SARS-CoV-2's brain impact: revealing cortical and cerebellar differences via cluster analysis in COVID-19 recovered patients.

BACKGROUND: COVID-19 is a disease known for its neurological involvement. SARS-CoV-2 infection triggers neuroinflammation, which could significantly contribute to the development of long-term neurological symptoms and structural alterations in the gray matter. However, the existence of a consistent pattern of cerebral atrophy remains uncertain. OBJECTIVE: Our study aimed to identify patterns of brain involvement in recovered COVID-19 patients and explore potential relationships with clinical variables during hospitalization. METHODOLOGY: In this study, we included 39 recovered patients and 39 controls from a pre-pandemic database to ensure their non-exposure to the virus. We obtained clinical data of the patients during hospitalization, and 3 months later; in addition we obtained T1-weighted magnetic resonance images and performed standard screening cognitive tests. RESULTS: We identified two groups of recovered patients based on a cluster analysis of the significant cortical thickness differences between patients and controls. Group 1 displayed significant cortical thickness differences in specific cerebral regions, while Group 2 exhibited significant differences in the cerebellum, though neither group showed cognitive deterioration at the group level. Notably, Group 1 showed a tendency of higher D-dimer values during hospitalization compared to Group 2, prior to p-value correction. CONCLUSION: This data-driven division into two groups based on the brain structural differences, and the possible link to D-dimer values may provide insights into the underlying mechanisms of SARS-COV-2 neurological disruption and its impact on the brain during and after recovery from the disease.

Association between muscle quality index and pulmonary function in post-COVID-19 subjects.

BACKGROUND: The SARS-CoV2 pandemic impacted many critically ill patients, causing sequelae, affecting lung function, and involving the musculoskeletal system. We evaluated the association between lung function and muscle quality index in severely ill post-COVID-19 patients. METHODS: A cross-sectional study was conducted on a post-COVID-19 cohort at a third-level center. The study included patients who had experienced severe-to-critical COVID-19. Anthropometric measurements, such as body mass index (BMI) and handgrip strength, were obtained to calculate the muscle quality index (MQI). Additionally, spirometry, measurements of expiratory and inspiratory pressure, and an assessment of DLCO in the lungs were performed. The MQI was categorized into two groups: low-MQI (below the 50th percentile) and high-MQI (above the 50th percentile), based on sex. Group differences were analyzed, and a multivariate linear regression analysis was performed to assess the association between respiratory function and MQI. RESULTS: Among the 748 patients analyzed, 61.96% required mechanical ventilation, and the median hospital stay was 17 days. In patients with a low MQI, it was observed that both mechanical respiratory function and DLCO were lower. The multivariate analysis revealed significantly lower findings in mechanical respiratory function among patients with a low MQI. CONCLUSION: The Low-MQI is an independent predictor associated with pulmonary function parameters in subjects with Post-COVID-19 syndrome.

Body composition and risk factors associated with sarcopenia in post-COVID patients after moderate or severe COVID-19 infections.

BACKGROUND: Post-COVID-19 syndrome is characterized by diverse symptoms and abnormalities that persist beyond 12 weeks from the onset of acute COVID-19. Severity disease has been associated with more musculoskeletal alterations such as muscle weakness, dyspnea, and distance walking. The aim was to evaluate the impact of invasive mechanical ventilation (IMV) on body composition and investigate risk factors associated with sarcopenia in post-COVID-19 patients three months after moderate or severe COVID-19 infections. METHODS: Cross-sectional study. 530 patients with PCR-confirmed diagnoses of moderate to severe COVID-19, > 18 years old, oxygen saturation ≤ 93%, PaO2/FiO2 ratio < 300, who required hospitalization and were discharged were included. We excluded those who died before the follow-up visit, declined to participate, or could not be contacted. RESULTS: The mean age was 53.79 ± 12.90 years. IMV subjects had lower phase angle and handgrip strength and higher impedance index, frequency of low muscle mass, and low muscle strength than those without IMV. The risk factors of sarcopenia were > 60 years of age, diabetes, obesity, IMV, and prolonged hospital stay. The multivariate model showed that age > 60 years (OR: 4.91, 95% CI: 2.26-10.63), obesity (OR: 3.73, 95% CI: 1.21-11.54), and interaction between prolonged length of hospital stay and IMV (OR: 2.92; 95% CI: 1.21-7.02) were related to a higher risk of sarcopenia. CONCLUSION: Obesity and the interaction between prolonged length of hospital stay and IMV are associated with a higher risk of sarcopenia at 3 months after severe or moderate COVID-19 infection.

Diagnostic Value of the Morphometric Model and Adjusted Neck Circumference in Adults with Obstructive Sleep Apnea Syndrome.

BACKGROUND: Obstructive sleep apnea syndrome is a major public health problem. The morphometric model and the Sleep Apnea Clinical Score are widely used to evaluate adults; however, neither of these tools has been validated in a Mexican population. OBJECTIVE: To determine the diagnostic value of the morphometric model and the Sleep Apnea Clinical Score and compare them with conventional clinical instruments. METHODS: A total of 97 individuals were recruited prospectively. Initial screening excluded 36, of whom nine were subjects without apnea; the remaining 52 were consecutive patients with obstructive sleep apnea syndrome diagnosed by nocturnal polysomnography. Diagnostic values of each test were calculated. RESULTS: Obstructive sleep apnea syndrome patients had significantly higher scores with both instruments than controls: morphometric model: 61.3 (95% CI: 45.5-75.3) vs. 41.0 (95% CI: 35.6-45.6); Sleep Apnea Clinical Score: 45.3 (95% CI: 39.5-40.3) vs. 36 (95% CI: 34.0-36.5), respectively. For severe cases, the best cutoff point for morphometric model was 46, with a sensitivity of 81% (95% CI: 62.5-92.6) and specificity of 46.7% (95% CI: 66.4-100), while for Sleep Apnea Clinical Score it was > 48, with a sensitivity of 61% (95% CI: 46.1-74.2) and specificity of 80.4% (95% CI: 66-90.6). CONCLUSIONS: A morphometric model value of ≥ 46 or an adjusted neck circumference (Sleep Apnea Clinical Score) > 48 were adequate for diagnosing obstructive sleep apnea syndrome.

Assessment of visuospatial functions in post-Covid 19 patients: Beyond the traditional paradigm.

Several studies indicate that some cognitive changes occur after COVID-19. Visuospatial alterations have been reported in 24-40 %. These alterations may be useful as early biomarkers of neurodegenerative disease. Thus, we can emphasize the importance of visuospatial processes in cognition through quantitative and qualitative analysis of performance on the Clock Test (CDT) and the Rey-Osterrieth Complex Figure (FCRO). Our objective was to describe the performance of post COVID 19 patients in visuospatial tests, with different degrees of respiratory impairment and to perform a qualitative analysis of the performance to check its relationship with alterations in attention and executive functions. This will allow highlighting the executive component of the performance of the CDT and ROCF and differentiate patients with possible cognitive impairment. 77 patients with SARS-CoV-2 infection were evaluated (3 months post-infection) with a complete neuropsychological battery and MRI. Overall, there is a significant difference between FCRO and CDT, with FCRO having only 9 % change and CDT having 51.9 % change. Regarding the correlations observed between groups (VM Inv, VM non I and non hospitalized) the highest correlations were observed between Boston with FCRO copy (r=0.497; p=0.001) and with FCRO memory (r=0.429; p=0.001). Comparing the performance between groups by severity, significant differences were observed only in the TMT A (13.706 p=0.001) and B (9.583 p=0.008) tests and in the phonological fluency letter A (13.445 p=0.001), we observed that the group of non-hospitalized patients had a better performance. Neuropsychological deficits often have a direct impact on daily life by affecting the ability to learn and adapt. Thus, a useful strategy for the neuropsychological characterization of post-COVID-19 patients is the qualitative analysis of visuospatial abilities in conjunction with executive functions that cannot be analyzed in isolation.

Dynapenia and Sarcopenia in Post-COVID-19 Syndrome Hospitalized Patients Are Associated with Severe Reduction in Pulmonary Function.

BACKGROUND: After hospital discharge, post-COVID-19 syndrome has been observed to be associated with impaired diffusing capacity, respiratory muscle strength, and lung imaging abnormalities, in addition to loss of muscle mass/strength, sarcopenia, and obesity impact exercise tolerance, pulmonary functions, and overall prognosis. However, the relationship between lung function and the coexistence of obesity with low muscle strength and sarcopenia in post-COVID-19 patients remains poorly investigated. Therefore, our aim was to evaluate the association between lung function and the coexistence of obesity with dynapenia and sarcopenia in post-COVID-19 syndrome patients. METHODS: This cross-sectional study included subjects who were hospitalized due to moderate to severe COVID-19, as confirmed by PCR testing. Subjects who could not be contacted, declined to participate, or died before the follow-up visit were excluded. RESULTS: A total of 711 subjects were evaluated; the mean age was 53.64 ± 13.57 years, 12.4% had normal weight, 12.6% were dynapenic without obesity, 8.3% had sarcopenia, 41.6% had obesity, 21.2% had dynapenic obesity, and 3.8% had sarcopenic obesity. In terms of pulmonary function, the dynapenic subjects showed decreases of -3.45% in FEV1, -12.61 cmH2O in MIP, and -12.85 cmH2O in MEP. On the other hand, the sarcopenic subjects showed decreases of -6.14 cmH2O in MIP and -11.64 cmH2O in MEP. The dynapenic obesity group displayed a reduction of -12.13% in PEF. CONCLUSIONS: In post-COVID-19 syndrome, dynapenia and sarcopenia-both with and without obesity-have been associated with lower lung function.

Validation of the Nasal Obstruction Symptom Evaluation Scale in Mexican Adults.

BACKGROUND: Nasal obstruction is a feeling of impaired airflow through the nose, caused by diverse factors with high prevalence. There are numerous methods to study it, being the most important subjective instrument the Nasal Obstruction Symptom Evaluation score, NOSE, with good structural validity and internal consistency. It has been translated and validated in several languages, including European Spanish, but hasn't been validated in Mexico. AIM: Adapt and validate the NOSE scale to the Spanish language for a Mexican adult population. METHODS: This study was conducted from May-August 2015. The scale was translated from English to Spanish and assessed by two experts to confirm its acceptability, being retranslated later. Adult subjects with native Mexican Spanish were recruited from the outpatient clinic, with chronic rhinopathy and without evidence of respiratory pathology. Both groups filled the scale, and anthropometric data were collected. A subgroup completed the instrument again after one month. STATA 15.1 was used for analysis. RESULTS: The sample were 261 subjects. Cronbach alpha was 0.89, intraclass correlation coefficient 0.84, agreement limits -9.62 to 16.29. There was a statistically significant difference in score between groups. The area under the ROC curve was 0.855, with 83% sensibility and 76% specificity for a 20 total score. Moderate to strong item-total association was found with Spearman. The response model showed moderate item discrimination. In the factorial analysis, one factor was found, with an Eigenvalue of 3.21. CONCLUSION: The adaptation of the NOSE scale is reliable and valid for its application in Mexican adult population.

[Sleep medicine: development, contributions and perspectives. Report of the work group on sleep medicine]. / Medicina del dormir: desarrollo, contribuciones y perspectivas. Reporte del grupo de trabajo en medicina del dormir.

Sleep is a basic biological process that has an impact on all the functions of the body, and interacts bidirectionally with virtually all of the body systems, so that the sleep disorders are associated with disturbances in other systems, either respiratory, neurological, cardiovascular, endocrine, immune, etc., and vice versa. The complexity of the regulatory mechanisms of sleep and the variety of their disorders, together with the clinical evidence accumulated in recent decades, have led to the birth of a new branch in medicine: the Sleep Medicine, with well defined intrinsic disorders. The consequences of sleep deprivation or fragmentation induced by changes in social and work dynamics, as well as sleep disorders have harmful effects on individuals in the short and long-term, the most important are an elevated risk for vehicular and occupational accidents, cardiovascular damage, cognitive impairment, obesity, diabetes mellitus, among others, impacting individuals of all ages. The sleep clinics and laboratories in Mexico, have made significant contributions, at both the basic and clinical levels, for the diagnosis and treatment of sleep disorders; however, without a specific health policy, we will continue to commit resources only on the attention of its effects and not on prevention, making the impact on the economy and quality of life of patients with sleep disorders, much higher than in developed countries. It is necessary to build a program of medical care to incorporate the Sleep Medicine in the priorities of medical care in the National Institutions of Health at all levels. Solutions and guides to optimize the achievement of the proposed results, and increase efficiency and effectiveness of the resources applied in this new field of Medicine are offered.

Effect of LTRA in L-ASA Challenge for Aspirin-Exacerbated Respiratory Disease Diagnosis.

BACKGROUND: Aspirin-exacerbated respiratory disease (AERD) consists of asthma, chronic rhinosinusitis with polyps, and hypersensitivity to aspirin and/or nonsteroidal anti-inflammatory drugs (NSAIDs). Nasal Lysine Aspirin Challenge is an effective tool for the diagnosis of hypersensitivity to aspirin and/or NSAIDs in patients with AERD. However, there is no unified international consensus version to perform nasal provocation tests (NPTs). OBJECTIVE: To investigate the effect of a leukotriene receptor antagonist (LTRA), montelukast, on the lysine-acetylsalicylate (L-ASA) nasal challenge. METHODS: We included 86 patients divided into 3 samples: group A (AERD without LTRA), group B (AERD with LTRA), and the control group (NSAID-tolerant asthmatics). NPT with L-ASA was performed with 25 mg of L-ASA every 30 minutes 4 times followed by rhinomanometry and spirometric measurements and evaluation of symptoms using a novel clinical scale. RESULTS: In group A, 94.5% of patients (35 of 37) developed a positive response to NPT (drop >40% in total nasal flow), whereas only 46% of group B subjects (13 of 28) showed a positive response to the nasal challenge (P < .001). Control subjects did not show any response to the L-ASA challenge. A novel clinical score demonstrated accuracy in classifying the hypersensitivity to aspirin and/or NSAIDs when patients avoid LTRA (33 of 37). CONCLUSION: Patients with AERD without LTRA showed a greater positive response to the L-ASA challenge than those taking this drug; therefore, LTRA treatment should be discontinued before the challenge for optimal diagnostic accuracy.

Low Incidence and Mortality by SARS-CoV-2 Infection Among Healthcare Workers in a Health National Center in Mexico: Successful Establishment of an Occupational Medicine Program.

Background: Coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Healthcare workers (HCWs) constitute a population which is significantly affected by SARS-CoV-2 infection worldwide. In Mexico, the Instituto Nacional de Enfermedades Respiratorias (INER) is the principal national reference of respiratory diseases. Aim: To evaluate the efficiency of the INER-POL-TRAB-COVID19 program to mitigate the SARS-CoV-2 infection risk among the INER-healthcare workers (INER-HCW). Methods: Currently, the INER has 250 beds and 200 respiratory ventilators to support COVID-19 patients in critical condition. On March 1st, 2020, the INER-POL-TRAB-COVID19 program was launched to mitigate the SARS-CoV-2 infection risk among the INER-HCW. Findings: From March 1st to October 1st, 2020, 71.5% of INER-HCWs were tested for SARS-CoV-2 infection, and 77% of them were frontline workers. Among the tested INER-HCWs, 10.4% were positive for SARS-CoV-2 infection. Nonetheless, nosocomial infection represented only 3.8% of the cases and the mortality was null. Fifty-three of INER-HCWs positive to SARS-CoV-2 had a negative test 42-56 days post-diagnosis and were returned to service. Finally, although a change in the PPE implemented on May 11th, 2020, the incidence of SARS-CoV-2 infection was not affected. Conclusion: INER has a lower incidence of HCWs infected with SARS-CoV-2 as compared to the mean of the national report. The implementation of the INER-POL-TRAB-COVID19 program is efficient to decrease the risk of infection among the HCWs. Our findings suggest that the implementation of a similar program at a national level can be helpful to provide a safe environment to HCWs and to prevent the collapse of health institutions.

Airway Biopsy Results From Patients With Suspected Granulomatosis With Polyangiitis (2005-2015): Clinicopathological Correlation and Proposal of an Algorithm to Improve Diagnosis.

OBJECTIVES: The aim of this study was to review the histologic diagnostic yield of airway biopsies with a suspected granulomatosis with polyangiitis (GPA) diagnosis at a single center devoted to respiratory diseases using previously published criteria. A secondary aim was to apply the algorithm proposed by the European Medicines Agency to determine whether more biopsies were confidently identified as having GPA diagnoses. METHODS: From a total of 132 airway biopsies (2005-2015), 50 were randomly selected for second review by an expert pathologist, and previously published criteria were applied. Thereafter, antineutrophil cytoplasm autoantibody testing results and the European Medicines Agency algorithm were applied. RESULTS: Repeat review and application of the published criteria resulted in an increase from 16 to 25 diagnoses of GPA. This increased to 35 of 50 when antineutrophil cytoplasm autoantibody results and the European Medicines Agency algorithm were applied. Interobserver correlation was 57.5% among pathologists (κ = 0.19), which was likely due to missing clinical information and inadequate tissue samples. Patients with generalized disease were 2.6 times more likely to obtain diagnostic GPA airway biopsy results than those with limited disease (airway only). CONCLUSIONS: An increase in the diagnostic yield of this malady could be attained by following an algorithm that incorporates carefully retrieved clinical, endoscopic, and serologic data, coupled with systematic histopathologic sample review.

[Mechanisms of cardiovascular damage in obstructive sleep apnea]. / Mecanismos de daño cardiovascular en apnea obstructiva del sueño.

Obstructive sleep apnea syndrome (OSAS) is an independent and modifiable risk factor for cardiovascular diseases; however, the pathophysiological mechanisms underlying this association are not yet fully understood. Intermittent hypoxemia, one of the physiological markers of OSAS, is characterized by transient periods of oxygen desaturation followed by reoxygenation. The cycles of hypoxia-reoxygenation are associated with oxidative stress that, in turn, triggers the activation of pathways that lead to cardiovascular damage. These pathways include an increased chemoreflex sensitivity that induces the over-activation of the sympathetic nervous system, decreased baroreflex sensitivity, the activation of systemic inflammation pathways mediated primarily by the nuclear transcriptional factor kappaB that favors the development of atherosclerosis through the synthesis of cytokines and the expression of adhesion molecules, endothelial dysfunction with a decreased availability of nitric oxide, dyslipidemia, insulin resistance and stimulation of the renin-angiotensin system. Other mechanisms proposed include arousals that increase sympathetic activity and exaggerated intrathoracic pressure changes that generate high transmural pressure. Most of these mechanisms respond favorably to treatment with CPAP. A better understanding of the mechanisms of cardiovascular damage opens the possibility of instituting new treatments that will contribute to limiting the cardiovascular consequences associated with OSAS.

[Cardiovascular risk among adults with obstructive sleep apnea syndrome]. / Riesgo cardiovascular en adultos con síndrome de apnea obstructiva del sueño. A 25 años de los primeros estudios de asociación.

Cardiovascular diseases and sleep-disordered breathing have been recognized as a public health problem in Mexico and worldwide. These two groups of disorders are closely associated and the evidence accumulated over the last 25 years indicates that obstructive sleep apnea syndrome (OSAS) is an independent risk factor in systemic arterial hypertension, coronary artery disease and stroke. Other associations have also been described, linking these disorders with pulmonary hypertension, cardiac arrhythmias, sudden death during sleep and congestive heart failure. Treatment with continuous positive airway pressure in patients with OSAS has proven to be an efficient primary and secondary cardiovascular prevention strategy. This article reviews the epidemiological evidence that links OSAS with increased cardiovascular risk, and proposes strategies designed to address this growing health problem.

[Agreement between oxygen desaturation index and apnea-hypopnea index in adults with suspected obstructive sleep apnea at an altitude of 2240 m]. / Indice de desaturación de oxígeno frente a índice de apneas-hipopneas en adultos con sospecha de apnea obstructiva durante el sueño a 2.240 m de altitud.

OBJECTIVE: Altitude can affect the diagnostic accuracy of portable monitors used to diagnose suspected obstructive sleep apnea syndrome on the basis of oxygen desaturation measurements. The aim of this study was to determine agreement between the desaturation index measured by oximetry and the apnea-hypopnea index measured by polysomnography in Mexico City (2240 m above sea level). We also wished to determine agreement between the desaturation index and the respiratory disturbance index measured by monitoring airflow with a single-channel recording device. PATIENTS AND METHODS: We used standard polysomnography and nocturnal oximetry to simultaneously measure the apnea-hypopnea index and the desaturation index, respectively, in a group of 38 patients aged over 18 years with suspected obstructive sleep apnea syndrome. In a second group of 30 patients, we compared the desaturation index to the respiratory disturbance index, which we measured using a single-channel device monitoring nasal airflow. RESULTS: The mean (SD) intraclass correlation coefficient between the apnea-hypopnea index and the desaturation index was 0.89 (0.03) (95% confidence interval, 0.83-0.96), and the mean of the differences was -0.9 (14.2). The mean intraclass correlation coefficient for the desaturation index and the respiratory disturbance index was 0.93 (0.02) (95% confidence interval, 0.89-0.97), and the mean of the differences was -6.6 (8.3). CONCLUSIONS: Agreement was high between the desaturation index and both the apnea-hypopnea index and the respiratory disturbance index in adults with suspected obstructive sleep apnea syndrome in Mexico City.

[Continuous positive airway pressure used by adults with obstructive sleep apneas after prescription in a public referral hospital in Mexico City]. / Uso de CPAP en adultos con síndrome de apneas obstructivas durante el sueño después de prescripción en un hospital público de referencia de la Ciudad de México.

OBJECTIVE: The aim of this study was to analyze the frequency of initiation of continuous positive airway pressure (CPAP) in patients with obstructive sleep apnea syndrome (OSAS) in a referral hospital in Mexico City serving mainly patients without public health insurance coverage and to assess their level of adherence. PATIENTS AND METHODS: Patients with OSAS diagnosed by polysomnography or by simplified respiratory polygraphy for whom nasal CPAP was prescribed were enrolled in the study. Titration of CPAP was performed during polysomnography or with an automatic CPAP device. Compliance with treatment was assessed during a medical visit or by telephone interview. RESULTS: A total of 304 patients were enrolled upon prescription of nasal CPAP; 169 (55.5%) either purchased a device or were provided with one by the social security system. The patients most seriously ill and who had public health insurance coverage were the ones who most often acquired a device. These patients took 1.5 months to obtain the equipment and had a compliance rate of 80% at a mean 34 months of follow-up. The respiratory events index was correlated with compliance, whereas excessive daytime sleepiness (Epworth scale score) and body mass index were predictors of therapeutic CPAP pressure. CONCLUSIONS: Nearly half the patients who were prescribed CPAP did not acquire the device. Most of those who acquired a device adhered to the treatment. In Mexico access to procedures for diagnosing OSAS is limited and access to treatment is also restricted for patients who do not have public health insurance coverage.

[Congenital central alveolar hypoventilation syndrome]. / Síndrome de hipoventilación alveolar central congénita.

BACKGROUND: Congenital central alveolar hypoventilation syndrome (CCAHS) is a rare sleep-related breathing disorder. Although increasingly frequently diagnosed in sleep clinics and pediatric pulmonology services, its epidemiology is not known. There are about 300 reported cases reported in the literature with an incidence of 1 case per 200,000 live births. CCAHS is characterized by alveolar hypoventilation that occurs or worsens during sleep and is secondary to a reduction/absence of the ventilatory response to hypercapnia and/or hypoxemia. In 90% of the cases it is due to a PARM-type mutation of the PHOX2B gene. Treatment includes mechanical ventilation and diaphragmatic pacemaker. If therapy is not initiated promptly the patient can evolve to chronic respiratory failure, pulmonary hypertension, cor pulmonale and death. CASE REPORTS: In this paper we present three cases of CCAHS diagnosed, treated and followed up at the Sleep Disorders Clinic of the National Institute of Respiratory Diseases in Mexico. CONCLUSIONS: Early diagnosis is important to initiate ventilatory support so as to prevent any complications and to reduce mortality.

Anxiety and depression symptoms in patients with sleep-disordered breathing.

INTRODUCTION: Information concerning the frequency of anxiety and depression symptoms in patients with sleep-disordered breathing (SDB) is controversial. Hence, the objectives of this study were to: determine the frequency of anxiety and depression symptoms in patients with SDB; explore whether the frequency of anxiety and depression symptoms rises with increasing parameters of SDB severity; and investigate the factors potentially associated with anxiety and depression. MATERIALS AND METHODOLOGY: Data was collected from consecutive adult patients referred to the National Institute of Respiratory Diseases' Sleep Medicine Unit from October 2008 to October 2009. SDB diagnoses were established using standard polysomnography or simplified respiratory polygraphy. All patients routinely completed the Hospital Anxiety and Depression Scale (HADS) on their first visit to the Sleep Medicine Unit. RESULTS: 382 patients with SDB were included. Mean age was 50.8±13.6 years, 62% were male. Anxiety symptoms were acknowledged by 71 patients (18.5%), while 29 (7.6%) had depression symptoms, and 116 (30.4%) had symptoms of anxiety plus depression. Patients who reported anxiety and depression symptoms scored higher on the Epworth Sleepiness Scale (ESS, 16±7) than those with no symptoms (11±6) (p<0.0001). Patients with symptoms of anxiety plus depression also had higher BMIs (36 ± 8 K/m(2)) than patients with SDB without anxiety or depression. No other differences were observed, not even with respect to the parameters of the severity of their SDB. CONCLUSIONS: Our results support the recommendation that due to their high frequency and potential importance for long-term adherence to CPAP, anxiety and depression symptoms should be included in the routine evaluation of all adults with SDB.

Sleep apnea in patients with acromegaly. Frequency, characterization and positive pressure titration.

OBJECTIVES: to describe the frequency of sleep apnea in patients with acromegaly;to identify the proportion of candidates for treatment with positive airway pressure;to report our experience with the positive pressure titration process in acromegaly patients. METHODS: A cross-sectional study that included the acromegaly cohort at the Centro Medico Nacional "20 de Noviembre" in Mexico City (n=44). A standard polysomnography (PSG) was carried out for each patient. A second PSG was done for purposes of CPAP titration. RESULTS: A total of 35 patients were studied (80% of the cohort, 20 [57%] women). Polysomnography results showed that 34 subjects (97%, 95%CI 91-100%) had apnea hypopnea indexes (AHI) ≥ 5. No patient had central apnea. We identified 19 subjects with AHI ≥5 and Epworth ≥10, for a frequency of obstructive sleep apnea syndrome of 54% (95%CI 36-71%). A total of 31 patients (88%; 95%CI 77-99%) were deemed to be candidates for positive pressure treatment, but only 8 of them accepted CPAP. They required pressures that ranged from 10 to 18 cmH(2)O. CONCLUSIONS: Our results confirm a high prevalence of sleep apnea in patients with acromegaly, and provide evidence that the majority of those patients are candidates for treatment with positive pressure. Contrary to what has been reported, we identified no patients with central apnea.

Accuracy and linearity of positive airway pressure devices: a technical bench testing study.

STUDY OBJECTIVES: To analyze the accuracy and linearity of different CPAP devices outside of the manufacturers' own quality control environment. METHODS: Accuracy (how well readings agree with the gold standard) and linearity were evaluated by comparing programmed pressure to measured CPAP pressure using an instrument established as the gold standard. Comparisons were made centimeter-by-centimeter (linearity) throughout the entire programming spectrum of each device (from 4 to 20 cm H2O). RESULTS: A total of 108 CPAP devices were tested (1836 measurements); mean use of the devices was 956 hours. Twenty-two of them were new. The intra-class correlation coefficient (ICC) decreased from 0.97 at pressures programmed between 4 and 10 cm H2O, to 0.84 at pressures of 16 to 20 cm H2O. Despite this high ICC, the 95% agreement limit oscillated between -1 and 1 cm H2O. This same behavior was observed in relation to hours of use: the ICC for readings taken on devices with < 2,000 hours of use was 0.99, while that of the 50 measurements made on devices with > 6,000 hours was 0.97 (the agreement limit oscillated between -1.3 and 2.5 cm H2O). "Adequate adjustments" were documented in 97% of measurements when the definition was +/- 1 cm H2O of the programmed pressure, but this index of adequate adjustment readings decreased to 85% when the +/- 0.5 cm H2O criterion was applied. CONCLUSIONS: In general, the CPAP devices were accurate and linear throughout the spectrum of programmable pressures; however, strategies to assure short- and long-term equipment reliability are required in conditions of routine use.