A three-phase epidemiological study of short and long sleepers in a middle-aged Chinese population: prevalence and characteristics

Epidemiological studies of short and long sleepers have not been conducted previously. We collected socioeconomic, psychological, and polysomnographic characteristics of 6501 parents (3252 men and 3249 women) of 4036 primary school children in Guangzhou city. The study data were collected in three phases. The overall prevalence of short (5 h or less) and long (10 h or more) sleep duration was 0.52 and 0.64%, respectively. Long sleepers had higher Eysenck Personality Questionnaire neuroticism scores [odds ratio (OR)=1.224, 95% confidence interval (CI)=1.047-1.409] and lower education levels (OR=0.740, 95%CI=0.631-0.849) than short sleepers. In the polysomnographic assessment, short, long, and normal sleepers (7-8 h) shared similar durations of Stage 3 sleep (short=25.7±10.7, long=20.3±7.9, and normal=28.0±12.8 min, F=1.402, P=0.181). In daytime multiple sleep latency tests, short sleepers (10/19, 52.6%) were more prone to have a short sleep latency (≤8 min) than long sleepers (2/23, 8.7%). In addition to different sleep durations, neuroticism might also contribute to differences between short and long sleepers in social achievements. Stage 3 sleep might be essential for humans. The short sleep latency (≤8 min) of short sleepers in multiple sleep latency tests should be interpreted cautiously, since it was of the same severity as required for a diagnosis of narcolepsy or idiopathic hypersomnia.

Effect of L-carnitine on exercise performance in patients with mitochondrial myopathy

Exercise intolerance due to impaired oxidative metabolism is a prominent symptom in patients with mitochondrial myopathy (MM), but it is still uncertain whether L-carnitine supplementation is beneficial for patients with MM. The aim of our study was to investigate the effects of L-carnitine on exercise performance in MM. Twelve MM subjects (mean age±SD=35.4±10.8 years) with chronic progressive external ophthalmoplegia (CPEO) were first compared to 10 healthy controls (mean age±SD=29±7.8 years) before they were randomly assigned to receive L-carnitine supplementation (3 g/daily) or placebo in a double-blind crossover design. Clinical status, body composition, respiratory function tests, peripheral muscle strength (isokinetic and isometric torque) and cardiopulmonary exercise tests (incremental to peak exercise and at 70% of maximal), constant work rate (CWR) exercise test, to the limit of tolerance [Tlim]) were assessed after 2 months of L-carnitine/placebo administration. Patients with MM presented with lower mean height, total body weight, fat-free mass, and peripheral muscle strength compared to controls in the pre-test evaluation. After L-carnitine supplementation, the patients with MM significantly improved their Tlim (14±1.9 vs 11±1.4 min) and oxygen consumption ( V ˙ O 2 ) at CWR exercise, both at isotime (1151±115 vs 1049±104 mL/min) and at Tlim (1223±114 vs 1060±108 mL/min). These results indicate that L-carnitine supplementation may improve aerobic capacity and exercise tolerance during high-intensity CWRs in MM patients with CPEO.

Influência da embalagem na aceitação de diferentes marcas comerciais de cerveja tipo Pilsen

Foram estudadas nove marcas de cervejas comerciais brasileiras tipo Pilsen, com o objetivo de avaliar a influência da embalagem na aceitação das mesmas. As amostras foram separadas em três grupos e baseadas na pesquisa Top of Mind/2005. As marcas 1, 2, 3 e 4 (grupo a) foram as mais citadas pelos consumidores nacionais; as 5 e 6 (grupo b) tiveram citação intermediária; e as 7, 8 e 9 (grupo c) são consideradas regionais. O trabalho foi dividido em 3 etapas: teste cego, teste com embalagem e teste com informação. Os testes foram aplicados a 54 julgadores, em condições laboratoriais, usando escala hedônica de 9 categorias. Os resultados foram analisados por ANOVA e teste de Tukey (p < 0,05). No teste cego, a marca 1 diferiu significativamente das marcas 4, 7 e 8, sendo a menos aceita. No teste com embalagem, a situação se inverteu, sendo a marca 1 a mais aceita, juntamente com as marcas 3, 4 e 9, e a marca 7 foi a menos aceita. Já no teste com informação, as cervejas do grupo a e a marca 8 (regional) foram as mais aceitas. Os resultados indicam que muitas vezes a embalagem influencia e pode modificar a aceitação de algumas cervejas.