Effects of exercise on sleep symptoms in patients with severe obstructive sleep apnea / Efeitos do exercício nos sintomas do sono em pacientes com apneia obstrutiva do sono

ABSTRACT Objective: To investigate the extent to which exercise is associated with symptoms in patients with severe obstructive sleep apnea (OSA). Methods: We included subjects with an apnea-hypopnea index (AHI) > 30 events/h who completed validated sleep and exercise questionnaires. We compared symptom frequency/scores between exercisers and nonexercisers, adjusting for the usual confounders. Results: The sample included 907 nonexercisers and 488 exercisers (mean age, 49 ± 14 years; mean AHI, 53 ± 20 events/h; 81% men). Nonexercisers and exercisers differed significantly in terms of obesity (72% vs. 54%), the mean proportion of sleep in non-rapid eye movement stage 3 sleep (9 ± 8% vs. 11 ± 6%), and tiredness (78% vs. 68%). Nonexercisers had a higher symptom frequency/scores and poorer sleep quality. Adjustment for exercise weakened the associations between individual symptoms and the AHI, indicating that exercise has a mitigating effect. In binary logistic models, exercise was associated with approximately 30% lower adjusted questionnaire1 score > 2, tiredness; poor-quality sleep, unrefreshing sleep, and negative mood on awakening. Although the odds of an Epworth Sleepiness Scale score > 10 were lower in exercisers, that association did not withstand adjustment for confounders. Conclusions: Exercise is associated with lower frequency/intensity of symptoms in patients with severe OSA. Because up to one third of patients with severe OSA might exercise regularly and therefore be mildly symptomatic, it is important not to rule out a diagnosis of OSA in such patients.

RESUMO Objetivo: Investigar até que ponto o exercício está associado a sintomas em pacientes com apneia obstrutiva do sono (AOS) grave. Métodos: Foram incluídos indivíduos com um índice de apneia-hipopneia (IAH) > 30 eventos/h que completaram questionários de sono e exercício validados. Comparamos a frequência/pontuação de sintomas entre praticantes e não praticantes de exercícios, ajustados para os fatores de confusão habituais. Resultados: A amostra incluiu 907 não praticantes e 488 praticantes (idade média de 49 ± 14 anos; IAH médio, 53±20 eventos/h; 81% homens). Não praticantes e praticantes diferiram significativamente em termos de obesidade (72% vs. 54%), proporção média de sono em estágio de sono 3 com non-rapid eye movement (9 ± 8% vs. 11 ± 6%) e cansaço (78% vs. 68%). Os não praticantes tiveram uma maior frequência/pontuação de sintomas e uma pior qualidade do sono. O ajuste para exercício enfraqueceu as associações entre sintomas individuais e o IAH, indicando que o exercício tem um efeito atenuante. Nos modelos logísticos binários, o exercício foi associado a uma redução de aproximadamente 30% no escore > 2 no questionário ajustado1 para cansaço; sono de má qualidade, sono não reparador e humor negativo ao despertar. Embora as chances de um escore >10 na Escala de Sonolência de Epworth ter sido menor nos praticantes, essa associação não resistiu ao ajuste para fatores de confusão. Conclusões: O exercício está associado a uma menor frequência/intensidade de sintomas em pacientes com AOS grave. Como até um terço dos pacientes com AOS grave pode se exercitar regularmente e, portanto, ser levemente sintomático, é importante não descartar um diagnóstico de AOS nesses pacientes.

The effect of caffeine supplementation on exercise performance evaluated by a novel animal model

Introduction: Caffeinated drinks are used for improve performance. Animal models represent investigational strategy that circumvents most of the drawbacks of research in humans, including motivational factors and the placebo effect. No animal model that could test whether different forms of administering caffeine affect exercise propensity was found in the literature. Methods: An animal model of grouped voluntary exercise was tested. Two-month-old male C57/bl mice were housed in a cage fitted with one running wheel and a monitoring system. Six animals per cage were introduced individually. To assess the sensitivity of the model, the effect of different caffeinated drinks was observed in mice exercising ad libitum. During 2 days, the mice received: 1) pure anhydrous caffeine 0.125 mg/mL (PC), 2) cola drink (CC), and 3) caffeine-taurine-glucuronolactone drink (CTG), intercalating wash-out periods of 2 days, receiving pure water. Results: The distance run during the periods of water ingestion was significantly lower than during the periods of stimulant drinks ingestion: PC (5.6 ± 1.3 km; p = 0.02), of CC ingestion (7.6 ± 0.6 km; p = 0.001), and of CTG ingestion (8.3 ± 1.6 km; p = 0.009). The performances when ingesting the three caffeinated drinks do not follow a dose-response curve. Conclusions: The model described here was able to measure the effect of caffeine intake on voluntary exercise of mice. The sensitivity of the model to the effect of caffeine needs to be further validated. The action of each component of the drinks on exercise performance needs to be clarified in future research. The present model is adequate for such investigation (AU)

Ecocardiografia em pacientes com apneia do sono grave com e sem pressão arterial controlada: estudo transversal / Echocardiography in patients with severe sleep apnea with and without controlled blood pressure: cross sectional study

A apneia obstrutiva do sono (AOS) afeta a anatomia e função do coração. Ocorre hipertensão arterial em metade dos casos de AOS, dificultando atribuir a etiologia dessas alterações separadamente à hipertensão arterial ou à apneia do sono. Métodos: Estudo transversal de pacientes com índice de apneia-hipopneia maior que 50 eventos por hora. As variáveis ecocardiográficas comparadas em indivíduos com hipertensão arterial controlada e não controlada foram: 1) fração de ejeção, 2) diâmetro da aorta, 3) diâmetro do átrio esquerdo, 4) diâmetro de ventrículo direito, 5) diâmetros do ventrículo esquerdo diastólico e sistólico, 6) percentagem delta, 7) espessura do septo, 8) espessura da parede posterior. Resultados: Foram incluídos 83 voluntários, 50 com pressão arterial não controlada. Em média, a idade era 47 ± 9,5 anos, o índice de massa corporal 34 ± 5,4 Kg/m2 , o índice de apneia-hipopneia 86 ± 18 eventos/hora. Sessenta pacientes apresentaram anormalidade no ecocardiograma. A hipertrofia de ventrículo esquerdo foi o achado mais comum, sem diferença de frequência em controles (39%) e em hipertensos (48%), seguida por disfunção diastólica em controles (27%) e em hipertensos (32%). Conclusões: Indivíduos com apneia do sono grave e pressão arterial controlada apresentam alterações no ecocardiograma de tipo e frequência semelhantes aos com hipertensão não controlada. Isso sugere que a apneia do sono pode causar dano cardíaco independentemente de hipertensão. Quando não explicáveis por hipertensão arterial, achados como hipertrofia de ventrículo esquerdo podem ser provocados por apneia do sono...

Obstructive sleep apnea (OSA) affects the cardiac anatomy and function. Hypertension occurs in half the OSA cases, making it difficult to attribute the cause of these changes separately to arterial hypertension or sleep apnea. Methods: Prospective cross-sectional study of volunteers with apnea-hypopnea index >50 events per hour. The echocardiographic variables were analyzed: 1) ejection fraction, 2) aortic diameter, 3) left atrial diameter, 4) right ventricular diameter, 5) diastolic and systolic diameters of the left ventricle, 6) delta percentage, 7) septum thickness, 8) posterior wall thickness. Results: There were 83 participants, 74 men, 50 with hypertension. The average age was 47 ± 9.5 years, body mass index of 34 ± 5.4 kg/m2 , apnea-hypopnea index of 86±18 events/hour, and minimum oxygen saturation of 55 ± 17%. Left ventricular hypertrophy was the most common echocardiographic abnormality in subjects without hypertension (39%) and with hypertension (48%), followed by diastolic dysfunction in subjects with normal blood pressure (27%) and with high blood pressure (32%). There was no statistically significant difference in echocardiographic characteristics between hypertensive subjects with those with normal pressure. Conclusions: Individuals with normal blood pressure and severe sleep apnea show abnormalities in the echocardiogram with frequency similar to that observed in patients with high blood pressure. This suggests that sleep apnea can cause ventricular overload independently of hypertension. When not explained by high blood pressure, left ventricular hypertrophy can be caused by sleep apnea...

Scores of a web-based version of the Seasonal Pattern Assessment Questionnaire in Brazil

Seasonal affective disorder (SAD) is a proposed mental disorder still controversial. This condition is prevalent in northern latitudes, but few studies have been conducted at locations in the southern hemisphere. It is usually assessed by the Seasonal Pattern Assessment Questionnaire (SPAQ). This study aimed to evaluate, through on-line questionnaire, the hypothesis that, in the Brazilian population, latitude and longitude influence SPAQ scores. Methods: An advertisement was posted on a sleep medicine website inviting visitors to investigate seasonal patterns of behavior and mood, using a Brazilian Portuguese version of the SPAQ. The geographic coordinates of the place of residence of each respondent were analyzed as a continuous variable or distributed in quartiles of latitude and longitude. The psychometric properties of the SPAQ were assessed by reliability and factor analyses. Results: Answers from 1001 respondents out of 1045 were considered eligible. High SPAQ scores were observed in 287 respondents, equally distributed among all latitude and longitude quartiles. Data collected in different seasons and during daylight saving time did not differ significantly in any of the scores for SPAQ dimensions. No correlations between SPAQ scores and latitude or longitude were observed. Psychometric properties of the SPAQ were preserved in all geographic locations. Conclusion: The finding of similar SPAQ scores at a wide latitude range defies the concept of SAD symptoms as latitude or longitude-dependent phenomena...