.6 ± 5.1 vs. 29.2 ± 7.3 kg/m2, P > .05), including the three subgroups. Men were more likely to have severe obstructive sleep apnea (46.9%) than women (35.2%). Women exhibited a higher proportion of slow-wave sleep than men (129.4 ± 52.8 vs. 104.2 ± 53.2 min; P < .001). The apnea-hypopnea index of total sleep time was significantly greater in male than female patients (32.9 ± 21.2 vs. 27.2 ± 20.2 per hour; P < .001). Female patients had a higher apnea-hypopnea index during rapid-eye-movement (REM) sleep (34.0 ± 23.8 vs. 31.8 ± 22.3 per hour; P = .171). A statistically significant difference in the apnea-hypopnea index during REM sleep between sexes was found when the obstructive sleep apnea severity was considered. Women had a lower apnea-hypopnea index in non-rapid eye-movement (NREM) sleep than men (25.7 ± 21.1 vs. 32.7 ± 22.3 per hour; P < .001). The oxygen desaturation index (29.9 ± 20.3 vs. 22.4 ± 19.4%; P < .001) and an oxygen desaturation below 90% (9.4 ± 14.0 vs. 6.8 ± 11.7%; P = .003) was greater in men than in women. In severe obstructive sleep apnea, the oxygen desaturation index was similar between the sexes (45.0 ± 17.8 vs. 41.1 ± 20.9%; P = .077). Male patients showed a higher supine apnea-hypopnea-index than female patients. (45.7 ± 26.7 vs 36.1 ± 22.7 per hour; P < .001). CONCLUSION: The present noninvasive, retrospective registry study is the first to examine sex differences in OSA in such a large German population in terms of respiratory and sleep parameters, taking into account the effects of body position and severity of the disease. We could confirm and extend observations from previous studies. Female patients were significantly older than the male patients. The apnea-hypopnea index was higher in male than in female patients. Women showed a higher apnea-hypopnea index in REM sleep and a lower one in NREM sleep. Men were desaturated more often and were more affected by supine-dependent obstructive sleep apnea than women. Contrary to the literature, there were no significant differences in body mass index (BMI) between the sexes. With increasing age and BMI, the gender differences become less significant.

The Role of Reduced Graphene Oxide in the Suspension Polymerization of Styrene and Its Effect on the Morphology and Thermal Properties of the Polystyrene/rGO Nanocomposites.

Reduced graphene oxide (rGO) was used to obtain Polystyrene (PS)/rGO nanocomposites via in-situ suspension polymerization. The main goal of the article was to determine how rGO influences the morphology and thermal properties of PS beads. The obtained samples were studied by means of a scanning electron microscope (SEM), and calorimetric and thermogravimetric analysis (DCS, TGA). It was proven that the addition of rGO, due to the presence of polar functional groups, causes significant changes in bead sizes and size distribution, and in their morphology (on the surface and in cross-section). The increasing amount of rGO in the polymer matrix increased the size of beads from 0.36 to 3.17 mm for pure PS and PS with 0.2 wt% rGO content, respectively. PS/rGO nanocomposites are characterized by distinctly improved thermostability, which is primarily expressed in the increase in their decomposition temperature. For a sample containing 0.3 wt% rGO, the difference is more than 12 °C in comparison to pure PS beads.

A Polymeric Composite Material (rGO/PANI) for Acid Blue 129 Adsorption.

Over the years, polyaniline (PANI) has received enormous attention due to its unique properties. Herein, it was chosen to develop a new polymeric composite material: reduced graphene oxide/polyaniline (rGO/PANI). The composite was prepared by a simple and cost-effective fabrication method of formation by mixing and sonication in various conditions. The obtained materials were characterized and identified using various techniques such as scanning electron microscopy (SEM), Raman and ATR-FTIR spectroscopy, and X-ray diffraction (XRD). The objective of the paper was to confirm its applicability for the removal of contaminants from water. Water could be contaminated by various types of pollutants, e.g., inorganics, heavy metals, and many other industrial compounds, including dyes. We confirmed that the Acid Blue 129 dyes can be substantially removed through adsorption on prepared rGO/PANI. The adsorption kinetic data were modeled using the pseudo-first-order and pseudo-second-order models and the adsorption isotherm model was identified.

[Rheumatological Diseases and Sleep: Somnological Aspects of Diagnostics and Therapy]. / Rheumatologische Erkrankungen und Schlaf ­ Schlafmedizinische Aspekte der Diagnostik und Therapie ­ Eine literaturbasierte Übersicht.

This PubMed-based review discusses primary and secondary sleep disorders associated with rheumatological diseases. It presents the pathophysiological interaction of sleep-related diseases and rheumatological disorders and summarises clinical symptoms, diagnostic investigation and therapies from a somnological perspective. EPIDEMIOLOGY: 70 % of patients suffering from rheumatological diseases report poor sleep quality, numerous awakenings at night and non-restorative sleep. More than 20 % of these patients are found to have primary sleep disorders such as obstructive sleep apnoea (OSA) and the restless legs syndrome (RLS). PATHOGENESIS: Primary and secondary sleep disorders may increase symptoms associated with rheumatological diseases, e. g. excessive daytime sleepiness, fatigue, depression, pain intensity, and disease activity. Vice versa, pain intensity and inflammatory markers worsen sleep quality. In patients with rheumatic diseases, obesity as well as disease-related skeletal characteristics may be predisposing factors for obstructive sleep apnoea. The restless legs syndrome, which frequently occurs in rheumatological diseases, lowers sleep quality due to a sensory stimulus and periodic leg movements causing sleep fragmentation. DIAGNOSTIC INVESTIGATION: Somnological diagnostic investigation consists of sleep-related questionnaires and scales. Objective tests are used to measure reaction time and vigilance. Sleep-related breathing and movement disorders can be identified with screening devices and polygrafic monitoring. A final polysomnografic sleep study is necessary to make the diagnosis and to initiate a specific treatment and follow-up examinations. TREATMENT: Sleep disorders associated with rheumatological diseases may be treated with behavioural and drug therapies. Drug therapy is commonly used in the management of insomnia and RLS. Most cases of OSAS can be treated with CPAP or UPS devices. Interdisciplinary cooperation in the fields of somnology and rheumatology may improve treatment in RA patients.

Differences in clinical features of upper airway resistance syndrome, primary snoring, and obstructive sleep apnea/hypopnea syndrome.

BACKGROUND: The clinical features of patients with upper airway resistance syndrome (UARS) have previously been compared to patients with obstructive sleep apnea/hypopnea syndrome (OSAHS). No data regarding differences between patients with primary snoring (PS) or patients with obstructive sleep apnea/hypopnea without daytime sleepiness (OSAH) are available. We conducted a study to investigate clinical features of UARS, comparing them to those in patients with PS, OSAH, and OSAHS. METHODS: Retrospective chart analysis of 157 patients with PS, 424 patients with UARS, 562 patients with OSAH, and 1610 patients with OSAHS seen in two sleep disorders clinics between 1996 and 2006. All patients had a diagnostic polysomnography (PSG) and a comprehensive clinical history taken by board-certified sleep specialists. RESULTS: PS and UARS patients were significantly younger, less overweight and had lower weight gain during the past 5years. The female-to-male ratio was highest in the UARS group. UARS patients had significantly less stage non-rapid eye movement sleep (NREM) 1 and NREM 2 and significantly more NREM 3 and NREM 4 sleep than OSAH and OSAHS patients. Arousal indices between PS/UARS and OSAH/OSAHS patients were significantly lower, with no significant difference within these diagnostic categories. Patients with UARS presented the highest degree of subjective impairment. CONCLUSIONS: UARS patients share some clinical features of patients with OSAHS and PS, although these two groups differ in their presentation of clinical sleepiness. Patients with UARS were most impaired in terms of their daily functioning and perception of sleep quality. This finding could not be corroborated by objective measures.