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.

An assessment of oxidized LDL in the lipid profiles of patients with obstructive sleep apnea and its association with both hypertension and dyslipidemia, and the impact of treatment with CPAP.

OBJECTIVE: Obstructive sleep apnea (OSA) has been linked to increased oxidative stress, lipid peroxidation and worsening atherosclerosis. This study investigated oxidized low-density lipoprotein (oxLDL) as a marker of lipid peroxidation, and total LDL cholesterol (direct LDL-C), as a marker of the lipid profile among individuals with OSA, and its association with hypertension (HYP) and dyslipidemia (DYS). The impact of one year of continuous positive airway pressure (CPAP) was also assessed. METHODS: Blood was collected after 12 h of fasting from 99 consecutive patients who were diagnosed with OSA via polysomnography, and were also diagnosed with both HYP and DYS via clinical and laboratory studies. The patients were classified into the following three groups: GI [OSA with comorbidities (HYP or DYS)], GII [OSA without comorbidities], and GIII [control]. Thirty-five patients with an apnea/hypopnea index >20 per hour of sleep were randomized to groups that received either Sham-CPAP or CPAP treatments over 12 months. RESULTS: In a binary regression controlled for sex, age, body mass index, and glycemia, model 1 which analyzed direct LDL-C, demonstrated significant levels of risk in the setting of DYS but not in the settings of HYP and OSA. In model 2, which analyzed oxLDL, DYS (p = 0.01), HYP (p = 0.032), and OSA (p = 0.039) were statistically significant. Significant alterations were observed in only the sleep parameters following one year of CPAP. CONCLUSIONS: Based on the statistical regression model, only the presence of DYS (p = 0.001) was associated with the levels of direct LDL-C. The remaining comorbidities (OSA and HYP) were not significantly related to the levels of direct LDL-C. Regarding oxLDL, OSA, HYP and DYS each added significant score values to the levels of oxLDL. These findings are suggestive of the importance of assessing oxLDL among patients presenting with OSA, both with and without comorbidities.

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.

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.

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.

Perfil cardiovascular em pacientes com apneia obstrutiva do sono / Cardiovascular profile in patients with obstructive sleep apnea / Perfil cardiovascular en pacientes con apnea obstructiva del sueño

FUNDAMENTO: Apneia Obstrutiva do Sono (AOS) é um fator de risco para várias condições cardiovasculares incluindo aumento na mortalidade cardiovascular. Sendo assim, é essencial o conhecimento das principais repercussões cardiovasculares dos distúrbios respiratórios do sono durante uma avaliação clínica. OBJETIVO: Analisar as características cardiovasculares de pacientes com AOS. MÉTODOS: Pacientes submetidos a polissonografia basal foram consecutivamente selecionados do banco de dados do Instituto do Sono entre março de 2007 e março de 2009. Todos os pacientes foram orientados a comparecer ao ambulatório para coleta de sangue, exame físico, eletrocardiograma de 12 derivações, espirometria, teste cardiopulmonar em esteira ergométrica e ecocardiograma transtorácico. O estudo foi aprovado pelo comitê de ética e pesquisa e registrado no site http://clinicaltrials.gov/ sob o número: NCT00768625. RESULTADOS: Foram analisados 261 pacientes e 108 controles. As principais características dos pacientes com AOS foram: obesidade, hipertensão, baixos níveis plasmáticos de lipoproteínas de alta densidade (HDL) e aumento no diâmetro do átrio esquerdo quando comparados com controles (3,75 ± 0,42; 3,61 ± 0,41, p = 0,001), respectivamente. Essas características associadas correspondem a um acréscimo de 16,6 vezes na probabilidade de ocorrência de AOS independentemente do relato de algum sintoma dessa desordem, como sonolência ou ronco. CONCLUSÃO: Na amostra avaliada, o perfil cardiovascular dos pacientes com AOS mais encontrado foi: obesidade, hipertensão arterial, baixos níveis plasmáticos de HDL e átrio esquerdo com diâmetro aumentado.

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: Apnea obstructiva del sueño (AOS) es un factor de riesgo para diversas condiciones cardiovasculares, incluido el aumento en la mortalidad cardiovascular. Por tanto, es imprescindible conocer las principales repercusiones cardiovasculares de los trastornos respiratorios del sueño durante una evaluación clínica. OBJETIVO:Analizar las características cardiovasculares de pacientes con AOS. MÉTODOS:Los pacientes sometidos a la polisomnografía basal fueron seleccionados de forma consecutiva a partir del banco de datos del Instituto del Sueño entre marzo de 2007 y marzo de 2009. Todos los pacientes fueron orientados a comparecer al ambulatorio para la recolección de sangre, examen físico, electrocardiograma de 12 derivaciones espirometria, prueba cardiopulmonar en cinta ergométrica y ecocardiograma transtorácico. El estudio fue aprobado por el comité de ética e investigación y registrado en la página web http://clinicaltrials.gov/ con el número: NCT00768625. RESULTADOS:Se analizaron a 261 pacientes y 108 controles. Las principales características de los pacientes con AOS fueron: la obesidad, la hipertensión, los bajos niveles plasmáticos de lipoproteínas de alta densidad (HDL) y el aumento de diámetro de la aurícula izquierda en comparación con los controles (3,75 1 0,42, 3,61 1 0,41, p = 0,001), respectivamente. Estas características asociadas corresponden a un aumento de 16,6 veces en la probabilidad de ocurrencia de AOS, independientemente de reportar cualquier síntoma de este trastorno, como la somnolencia o el ronquido. CONCLUSIÓN:En la muestra estudiada, el perfil cardiovascular de los pacientes con AOS más encontrado ha sido: obesidad, hipertensión arterial, bajos niveles plasmáticos de HDL y el diámetro de la aurícula izquierda mayor.

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.