Effects of exercise training on autonomic modulation and mood symptoms in patients with obstructive sleep apnea

We evaluated the effects of exercise training (ET) on the profile of mood states (POMS), heart rate variability, spontaneous baroreflex sensitivity (BRS), and sleep disturbance severity in patients with obstructive sleep apnea (OSA). Forty-four patients were randomized into 2 groups, 18 patients completed the untrained period and 16 patients completed the exercise training (ET). Beat-to-beat heart rate and blood pressure were simultaneously collected for 5 min at rest. Heart rate variability (RR interval) was assessed in time domain and frequency domain (FFT spectral analysis). BRS was analyzed with the sequence method, and POMS was analyzed across the 6 categories (tension, depression, hostility, vigor, fatigue, and confusion). ET consisted of 3 weekly sessions of aerobic exercise, local strengthening, and stretching exercises (72 sessions, achieved in 40±3.9 weeks). Baseline parameters were similar between groups. The comparisons between groups showed that the changes in apnea-hypopnea index, arousal index, and O2 desaturation in the exercise group were significantly greater than in the untrained group (P<0.05). The heart rate variability and BRS were significantly higher in the exercise group compared with the untrained group (P<0.05). ET increased peak oxygen uptake (P<0.05) and reduced POMS fatigue (P<0.05). A positive correlation (r=0.60, P<0.02) occurred between changes in the fatigue item and OSA severity. ET improved heart rate variability, BRS, fatigue, and sleep parameters in patients with OSA. These effects were associated with improved sleep parameters, fatigue, and cardiac autonomic modulation, with ET being a possible protective factor against the deleterious effects of hypoxia on these components in patients with OSA.

Ethnicity as a risk factor for obstructive sleep apnea: comparison of Japanese descendants and white males in São Paulo, Brazil

Some studies showed that Asians with obstructive sleep apnea (OSA) are thinner than Caucasians. Because obesity is a major risk factor for OSA, it was concluded that Asians are predisposed to OSA. However, body fat composition varies for a same body mass index (BMI) according to ethnicity. We firstly compared anthropometric characteristics, symptoms and associated disorders in all consecutive male Japanese descendants and white males with OSA referred for polysomnography. In a second analysis, all Japanese descendants were compared to a subgroup of white males, matched for apnea/hypopnea index and age. In the first analysis, age, symptoms, OSA severity and co-morbidities were similar among Japanese descendants (N = 54) and white patients (N = 466). However, Japanese descendants had a lower BMI than white patients: 27.1 (25.5-28.4) vs 29.4 (26.5-33.0) kg/m², respectively (P < 0.001). In the second analysis, Japanese descendants had a lower BMI than white patients (P < 0.001). Multiple linear regression considering the entire group revealed that age, BMI, neck circumference, Epworth sleepiness scale, ethnicity and percentREM sleep were independent predictors for apnea/hypopnea index (P < 0.001). Ethnicity was no longer significantly associated with OSA severity when we adopted the World Health Organization criteria for obesity (≥25 and 30 kg/m² among Japanese descendants and white males, respectively). Japanese descendants with OSA have a lower BMI than white subjects of similar severity. However, ethnicity was not associated with OSA severity when an ethnical difference in obesity criteria was respected. Our data suggest that Japanese descendants are not predisposed to OSA.

Breathing disorders in congestive heart failure: gender, etiology and mortality

We investigated the relationship between sleep-disordered breathing (SDB) and Cheyne-Stokes respiration (CSR) while awake as well as mortality. Eighty-nine consecutive outpatients (29 females) with congestive heart failure (CHF; left ventricular ejection fraction, LVEF <45 percent) were prospectively evaluated. The presence of SDB and of CSR while awake before sleep onset was investigated by polysomnography. SDB prevalence was 81 and 56 percent, using apnea-hypopnea index cutoffs >5 and >15, respectively. CHF etiologies were similar according to the prevalence of SDB and sleep pattern. Males and females were similar in age, body mass index, and LVEF. Males presented more SDB (P = 0.01), higher apnea-hypopnea index (P = 0.04), more light sleep (stages 1 and 2; P < 0.05), and less deep sleep (P < 0.001) than females. During follow-up (25 ± 10 months), 27 percent of the population died. Non-survivors had lower LVEF (P = 0.01), worse New York Heart Association (NYHA) functional classification (P = 0.03), and higher CSR while awake (P < 0.001) than survivors. As determined by Cox proportional model, NYHA class IV (RR = 3.95, 95 percentCI = 1.37-11.38, P = 0.011) and CSR while awake with a marginal significance (RR = 2.96, 95 percentCI = 0.94-9.33, P = 0.064) were associated with mortality. In conclusion, the prevalence of SDB and sleep pattern of patients with Chagas' disease were similar to that of patients with CHF due to other etiologies. Males presented more frequent and more severe SDB and worse sleep quality than females. The presence of CSR while awake, but not during sleep, may be associated with a poor prognosis in patients with CHF.

Effects of formaldehyde on the frog's mucociliary epithelium as a surrogate to evaluate air pollution effects on the respiratory epithelium

The increasing use of alcohol as an alternative fuel to gasoline or diesel can increase emission of formaldehyde, an organic gas that is irritant to the mucous membranes. The respiratory system is the major target of air pollutants and its major defense mechanism depends on the continuous activity of the cilia and the resulting constant transportation of mucous secretion. The present study was designed to evaluate the effects of formaldehyde on the ciliated epithelium through a relative large dose range around the threshold limit value adopted by the Brazilian legislation, namely 1.6 ppm (1.25 to 5 ppm). For this purpose, the isolated frog palate preparation was used as the target of toxic injury. Four groups of frog palates were exposed to diluted Ringer solution (control, N = 8) and formaldehyde diluted in Ringer solution at three different concentrations (1.25, 2.5 and 5.0 ppm, N = 10 for each group). Mucociliary clearance and ciliary beat frequency decreased significantly in contact with formaldehyde at the concentrations of 2.5 and 5.0 ppm after 60 min of exposure (P<0.05). We conclude that relatively low concentrations of formaldehyde, which is even below the Brazilian threshold limit value, are sufficient to cause short-term mucociliary impairment

Ventilação não-invasiva no cardiopata grave / Noninvasive ventilation in the severe congestive heart failure patient

A insuficiência cardíaca congestiva leva a aumento na água extravascular pulmonar, redução do volume e da complacência pulmonar e aumento da resistência de vias aéreas, resultando em aumento do trabalho respiratório, aumento do consumo de oxigênio e aumento da sobrecarga ventricular esquerda. A utilização de pressão positiva contínua nesses pacientes melhora a oxigenação, diminui o trabalho respiratório, melhora a mecânica pulmonar, reduz a pressão transmural sobre o ventrículo esquerdo e diminui o retorno venoso, contribuindo para maior desempenho cardíaco. O uso de pressão positiva contínua diminui a necessidade de ventilação mecânica no edema agudo de pulmão e reduz o tempo de internação na unidade de terapia intensiva. A utilização de pressão positiva contínua noturna em cardiopatas crônicos demonstrou melhora significativa da fração de ejeção durante o dia, em associação com melhora da classe funcional, após o tratamento por um mês em pacientes com cardiomiopatia dilatada e apnéia obstrutiva do sono concomitante. O uso de pressão positiva contínua deve ser entendido não só como o primeiro suporte ventilatório no edema agudo dos pulmöes, como também um tratamento não-farmacológico que tem o potencial de melhorar a função cardíaca nos pacientes clinicamente estáveis, porém com insuficiência cardíaca grave.

Pulmonary emphysema induced by passive smoking: an experimental study in rats

We describe a short time model for inducing experimental emphysema in rats chronic tobacco smoke inhalation. Three groups of male Wistar rats (6 months old) were studied: controls (N = 8), rats intoxicated for 45 days (s-45, N = 7) or for 90 days (s-90, N = 8). The exposed animals were intoxicated 3 times a day (10 cigarettes per exposure period), 5 days a week. Pulmonary damage was assessed by means of functional tests and quantitative pathological examination of the airways and lung parenchyma. The s-45 and s-90 animals were similar in terms of functional residual capacity (FRC) corrected for body weight (FRC/kg) but both groups of smoking rats exhibited significantly higher FRC/kg values than the controls (s-45=6.33; s-90=6.46; controls=3.78;P<0.05). When the two groups of smoking rats were pooled together and compared to controls, they showed decreased lung elastance (1.6 vs 2.19; P = 0.046) and increased mean linear intercept (Lm) (85.14 vs 66.44; P = 0.025). The s-90 animals presented higher inflammation and muscular hypertrophy at the level of the axial bronchus than the controls (P<0.05). When smoking groups were pooled and compared to controls, they presented significantly higher inflammation at the lateral level (P = 0.028), as well as airway secretory hyperplasia (P = 0.024) and smooth muscle hypertrophy ( P = 0.005) at the axial level. Due to its simplicity, low cost and short duration, this technique may be a useful model to obtain new information about airspace remodeling due to chronic tobacco consumption.

Methods for studying respiratory mucus and mucus clearance

We describe some basic procedures for studying the properties of mucus. These techniques can be applied in both clinical and physiological studies to improve the understanding of the mechanisms related to epithelial defense in health and disease. Mucus collection - A major difficulty is the lack of simple and noninvasive methods for collecting normal mucus in sufficient quantity for later analysis. Physical properties of mucus - A. Rheology: Mucus exhibits both solid and liquid properties and the important factor governing the actual behavior is time. The magnetic microrheometer provides an elegant method for measuring rheological properties of microsamples. B. Adhesivity: It characterizes the forces of attraction between an adherent surface and an adhesive system and can be calculated by measuring the contact angle between a mucus drop and a surface. Mucus Transport - A. Mucus transport by cilia: Mucus is primarily cleared by the continuous ciliary beating, which can be studied using techniques such as the frog palate preparation as well as direct measurement. i.e., in situ mucus clearance. B. Cough clearance: It is essential for elimination of secretions in diseases leading to hypersecretory states. The cough machine simulates the flow-time profile of human coughing. Transepithelial potential difference - A potential difference exists between the epithelial surface and the submucosa and is the net result of the activity of the ion-transport system of the pulmonary epithelium. The potential can be measured using appropriate microelectrodes. Quantitative morphology - Methods may be used to characterize the epithelial surface condition that continuously changes during aggressive conditions.

Resposta a administracao de corticosteroide em pacientes portadores de doenca pulmonar obstrutiva cronica e asma / Response to administration of corticosteroids in patients with chronic obstructive lung disease and asthma

Realizamos estudo espirometrico avaliando a resposta a adminisatracao de 200 mcg de salbutamol via inalatoria, antes e apos a administracao diaria de 8 mg de triancinolona, via oral, por um periodo de em media duas semanas, em 21 pacientes portadores de doenca pulmonar obstrutiva cronica (DPOC) ou asma. Onze pacientes responderam com aumento significante da CVF ou "VEF IND. 1" ou "FEF IND. 25-75 por cento", apos o uso de corticosteroides. Dez pacientes nao responderam. Houve em media aumento significante da CVF e "VEF IND. 1" (p < 0,01) e do "FEF IND. 25-75 por cento" (p < 0,05), apos o uso de corticosteroide. Nao houve diferenca significante entre os respondedores e nao respondedores ao uso de corticosteroide quanto a idade, a CVF, "VEF IND. 1" e "FEF IND. 25-75 por cento" iniciais (percentagem do predito). O grupo dos pacientes respondedores ao uso de corticosteroide, tambem respondeu ao uso do broncodilatador, quanto ao "FEF IND. 25-75 por cento", deferindo significativamente do grupo dos nao respondedores (p < 0,02). Houve correlacao negativa significante entre a intensidade da resposta ao corticosteroide e ao broncodilatador, avaliada pelo delta "FEF IND. 25-75 por cento" (p < 0,05). A administracao do corticoide nao modificou a resposta ao broncodilatador.

Estenose bronquica de etiologia tuberculosa: patogenia e tratamento / Bronchial stenosis of tuberculous etiology: pathogenesis and treatment

Descrevemos quatro casos de estenose bronquica, uma complicacao rara de tuberculose pulmonar. No primeiro caso, uma mulher de 18 anos, sem tratamento previo para tuberculose, apresentou estenose bronquica como resultado da cicatrizacao de complexo primario. Nao havia lesao de parenquima ao raio X. Nos outros tres pacientes a estenose bronquica foi atribuida a tuberculose ativa com pesquisa positiva para bacilo alcool-acido resistente em escarro. Estes receberam tratamento para tuberculose. Em um deles isto foi suficiente para a resolucao da estenose, mas nos outros dois pacientes ocorreu estenose bronquica devido a fibrose.

Proteinose alveolar: apresentacao de quatro casos / Alveolar proteinosis: report of 4 cases

A proteinose alveolar e uma entidade rara caracterizada pelo acumulo de material lipoproteinaceo PAS-positivo na luz alveolar. Apesar da caracterizacao precisa do material acumulado, a etiopatogenia da doenca permanece mal definida. Apresentamos quatro casos acompanhados em nosso servico no periodo de 1983 a 1989. Houve confirmacao diagnostica por biopsia em todos os casos. Tres pacientes apresentaram melhora clinica e radiologica apos a lavagem pulmonar e um paciente apresentou remissao espontanea.