Márcia Cristina Feres

Does Obstructive Sleep Apnea Impair the Cardiopulmonary Response to Exercise

STUDY OBJECTIVES The aim of this study was to evaluate cardiopulmonary exercise performance in lean and obese patients with obstructive sleep apnea (OSA) compared with controls. DESIGN Case-control study. SETTING The study was carried out in Sao Paulo Sleep Institute, Sao Paulo, Brazil. PATIENTS AND PARTICIPANTS INDIVIDUALS WITH SIMILAR AGES WERE ALLOCATED INTO GROUPS: 22 to the lean OSA group, 36 to the lean control group, 31 to the obese OSA group, and 26 to the obese control group. INTERVENTIONS The participants underwent a clinical evaluation, polysomnography, a maximum limited symptom cardiopulmonary exercise test, two-dimensional transthoracic echocardiography, and spirometry. MEASUREMENTS AND RESULTS The apnea-hypopnea index, arousal index, lowest arterial oxygen saturation (SaO2) and time of SaO2 < 90% were different among the groups. There were differences in functional capacity based on the following variables: maximal oxygen uptake (VO2max), P < 0.01 and maximal carbon dioxide production (VCO2max), P < 0.01. The obese patients with OSA and obese controls presented significantly lower VO2max and VCO2max values. However, the respiratory exchange ratio (RER) and anaerobic threshold (AT) did not differ between groups. Peak diastolic blood pressure (BP) was higher among the obese patients with OSA but was not accompanied by changes in peak systolic BP and heart rate (HR). When multiple regression was performed, body mass index (P < 0.001) and male sex in conjunction with diabetes (P < 0.001) independently predicted VO2max (mL/kg/min). CONCLUSIONS The results of this study suggest that obesity alone and sex, when associated with diabetes but not OSA, influenced exercise cardiorespiratory function.

Validação laboratorial de um método automatizado de dosagem da atividade de adenosina desaminase em líquido pleural e em líquido cefalorraquidiano

OBJECTIVE The incidence of tuberculosis worldwide has emphasized the need for better assays designed to diagnose the disease, principally the extrapulmonary form. The objective of the present study was to validate the performance of an automated method for the determination of adenosine deaminase (ADA) activity in pleural fluid (PF) and cerebrospinal fluid (CSF), comparing it with a conventional method (the modified Giusti method). METHODS In total, 134 samples were selected from among those tested in our laboratory: 94 PF samples and 40 CSF samples. The ADA activity was determined using the two methods. Inter- and intra-assay precision was determined, linear regression analysis was performed, simple concordance tests were conducted, and the means of the differences were calculated. RESULTS The correlation coefficients for PF and CSF samples were, respectively, 0.96 and 0.95. Inter-assay precision was determined using 21 replicates at 3 different activity levels: low, medium and high. The percentage coefficient of variation (%CV) was, respectively, 5.9, 8.1 and 5.8 for PF samples, compared with 21.9, 18.6 and 13.8 for CSF samples. Intra-assay precision in %CV was 1.3 and 11.7, respectively, for PF and CSF samples. The concordance between the methods in PF and CRF samples was, respectively, 96.8% and 100%, considering the reference values for the diagnosis of TB to be 40 U/L (conventional) and 30 U/L (automated) in PF samples, versus 9 U/L (for both methods) in CSF samples. CONCLUSIONS The results validate the use of the automated method of determining ADA activity in PF and CSF samples as an alternative to the conventional method.

Implications for the use of acid preservatives in 24-hour urine for measurements of high demand biochemical analytes in clinical laboratories.

BACKGROUND Evaluate the level of interference of biochemists dosages in the 24-hour urine using or not the 6 mol/l HCl acid in different concentrations and conditions and its implications in the most demanded analytes in clinical laboratory. METHODS Twenty-two volunteers collected three 24-hour urine in 3 conditions: with 5 ml/l and 20 ml/l of 6 mol/l HCl in the container, and without acid preservative. The samples collected without preservative were separated in aliquots and added 5 ml/l of 6 mol/l HCl after 24 h. Analytes, uric acid creatinine, urea, chlorides, glucose, magnesium, sodium, potassium, microalbumin, proteins, amylase, aldosterone, calcium, cortisol, phosphorus, citric acid, oxalate, and metanephrines, were determined. RESULTS Uric acid, glucose, microalbumin, protein, amylase and aldosterone showed that %CV ranging from 16 to 57% in the presence of acid preservative. Analytes that need acid preservative cortisol, citric acid and oxalate showed %CV ranging from 6 to 27% with r=0.66, r=0.77, r=0.70 respectively provided 5 ml/l after delivery and r=0.31, r=0.70 and r=0.48 without preservative acid when compared with the gold standard (with 20 ml/l of 6 mol/l HCl). CONCLUSIONS Glucose, microalbumin, protein, amylase and aldosterone urinary did not show good performance in the presence of acid preservative. Analytes that need acid preservative showed variation acceptable in condition 5 ml/l of 6 mol/l HCl added after 24 h.

Cardiovascular profile in patients with obstructive sleep apnea

BACKGROUND Obstructive Sleep Apnea (OSA) is a risk factor for several cardiovascular conditions including increased cardiovascular mortality. It is therefore essential to know the major cardiovascular effects of sleep-disordered breathing during a clinical evaluation. OBJECTIVE To analyze the cardiovascular characteristics of patients with OSA. METHODS Patients underwent baseline polysomnography and were consecutively selected from the database of the Sleep Institute between March 2007 and March 2009. All patients were instructed to attend the clinic for blood collection, physical examination, 12-lead electrocardiogram, spirometry, cardiopulmonary exercise testing on a treadmill and transthoracic echocardiography. The study was approved by the Research Ethics Committee and recorded at http://clinicaltrials.gov/ under number: NCT00768625. RESULTS We analyzed 261 patients and 108 controls. The main characteristics of patients with OSA were: obesity, hypertension, low plasma levels of high density lipoprotein (HDL) and increased left atrial diameter compared with controls (3.75 ± 0.42; 3.61 ± 0.41, p = 0.001), respectively. These associated characteristics correspond to a 16.6 increase in the likelihood of OSA regardless of reporting any symptoms of this disorder, such as sleepiness or snoring. CONCLUSION In the sample studied, the mostly found cardiovascular profile of patients with OSA was: obesity, hypertension, low plasma levels of HDL and left atrial diameter increased.FUNDAMENTO: Apneia Obstrutiva do Sono (AOS) e um fator de risco para varias condicoes cardiovasculares incluindo aumento na mortalidade cardiovascular. Sendo assim, e essencial o conhecimento das principais repercussoes cardiovasculares dos disturbios respiratorios do sono durante uma avaliacao clinica. OBJETIVO: Analisar as caracteristicas cardiovasculares de pacientes com AOS. METODOS: Pacientes submetidos a polissonografia basal foram consecutivamente selecionados do banco de dados do Instituto do Sono entre marco de 2007 e marco de 2009. Todos os pacientes foram orientados a comparecer ao ambulatorio para coleta de sangue, exame fisico, eletrocardiograma de 12 derivacoes, espirometria, teste cardiopulmonar em esteira ergometrica e ecocardiograma transtoracico. O estudo foi aprovado pelo comite de etica e pesquisa e registrado no site http://clinicaltrials.gov/ sob o numero: NCT00768625. RESULTADOS: Foram analisados 261 pacientes e 108 controles. As principais caracteristicas dos pacientes com AOS foram: obesidade, hipertensao, baixos niveis plasmaticos de lipoproteinas de alta densidade (HDL) e aumento no diâmetro do atrio esquerdo quando comparados com controles (3,75 ± 0,42; 3,61 ± 0,41, p = 0,001), respectivamente. Essas caracteristicas associadas correspondem a um acrescimo de 16,6 vezes na probabilidade de ocorrencia de AOS independentemente do relato de algum sintoma dessa desordem, como sonolencia ou ronco. CONCLUSAO: Na amostra avaliada, o perfil cardiovascular dos pacientes com AOS mais encontrado foi: obesidade, hipertensao arterial, baixos niveis plasmaticos de HDL e atrio esquerdo com diâmetro aumentado.

Obstructive sleep apnea and objective short sleep duration are independently associated with the risk of serum vitamin D deficiency

Background Studies demonstrate an association between vitamin D (25(OH)D) deficiency and sleep disturbances, such as obstructive sleep apnea (OSA) and short sleep duration. However, to date, no studies have concurrently and objectively evaluated the effect of these factors on 25(OH)D. Objectives To evaluate whether OSA and objective short sleep duration are independently associated with reduced 25(OH)D in an adult population sample. Methods A cross-sectional study included 657 individuals from the city of Sao Paulo, Brazil, as part of the ERA project. Participants fulfilled questionnaires and underwent clinical evaluation, polysomnography and blood sample collection for 25(OH)D quantification. OSA was classified into three categories (mild, moderate and severe). The risk of 25(OH)D deficiency was considered as levels<30 ng/mL. Short sleep duration was defined as total sleep time<6 hours. Results The risk of 25(OH)D deficiency was observed in 59.5% of the sample, affecting more individuals of the female gender, obese, with African American ethnicity, and those that were smokers, sedentary and presented hypertension and diabetes. In the final logistic model adjusted for age, gender, ethnicity, obesity, smoking, hypertension, diabetes, sedentary lifestyle, seasonality and creatinine serum levels, both OSA and short sleep duration showed significant independent associations with the risk of 25(OH)D deficiency (moderate OSA: OR for 25(OH)D<30 = 2.21, 95% CI: 1.35–3.64, p<0.01; severe OSA: OR for 25(OH)D<30 = 1.78, 95% CI: 1.06–3.00, p = 0.03; short sleep duration: OR for 25(OH)D<30 = 1.61, 95% CI: 1.15–2.26, p = 0.01). After a subgroup analysis, similar results were observed only in participants ≥50 years. Conclusion OSA and short sleep duration are independently associated with the risk of 25(OH)D deficiency in an adult population. Age-related changes in vitamin D metabolism and the frequency of sleep disorders may be involved in these associations. Future studies exploring whether 25(OH)D levels may modulate OSA and sleep curtailment-related outcomes are needed.

Perfil cardiovascular em pacientes com apneia obstrutiva do sono

BACKGROUND Obstructive Sleep Apnea (OSA) is a risk factor for several cardiovascular conditions including increased cardiovascular mortality. It is therefore essential to know the major cardiovascular effects of sleep-disordered breathing during a clinical evaluation. OBJECTIVE To analyze the cardiovascular characteristics of patients with OSA. METHODS Patients underwent baseline polysomnography and were consecutively selected from the database of the Sleep Institute between March 2007 and March 2009. All patients were instructed to attend the clinic for blood collection, physical examination, 12-lead electrocardiogram, spirometry, cardiopulmonary exercise testing on a treadmill and transthoracic echocardiography. The study was approved by the Research Ethics Committee and recorded at http://clinicaltrials.gov/ under number: NCT00768625. RESULTS We analyzed 261 patients and 108 controls. The main characteristics of patients with OSA were: obesity, hypertension, low plasma levels of high density lipoprotein (HDL) and increased left atrial diameter compared with controls (3.75 ± 0.42; 3.61 ± 0.41, p = 0.001), respectively. These associated characteristics correspond to a 16.6 increase in the likelihood of OSA regardless of reporting any symptoms of this disorder, such as sleepiness or snoring. CONCLUSION In the sample studied, the mostly found cardiovascular profile of patients with OSA was: obesity, hypertension, low plasma levels of HDL and left atrial diameter increased.FUNDAMENTO: Apneia Obstrutiva do Sono (AOS) e um fator de risco para varias condicoes cardiovasculares incluindo aumento na mortalidade cardiovascular. Sendo assim, e essencial o conhecimento das principais repercussoes cardiovasculares dos disturbios respiratorios do sono durante uma avaliacao clinica. OBJETIVO: Analisar as caracteristicas cardiovasculares de pacientes com AOS. METODOS: Pacientes submetidos a polissonografia basal foram consecutivamente selecionados do banco de dados do Instituto do Sono entre marco de 2007 e marco de 2009. Todos os pacientes foram orientados a comparecer ao ambulatorio para coleta de sangue, exame fisico, eletrocardiograma de 12 derivacoes, espirometria, teste cardiopulmonar em esteira ergometrica e ecocardiograma transtoracico. O estudo foi aprovado pelo comite de etica e pesquisa e registrado no site http://clinicaltrials.gov/ sob o numero: NCT00768625. RESULTADOS: Foram analisados 261 pacientes e 108 controles. As principais caracteristicas dos pacientes com AOS foram: obesidade, hipertensao, baixos niveis plasmaticos de lipoproteinas de alta densidade (HDL) e aumento no diâmetro do atrio esquerdo quando comparados com controles (3,75 ± 0,42; 3,61 ± 0,41, p = 0,001), respectivamente. Essas caracteristicas associadas correspondem a um acrescimo de 16,6 vezes na probabilidade de ocorrencia de AOS independentemente do relato de algum sintoma dessa desordem, como sonolencia ou ronco. CONCLUSAO: Na amostra avaliada, o perfil cardiovascular dos pacientes com AOS mais encontrado foi: obesidade, hipertensao arterial, baixos niveis plasmaticos de HDL e atrio esquerdo com diâmetro aumentado.

Evaluation and Validation of a Method for Determining Platelet Catecholamine in Patients with Obstructive Sleep Apnea and Arterial Hypertension

Background Measurements of plasma and urinary catecholamine are susceptible to confounding factors that influence the results, complicating the interpretation of sympathetic nervous system (SNS) activity in the Obstructive sleep apnea (OSA) and arterial hypertension (HYP) conditions. Objective In this study, we validated a test for platelet catecholamine and compared the catecholamine levels (adrenaline and noradrenaline) in urine, plasma and platelets in patients with OSA and HYP compared with controls. Methods In the validation, 30 healthy, nonsmoking volunteers who were not currently undergoing treatment or medication were selected as the control group. One hundred fifty-four individuals (114 OSA, 40 non-OSA) were consecutively selected from the outpatient clinic of the Sleep Institute and underwent clinical, polysomnographic and laboratory evaluation, including the urinary, plasma and platelet levels of adrenaline (AD) and noradrenaline (NA). Patients were then allocated to groups according to the presence of OSA and/or hypertension. Results A logistic regression model, controlled for age and BMI, showed that urinary AD and urinary NA were risk factors in the OSA+HYP group and the HYP group; however, the model showed higher levels of platelet NA for OSA without HYP. After 1 year of CPAP (continuous upper airway pressure) treatment, patients (n = 9) presented lower levels of urinary NA (p = 0.04) and platelet NA (p = 0.05). Conclusion Urinary NA and AD levels were significantly associated with the condition of hypertension with and without OSA, whereas platelet NA with OSA without comorbidity. These findings suggest that platelet catecholamine levels might reflect nocturnal sympathetic activation in OSA patients without hypertension.

Perfil cardiovascular en pacientes con apnea obstructiva del sueño

BACKGROUND Obstructive Sleep Apnea (OSA) is a risk factor for several cardiovascular conditions including increased cardiovascular mortality. It is therefore essential to know the major cardiovascular effects of sleep-disordered breathing during a clinical evaluation. OBJECTIVE To analyze the cardiovascular characteristics of patients with OSA. METHODS Patients underwent baseline polysomnography and were consecutively selected from the database of the Sleep Institute between March 2007 and March 2009. All patients were instructed to attend the clinic for blood collection, physical examination, 12-lead electrocardiogram, spirometry, cardiopulmonary exercise testing on a treadmill and transthoracic echocardiography. The study was approved by the Research Ethics Committee and recorded at http://clinicaltrials.gov/ under number: NCT00768625. RESULTS We analyzed 261 patients and 108 controls. The main characteristics of patients with OSA were: obesity, hypertension, low plasma levels of high density lipoprotein (HDL) and increased left atrial diameter compared with controls (3.75 ± 0.42; 3.61 ± 0.41, p = 0.001), respectively. These associated characteristics correspond to a 16.6 increase in the likelihood of OSA regardless of reporting any symptoms of this disorder, such as sleepiness or snoring. CONCLUSION In the sample studied, the mostly found cardiovascular profile of patients with OSA was: obesity, hypertension, low plasma levels of HDL and left atrial diameter increased.FUNDAMENTO: Apneia Obstrutiva do Sono (AOS) e um fator de risco para varias condicoes cardiovasculares incluindo aumento na mortalidade cardiovascular. Sendo assim, e essencial o conhecimento das principais repercussoes cardiovasculares dos disturbios respiratorios do sono durante uma avaliacao clinica. OBJETIVO: Analisar as caracteristicas cardiovasculares de pacientes com AOS. METODOS: Pacientes submetidos a polissonografia basal foram consecutivamente selecionados do banco de dados do Instituto do Sono entre marco de 2007 e marco de 2009. Todos os pacientes foram orientados a comparecer ao ambulatorio para coleta de sangue, exame fisico, eletrocardiograma de 12 derivacoes, espirometria, teste cardiopulmonar em esteira ergometrica e ecocardiograma transtoracico. O estudo foi aprovado pelo comite de etica e pesquisa e registrado no site http://clinicaltrials.gov/ sob o numero: NCT00768625. RESULTADOS: Foram analisados 261 pacientes e 108 controles. As principais caracteristicas dos pacientes com AOS foram: obesidade, hipertensao, baixos niveis plasmaticos de lipoproteinas de alta densidade (HDL) e aumento no diâmetro do atrio esquerdo quando comparados com controles (3,75 ± 0,42; 3,61 ± 0,41, p = 0,001), respectivamente. Essas caracteristicas associadas correspondem a um acrescimo de 16,6 vezes na probabilidade de ocorrencia de AOS independentemente do relato de algum sintoma dessa desordem, como sonolencia ou ronco. CONCLUSAO: Na amostra avaliada, o perfil cardiovascular dos pacientes com AOS mais encontrado foi: obesidade, hipertensao arterial, baixos niveis plasmaticos de HDL e atrio esquerdo com diâmetro aumentado.