Luis Torre-Bouscoulet

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 cmH2O. 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.

Agreement Between Oxygen Desaturation Index and Apnea-Hypopnea Index in Adults With Suspected Obstructive Sleep Apnea at an Altitude of 2240 m

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.

Prevalence of oxygen desaturation and use of oxygen at home in adults at sea level and at moderate altitude

The aim of this study was to determine the prevalence of oxygen desaturation in adults aged ≥40 yrs as altitude above sea level increases. A population-based, cross-sectional study with a multistage cluster sampling of 1,063 subjects from metropolitan Mexico City (Mexico; 2,240 m above sea level), 1,357 from Caracas (Venezuela; 950 m) and 943 from Montevideo (Uruguay; 35 m). The mean of six measurements of arterial oxygen saturation (SP,O2) was estimated using a pulse oximeter. Mean SP,O2 decreased with altitude. No subject from Montevideo had a mean SP,O2 ≤88%. Prevalence of subjects with SP,O2 ≤88%, a common criterion used for oxygen prescription, was 1.0% in Caracas and 6.0% in Mexico City. Additional predicting factors for hypoxaemia in multiple regression models were age, body mass index and a low forced expiratory volume in one second as a percentage of the predicted value. In Mexico City and Caracas, <10% of the hypoxaemic subjects reported use of domiciliary oxygen, whereas at least half of the subjects reporting use of oxygen at home had a resting SP,O2 >88%. In conclusion, the prevalence of hypoxaemia was closely related to altitude. Priorities for oxygen prescription must be defined in moderate altitudes because it is unfeasible to provide it to all subjects fulfilling the criteria commonly used.

Values of Impulse Oscillometry in Healthy Mexican Children and Adolescents

BACKGROUND: The impulse oscillometry system (IOS) is increasingly used to evaluate lung function, but individual results must be compared with appropriate reference values. We aimed to obtain such reference values in Mexican children and adolescents. METHODS: Healthy subjects were recruited from kindergartens and schools after their parents signed a consent letter. Respiratory system impedances (Zrs), resistances (Rrs), and reactances (Xrs) were measured at 5, 10, 15, and 20 Hz, and the resonant frequency, reactance area, and difference between Rrs5 minus Rrs20 were also calculated. RESULTS: After exclusion of 4 children who were unable to perform an acceptable IOS recording, the final population comprised 283 children (153 females) 2.7–15.4 y of age. As a group, girls tended to have lower Xrs5 and higher Zrs20 and Rrs20 values. In bivariate analyses, all IOS variables had good correlation with age, height, and weight, and a better straight-line fitting was obtained through data transformation to the log10 (age) or reciprocal (height and weight) values. Comparison of regression lines revealed small differences between males and females, especially in Xrs. Multiple linear regression analysis identified height as the most influential variable in the majority of IOS variables, but age also accounted for a moderate-to-large influence in the regression models in many IOS variables. CONCLUSIONS: In this study, we generated reference equations for each IOS variable in healthy children and adolescents. Although these equations were generated in a Mexican population, they are probably also applicable in other Latin American populations with the same ethnic background.

TIM-3 Regulates Distinct Functions in Macrophages.

The transmembrane protein TIM-3 is a type I protein expressed by sub-types of lymphoid cells, such as lymphocytes Th1, Th17, Tc1, NK, as well as in myeloid cells. Scientific evidence indicates that this molecule acts as a negative regulator of T lymphocyte activation and that its expression is modified in viral infections or autoimmune diseases. In addition to evidence from lymphoid cells, the function of TIM-3 has been investigated in myeloid cells, such as monocytes, macrophages, and dendritic cells (DC), where studies have demonstrated that it can regulate cytokine production, cell activation, and the capture of apoptotic bodies. Despite these advances, the function of TIM-3 in myeloid cells and the molecular mechanisms that this protein regulates are not yet fully understood. This review examines the most recent evidence concerning the function of TIM-3 when expressed in myeloid cells, primarily macrophages, and the potential impact of that function on the field of basic immunology.

[Respiratory medicine and the new A/H1N1 flu: from a Mexican point of view].

.Para el Instituto Nacional de Enfermedades Respiratorias(INER) en la Ciudad de Me´xico, la epidemia se manifesto´ por unincremento notable del nu´mero de pacientes con neumoni´asati´picas, con opacidades radiogra´ficas bilaterales en parches,habitualmente sin leucocitosis, con incremento de la lactatodes-hidrogenasa, linfopenia y frecuentemente con aumento de lacreatincinasa, detectado prontamente en una institucio´n dedicadaa enfermedades respiratorias. El Servicio de Urgencias se inundo´de personas con si´ntomas indicativos de gripe; los pacientes conneumoni´a ingresados, la mitad de los cuales requeri´a ventilacio´nmeca´nica, ocupaban totalmente la Unidad de Cuidados Intensivosy se esparci´an por algunos pabellones de hospitalizacio´n

Ajuste de varias ecuaciones de referencia espirométrica a una muestra poblacional en México

Objetive. To compare several forced spirometry reference equations used in Mexico in order to know which of them have a better fit to a population-based sample. Material and Methods. Spirometric values of 225 healthy subjects 40 years of age or older from Metropolitan area of Mexico City, were compared to several reference equations. The sample is population-based and it was done from June to December 2003. The difference between observed and expected values was calculated. A concordance analysis between both observed and expected values was done and the percentage of subjects under normality lower limit was obtained. Results. The equations with better fit for FEV1 and FVC were: NHANES III for Mexican-Americans and Euro-Americans; and from PLATINO. Predicted values according to Knudson were lower, and those from Cruz-Merida, larger than observed values. Percentage of subjects below lower limit of normal was closest to 5% in the reference values from PLATINO. Conclusions. We recommend the use of reference values from the study NHANES III (for Mexican-Americans or European-Americans) and PLATINO.

PIKO-6® vs. forced spirometry in asthmatic children

The PIKO‐6® is an electronic device that measures forced expiratory volume at seconds 1 (FEV1) and 6 (FEV6) of a forced vital capacity (FVC) maneuver. This device could aid in diagnosing obstructive respiratory diseases.

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/m2) 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.

La medicina respiratoria y la nueva gripe A/H1N1: la visión desde México

Marzo y abril de 2009 serán recordados por la epidemia causada por una nueva cepa del virus de la gripe llamada A/H1N1 2009. Está en discusión dónde apareció por primera vez el virus; sin embargo, en México sufrimos su diseminación amplia, que ha causado, hasta ahora, miles de infectados, muchos en riesgo de muerte. Para el Instituto Nacional de Enfermedades Respiratorias (INER) en la Ciudad de México, la epidemia se manifestó por un incremento notable del número de pacientes con neumonı́as atı́picas, con opacidades radiográficas bilaterales en parches, habitualmente sin leucocitosis, con incremento de la lactatodeshidrogenasa, linfopenia y frecuentemente con aumento de la creatincinasa, detectado prontamente en una institución dedicada a enfermedades respiratorias. El Servicio de Urgencias se inundó de personas con sı́ntomas indicativos de gripe; los pacientes con neumonı́a ingresados, la mitad de los cuales requerı́a ventilación mecánica, ocupaban totalmente la Unidad de Cuidados Intensivos y se esparcı́an por algunos pabellones de hospitalización. El INER, antiguo sanatorio para tuberculosos, tuvo en los alrededores, durante semanas, reporteros y cámaras de televisión que dieron voz a pacientes, familiares y trabajadores de la salud, todos preocupados por la epidemia. En esta contingencia sanitaria, la medicina respiratoria representada por nuestro instituto tuvo un papel relevante en la identificación del brote y en el diagnóstico y tratamiento de los pacientes afectados, al igual que lo ha tenido en la tuberculosis (la ‘‘peste blanca’’) o, más recientemente, en la atención hospitalaria de los pacientes con infección por el virus de la inmunodeficiencia humana, y como centro de valoración y atención de pacientes con sospecha de sı́ndrome respiratorio agudo grave. La participación del INER en dichas emergencias sanitarias demuestra el importante papel que desempeña la medicina respiratoria para la sociedad, sobre todo en momentos de miedo entre la población y en el mismo personal de salud, que añade dificultad a la carga que genera la enfermedad. Los periódicos se olvidaron durante unos dı́as del narcotráfico y de la crisis económica y se saturaron de noticias sobre la gripe. Las calles de la Ciudad de México, que habitamos 20 millones de personas, lucı́an tan vacı́as como los parques, las escuelas, los