Objective: People with Alzheimer’s disease (AD) dementia have impaired sleep. However, the characteristics of sleep in the early stages of AD are not well known, and studies with the aid of biomarkers are lacking. We assessed the subjective sleep characteristics of non-demented older adults and compared their amyloid profiles. Methods: We enrolled 30 participants aged ≥ 60 years, with no dementia or major clinical and psychiatric diseases. They underwent [11C]PiB-PET-CT, neuropsychological evaluations, and completed two standardized sleep assessments (Pittsburgh Sleep Quality Inventory and Epworth Sleep Scale). Results: Comparative analysis of subjective sleep parameters across the two groups showed longer times in bed (p = 0.024) and reduced sleep efficiency (p = 0.05) in individuals with positive amyloid. No differences in other subjective sleep parameters were observed. We also found that people with multiple-domain mild cognitive impairment (MCI) had shorter self-reported total sleep times (p = 0.034) and worse overall sleep quality (p = 0.027) compared to those with single-domain MCI. Conclusions: Older adults testing positive for amyloid had a longer time in bed and lower sleep efficiency, regardless of cognitive status. In parallel, individuals with multiple-domain MCI reported shorter sleep duration and lower overall sleep quality.

RESUMO A associação entre Doença de Alzheimer (DA) e distúrbios do sono vem recebendo atenção crescente nas últimas décadas. No entanto, pouco se sabe sobre o impacto do sono e suas alterações no desenvolvimento de estágios pré-clínicos da doença, como é o caso do Comprometimento Cognitivo Leve (CCL). Esta revisão descreve a evolução do conhecimento sobre as relações potencialmente bidirecionais entre DA e distúrbios do sono, explorando grandes estudos prospectivos e meta-análises, assim como estudos dos possíveis mecanismos da associação entre o sono e as doenças neurodegenerativas. Também revisamos amplamente as características do sono de pessoas idosas, incluindo indivíduos cognitivamente normais, com CCL e com demência por DA.

ABSTRACT The association between Alzheimer's disease (AD) and sleep disturbances has received increasing scientific attention in the last decades. However, little is known about the impact of sleep and its disturbances on the development of preclinical AD stages, such as mild cognitive impairment. This review describes the evolution of knowledge about the potential bidirectional relationships between AD and sleep disturbances exploring recent large prospective studies and meta-analyses and studies of the possible mechanisms through which sleep and the neurodegenerative process could be associated. The review also makes a comprehensive exploration of the sleep characteristics of older people, ranging from cognitively normal individuals, through patients with mild cognitive impairment, up to the those with dementia with AD.

Objetivo Avaliar a associação entre insônia com tempo de sono curto e alterações sanguíneas relacionados com a atividade do eixo hipotálamo-hipófise-adrenal (HPA).Método Estudo piloto transversal, com 30 adultos de meia-idade, distribuídos em 2 grupos de acordo com o tempo total de sono (TTS) pela polisonografia (PSG) (TTS > 5h e < 5h). Os pacientes foram submetidos a análise subjetiva da qualidade do sono, medidas antropométricas, PSG e parâmetros sanguíneos em jejum.Resultados Revelaram baixa eficiência do sono e maior latência do sono para aqueles com TTS < 5h. A qualidade subjetiva do sono foi pior no TTS < 5h. Significativamente, os níveis de glicose e cortisol mais elevados foram observados no grupo com TTS < 5h. Os níveis de glicose, cortisol e ACTH foram inversamente correlacionados com o TTS da PSG.Conclusão Pacientes com insônia com tempo de sono curto apresentaram desequilíbrios endócrinos e metabólicos associados a atividade do eixo HPA, correlacionados ao aumento do risco cardiovascular observado neste fenótipo mais grave de insônia.

Objective To evaluate the association between objective short sleep duration in patients with insomnia and changes in blood parameters related to hypothalamic-pituitary-adrenal (HPA) axis activity.Method A cross-sectional pilot study was conducted in 30 middle-aged adults with chronic insomnia who were divided into 2 groups according to polysomnography (PSG) total sleep time (TST) (TST > 5h and < 5h). All patients underwent subjective analysis of sleep quality, anthropometric measurements, PSG, and determination off asting blood parameters.Results The results revealed lower sleep efficiency and higher sleep latency for those with a TST < 5h. The subjective sleep quality was worse in the TST < 5h. Significantly, higher glucose and cortisol levels were observed with a TST < 5h. Glucose, cortisol and ACTH levels were inversely correlated with the PSG total sleep time.Conclusion Patients with insomnia with objective short sleep duration had HPA-associated endocrine and metabolic imbalances chronically linked to increases in cardiovascular risk observed with this more severe insomnia phenotype.

A avaliação do raciocínio clínico em situações de incerteza é pouco pesquisada na educação médica. Os testes escritos mais aplicados são de múltipla escolha, capazes de avaliar como se lida com problemas bem definidos. Porém, a maioria das situações contém incertezas. Um método de avaliação do raciocínio clínico em contextos de incerteza foi desenvolvido a partir da teoria de scripts, com situações em geriatria. Um grupo de especialistas e um grupo de estudantes de graduação resolveram o teste. Acomparação entre os resultados trouxe indícios da validade do instrumento, capaz de diferenciar o raciocínio relacionado ao nível de experiência profissional. A média dos escores dos especialistas (80,41) foi superior à dos estudantes (70,71), p < 0,001. As análises de consistência interna e um estudo G forneceram resultados que estão de acordo com metodologias que buscam avaliar uma competência profissional. Concluiu-se que uma proposta de teste de concordância de scripts em língua portuguesa aplicado em uma instituição de ensino brasileira pode ser uma alternativa para a avaliação do raciocínio clínico em contextos de incerteza.

Little research has been done in Brazilian medical education on the evaluation of clinical reasoning in situations of uncertainty. The most common tests are still multiple-choice, which are capable of evaluating skills when dealing with well-defined problems. However, in practice the majority of situations involve uncertainties. A method for the evaluation of clinical reasoning in contexts of uncertainty was developed on the basis of the cognitive script theory in relation to professional reasoning. The objectives of the research were to develop, apply, and analyze this methodology in a Brazilian educational setting, based on clinical situations in Geriatrics that involved diagnostic, therapeutic, or ethical dilemmas. A group of specialists in this area and a group of undergraduate students that were completing their training in the Geriatrics internship took the test. Comparison of the results led to evidence of the instrument's validity, capable of distinguishing clinical reasoning according to the participants' level of experience. The mean score for the specialists (80,41) was higher than that of students (70,71) (p < 0,001). In addition, analyses of the internal consistency and a G study design furnished results that are consistent with a scoring system that seeks to evaluate a professional skill. In conclusion, a proposal for a script concordance test in the Portuguese language, applied in a Brazilian teaching institution, may be a viable alternative for evaluating clinical reasoning in contexts of uncertainty.