RESUMO
Introduction: Cross-sectional evidence suggests that sleep problems increased the risk of suicide during the 2019 coronavirus disease (COVID-19) pandemic. However, a lack of longitudinal studies examined the relationship between pre-COVID-19 sleep duration, chronotype and incident suicide during the COVID-19 pandemic. Thus, we examined these associations in a longitudinal study of medical students. Methods: From the Shantou College Student Sleep Cohort, a total of 333 first and second grade medical students (age 19.41 ± 0.82 years, female 61.26%), without suicidal ideation (SI) at pre-COVID-19 period, were followed up during the COVID-19 pandemic. Incident SI was defined by their response to the 9th question from the Beck Depression Inventory. Short sleep duration was defined as less than 7 h/night. The Morningness-Eveningness Questionnaire was used to evaluate the participants' chronotype. Logistic regression with adjusted odds ratios (AOR) and 95% confidence intervals (95% CI) was used to examine the association between sleep and SI. Results: The incidence of SI during the COVID-19 pandemic was 5.71%. Logistic regressions with confounding factors adjustment showed that both short sleep duration (AOR = 4.91, 95% CI = 1.16-20.74) and eveningness (AOR = 3.80, 95% CI = 1.08-13.30) in the pre-COVID-19 period were associated with increased risk of incident SI during the COVID-19 pandemic. Conclusion: Pre-COVID-19 short sleep duration and eveningness predict incident SI during the COVID-19 pandemic in medical students. Prolonging sleep duration may help to decrease SI during major public health crises.
Assuntos
COVID-19 , Duração do Sono , Estudantes de Medicina , Ideação Suicida , Adolescente , Feminino , Humanos , Masculino , Adulto Jovem , Cronotipo , COVID-19/epidemiologia , COVID-19/psicologia , Incidência , Estudos Longitudinais , Pandemias , Estudos Retrospectivos , Fatores de Risco , Estudantes de Medicina/psicologia , Estudantes de Medicina/estatística & dados numéricos , Inquéritos e QuestionáriosRESUMO
OBJECTIVE: To analyze the changes of cerebral blood flow (CBF), cerebral blood volume (CBV), oxygen utilization (CMRO2) and oxygen extraction fraction (OEF) with age. METHODS: The PET images of 7 young (21.0-/+1 years old) and 7 aged volunteers (60.9-/+4.7 years old) were analyzed to identify the areas where CBF, CBV, CMRO2, OEF had significant differences with age. The images were anatomically normalized by statistical parametric mapping (SPM2). A voxel by voxel calculation was performed to obtain the slope with age. Voxels which had statistically significant differences (P<0.05) with age were shown both on global and ROIs brain images. RESULTS: The CBF decreased with age as was consistent with previous reports. The age-related changes in CBV and CMRO2 were similar to CBF, but OEF increased with age. CONCLUSION: CBF, CBV and CMRO2 generally decline with age. The increase in OEF with age suggests a greater reduction in CBF than in CMRO2. The most significant decreases of CBF and CMRO2 occur in the convexity of the frontal cortex and inferior parietal cortex in all the functional images, while in the white matter, the influence of age is minimal.