Efeito do Treinamento Resistido na Contratilidade Miocárdica In Vitro após a Privação de Sono / Effect Of Resistance Training On Myocardial Contractility In Vitro After Sleep Deprivation

Fundamento: O treinamento resistido promove benefícios à saúde cardiovascular, a qual é influenciada pela privação de sono. Objetivo: Investigar o efeito prévio do treinamento resistido de alta intensidade sobre a contratilidade miocárdica de ratos privados de sono paradoxal. Métodos: Quarenta ratos machos Wistar foram distribuídos nos grupos controle (CTRL), treinamento resistido (TRES), privação de sono paradoxal por 96 horas (PSP96) e treinamento resistido seguido de privação de sono paradoxal por 96 horas (TRES/PSP96). O treinamento resistido foi de alta intensidade, por 8 semanas, 5x/semana. Vinte e quatro horas após a última sessão de treinamento, os grupos PSP96 e TRES/PSP96 foram submetidos ao protocolo de privação de sono paradoxal e em seguida foi realizado o estudo in vitro da mecânica contrátil do músculo papilar isolado. Resultados: Em comparação ao CTRL, os grupos PSP96 e TRES/PSP96 apresentaram menor comprimento do músculo papilar e aumento da área de secção transversa. Associado a essas alterações, verificou-se a diminuição das derivadas temporais da força na contração e relaxamento em todas as condições avaliadas. Somente o grupo PSP96 apresentou redução da tensão de repouso e lentidão no tempo de relaxamento, sendo este último atenuado pelo treinamento resistido prévio. Conclusão: O treinamento resistido prévio à PSP foi parcialmente protetor contra as alterações contráteis do músculo papilar, minimizando a lentidão no tempo de relaxamento. Assim, o caráter de alta intensidade do protocolo adotado parece não proteger plenamente o tecido cardíaco frente a PSP

Background: Resistance training promotes cardiovascular health benefits that may affected by sleep deprivation. Objective: To evaluate the effect of high-intensity resistance training on myocardial contractility in rats subsequently subjected to paradoxical sleep deprivation. Methods: Forty male Wistar rats were distributed into control group (CTRL), resistance training (REST), 96-hour paradoxical sleep deprivation (PSD96) and resistance training followed by 96-hour paradoxical sleep deprivation (REST/PSD96). The animals underwent highintensity resistance training for 8 weeks, 5x/week. Twenty-four hours after the last training session, the PSD96 and REST/PSD96 groups were submitted to paradoxical sleep deprivation, which was followed by the in vitro study of isolated papillary muscle contractile mechanics. Results: In comparison with the CTRL group, a lower papillary muscle length and increased cross sectional area were found in PSD96 and RETS/PSD96, which were associated with decreased temporal parameters of contraction force and relaxation. Decreased resting tension and slowing of relaxation time were found in the PSD96 group only. This effect was attenuated by previous resistance training. Conclusion: Resistance training partially prevented contractile changes induced by PSD, minimizing the slowing in relaxation time. Thus, high-intensity exercise seems to not fully protect the cardiac tissue from PSD-induced effects

Robust evaluation of time since awakening using force platform posturography

INTRODUCTION: Sleepiness is responsible for a considerable proportion of traffic accidents. It is thus an important traffic safety issue to find a robust, objective and practical way to estimate the amount of time a person has been awake. To attempt to meet this goal, we investigated the relationship between sleepiness and posture control. METHODS: Subjects were kept awake for 36 hours and posturographic data during quiet standing were collected every two hours by means of a force platform. The standing surface (rigid surface or foam surface) and visual (eyes open or eyes closed) conditions were manipulated. RESULTS: In the more challenging conditions (with foam surface and/or eyes closed), the body sway variables derived from the center of the pressure measurement increased significantly when time since awakening became greater than 21 h in almost all subjects. CONCLUSION: Based on this result, we propose a practical protocol that could robustly assess whether time since awakening was greater than 21 h.

Passive body heating improves sleep patterns in female patients with fibromyalgia

OBJECTIVE: To assess the effect of passive body heating on the sleep patterns of patients with fibromyalgia. METHODS: Six menopausal women diagnosed with fibromyalgia according to the criteria determined by the American College of Rheumatology were included. All women underwent passive immersion in a warm bath at a temperature of 36 ±1 °C for 15 sessions of 30 minutes each over a period of three weeks. Their sleep patterns were assessed by polysomnography at the following time-points: pre-intervention (baseline), the first day of the intervention (acute), the last day of the intervention (chronic), and three weeks after the end of the intervention (follow-up). Core body temperature was evaluated by a thermistor pill during the baseline, acute, chronic, and follow-up periods. The impact of this treatment on fibromyalgia was assessed via a specific questionnaire termed the Fibromyalgia Impact Questionnaire. RESULTS: Sleep latency, rapid eye movement sleep latency and slow wave sleep were significantly reduced in the chronic and acute conditions compared with baseline. Sleep efficiency was significantly increased during the chronic condition, and the awakening index was reduced at the chronic and follow-up time points relative to the baseline values. No significant differences were observed in total sleep time, time in sleep stages 1 or 2 or rapid eye movement sleep percentage. The core body temperature and Fibromyalgia Impact Questionnaire responses did not significantly change over the course of the study. CONCLUSION: Passive body heating had a positive effect on the sleep patterns of women with fibromyalgia.

Fibromialgia: nível de atividade física e qualidade do sono / Fibromyalgia: level of physical activity and quality of sleep

O objetivo foi identificar o nível de atividade física e sua relação com sonolência excessiva diurna e qualidade de sono em 15 mulheres com fibromialgia, com idade média de 58±7 anos. Foi utilizado o Questionário Internacional de Atividade Física, o Índice de Qualidade de Sono de Pittsburgh e a Escala de Sonolência de Epworth. O programa SPSS Statistics versão 17 foi utilizado para as analises estatísticas e o valor para significância foi de α ≤ 0,05. Os resultados evidenciaram que 33,3% das pacientes classificaram-se inativas e 66,7% minimamente ativas. Observou-se sonolência excessiva diurna em 60% das pacientes. A qualidade ruim de sono foi observada em 55,6% das pacientes minimamente ativas e em 60% das inativas. O tempo médio para adormecer foi 34,3 minutos, a eficiência do sono foi 81% e o tempo total de sono foi 5,9 horas. O baixo nível de atividade física parece ser um dos fatores capazes de piorar a qualidade do sono de mulheres com fibromialgia.

The objective was to identify the level of physical activity and its relation to excessive daytime sleepiness and sleep quality in 15 women with fibromyalgia and mean age 58 ± 7 years. We used the International Physical Activity Questionnaire, the Sleep Quality Index in Pittsburgh and Epworth Sleepiness Scale. We used SPSS Statistics Version 17 and the value for significance was α ≤ 0.05. The results showed that 33,3% of patients rated themselves inactive and 66,7% minimally active. We observed excessive daytime sleepiness in 60% of patients. The poor quality of sleep was observed in 55,6% of patients in minimally active and 60% of inactive. The average time was 34,3 minutes to fall asleep, sleep efficiency was 81% and total sleep time was 5,9 hours. The low level of physical activity seems to be one of the factors that can worsen sleep quality in women with fibromyalgia.