Procoagulant State of Sleep Apnea Depends on Systemic Inflammation and Endothelial Damage

INTRODUCTION

Growing evidence shows a hypercoagulable state in obstructive sleep apnea (OSA) that could be a risk factor for thromboembolic disease.

OBJECTIVES

We aimed to elucidate mechanisms involved in the procoagulant profile observed in patients with OSA and to investigate the potential utility of global tests in its characterization.

METHODS

Thirty-eight patients with severe OSA without previous history of thrombosis and nineteen healthy age- and sex-matched controls were included. Kinetic of clot formation was determined using rotational thromboelastometry. Haemostatic capacity of plasma and microparticles was determined by Calibrated Automated Thrombinography. Platelet surface receptors, activation markers and formation of platelet/leukocytes aggregates were analyzed by flow cytometry.

RESULTS

Thromboelastometry showed a procoagulant state in patients with OSA that did not seem to be related to a basal activation of platelets but by the increased existence of platelet/leukocyte aggregates. Patients with OSA presented many signs of endothelial damage such as increased plasma levels of E-selectin and cfDNA and enhanced thrombin generation due to the presence of microparticles rich in tissue-factor, which is related to OSA severity.

CONCLUSIONS

OSA induces an enhancement in the dynamics of clot formation which appears to be caused by at least two pathological mechanisms. First, a greater formation of platelet-leukocyte aggregates; secondly, endothelial damage which provokes a greater procoagulant potential due to the increase in tissue factor-rich microparticles. Moreover, this study has identified thromboelastometry and thrombin generation assay as useful tools to evaluate the prothrombotic state in these patients.

In Vivo 3D Analysis of Thoracic Kinematics: Changes in Size and Shape During Breathing and Their Implications for Respiratory Function in Recent Humans and Fossil Hominins

The human ribcage expands and contracts during respiration as a result of the interaction between the morphology of the ribs, the costo-vertebral articulations and respiratory muscles. Variations in these factors are said to produce differences in the kinematics of the upper thorax and the lower thorax, but the extent and nature of any such differences and their functional implications have not yet been quantified. Applying geometric morphometrics we measured 402 three-dimensional (3D) landmarks and semilandmarks of 3D models built from computed tomographic scans of thoraces of 20 healthy adult subjects in maximal forced inspiration (FI) and expiration (FE). We addressed the hypothesis that upper and lower parts of the ribcage differ in kinematics and compared different models of functional compartmentalization. During inspiration the thorax superior to the level of the sixth ribs undergoes antero-posterior expansion that differs significantly from the medio-lateral expansion characteristic of the thorax below this level. This supports previous suggestions for dividing the thorax into a pulmonary and diaphragmatic part. While both compartments differed significantly in mean size and shape during FE and FI the size changes in the lower compartment were significantly larger. Additionally, for the same degree of kinematic shape change, the pulmonary thorax changes less in size than the diaphragmatic thorax. Therefore, variations in the form and function of the diaphragmatic thorax will have a strong impact on respiratory function. This has important implications for interpreting differences in thorax shape in terms of respiratory functional differences within and among recent humans and fossil hominins. Anat Rec, 300:255-264, 2017. © 2016 Wiley Periodicals, Inc.

Differential growth and development of the upper and lower human thorax

The difficulties in quantifying the 3D form and spatial relationships of the skeletal components of the ribcage present a barrier to studies of the growth of the thoracic skeleton. Thus, most studies to date have relied on traditional measurements such as distances and indices from single or few ribs. It is currently known that adult-like thoracic shape is achieved early, by the end of the second postnatal year, with the circular cross-section of the newborn thorax transforming into the ovoid shape of adults; and that the ribs become inclined such that their anterior borders come to lie inferior to their posterior. Here we present a study that revisits growth changes using geometric morphometrics applied to extensive landmark data taken from the ribcage. We digitized 402 (semi) landmarks on 3D reconstructions to assess growth changes in 27 computed tomography-scanned modern humans representing newborns to adults of both sexes. Our analyses show a curved ontogenetic trajectory, resulting from different ontogenetic growth allometries of upper and lower thoracic units. Adult thoracic morphology is achieved later than predicted, by diverse modifications in different anatomical regions during different ontogenetic stages. Besides a marked increase in antero-posterior dimensions, there is an increase in medio-lateral dimensions of the upper thorax, relative to the lower thorax. This transforms the pyramidal infant thorax into the barrel-shaped one of adults. Rib descent is produced by complex changes in 3D curvature. Developmental differences between upper and lower thoracic regions relate to differential timings and rates of maturation of the respiratory and digestive systems, the spine and the locomotor system. Our findings are relevant to understanding how changes in the relative rates of growth of these systems and structures impacted on the development and evolution of modern human body shape.

[Physiology and physiopathology of the distal airways in asthma]

The small airways are those with an internal diameter of less than 2 mm. The contribution of these airways to total airflow resistance is small in healthy individuals but can represent 50-90 % of total airflow resistance in asthmatics. Suspicion of small airways disease has been based on reduction of midexpiratory and instantaneous flows, although wide variability in their values and the absence of a sufficiently validated cut-off point has limited their clinical application. Static pulmonary volumes can provide indirect evidence of the state of the most distal airways, revealing two effects of their alteration: air trapping and dynamic hyperinflation. While determination of airway resistance by plethysmography and of respiratory system resistance measured by flow interruption are highly non-specific, the forced oscillation technique allows obstruction of the small airways to be distinguished from that of medium-caliber airways. The characteristic pattern of peripheral obstruction includes a decrease in frequency-dependent resistance, reduced reactivity and an increase in resonance frequency. Single-or multiple-breath nitrogen washout can also provide specific information on the small airways, although the apparatus required is less frequently available. Analysis through bicompartmental models of exhaled nitric oxide allows alveolar nitric oxide concentrations to be determined, which seems to provide information on inflammatory activity in the small airways.

[Geographical variations in the prevalence of COPD in Spain: relationship to smoking, death rates and other determining factors]

BACKGROUND

The EPI-SCAN study (Epidemiologic Study of COPD in Spain), conducted from May 2006 to July 2007, determined that the prevalence of COPD in Spain according to the GOLD criteria was 10.2% of the 40 to 80 years population. Little is known about the current geographical variation of COPD in Spain.

OBJECTIVES

We studied the prevalence of COPD, its under-diagnosis and under-treatment, smoking and mortality in the eleven areas participating in EPI-SCAN. COPD was defined as a post-bronchodilator FEV₁/FVC ratio <0.70 or as the lower limit of normal (LLN).

RESULTS

The ratio of prevalences of COPD among the EPI-SCAN areas was 2.7-fold, with a peak in Asturias (16.9%) and a minimum in Burgos (6.2 %) (P<0.05). The prevalence of COPD according to LLN was 5.6% (95% CI 4.9-6.4) and the ratio of COPD prevalence using LLN was 3.1-fold, but with a peak in Madrid-La Princesa (10.1%) and a minimum in Burgos (3.2%) (P<0.05). The ranking of prevalences of COPD was not maintained in both sexes or age groups in each area. Variations in under-diagnosis (58.6% to 72.8%) and under-treatment by areas (24.1% to 72.5%) were substantial (P<0.05). The prevalence of smokers and former smokers, and cumulative exposure as measured by pack-years, and the age structure of each of the areas did not explain much of the variability by geographic areas. Nor is there any relation with mortality rates published by Autonomous Communities.

CONCLUSION

There are significant variations in the distribution of COPD in Spain, either in prevalence or in under-diagnosis and under-treatment.

[Differences in clinical and polysomnographic variables between male and female patients with sleep apnea-hypopnea syndrome]

OBJECTIVE

The aim of this study was to compare the clinical, anthropometric, and polysomnographic characteristics of a broad group of patients with sleep apnea-hypopnea syndrome according to sex.

PATIENTS AND METHODS

The study, conducted in 6 Spanish university hospitals, included consecutive patients attended from 2003 through 2005 with an apnea-hypopnea index greater than 5. Groups were formed according to sex and then stratified into age subgroups of younger (< or = 45 years) and older patients (> 45 years) for further comparison.

RESULTS

The study included 2464 men and 424 women. Women were older (mean [SD] age, 56 [12] years vs 51 [12] years), weighed more (body mass index, 31 [6] kg/m(2) vs 30 [5] kg/m2), and had a larger hip circumference (119 [15] cm vs 111 [12] cm) and smaller neck circumference (38 [3] cm vs 42 [9] cm) than men (P< .001 in all cases). The degree of daytime sleepiness (Epworth scale) and the apnea-hypopnea index were similar in both groups, although women had a longer sleep latency (23 [28] minutes vs 27 [32] minutes; P< .004) and a higher mean oxygen saturation (92% [4%] vs 91% [5%]) and minimum oxygen saturation (78% [11%] vs 75% [12%]; P< .0001) than men. On stratification by age, only weight differences between men and women were observed in the younger group whereas the older group also showed differences in oxygen saturation during sleep.

CONCLUSIONS

Women with sleep apnea-hypopnea are more overweight than men and tend to seek medical attention at an older age. The clinical and polysomnographic variables were generally similar for men and womenthe only differences were that sleep latency was longer and hypoxemia during sleep was more accentuated in women.

[Methodology and clinical impact of studies on disease progression]

Because of the progressive nature of chronic obstructive pulmonary disease (COPD), interventions designed to halt disease progression are especially important. Two of the most commonly evaluated variables are the yearly decrease in forced expiratory volume in 1 second (FEV(1)) and the number of exacerbations. The effect of inhaled corticosteroids on deterioration of FEV(1) is slight, being limited to a mild transitory improvement. Tiotropium may have a greater effect on the yearly decrease in FEV(1), although more information is required. Both tiotropium and inhaled corticosteroids reduce the number of COPD exacerbations. However, to interpret these results, several methodological limitations need to be assessed, such as the variability and accuracy of FEV(1) measurements, the high withdrawal rate, dependence on baseline function, the effect of steroid suppression, and the computation and analysis of exacerbation rates.

Spanish Productivity in Smoking Research Relative to World and European Union Productivity From 1999 Through 2003, Analyzed With the Science Citation Index

OBJECTIVE

To analyze Spanish scientific productivity from 1999 through 2003 in the area of smoking research, in comparison with world and European Union research, based on data in the Science Citation (SCI) Index.

MATERIAL AND METHODS

This bibliometric study was carried out by searching the title field of the Science Citation Index Expanded. Descriptive statistics with 95% confidence intervals (CI) were compiled.

RESULTS

Two-hundred ninety-two documents on smoking by Spanish authors were located. The most productive subspecialties were the group comprised of public health, education and health economics with 57 articles, and areas of the respiratory system, experimental research, and internal medicine with 36 articles each. The journals that published the largest number of articles located were Medicina Clínica, with 35 articles (12%) and Archivos de Bronconeumología with 20 (6.8%). International collaboration was undertaken with institutions in the United States of America and other European Union countries. The mean (SD) number of citations received was 5.12 (8.6) (range 59-0). Spain contributed 8.34% of the SCI-indexed smoking research overall and 12.85% of SCI-indexed smoking research from the European Union.

CONCLUSIONS

Smoking research is developing appropriately in Spain and has high impact, even though output is modest. Factors associated with increased citation are international collaboration, language (being written in English), and having a non-Spanish first author.

[High-resolution computed tomography patterns of organizing pneumonia]

Organizing pneumonia is an uncommon lung disease with a wide variety of radiologic findings, few of which have been discussed in the literature. We performed high resolution computed tomography on 34 patients with a histological diagnosis of organizing pneumonia and studied the images they presented. Twenty-five of the cases were idiopathic and 9 secondary. The findings observed were parenchymal consolidation (76%), ground glass opacity (59%), bronchial dilatation (53%), centrilobular nodules (35%), septal thickening (23%), halo sign (15%), and reversed halo sign (12%). Secondary cases presented more findings of septal thickening and fewer complete remissions.

Spanish Medical Center Collaboration on Smoking Research From 1999 Through 2003 According to the Science Citation Index

OBJECTIVE

To analyze the network structure of collaboration between medical centers sharing authorship of scientific articles on smoking.

MATERIAL AND METHODS

Articles reporting smoking research by authors from 2 or more Spanish medical centers between 1999 and the end of 2003 were identified through the Science Citation Index. The network of collaboration behind the research was analyzed and the most important measures of centrality were compared. To display the data, scientometric maps were constructed using UCINET and NETDRAW network analysis tools.

RESULTS

Thirty-five Spanish medical centers (29 hospitals and 6 health care clinics) in 8 autonomous communities were involved in 21 collaborative research projects. Hospital de La Princesa was the network core institution with the highest degrees of nodal (16), closeness (88.66), and betweenness (39) centrality. Other core nodes in the network were the following hospitals: de Cruces, San Pedro de Alcántara, La Paz, Vall d'Hebron, and General Yagüe. The autonomous communities of Castile and Leon, Madrid, and Catalonia were assigned positions at the core of the intercommunity collaborative network based on coauthorship of scientific papers shared among their medical centers.

CONCLUSIONS

Network analysis helps identify the most influential institutions in a scientific community that generates coauthored articles in the field of smoking research. Hospital de la Princesa had the highest measures of centrality. The autonomous communities of Castile and Leon, Madrid, and Catalonia form a highly connected, cohesive subgroup within the network.