RESUMO
Scale-down models (SDM) are pivotal tools for process understanding and improvement to accelerate the development of vaccines from laboratory research to global commercialization. In this study, a 3 L SDM representing a 50 L scale Vero cell culture process of a live-attenuated virus vaccine using microcarriers was developed and qualified based on the constant impeller power per volume principle. Both multivariate data analysis (MVDA) and the traditional univariate data analysis showed comparable and equivalent cell growth, metabolic activity, and product quality results across scales. Computational fluid dynamics simulation further confirmed similar hydrodynamic stress between the two scales.
RESUMO
Understanding polymer transport in nanopores is crucial for optimizing heterogeneously catalyzed processes in polymer upcycling and fabricating high-performance nanocomposite films and membranes. Although confined polymer dynamics have been extensively studied, the behavior of polyethylene (PE)-the most widely used commodity polymer-in pores smaller than 20 nm remains largely unexplored. We investigate the effects of extreme nanoconfinement on PE transport using capillary rise infiltration in silica nanoparticle packings with average pore radii ranging from â¼1 to â¼9 nm. Using in situ ellipsometry and the Lucas-Washburn model, we discover a previously unknown inverse relationship between effective viscosity (ηeff) and average pore radius (Rpore). Additonally, we determine that PE transport under these extreme conditions is primarily governed by physical confinement, rather than pore surface chemistry. We refine an existing theory to provide a generalized formalism to describe the polymer transport dynamics over a wide range of pore radii (from 1 nm and larger). Our results offer valuable insights for optimizing catalyst supports in polymer upcycling and improving infiltration processes for nanocomposite fabrication.
RESUMO
We report a synthesis method for highly monodisperse Cu-Pt alloy nanoparticles. Small and large Cu-Pt particles with a Cu/Pt ratio of 1:1 can be obtained through colloidal synthesis at 300 °C. The fresh particles have a Pt-rich surface and a Cu-rich core and can be converted into an intermetallic phase after annealing at 800 °C under H2. First, we demonstrated the stability of fresh particles under redox conditions at 400 °C, as the Pt-rich surface prevents substantial oxidation of Cu. Then, a combination of in situ scanning transmission electron microscopy, in situ X-ray absorption spectroscopy, and CO oxidation measurements of the intermetallic CuPt phase before and after redox treatments at 800 °C showed promising activity and stability for CO oxidation. Full oxidation of Cu was prevented after exposure to O2 at 800 °C. The activity and structure of the particles were only slightly changed after exposure to O2 at 800 °C and were recovered after re-reduction at 800 °C. Additionally, the intermetallic CuPt phase showed enhanced catalytic properties compared to the fresh particles with a Pt-rich surface or pure Pt particles of the same size. Thus, the incorporation of Pt with Cu does not lead to a rapid deactivation and degradation of the material, as seen with other bimetallic systems. This work provides a synthesis route to control the design of Cu-Pt nanostructures and underlines the promising properties of these alloys (intermetallic and non-intermetallic) for heterogeneous catalysis.
RESUMO
Optimizing the use of expensive precious metals is critical to developing sustainable and low-cost processes for heterogeneous catalysis or electrochemistry. Here, we report a synthesis method that yields core-shell Cu-Ru, Cu-Rh, and Cu-Ir nanoparticles with the platinum-group metals segregated on the surface. The synthesis of Cu-Ru, Cu-Rh, and Cu-Ir particles allows maximization of the surface area of these metals and improves catalytic performance. Furthermore, the Cu core can be selectively etched to obtain nanoshells of the platinum-group metal components, leading to a further increase in the active surface area. Characterization of the samples was performed with X-ray absorption spectroscopy, X-ray powder diffraction, and ex situ and in situ transmission electron microscopy. CO oxidation was used as a reference reaction: the three core-shell particles and derivatives exhibited promising catalyst performance and stability after redox cycling. These results suggest that this synthesis approach may optimize the use of platinum-group metals in catalytic applications.
Assuntos
Nanopartículas , Platina , Catálise , Eletroquímica , Microscopia Eletrônica de Transmissão , Nanopartículas/química , Platina/químicaRESUMO
Understanding and modulating the interactions between molten polymers and porous solids is important for numerous processes and phenomena including catalytic conversion of polymers and fabrication of nanocomposites and nanostructured materials. Although changing the surface composition of pores would enable modulation of interactions between polymers and nanoporous solids, it is challenging to achieve such a control without inducing significant changes to the size and structure of nanopores. In this work, we demonstrate that the interactions between molten polystyrene (PS) and disordered packings of SiO2 nanoparticles (NPs) can be modulated by changing the surface composition of the NPs using atomic layer deposition (ALD). A disordered packing of silica NPs is modified with varying surface coverages of TiO2, WO3, and CaCO3, with coverages estimated by the mass gain and the refractive index change of NP packings. Based on the time required to fully infiltrate these ALD-modified NP packings via capillarity, the contact angles for PS on different surfaces prepared via ALD are determined. The contact angle gradually changes from that of pure SiO2 to that of the fully covered surfaces. The contact angles for PS on SiO2, TiO2, WO3, and CaCO3 are found to be 20, 62, 70, and 10°, respectively. Interestingly, the contact angles and interfacial energies between PS and the ALD-modified surfaces do not correlate strongly with the water contact angle of these surfaces; thus, caution must be exercised in predicting how a polymer would wet or interact with porous solids solely based on their hydrophilicity. The method presented in this work can be extended to study the interactions between a wide range of polymers and surfaces in porous media, which will have important implications for designing new catalytic materials for polymer upcycling reactions and novel NP-polymer composite films and membranes with enhanced mechanical and transport properties.
RESUMO
Sleep-disordered breathing (SDB) causes hypoxic stress and can trigger uric acid (UA) overproduction. We comprehensively investigated whether SDB, interacting with components of metabolic syndrome, hepatic and renal dysfunctions, low physical fitness, sedentary lifestyle, disrupted sleep, and chronic systemic inflammation (CSI), is directly associated with hyperuricaemia. In 528 community-based males (mean [SD] age 46.2 [7.4] years), we cross-sectionally analysed measures of anthropometry; self-reported lifestyle habits; overnight sleep polysomnography data; cardiopulmonary exercise tests; and biomarkers of cardiometabolic, hepatic, and renal functions; and CSI, using structural equation modelling. Objective disrupted sleep, C-reactive protein, low physical fitness, and sedentary lifestyle were not related to UA levels in univariate analysis and were excluded. The latent variables (with corresponding manifest variables) obesity (body mass index, waist-hip ratio), hypertension (post-sleep systolic, diastolic blood pressure), dyslipidaemia (total cholesterol, triglyceride/high-density lipoprotein cholesterol), hepatic dysfunction (alanine aminotransferase, aspartate transaminase), and renal dysfunction (blood urea nitrogen, serum creatinine) were positively; and hyperglycaemia (fasting glucose, glycated haemoglobin) was negatively associated with hyperuricaemia (serum UA), except for SDB (Apnea-Hypopnea Index, percentage of oxygen saturation <90% period against total sleep time, oxygen desaturation index) in the one-stage influence model. In the two-stage model, SDB, closely interacting with obesity, was positively indirectly associated with hyperuricaemia through directly linked renal dysfunction and obesity-linked hypertension, inverse hyperglycaemia, dyslipidaemia, and hepatic dysfunction. In conclusion, structural equation modelling reveals that SDB closely interacts with obesity and is positively but indirectly related to hyperuricaemia in males. This suggests that urinary UA excretion modulates and obesity confounds the SDB-hyperuricaemia relationship.
Assuntos
Biomarcadores/sangue , Obesidade/fisiopatologia , Polissonografia/métodos , Síndromes da Apneia do Sono/fisiopatologia , Ácido Úrico/sangue , Índice de Massa Corporal , Humanos , Hiperuricemia/complicações , Masculino , Pessoa de Meia-IdadeRESUMO
OBJECTIVE: To investigate whether objective polysomnographic measures of prevalent sleep problems such as sleep-disordered-breathing (SDB) and insomnia are associated with activities of daily living levels in inpatients at rehabilitation units. DESIGN: Retrospective and observational study. SETTING: Single rehabilitation center. PARTICIPANTS: Inpatients with subacute stroke (N=123) (61.6±13.1 years; 23.8±3.4 kg/m2; 33% women; 90.5±36.7 days post-stroke) underwent a 1-night polysomnographic study and a 1-month inpatient rehabilitation program. MAIN OUTCOME MEASURES: Admission and discharge Barthel Index (BI) scores and its change scores. RESULTS: One hundred three (92%) patients had moderate-to-severe SDB (46.7±25.1 events/h in the apnea-hypopnea index), and 24 (19.5%) patients had acceptable continuous positive airway pressure adherence. Diverse values were found for total sleep time (259±71 min), sleep efficiency (69.5%±19.3%), sleep latency (24.3±30.9 min), and wakefulness after sleep onset (93.1±74.2 min). Admission BI scores and the BI change scores were 33.8±23.2 and 10.1±9.2, respectively. The National Institutes of Health Stroke Scale (NIHSS, 10.2±5.6), available in 57 (46%) patients, was negatively associated with admission levels and gains in BI change scores (P<.001, =0.002, respectively) in a univariate analysis. In regression models with backward selection, excluding NIHSS score, both age (P=.025) and wakefulness after sleep onset (P<.001) were negatively associated (adjusted R2=0.260) with admission BI scores. Comorbidity of hypertension; sleep latency percentage of stage 1, non-rapid eye movement sleep; and desaturation events ≥4% (P<.001, 0.001, 0.021, and 0.043, respectively; adjusted R2=0.252) were negatively associated with BI score gains. CONCLUSIONS: Based on objective sleep measures, insomnia rather than SDB in inpatients with subacute stroke was associated negatively with admission levels of activity of daily living and its improvement after a 1-month rehabilitation course.
Assuntos
Atividades Cotidianas , Síndromes da Apneia do Sono/fisiopatologia , Distúrbios do Início e da Manutenção do Sono/fisiopatologia , Reabilitação do Acidente Vascular Cerebral , Acidente Vascular Cerebral/fisiopatologia , Idoso , Feminino , Hospitalização , Humanos , Pacientes Internados , Masculino , Pessoa de Meia-Idade , Polissonografia , Recuperação de Função Fisiológica , Centros de Reabilitação , Estudos Retrospectivos , Índice de Gravidade de Doença , Sono/fisiologia , Síndromes da Apneia do Sono/etiologia , Distúrbios do Início e da Manutenção do Sono/etiologia , Acidente Vascular Cerebral/complicaçõesRESUMO
PURPOSE: To assess the physiological meanings of the detrended fluctuation analysis (DFA) slope α and its relationship to spectral measures in heart rate variability, this study investigated changes of α and its corresponding spectral measures over various night-sleep stages. METHODS: The overall DFA α and natural-logarithm-transformed power values of the spectral parameters ln[high-frequency (HF)], ln[low-frequency (LF)], and ln[very-low-frequency (VLF)], and their relationship from one 5-min proper electrocardiography segment in each of pre-sleep-wakefulness (AWK), non-rapid eye movement stage 2 (N2), slow-wave (N3), the first and the latest rapid-eye movement sleep (REM1, and REM2), were computed in 93 otherwise healthy males (44.1 ± 7.7 years.) with wide-ranged apnea-hypopnea, periodic-limb movement and arousal indices (19.0 ± 20.9, 4.7 ± 9.9, and 10.7 ± 18.2 h, respectively). RESULTS: While ln(HF) dipped from AWK, N2, and N3 to REM1 then rebounded to the origin level at REM2, ln(VLF) dipped from AWK to N2, N3 trough, and then surged to levels surpassing AWKs and N2s at REM1 and REM2. ln(LF/HF), ln(VLF/HF), and α dipped from AWK and N2 to N3 trough, surged to levels surpassing AWKs, and N2s at REM1 then became attenuated at REM2. By general linear modeling, the relationship between α and the corresponding spectral values can be seen over various stages as α = b 0 + 0.147 × ln(VLF/HF) (R (2) = 0.766), regardless of age and sleep-sympathoexcitatory episodes. CONCLUSION: The REM sleep attenuations appeared in ln(HF) and its derivatives, such as ln(LF/HF), ln(VLF/HF), and the overall DFA slope α values. The quantitative function of ln(VLF/HF) describes the α values constantly for overnight sleep stages, and it is not affected by age, LF, PLM, and AHI. Our findings therefore suggest that in sleep studies with spectral HRV measures, ln(VLF/HF) as a surrogate of the overall DFA slope α should be calculated at the same time.
Assuntos
Sistema Nervoso Autônomo/fisiopatologia , Eletrocardiografia , Frequência Cardíaca/fisiologia , Polissonografia , Processamento de Sinais Assistido por Computador , Apneia Obstrutiva do Sono/fisiopatologia , Fases do Sono/fisiologia , Nervo Vago/fisiopatologia , Adulto , Regulação da Temperatura Corporal/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Apneia Obstrutiva do Sono/diagnóstico , Estatística como Assunto , Sistema Nervoso Simpático/fisiopatologiaRESUMO
BACKGROUND: Both proteinuria and obstructive sleep apnea (OSA) are associated with cardiovascular events and consequent mortality. To examine whether age, OSA, diabetes, and obesity are potential predictors of proteinuria, a data-driven analysis was performed to delineate a potential categorical classification algorithm. METHODS: In this cross-sectional community-based cohort study, demographic data, blood pressure, serum biochemical analyses, proteinuria via single dipstick urinalysis, and overnight polysomnographies were measured in 300 males with sedentary work styles. RESULTS: Sixty-one (20.3 %) of all these participants had proteinuria. Logistic regression analysis showed that glycated hemoglobin (HbA1c), duration of arterial oxygen saturation <90 %, age, and log high-sensitivity C-reactive protein, but not apnea-hypopnea index (AHI), were responsible for 16.7 % of the variance of proteinuria's presence. A decision tree analysis showed that subjects over 49 years old had a higher risk for proteinuria than those subjects of 49 years old, or less. In the over 49-year-old group, subjects with an AHI >21 events/h had a higher risk for proteinuria; whereas in the 49-year-old and less group, subjects with HbA1c >7 %, or with HbA1c ≤7, and body mass index (BMI) >27.4 kg/m(2) had a higher risk for proteinuria than their counterparts. CONCLUSIONS: AHI was the major determinant responsible for the presence of proteinuria in late mid-aged male workers, while HbA1c and BMI were found in the junior subgroup. By algorithmic analysis, this study provides a comprehensive hierarchical model for better understanding of the correlates of proteinuria and sleep apnea.
Assuntos
Árvores de Decisões , Diabetes Mellitus Tipo 2/diagnóstico , Diabetes Mellitus Tipo 2/epidemiologia , Obesidade/diagnóstico , Obesidade/epidemiologia , Proteinúria/diagnóstico , Proteinúria/epidemiologia , Apneia Obstrutiva do Sono/diagnóstico , Apneia Obstrutiva do Sono/epidemiologia , Fatores Etários , Algoritmos , Estudos de Coortes , Estudos Transversais , Diabetes Mellitus Tipo 2/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Obesidade/fisiopatologia , Polissonografia , Proteinúria/fisiopatologia , Fatores de Risco , Comportamento Sedentário , Apneia Obstrutiva do Sono/fisiopatologia , Estatística como Assunto , TaiwanRESUMO
BACKGROUND: Sleepiness-at-the-wheel has been identified as a major cause of highway accidents. The aim of our study is identifying the candidate measures for home-based screening of sleep disordered breathing in Taiwanese bus drivers, instead of polysomnography. METHODS: Overnight polysomnography accompanied with simultaneous measurements of alternative screening devices (pulse oximetry, ApneaLink, and Actigraphy), heart rate variability, wake-up systolic blood pressure and questionnaires were completed by 151 eligible participants who were long-haul bus drivers with a duty period of more than 12 h a day and duty shifting. RESULTS: 63.6% of professional bus drivers were diagnosed as having sleep disordered breathing and had a higher body mass index, neck circumference, systolic blood pressure, arousal index and desaturation index than those professional bus drivers without evidence of sleep disordered breathing. Simple home-based candidate measures: (1) Pulse oximetry, oxygen-desaturation indices by ≥3% and 4% (r = 0.87~0.92); (2) Pulse oximetry, pulse-rising indices by ≥7% and 8% from a baseline (r = 0.61~0.89); and (3) ApneaLink airflow detection, apnea-hypopnea indices (r = 0.70~0.70), based on recording-time or Actigraphy-corrected total sleep time were all significantly correlated with, and had high agreement with, corresponding polysomnographic apnea-hypopnea indices [(1) 94.5%~96.6%, (2) 93.8%~97.2%, (3) 91.1%~91.3%, respectively]. Conversely, no validities of SDB screening were found in the multi-variables apnea prediction questionnaire, Epworth Sleepiness Scale, night-sleep heart rate variability, wake-up systolic blood pressure and anthropometric variables. CONCLUSIONS: The indices of pulse oximetry and apnea flow detection are eligible criteria for home-based screening of sleep disordered breathing, specifically for professional drivers.
Assuntos
Actigrafia/métodos , Condução de Veículo , Eletrocardiografia/métodos , Veículos Automotores , Oximetria/métodos , Testes de Função Respiratória/métodos , Síndromes da Apneia do Sono/diagnóstico , Adulto , Exame para Habilitação de Motoristas , Humanos , Masculino , Programas de Rastreamento/métodos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Síndromes da Apneia do Sono/fisiopatologia , TaiwanRESUMO
BACKGROUND: In the last 40 years, the number of deaths due to cancer has been the highest in TaiwanOBJECTIVE: To optimize the readout system of the thermoluminescent dosimeter (TLD)-100H, the radiation rates among the Tomotherapy (TOMO) facility of the Department of Radiology Oncology of Chung Shan Medical University Hospital (CSMUH) were calculated with a 32 full factorial design (FFD). METHODS: A ten-month survey of the facility was employed using the sensitive and accurate TLD method. The TLD system was optimized for maximum temperature, heat rate, and preheat temperature of Harshaw 3500 reader. Eight analyzed groups with different factors were tested. RESULTS: The TOMO facility had significantly different radiation rates. The farther away from the gantry head, environmental radiation rates. The half value layer (HVL) was also determined. These results were compared with published. No significant contributions of environmental gamma radiations were detected except in the treatment room. CONCLUSIONS: Those were far below the occupational doses recommended by ICRP 60.
Assuntos
Dosímetros de Radiação , Radioterapia de Intensidade Modulada , Raios gama , Humanos , Doses de Radiação , Dosimetria Termoluminescente/métodosRESUMO
This article investigates the effects of continuous positive airway pressure (CPAP) on hearing impairment in sensorineural hearing loss (SNHL) patients with sleep-disordered breathing (SDB). This retrospective and observational study took place from September 2016 to February 2021, accumulating 77 subjects with SNHL and SDB (60.7 ± 11.1 years). Of which, 28 received CPAP treatment (63.0 ± 8.5 years). In our methodology, hearing thresholds at low, medium, high, and average frequencies are assessed by pure-tone audiometry at baseline (BL), three (3 m), six (6 m), and 12 (12 m) months. Our results show that the BL of at least three frequencies in all subjects is positively associated with old age, males, smoking, alcohol, coronary artery disease, hypertension, and apnea-hypopnea index [AHI] (all p < 0.05). Moreover, low, medium, and average frequencies are negatively correlated at CPAP-6 m (-5.60 ± 2.33, -5.82 ± 2.56, and -5.10 ± 2.26 dB; all p < 0.05) and CPAP-12 m (-7.97 ± 2.74, -8.15 ± 2.35, and -6.67 ± 2.37 dB; all p < 0.01) against corresponding measures of CPAP-BL. High, medium, and average frequencies positively correlated with age (p < 0.001 for high and average frequencies and <0.01 for medium frequencies). We conclude that in SNHL patients with SDB, hearing thresholds at low and medium frequencies improves under CPAP use after six months, which persists at least to the end of one year.
Assuntos
Perda Auditiva Neurossensorial , Síndromes da Apneia do Sono , Idoso , Audiometria de Tons Puros , Pressão Positiva Contínua nas Vias Aéreas , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Polissonografia , Estudos RetrospectivosRESUMO
Unlike Co clusters, isolated Co atoms have been shown to be selective for catalytic dehydrogenation of ethane to ethylene; however, preparation of isolated Co sites requires special preparation procedures. Here, we demonstrate that Atomic Layer Deposition (ALD) of tris(2,2,6,6-tetramethyl-3,5-heptanedionato)cobalt(III) (Co(TMHD)3) on silica and other supports is effective in producing these isolated species. Silica-supported catalysts prepared with one ALD cycle showed ethylene selectivities greater than 96% at 923 K and were stable when CO2 was co-fed with the ethane. Co catalysts prepared by impregnation formed clusters that were significantly less active, selective, and stable. Rates and selectivities also decreased for catalysts with multiple ALD cycles. Isolated Co catalysts prepared on Al2O3 and MgAl2O4 showed reasonable selectivity for ethane dehydrogenation but were not as effective as their silica counterpart.
RESUMO
Controlling effective separation of carriers at the interface is a key element to realize highly efficient halogenated perovskite-based optoelectronic devices. Here, a comprehensive study of interfacial properties for CsPbBr3 nanocrystals (NCs)/graphene heterostructure is performed by the combination of theoretical and experimental methods. Enhanced visible light absorption is observed experimentally in the CsPbBr3 NCs/graphene heterostructure. The strong photoluminescence quenching phenomenon and improved photoresponse prove the efficient interfacial charge transfer from the perovskite CsPbBr3 NC layer to the graphene side. Significantly, theoretical calculations suggest that an intrinsic built-in electric field, pointing from graphene toward CsPbBr3, promotes the separation of photoinduced carriers at the CsPbBr3 NCs/graphene interface and simultaneously inhibits the recombination of electron-hole pairs. Thus, the high optoelectronic performance can be obtained in the CsPbBr3 NCs/graphene heterostructure, as shown in our experiment. Moreover, the CsPbBr3 NCs/graphene heterostructure exhibits smaller effective mass than that of CsPbBr3 NCs, indicating that the heterostructure does possess a high carrier mobility, which can further accelerate the separation of photogenerated carriers. Furthermore, the calculated results reveal that, accounting for the presence of the stronger built-in electric field, larger band bending value, and smaller effective mass, the PbBr2/graphene interface can realize the separation of the photoinduced carriers more effectively than the CsBr/graphene interface and thus more efficiently facilitate electron transfer from the perovskite optical absorber side to the graphene electronic transport side. Our findings provide valuable insight into perovskite/graphene-based photodetector devices via the interface engineering project.
RESUMO
Purpose: This study evaluated the DNA double strand breaks (DSBs) induced by indirect actions and its misrepairs to estimate the relative biological effectiveness (RBE) of proton beams.Materials and methods: From experimental data, DSB induction was evaluated in cells irradiated by 62 MeV proton beams in the presence of dimethylsulphoxide (DMSO) and under hypoxic conditions. The DNA damage yields for calculating the RBE were estimated using Monte Carlo Damage Simulation (MCDS) software. The repair outcomes (correct repairs, mutations and DSB conversions) were estimated using Monte Carlo Excision Repair (MCER) simulations.Results: The values for RBE of 62 MeV protons (LET = 1.051 keV/µm) for DSB induction and enzymatic DSB under aerobic condition (21% O2) was 1.02 and 0.94, respectively, as comparing to 60Co γ-rays (LET = 2.4 keV/µm). DMSO mitigated the inference of indirect action and reduced DSB induction to a greater extent when damaged by protons rather than γ-rays, resulting in a decreased RBE of 0.86. DMSO also efficiently prevented enzymatic DSB yields triggered by proton irradiation and reduced the RBE to 0.83. However, hypoxia (2% O2) produced a similar level of DSB induction with respect to the protons and γ-rays, with a comparable RBE of 1.02.Conclusions: The RBE values of proton beams estimated from DSB induction and enzymatic DSB decreased by 16% and 12%, respectively, in the presence of DMSO. Our findings indicate that the overall effects of DSB induction and enzymatic DSB could intensify the tumor killing, while alleviate normal tissue damage when indirect actions are effectively interrupted.
Assuntos
Quebras de DNA de Cadeia Dupla , DNA/efeitos da radiação , Oxigênio/metabolismo , Terapia com Prótons/métodos , Eficiência Biológica Relativa , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Radioisótopos de Cobalto , Reparo do DNA/efeitos da radiação , Dimetil Sulfóxido , Raios gama , Humanos , Hipóxia , Método de Monte Carlo , Mutação , Prótons , Espécies Reativas de Oxigênio/metabolismoRESUMO
STUDY OBJECTIVES: We investigated the interaction between objective sleep disturbance and obesity, sedentary lifestyle, and lung dysfunction and whether it is negatively associated with cardiorespiratory fitness. METHODS: In this community cohort study of 521 men (age 46.6 ± 7.5 years), measures of anthropometry, pulmonary function, overnight sleep polysomnography, and cardiopulmonary exercise testing were processed stepwise using structural equation modeling (SEM). RESULTS: A univariate correlation analysis was used to group the corresponding variables (in parentheses) into the following eligible latent variables for lower exercise capacity: obesity (body mass index, waist-to-hip ratio), irregular exercise, impaired lung function (predicted values of forced expiratory volume in the first second, forced vital capacity, maximal ventilatory volume, and lung diffusion capacity for carbon monoxide), disrupted sleep (total sleep time, percentage of slow-wave sleep, sleep efficiency), and sleep-disordered breathing (apnea-hypopnea index, lowest oxygen saturation, percentage of total period of oxygen saturation < 90%). Advanced SEM analyses produced a well-fitted final confirmatory model that obesity (direct strength ßd = .366, P < .001), irregular exercise (ßd = .274, P < .001), and impaired lung function (ßd = .152, P < .001), with their mutual interactions, as well as disrupted sleep (ßd = .135, P = .001) were independently and directly associated with low exercise capacity. By contrast, sleep-disordered breathing (ßd = 0, P = .215) was related to low exercise capacity indirectly through obesity into the mutual interaction cycle of obesity, irregular exercise, and impaired lung function. Sleep-disordered breathing was robustly and mutually correlated with obesity (mutual relationship index = .534, P < .001). CONCLUSIONS: Objectively measured disrupted sleep is directly and independently associated with low exercise capacity; however, sleep-disordered breathing is indirectly mediated by obesity and mutual interactions among obesity, lung dysfunction, and sedentary lifestyle and is linked to low exercise capacity. Our findings indicate that individuals with limited exercise capacity without definite causes should undertake a sleep study, particularly in those describing symptoms of sleep-disordered breathing or insomnia.
Assuntos
Aptidão Cardiorrespiratória , Teste de Esforço , Pneumopatias/diagnóstico , Obesidade/diagnóstico , Comportamento Sedentário , Transtornos do Sono-Vigília/diagnóstico , Adulto , Estudos de Coortes , Correlação de Dados , Humanos , Análise de Classes Latentes , Pneumopatias/epidemiologia , Masculino , Pessoa de Meia-Idade , Obesidade/epidemiologia , Polissonografia , Testes de Função Respiratória , Transtornos do Sono-Vigília/epidemiologiaRESUMO
BACKGROUND: Sleep-disordered breathing (SDB) and cardiometabolic risk factors are male prevalent. OBJECTIVE: This study investigated whether gender differences remained prominent after matching for the apnea hypopnea index (AHI) and postmenopause. METHODS: In a retrospective analysis of 350 eligible SDB patients, female patients were matched with male patients of the same age and body mass index (BMI) (age-BMI-matched [nAHImt]; n = 102 pairs) or were matched with male patients of the same age, BMI, and AHI (age-BMI-AHI-matched [AHImt]; n = 66 pairs). The nAHImt or AHImt patients were further separated into junior and senior subgroups. RESULTS: In the nAHImt/junior group, women had shorter neck circumferences, better sleep architecture, and lower AHI, Epworth Sleepiness Scale (ESS) score, blood pressure (BP), total cholesterol (TC), triglyceride (TG), and uric acid (UA) than nAHImt/junior men. In the AHImt/junior group, women had shorter neck circumferences, lower waist/hip ratios, ESS, BP, TG, and UA than AHImt junior men. In the nAHImt/senior group, women had lower AHI, neck circumferences, waist/hip ratios, diastolic BP, and UA than men. In contrast, in the AHImt/senior group, most cardiometabolic parameters were similar between women and men. After further matching for the AHI, many elements of gender differences disappeared. CONCLUSIONS: Compared with AHImt men, women had lower UA, TG, BP, and daytime sleepiness before menopause, but gender differences became indistinguishable postmenopause. We suggested that matching sleep quality or adjusting AHI would be noteworthy and required for studying gender differences.