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Chronotype is a proxy sleep measure that has been associated with neuropsychiatric disorders. By investigating how chronotype influences risk for neuropsychiatric disorders and vice versa, we may identify modifiable risk factors for each phenotype. Here we used Mendelian randomization (MR), to explore causal effects by (1) studying the causal relationships between neuropsychiatric disorders and chronotype and (2) characterizing the genetic components of these phenotypes. Firstly, we investigated if a causal role exists between five neuropsychiatric disorders and chronotype using the largest genome-wide association studies (GWAS) available. Secondly, we integrated data from expression quantitative trait loci (eQTLs) to investigate the role of gene expression alterations on these phenotypes. Evening chronotype was causal for increased risk of schizophrenia and autism spectrum disorder and schizophrenia was causal for a tendency toward evening chronotype. We identified 12 eQTLs where gene expression changes in brain or blood were causal for one of the phenotypes, including two eQTLs for SNX19 in hippocampus and hypothalamus that were causal for schizophrenia. These findings provide important evidence for the complex, bidirectional relationship that exists between a sleep-based phenotype and neuropsychiatric disorders, and use gene expression data to identify causal roles for genes at associated loci.
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BACKGROUND: There is uncertainty whether unipolar mania is a discrete sub-type of bipolar disorder. Disrupted rest/activity rhythms are a key feature of bipolar disorder (BD) but have not been well characterised in unipolar mania/hypomania (UM). We compared subjective and objective rest/activity patterns, demographic and mental health outcomes across BD, UM and control groups. METHODS: UK residents aged 37-73 years were recruited into UK Biobank from 2006 to 2010. BD, UM and control groups were identified via a mental health questionnaire. Demographic, mental health and subjective sleep outcomes were self-reported. Accelerometery data were available for a subset of participants, and objective measures of sleep and activity were derived. RESULTS: A greater proportion of males met UM criteria, and more females were in the BD group. Both BD and UM groups had poor mental health outcomes vs. controls. Objectively measured activity differed between all three groups: UM had highest levels of activity and BD lowest. The UM group had shorter sleep duration compared to controls. Subjective rest/activity measures showed that both mood disorder groups (compared to controls) had later chronotype preference, more disturbed sleep and increased difficulty getting up in the morning. However, the UM group were more likely to report an early chronotype compared to BD and control groups. CONCLUSIONS: BD and UM share features in common, but key differences support the proposition that UM may be a distinct and more clinically homogenous disorder. UM was characterised by a higher proportion of males, early chronotype, increased activity and shorter sleep duration.
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Transtorno Bipolar , Mania , Masculino , Feminino , Humanos , Transtorno Bipolar/psicologia , Ritmo Circadiano , Bancos de Espécimes Biológicos , Reino Unido/epidemiologiaRESUMO
A variety of innate immune responses and functions are dependent on time of day, and many inflammatory conditions are associated with dysfunctional molecular clocks within immune cells. However, the functional importance of these innate immune clocks has yet to be fully characterized. NRF2 plays a critical role in the innate immune system, limiting inflammation via reactive oxygen species (ROS) suppression and direct repression of the proinflammatory cytokines, IL-1ß and IL-6. Here we reveal that the core molecular clock protein, BMAL1, controls the mRNA expression of Nrf2 via direct E-box binding to its promoter to regulate its activity. Deletion of Bmal1 decreased the response of NRF2 to LPS challenge, resulting in a blunted antioxidant response and reduced synthesis of glutathione. ROS accumulation was increased in Bmal1-/- macrophages, facilitating accumulation of the hypoxic response protein, HIF-1α. Increased ROS and HIF-1α levels, as well as decreased activity of NRF2 in cells lacking BMAL1, resulted in increased production of the proinflammatory cytokine, IL-1ß. The excessive prooxidant and proinflammatory phenotype of Bmal1-/- macrophages was rescued by genetic and pharmacological activation of NRF2, or through addition of antioxidants. Our findings uncover a clear role for the molecular clock in regulating NRF2 in innate immune cells to control the inflammatory response. These findings provide insights into the pathology of inflammatory conditions, in which the molecular clock, oxidative stress, and IL-1ß are known to play a role.
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Fatores de Transcrição ARNTL/metabolismo , Interleucina-1beta/metabolismo , Macrófagos/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Estresse Oxidativo , Fatores de Transcrição ARNTL/genética , Animais , Células HEK293 , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Inflamação/induzido quimicamente , Inflamação/genética , Inflamação/metabolismo , Interleucina-1beta/genética , Lipopolissacarídeos/toxicidade , Macrófagos/patologia , Camundongos , Camundongos Knockout , Fator 2 Relacionado a NF-E2/genética , Espécies Reativas de Oxigênio/metabolismoRESUMO
The variable photoperiods of Northern latitudes challenge the entrainment capacity of the circadian pacemaker, which evolved under constant photoperiods in Equatorial regions. Entrainment to the erratic photoperiods facilitated by artificial light presents an additional challenge. Metabolic dysfunction and obesity are potential consequences of such desynchronization of circadian and environmental rhythms.
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Relógios Biológicos/fisiologia , Evolução Biológica , Ritmo Circadiano/fisiologia , Suscetibilidade a Doenças/patologia , Geografia , Migração Humana , Obesidade/fisiopatologia , Suscetibilidade a Doenças/fisiopatologia , Homeostase , Humanos , Estilo de Vida , SobrevidaRESUMO
Molecular timing mechanisms known as circadian clocks drive endogenous 24-h rhythmicity in most physiological functions, including innate and adaptive immunity. Consequently, the response to immune challenge such as vaccination might depend on the time of day of exposure. This study assessed whether the time of day of vaccination (TODV) is associated with the subsequent immune and clinical response by conducting a systematic review of previous studies. The Cochrane Library, PubMed, Google, Medline, and Embase were searched for studies that reported TODV and immune and clinical outcomes, yielding 3114 studies, 23 of which met the inclusion criteria. The global severe acute respiratory syndrome coronavirus 2 vaccination program facilitated investigation of TODV and almost half of the studies included reported data collected during the COVID-19 pandemic. There was considerable heterogeneity in the demography of participants and type of vaccine, and most studies were biased by failure to account for immune status prior to vaccination, self-selection of vaccination time, or confounding factors such as sleep, chronotype, and shiftwork. The optimum TODV was concluded to be afternoon (5 studies), morning (5 studies), morning and afternoon (1 study), midday (1 study), and morning or late afternoon (1 study), with the remaining 10 studies reporting no effect. Further research is required to understand the relationship between TODV and subsequent immune outcome and whether any clinical benefit outweighs the potential effect of this intervention on vaccine uptake.
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Vacinas contra COVID-19 , COVID-19 , Ritmo Circadiano , SARS-CoV-2 , Vacinação , Humanos , Ritmo Circadiano/imunologia , Ritmo Circadiano/fisiologia , COVID-19/prevenção & controle , COVID-19/imunologia , SARS-CoV-2/imunologia , Vacinas contra COVID-19/imunologia , Vacinas contra COVID-19/administração & dosagem , Fatores de Tempo , Relógios Circadianos/imunologia , Relógios Circadianos/fisiologiaRESUMO
Introduction: Childhood obesity is a chronic disease that requires multidisciplinary and specialist intervention to address its complex pathophysiology, though access to treatment is limited globally. Evaluating the impact of evidence-based interventions implemented in real-world clinical settings is essential, in order to increase the translation of research into practice and enhance child health outcomes. In Ireland, the National Model of Care for Obesity highlighted the need to develop and improve healthcare services for children and adolescents with obesity. Aims: This study aims to evaluate the impact of a family-based, Tier 3 multi-disciplinary child and adolescent obesity outpatient service (www.w82go.ie) on standardized body mass index (BMI-SDS). Methods: Following referral by pediatricians, patients were assessed by a pediatric multidisciplinary team (physiotherapist, dietician, and psychologist) and personalized obesity treatment plans were developed. Anthropometric and demographic information were recorded at baseline and final visit. Descriptive statistics were used to explore distribution, central tendency and variation in the demographic data, change in BMI-SDS over time was assessed using a t-test, and multiple linear regression analysis was used to investigate the association of demographic factors on the change in BMI-SDS. Results: The overall mean BMI-SDS reduction across the whole cohort (n = 692) was -0.17 (95% CI = -0.20, -0.13; P < 0.001). Younger age at admission and longer duration of treatment were associated with greater BMI-SDS reduction but there was no significant association between change in BMI-SDS and any of the other parameters (deprivation score, treatment type, sex, obesity category at admission or presence of comorbid condition). Conclusion: Engagement in a specialist Tier 3 pediatric obesity service was associated with reductions in BMI-SDS in children and adolescents with obesity.
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Seasonal rhythms are endogenous timing mechanisms that allow animals living at temperate latitudes to synchronize their physiology to the seasons. Human viral respiratory disease is prevalent in the winter at temperate latitudes, but the role of endogenous mechanisms in these recurring annual patterns is unclear. The Common Cold Project is a repository of data describing the experimental viral challenge of 1,337 participants across the seasons of the year. We report a secondary analysis of these data to investigate if susceptibility to the common cold is associated with day length. The majority of the participants (78%) showed signs of infection but only 32% developed clinical signs of disease, and the probability of infection was significantly higher in longer day lengths (summer), but the disease was more likely in short (winter) day lengths. The persistence of winter disease patterns in experimental conditions supports the role of endogenous seasonality in human susceptibility to viral infection.
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Obesity is a chronic disease that compromises the physical and mental health of an increasing proportion of children globally. In high-income countries, prevalence of paediatric obesity is increasing faster in those from marginalised populations such as low-income households, suggesting the disease as one that is largely systemic. Appropriate treatment should be prioritised in these settings to prevent the development of complications and co-morbidities and manage those that already exist. An array of clinical practice guidelines are available for managing overweight and obesity in children and adolescents, but no systematic review has yet compared their quality or synthesised their recommendations. We aimed to narratively review clinical practice guidelines published in English for treating child and adolescent obesity, to identify the highest quality guidelines, and assess similarities, conflicts, and gaps in recommendations. We systematically searched academic databases and grey literature for guidelines published. We used the AGREE II tool to assess the quality, and identified nine high quality guidelines for inclusion in a narrative review of recommendations. Guidelines predominantly recommended the delivery of multi-component behaviour-change interventions aimed at improving nutrition and physical activity. Treatment outcomes were generally focussed on weight, with less emphasis on managing complications or improving quality-of-life. There was no evidence-based consensus on the best mode of delivery, setting, or treatment format. The guidelines rarely included recommendations for addressing the practical or social barriers to behaviour change, such as cooking skills or supervised physical activity. There is insufficient evidence to evaluate pharmaceutical and surgical interventions in children, and these were generally not recommended. It should be noted that this review addressed documents published in English only, and therefore the included guidelines were applicable predominantly to high-resource settings.
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Seasonal disease outbreaks are perennial features of human infectious disease but the factors generating these patterns are unclear. Here we investigate seasonal and daytime variability in multiple immune parameters in 329,261 participants in UK Biobank and test for associations with a wide range of environmental and lifestyle factors, including changes in day length, outdoor temperature and vitamin D at the time the blood sample was collected. Seasonal patterns were evident in lymphocyte and neutrophil counts, and C-reactive protein CRP, but not monocytes, and these were independent of lifestyle, demographic, and environmental factors. All the immune parameters assessed demonstrated significant daytime variation that was independent of confounding factors. At a population level, human immune parameters vary across season and across time of day, independent of multiple confounding factors. Both season and time of day are fundamental dimensions of immune function that should be considered in all studies of immuno-prophylaxis and disease transmission.
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Comparative oncology is defined as the discipline that integrates naturally occurring cancers seen in veterinary medicine, into more general studies of cancer biology and therapy in humans, including the study of cancer-pathogenesis and new cancer treatments. While experimental studies in mice and rodents offer several advantages, including a wealth of genetic information, reduced variation and short generation intervals, their relevance in cancer biology is somewhat limited. Toward this end, as the biomedical research community works to make the promise of precision medicine a reality, more efficient animal cohort studies are critical. Like humans, companion animals such as cats and dogs living in family homes, are exposed to environmental factors that may influence the development of disease. Furthermore, it has been shown that the basic biochemical and physiological processes of companion animals more closely resemble humans compared to rodents. Research has demonstrated that female domestic cats (Felis catus) may represent a comparative model for investigation of mammary carcinogenesis, and in particular, Triple Negative Breast Cancer (TNBC). TNBC is a subtype of breast cancer that typically lacks the expression of the oestrogen receptor (ER), progesterone receptor (PR), and does not overexpress the human epidermal growth factor receptor 2 (HER2). An exciting and rapidly expanding area in cancer biology is the study of exosomes. Exosomes are nanoparticles released from cells and have been found in biological fluids of humans, domestic cats and dogs. In addition to their role as biomarkers, exosomes are implicated in the pathogenesis of certain diseases, including cancer. This review explores the current understanding of exosome biology in human TNBC, and of the potential benefits of comparative research in naturally-occurring mammary tumours in companion animals.
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Biomarcadores Tumorais/genética , Exossomos/genética , Neoplasias Mamárias Animais/genética , Neoplasias de Mama Triplo Negativas/genética , Animais , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Gatos , Ensaios Clínicos como Assunto , Modelos Animais de Doenças , Exossomos/efeitos dos fármacos , Feminino , Humanos , Neoplasias Mamárias Animais/tratamento farmacológico , Neoplasias de Mama Triplo Negativas/tratamento farmacológicoRESUMO
Triple negative breast cancer (TNBC) is a breast cancer subtype which is particularly aggressive and invasive. The treatment of TNBC has been limited due to the lack of well-defined molecular targets. Exosomes are nano-sized extracellular vesicles that are released from virtually all cell types into the extracellular space. Due to their endocytic origin, exosomes carry valuable information from their cells of origin. Exosomes were first thought to serve as "garbage disposals" that eliminate unwanted cellular components. Later, they were found to be involved in the pathology of many diseases including cancer. Despite their established roles in multiple diseases, only a small number of studies have focused on the role of exosomes in TNBC. In this review, we outline the roles of exosomes in cancer progression, metastasis and drug resistance in this breast cancer subtype. We then further illustrate the potential roles of exosomes as diagnostic tools, therapeutic targets and delivery systems.
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Antineoplásicos/farmacologia , Biomarcadores Tumorais/metabolismo , Sistemas de Liberação de Medicamentos , Exossomos/metabolismo , Neoplasias de Mama Triplo Negativas/patologia , Antineoplásicos/uso terapêutico , Biomarcadores Tumorais/antagonistas & inibidores , Progressão da Doença , Resistencia a Medicamentos Antineoplásicos , Exossomos/efeitos dos fármacos , Espaço Extracelular/metabolismo , Feminino , Humanos , Metástase Neoplásica/patologia , Neoplasias de Mama Triplo Negativas/diagnóstico , Neoplasias de Mama Triplo Negativas/tratamento farmacológicoRESUMO
Children and adolescents commonly suffer from sleep and circadian rhythm disturbances, which may contribute to poorer mental health and wellbeing during this critical developmental phase. Many studies however rely on self-reported sleep measures. This study assessed whether accelerometry data collection was feasible within the school setting as a method for investigating the extent of sleep and circadian disruption, and associations with subjective wellbeing, in Scotland. Fourteen days of wrist-worn accelerometry data were collected from 69 pupils, aged 10-14 years. Objective measures of sleep timing, sleep duration and circadian rest-activity patterns were derived. Questionnaires assessed subjective sleep timing, depressive symptoms, and experiences of wearing the accelerometer. Pupils slept on average less than 8 hours per night, failing to meet standard age-specific recommendations. Sleep timing was later and duration longer on weekends compared to weekdays (B = 0.87, 95% confidence interval (CI) 0.70, 1.04; B = 0.49, 95% CI 0.29, 0.69), indicating social jetlag. Lower daytime activity was correlated with higher depressive symptoms (r = -0.84, p = 0.008). Compared to primary school pupils, secondary pupils had shorter sleep window duration and lower circadian relative amplitude. Over half of participants reported some discomfort/inconvenience wearing the accelerometer. These data highlight that inadequate sleep is prevalent in this sample of schoolchildren. Future, larger scale investigations will examine in more detail the associations between sleep, circadian function and physical activity with mental health and wellbeing.
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Síndrome do Jet Lag/epidemiologia , Transtornos do Sono do Ritmo Circadiano/epidemiologia , Sono/fisiologia , Acelerometria , Actigrafia/métodos , Adolescente , Criança , Exercício Físico , Feminino , Humanos , Síndrome do Jet Lag/diagnóstico , Síndrome do Jet Lag/fisiopatologia , Masculino , Instituições Acadêmicas , Escócia/epidemiologia , Transtornos do Sono do Ritmo Circadiano/diagnóstico , Transtornos do Sono do Ritmo Circadiano/fisiopatologia , Inquéritos e QuestionáriosRESUMO
Circadian timekeeping is a ubiquitous feature of all eukaryotes which allows for the imposition of a biologically appropriate temporal architecture on an animal's physiology, behavior and metabolism. There is growing evidence that in mammals the processes of circadian timing are under the influence of the immune system. Such a role for the neuroimmune regulation of the circadian clock has inferences for phenomena such as sickness behavior. Conversely, there is also accumulating evidence for a circadian influence on immune function, raising the likelihood that there is a bidirectional communication between the circadian and immune systems. In this review, we examine the evidence for these interactions, including circadian rhythmicity in models of disease and immune challenge, distribution of cytokines and their receptors in the suprachiasmatic nucleus of the hypothalamus, the site of the master circadian pacemaker, and the evidence for endogenous circadian timekeeping in immune cells.
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Ritmo Circadiano/fisiologia , Fenômenos Fisiológicos do Sistema Nervoso/imunologia , Animais , Citocinas/fisiologia , Humanos , Mediadores da Inflamação/fisiologia , Sono/fisiologiaRESUMO
A seafood-based supplement from krill, rich in omega-3 phospholipids and proteins was tested on a group of dogs competing in the 2016 Iditarod dog sled race to investigate the effects of krill meal on exercise-induced inflammation and muscle damage in comparison to a control group. A single team of 16 dogs received 8% krill meal for 5â¯weeks prior to the start of race, while another team of 16 dogs received no supplementation. Ten dogs of the treatment and 11 dogs of the control group finished the race and their blood was analyzed for omega-3 index, inflammation (CRP) and muscle damage (CK). The omega-3 index of the krill meal-fed dogs was significantly higher at the beginning of the race (mean 6.2% in the supplemented vs 5.2% in the control group, pâ¯<â¯.001). CRP concentrations increased from 7.05⯱â¯2.27 to 37.04⯱â¯9.16⯵g/ml in the control and from 4.26⯱â¯0.69 to 16.56⯱â¯3.03⯵g/ml in the treatment group, with a significant difference between the groups (pâ¯<â¯.001). CK activity was increased from 90.75⯱â¯8.15â¯IU/l to 715.90⯱â¯218.9â¯IU/l in the control group and from 99.55⯱â¯12.15 to 515.69⯱â¯98.98 in the supplemented group, but there were no differences between groups (pâ¯=â¯.266). The results showed that krill meal supplementation led to significantly higher omega-3 index, which correlated with lower inflammation and a tendency for reduced muscle damage after this long-distance sled dog competition. However, these results need to be confirmed by more controlled studies, since it was a field study and effects of race speed or other performance-related factors such as fitness and musher skill on the results cannot be excluded.
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Suplementos Nutricionais/análise , Euphausiacea/química , Inflamação/tratamento farmacológico , Fadiga Muscular/efeitos dos fármacos , Músculo Esquelético/lesões , Condicionamento Físico Animal , Ração Animal/análise , Animais , Biomarcadores/sangue , Dieta/veterinária , Cães , Feminino , Inflamação/etiologia , Masculino , Fadiga Muscular/fisiologiaRESUMO
INTRODUCTION: The risk of mortality from cardiovascular disease (CVD) is higher in wintertime throughout the world, but it is not known if this reflects annual changes in diet or lifestyle, or an endogenous photoperiodic mechanism that is sensitive to changes in day length. METHODS: Phenotypic data on cardiometabolic and lifestyle factors were collected throughout a 4 year time period from 502,642 middle-aged participants in UK Biobank. To assess the impact of seasonal environmental changes on cardiovascular risk factors, we linked these data to the outdoor temperature and day length at the time of assessment. Self-reported information on physical activity, diet and disease status were used to adjust for confounding factors related to health and lifestyle. RESULTS: Mortality related to CVD was higher in winter, as were risk factors for this condition including blood pressure, markers of inflammation and body mass index (BMI). These seasonal rhythms were significantly related to day length after adjustment for other factors that might affect seasonality including physical activity, diet and outdoor temperature. CONCLUSIONS: The risk of CVD may be modulated by day length at temperate latitudes, and the implications of seasonality should be considered in all studies of human cardiometabolic health. Key messages In this cross-sectional study in UK Biobank, we report annual variations in cardiovascular risk factors and mortality that were associated with day length independent of environmental and lifestyle factors. These seasonal changes in day length might contribute to annual patterns in cardiovascular disease and mortality.
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Pressão Sanguínea/fisiologia , Doenças Cardiovasculares/mortalidade , Linfócitos/imunologia , Neutrófilos/imunologia , Estações do Ano , Bancos de Espécimes Biológicos/estatística & dados numéricos , Índice de Massa Corporal , Doenças Cardiovasculares/sangue , Doenças Cardiovasculares/imunologia , Estudos Transversais , Exercício Físico/fisiologia , Comportamento Alimentar/fisiologia , Feminino , Seguimentos , Humanos , Estilo de Vida , Contagem de Linfócitos , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Luz Solar , Temperatura , Reino Unido/epidemiologiaRESUMO
BACKGROUND: Circadian rhythms are fundamental to health and are particularly important for mental wellbeing. Disrupted rhythms of rest and activity are recognised as risk factors for major depressive disorder and bipolar disorder. METHODS: We conducted a genome-wide association study (GWAS) of low relative amplitude (RA), an objective measure of rest-activity cycles derived from the accelerometer data of 71,500 UK Biobank participants. Polygenic risk scores (PRS) for low RA were used to investigate potential associations with psychiatric phenotypes. OUTCOMES: Two independent genetic loci were associated with low RA, within genomic regions for Neurofascin (NFASC) and Solute Carrier Family 25 Member 17 (SLC25A17). A secondary GWAS of RA as a continuous measure identified a locus within Meis Homeobox 1 (MEIS1). There were no significant genetic correlations between low RA and any of the psychiatric phenotypes assessed. However, PRS for low RA was significantly associated with mood instability across multiple PRS thresholds (at PRS threshold 0·05: ORâ¯=â¯1·02, 95% CIâ¯=â¯1·01-1·02, pâ¯=â¯9·6â¯×â¯10-5), and with major depressive disorder (at PRS threshold 0·1: ORâ¯=â¯1·03, 95% CIâ¯=â¯1·01-1·05, pâ¯=â¯0·025) and neuroticism (at PRS threshold 0·5: Betaâ¯=â¯0·02, 95% CIâ¯=â¯0·007-0·04, pâ¯=â¯0·021). INTERPRETATION: Overall, our findings contribute new knowledge on the complex genetic architecture of circadian rhythmicity and suggest a putative biological link between disrupted circadian function and mood disorder phenotypes, particularly mood instability, but also major depressive disorder and neuroticism. FUNDING: Medical Research Council (MR/K501335/1).
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Bancos de Espécimes Biológicos , Ritmo Circadiano/genética , Estudo de Associação Genômica Ampla , Transtornos do Humor/genética , Herança Multifatorial/genética , Adulto , Idoso , Humanos , Transtornos Mentais/genética , Pessoa de Meia-Idade , Fenótipo , Polimorfismo de Nucleotídeo Único/genética , Locos de Características Quantitativas/genéticaRESUMO
BACKGROUND: We examined whether seasonal variations in depressive symptoms occurred independently of demographic and lifestyle factors, and were related to change in day length and/or outdoor temperature. METHODS: In a cross-sectional analysis of >150,000 participants of the UK Biobank cohort, we used the cosinor method to assess evidence of seasonality of a total depressive symptoms score and of low mood, anhedonia, tenseness and tiredness scores in women and men. Associations of depressive symptoms with day length and mean outdoor temperature were then examined. RESULTS: Seasonality of total depressive symptom scores, anhedonia and tiredness scores was observed in women but not men, with peaks in winter. In women, increased day length was associated with reduced reporting of low mood and anhedonia, but with increased reporting of tiredness, independent of demographic and lifestyle factors. Associations with day length were not independent of the average outdoor temperature preceding assessment. LIMITATIONS: This was a cross-sectional investigation - longitudinal studies of within-subject seasonal variation in mood are necessary. Outcome measures relied on self-report and measured only a subset of depressive symptoms. CONCLUSION: This large, population-based study provides evidence of seasonal variation in depressive symptoms in women. Shorter days were associated with increased feelings of low mood and anhedonia in women. Clinicians should be aware of these population-level sex differences in seasonal mood variations in order to aid recognition and treatment of depression and subclinical depressive symptoms.
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Transtorno Depressivo/epidemiologia , Estações do Ano , Adulto , Afeto , Idoso , Anedonia , Estudos de Coortes , Estudos Transversais , Feminino , Humanos , Letargia/epidemiologia , Estilo de Vida , Masculino , Pessoa de Meia-Idade , Reino Unido/epidemiologiaRESUMO
BACKGROUND: Disruption of sleep and circadian rhythmicity is a core feature of mood disorders and might be associated with increased susceptibility to such disorders. Previous studies in this area have used subjective reports of activity and sleep patterns, but the availability of accelerometer-based data from UK Biobank participants permits the derivation and analysis of new, objectively ascertained circadian rhythmicity parameters. We examined associations between objectively assessed circadian rhythmicity and mental health and wellbeing phenotypes, including lifetime history of mood disorder. METHODS: UK residents aged 37-73 years were recruited into the UK Biobank general population cohort from 2006 to 2010. We used data from a subset of participants whose activity levels were recorded by wearing a wrist-worn accelerometer for 7 days. From these data, we derived a circadian relative amplitude variable, which is a measure of the extent to which circadian rhythmicity of rest-activity cycles is disrupted. In the same sample, we examined cross-sectional associations between low relative amplitude and mood disorder, wellbeing, and cognitive variables using a series of regression models. Our final model adjusted for age and season at the time that accelerometry started, sex, ethnic origin, Townsend deprivation score, smoking status, alcohol intake, educational attainment, overall mean acceleration recorded by accelerometry, body-mass index, and a binary measure of childhood trauma. FINDINGS: We included 91â105 participants with accelerometery data collected between 2013 and 2015 in our analyses. A one-quintile reduction in relative amplitude was associated with increased risk of lifetime major depressive disorder (odds ratio [OR] 1·06, 95% CI 1·04-1·08) and lifetime bipolar disorder (1·11, 1·03-1·20), as well as with greater mood instability (1·02, 1·01-1·04), higher neuroticism scores (incident rate ratio 1·01, 1·01-1·02), more subjective loneliness (OR 1·09, 1·07-1·11), lower happiness (0·91, 0·90-0·93), lower health satisfaction (0·90, 0·89-0·91), and slower reaction times (linear regression coefficient 1·75, 1·05-2·45). These associations were independent of demographic, lifestyle, education, and overall activity confounders. INTERPRETATION: Circadian disruption is reliably associated with various adverse mental health and wellbeing outcomes, including major depressive disorder and bipolar disorder. Lower relative amplitude might be linked to increased susceptibility to mood disorders. FUNDING: Lister Institute of Preventive Medicine.
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Bancos de Espécimes Biológicos , Ritmo Circadiano/fisiologia , Cognição/fisiologia , Transtornos do Humor/psicologia , Acelerometria/instrumentação , Acelerometria/métodos , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Transtornos do Humor/epidemiologia , Sono/fisiologia , Reino Unido/epidemiologiaRESUMO
OBJECTIVE: To apply an in vitro model for assessment of the solid-phase binding capacity of acetaminophen and thus assess the reliability of this marker for evaluation of solid-phase gastric emptying in vivo in animals. SAMPLE POPULATION: 4 test meals. PROCEDURES: A spectrophotometric method for detection of acetaminophen was validated and applied for assessment of the percentage retention of acetaminophen in the solid phase of 4 test meals. The gastric milieu was simulated by incubating each meal in artificial gastric juice for 2 hours in a shaking water bath maintained at 37 degrees C. Solid-phase retention was then assessed 3 times by measuring the amount of acetaminophen that had leached into the liquid phase. RESULTS: Acetaminophen was poorly retained in the solid phase of all the test meals examined in the study. There was also a large degree of variability in the percentage retention for each meal when the experiment was repeated 3 times. CONCLUSIONS AND CLINICAL RELEVANCE: Analysis of the results of this in vitro study confirmed that acetaminophen may not be an appropriate marker of solid-phase gastric emptying. The acetaminophen gastric emptying test should be applied only for the assessment of liquid-phase emptying in animals.
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Acetaminofen/farmacocinética , Esvaziamento Gástrico/efeitos dos fármacos , Ração Animal , Ovos , Reprodutibilidade dos TestesRESUMO
Photoperiod disruption, which occurs during shift work, is associated with changes in metabolism or physiology (e.g. hypertension and hyperglycaemia) that have the potential to adversely affect stroke outcome. We sought to investigate if photoperiod disruption affects vulnerability to stroke by determining the impact of photoperiod disruption on infarct size following permanent middle cerebral artery occlusion. Adult male Wistar rats (210-290 g) were housed singly under two different light/dark cycle conditions ( n = 12 each). Controls were maintained on a standard 12:12 light/dark cycle for nine weeks. For rats exposed to photoperiod disruption, every three days for nine weeks, the lights were switched on 6 h earlier than in the previous photoperiod. T2-weighted magnetic resonance imaging was performed at 48 h after middle cerebral artery occlusion. Disruption of photoperiod in young healthy rats for nine weeks did not alter key physiological variables that can impact on ischaemic damage, e.g. blood pressure and blood glucose immediately prior to middle cerebral artery occlusion. There was no effect of photoperiod disruption on infarct size after middle cerebral artery occlusion. We conclude that any potentially adverse effect of photoperiod disruption on stroke outcome may require additional factors such as high fat/high sugar diet or pre-existing co-morbidities.