RESUMO
Health emerges from coordinated psychobiological processes powered by mitochondrial energy transformation. But how do mitochondria regulate the multisystem responses that shape resilience and disease risk across the lifespan? The Mitochondrial Stress, Brain Imaging, and Epigenetics (MiSBIE) study was established to address this question and determine how mitochondria influence the interconnected neuroendocrine, immune, metabolic, cardiovascular, cognitive, and emotional systems among individuals spanning the spectrum of mitochondrial energy transformation capacity, including participants with rare mitochondrial DNA (mtDNA) lesions causing mitochondrial diseases (MitoDs). This interdisciplinary effort is expected to generate new insights into the pathophysiology of MitoDs, provide a foundation to develop novel biomarkers of human health, and integrate our fragmented knowledge of bioenergetic, brain-body, and mind-mitochondria processes relevant to medicine and public health.
Assuntos
Mitocôndrias , Humanos , Mitocôndrias/metabolismo , Encéfalo/metabolismo , Doenças Mitocondriais/metabolismo , DNA Mitocondrial/genética , DNA Mitocondrial/metabolismoRESUMO
OBJECTIVES: Late adolescence (15-19 years) is a period of heightened susceptibility to stress, but regular physical activity may attenuate reactivity to stressors. We aimed to explore the effects of physical activity intensity on older adolescents' stress-reactivity and self-reported mental health. DESIGN AND METHODS: Three-arm randomised controlled trial in New South Wales, Australia (April-June 2021). Thirty-seven older adolescents (16.1 ± 0.2 years, 59.5 % female) were randomised to: i) non-active control (CON), ii) light-intensity physical activity (LPA), or iii) moderate-to-vigorous-intensity physical activity (MVPA). Physical activity groups participated in 2 x 20-min sessions/week for 6 weeks. Salivary cortisol (sCort) reactivity to induced stress was assessed using the Trier Social Stress Test for Groups and quantified as area under the curve (sCortAUC; Primary outcome). Secondary outcomes included peak cortisol (sCortPeak), subjective-reactivity, perceived stress, and non-specific psychological distress. Group differences were assessed using multiple linear regression and quantified using Cohen's d. RESULTS: No statistically significant effects were observed for sCortAUC or sCortPeak and the pattern of effects for subjective-reactivity was inconsistent. Effects for self-reported mental health were also non-significant (p > .05 for all) but of meaningful magnitude, favouring LPA and MVPA over CON (d's = -0.38 to -0.54). Delivery fidelity was high, satisfaction was moderate-to-high, and there was no evidence of harm. However, recruitment, retention for sCort measures, and adherence were lower than expected. CONCLUSION: Suboptimal recruitment, retention, and adherence limited our ability to conclude on the effect of physical activity intensity on older adolescents' sCort-reactivity to induced stress. We observed potentially meaningful effects on self-reported mental health for both physical activity conditions, which could be confirmed in a future powered trial.
RESUMO
OBJECTIVE: Growing research indicates that daily stress is associated with poorer same-day cognitive performance, for example, memory and attention. However, it is unclear whether this relationship holds across diverse ages and engagement in physical activity (PA), or whether these factors might buffer the relationship between daily stress and subjective cognitive function. METHODS: Ecological momentary assessment data were collected from adults aged 25 to 88 years across British Columbia, Canada. For 14 days, participants ( N = 204) wore a triaxial physical activity monitor, reported stressor occurrence in mobile surveys four times per day, and rated their subjective attention and memory at the end of each day. RESULTS: Multilevel models evaluated daily stressor occurrence as a predictor of subjective attention and memory, with same-day PA engagement and age as moderators. Subjective attention and memory were lower on days when a stressor had occurred, compared to stressor-free days. Neither PA nor age moderated the within-person associations of daily stressors with subjective cognition. CONCLUSION: The lack of stress-buffering effects for same-day PA and age raises questions about the contexts in which PA promotes cognitive functioning and about age-related processes underlying stress and cognition. Future work could examine the mechanisms that might explain the link between daily stress and cognition function, as well as the associations of different intensity and forms of physical activity on stress across age groups.
Assuntos
Atenção , Cognição , Avaliação Momentânea Ecológica , Exercício Físico , Estresse Psicológico , Humanos , Idoso , Pessoa de Meia-Idade , Feminino , Masculino , Adulto , Idoso de 80 Anos ou mais , Exercício Físico/fisiologia , Cognição/fisiologia , Atenção/fisiologia , Memória/fisiologia , Colúmbia Britânica , Fatores Etários , Envelhecimento/fisiologiaRESUMO
Exercise and nature exposure are independently recognised for their positive relationship with health, but their combined effects are not fully understood. The present review summarises the evidence that compares physiological and perceptual differences of a single bout of exercise performed outdoors versus indoors. Nine databases were searched for articles published before March 2021 which utilised controlled designs to assess at least one physiological outcome during or after a single acute bout of outdoor exercise. When appropriate, quantitative analyses were completed. Quality of articles was assessed using the Cochrane Risk of Bias Assessment Tool. The findings of 38 articles (Total N = 1168) were examined. Participants were primarily healthy. Summarised outcomes included objective exercise intensity, perceived exertion, performance, neuroendocrine and metabolic responses, cardiovascular responses, thermoregulation, enjoyment, intention for future exercise, and perceptions of the environment. Outdoor environments increased enjoyment (N = 234, K = 10, g = 1.24, 95% CI = [0.59, 1.89], p < 0.001). Findings for remaining outcomes were non-significant or inconclusive and challenging to interpret due to high risk of bias. Overall, outdoor exercise appears to feel more enjoyable than indoor exercise when matched for intensity, with equivocal physiological benefit.
RESUMO
Importance: During the COVID-19 pandemic, health care workers (HCWs) reported a significant decline in their mental health. One potential health behavior intervention that has been shown to be effective for improving mental health is exercise, which may be facilitated by taking advantage of mobile application (app) technologies. Objective: To determine the extent to which a 12-week app-based exercise intervention can reduce depressive symptoms, burnout, and absenteeism in HCWs, compared with a wait list control condition. Design, Setting, and Participants: A 2-group randomized clinical trial was conducted, with participants screened from April 6 to July 4, 2022. Participants were recruited from an urban health care organization in British Columbia, Canada. Participants completed measures before randomization and every 2 weeks thereafter. Interventions: Exercise condition participants were asked to complete four 20-minute sessions per week using a suite of body weight interval training, yoga, barre, and running apps. Wait-listed control participants received the apps at the end of the trial. Main Outcomes and Measures: The primary outcome consisted of the between-group difference in depressive symptoms measured with the 10-item Center for Epidemiological Studies Depression Scale. The secondary outcomes corresponded to 3 subfacets of burnout (cynicism, emotional exhaustion, and professional efficacy) and absenteeism. Intention-to-treat analyses were completed with multilevel structural equation modeling, and Feingold effect sizes (ES) were estimated every 2 weeks. Results: A total of 288 participants (mean [SD] age, 41.0 [10.8] years; 246 [85.4%] women) were randomized to either exercise (n = 142) or wait list control (n = 146) conditions. Results revealed that ESs for depressive symptoms were in the small to medium range by trial's end (week 12, -0.41 [95% CI, -0.69 to -0.13]). Significant and consistent treatment effects were revealed for 2 facets of burnout, namely cynicism (week 12 ES, -0.33 [95% CI, -0.53 to -0.13]) and emotional exhaustion (week 12 ES, -0.39 [95% CI, -0.64 to -0.14]), as well as absenteeism (r = 0.15 [95% CI, 0.03-0.26]). Adherence to the 80 minutes per week of exercise decreased from 78 (54.9%) to 33 (23.2%) participants between weeks 2 and 12. Conclusions and Relevance: Although exercise was able to reduce depressive symptoms among HCWs, adherence was low toward the end of the trial. Optimizing adherence to exercise programming represents an important challenge to help maintain improvements in mental health among HCWs. Trial Registration: ClinicalTrials.gov Identifier: NCT05271006.
Assuntos
Absenteísmo , Depressão , Adulto , Feminino , Humanos , Masculino , Colúmbia Britânica , Esgotamento Psicológico , Depressão/terapia , Pandemias , Pessoa de Meia-IdadeRESUMO
OBJECTIVE: In the context of COVID-19, Canadian healthcare workers (HCWs) worked long hours, both to respond to the pandemic and to compensate for colleagues who were not able to work due to infection and burnout. This may have had detrimental effects on HCWs' mental health, as well as engagement in health-promoting behaviours. This study aimed to identify changes in mental health outcomes and health behaviours experienced by Canadian HCWs throughout the COVID-19 pandemic. METHODS: Nine representative samples (Ntotal = 1615 HCWs) completed the iCARE survey using an online polling firm between April 2020 (Time 1) and February 2022 (Time 9). Participants were asked about the psychological effects of COVID-19 (e.g., feeling anxious) and about changes in their health behaviours (e.g., alcohol use, physical activity). RESULTS: A majority of the HCWs identified as female (65%), were younger than 44 years old (66%), and had a university degree (55%). Female HCWs were more likely than male HCWs to report feeling anxious (OR = 2.68 [1.75, 4.12]), depressed (OR = 1.63 [1.02, 2.59]), and irritable (OR = 1.61 [1.08, 2.40]) throughout the first two years of the pandemic. Female HCWs were more likely than their male counterparts to report eating more unhealthy diets (OR = 1.54 [1.02, 2.31]). Significant differences were also revealed by age, education level, income, parental status, health status, and over time. CONCLUSION: Results demonstrate that the impacts of COVID-19 on HCWs' mental health and health behaviours were significant, and varied by sociodemographic characteristics (e.g., sex, age, income).
RéSUMé: OBJECTIF: Dans le contexte de la COVID-19, les travailleurs de la santé canadiens ont travaillé de longues heures, à la fois pour répondre à la pandémie et pour compenser pour les collègues qui n'étaient pas en mesure de travailler en raison d'infection et d'épuisement professionnel. Cela a pu générer un important impact sur leur santé mentale, ainsi que sur leurs engagements dans des comportements favorables à la santé. MéTHODES: Neuf échantillons représentatifs (Ntotal = 1 615 travailleurs de la santé) ont répondu à l'enquête iCARE par l'intermédiaire d'une compagnie de sondage en ligne entre avril 2020 (temps 1) et février 2022 (temps 9). Les participants ont été interrogés sur les effets psychologiques de la COVID-19 (p.ex., le sentiment d'anxiété) et sur les changements dans leurs comportements de santé (p.ex., la consommation d'alcool, l'activité physique). RéSULTATS: La majorité des travailleurs de santé répondants sont des femmes (65 %), ont moins de 44 ans (66 %) et ont un diplôme universitaire (55 %). Les femmes travailleuses de la santé étaient plus susceptibles de se sentir anxieuses (OR = 2,68 [1,75, 4,12]), déprimées (OR = 1,63 [1,02, 2,59) et irritables (OR = 1,61 [1,08, 2,40]) que les hommes au cours des deux premières années de la pandémie. Les femmes travailleuses de la santé étaient plus susceptibles d'avoir une alimentation plus malsaine (OR = 1,54 [1,02, 2,31]) que leurs homologues masculins. Des différences significatives ont également été révélées selon l'âge, le niveau d'éducation, le revenu, le statut parental, l'état de santé et à travers le temps. CONCLUSION: Les résultats démontrent que les impacts de COVID-19 sur la santé mentale et les comportements de santé des travailleurs de santé sont significatifs, mais varient selon les caractéristiques sociodémographiques (p.ex., le sexe, l'âge, le revenu).
Assuntos
COVID-19 , Saúde Mental , Feminino , Humanos , Masculino , Adulto , COVID-19/epidemiologia , Pandemias , Canadá/epidemiologia , Pessoal de Saúde , Comportamentos Relacionados com a SaúdeRESUMO
BACKGROUND: With the onset of the COVID-19 pandemic, many exercise programs moved online. The purpose of this study was to examine the extent to which older adults' social identification with other exercise program members contributed to their psychological flourishing and exercise program adherence. METHODS: The study represented a secondary analysis of data derived from the Seniors COVID-19 Pandemic and Exercise (SCOPE) Trial, in which older adults were randomized to a waitlist control condition or one of two online (personal v group) exercise programs. Only data from participants in the trial intervention conditions (N = 162; Mage = 73.52 years; SD = 5.61) were utilized in this secondary analysis. We assessed psychological flourishing and social identification at baseline and every two weeks, as well as program adherence over each 2-week block, for 12 weeks. RESULTS: Based on stepwise multilevel modeling the results revealed that older adults' social identification with others in their respective exercise program had a direct effect on psychological flourishing (ΔR2Unique Marginal = 0.063, p < .001) and program adherence (ΔR2Unique Marginal = 0.014, p = .03). CONCLUSIONS: The results highlight the value of bolstering older adults' social identification with others in an online exercise program to support adherence and well-being.
RESUMO
OBJECTIVE: It has been proposed that cumulative stress, one's experience of chronic stressors across multiple domains, worsens health by altering the extent to which daily stressors impact daily affect and physical symptoms. Recent work confirms that high cumulative stress exacerbates the association between daily stressor exposure and increased daily negative affect, though it remains untested the extent to which cumulative stress and daily stressor exposure interact to predict daily symptoms. METHOD: We employed data from the second wave of the midlife in the U.S. Survey (N = 2,022; Mage = 56.2; 57.2% female) to examine whether levels of cumulative stress compound daily symptoms on days with (vs. without) stressful events. Experiences of life stressors across eight domains, occurrence of daily stressors, and occurrence, number, and severity of daily physical symptoms were analyzed using multilevel modeling. RESULTS: Greater cumulative stress and experiencing (vs. not experiencing) a daily stressor independently increased the odds of occurrence, number, and severity of daily symptoms (ps ≤ .016). Moreover, after adjusting for covariates (e.g., sociodemographic characteristics, chronic health conditions, percent of days with reported stressors, and health behaviors), the associations between daily stressor exposure and odds of occurrence, number, and severity of daily symptoms were potentiated as levels of cumulative stress increased (ps ≤ .009). CONCLUSIONS: The negative implications of daily stressor exposure for daily health may be most pronounced in those who report higher levels of cumulative stress across multiple life domains and across time. (PsycInfo Database Record (c) 2023 APA, all rights reserved).
Assuntos
Saúde , Estresse Psicológico , Saúde/estatística & dados numéricos , Saúde Mental/estatística & dados numéricos , Estresse Psicológico/epidemiologia , Estresse Psicológico/fisiopatologia , Estresse Psicológico/psicologia , Humanos , Estados Unidos/epidemiologia , Masculino , Feminino , Pessoa de Meia-Idade , IdosoRESUMO
INTRODUCTION: Early childhood is a key time for the development of physical activity behaviors and physical literacy. A growing proportion of children spend a significant portion of their daytime in early childhood education and care settings where an early childhood educator cares for them. This systematic review (PROSPERO CRD42018087249) aimed to identify the differences between effective and noneffective educator-led interventions with a goal to improve physical literacy and/or physical activity in children aged 3-5 years in early childhood education and care settings. METHODS: Interventions were included if they aimed to improve at least 1 physical literacy component or physical activity time in children aged 2-6 years through educator training. MEDLINE, Embase, CINAHL, ERIC, Australian Education Index, and Sport Discus were searched in March 2018 and April 2021. Risk of bias was assessed through a modified Cochrane assessment tool. RESULTS: Data from 51 studies were analyzed in 2021 and 2022 and summarized narratively. Thirty-seven interventions aimed to promote physical activity, and 28 sought to promote physical literacy; 54% and 63% of these were effective, respectively. Interventions that were underpinned by theory, included ongoing support, or measured intervention fidelity were more effective, especially when all 3 were done. DISCUSSION: This review was limited by a high risk of bias and inconsistency in reporting results across interventions. Reporting physical activity by minutes per hour and reporting both sub and total scores in physical literacy assessments will allow for greater cross-comparison between trials. Future training of educators should be underpinned by theory and incorporate ongoing support and objective fidelity checks.
Assuntos
Exercício Físico , Alfabetização , Criança , Pré-Escolar , Humanos , Austrália , Atividade MotoraRESUMO
BACKGROUND: The aim of this study was to examine whether a low-cost standing desk intervention that reduced occupational sitting was associated with changes in work-time cognitive-affective states in real time using ecological momentary assessments at the start and end of the trial. METHODS: Forty-one office employees (91.7% female, mean age = 39.8 [10.1] y) were randomized to receive a low-cost standing desk or a waitlist control. Participants received 5 surveys each day for 5 workdays via smartphone application prior to randomization and at trial's end. Ecological momentary assessment assessed current work-time psychological states (valence and arousal, stress, fatigue, and perceived productivity). Multilevel models assessed whether changes in work-time outcomes over the course of the intervention were significantly different between treatment groups. RESULTS: There were no significant differences in outcomes between the groups except for fatigue, with the control group reporting a significant decrease in daily fatigue following the intervention (P < .001). The intervention group reported no significant changes in any of the work-time outcomes across the study period (P > .05). CONCLUSIONS: A low-cost standing desk intervention to reduce occupational sedentary behavior did not negatively impact work-time outcomes such as productivity and fatigue in the short term.
Assuntos
Saúde Ocupacional , Postura Sentada , Humanos , Feminino , Adulto , Masculino , Avaliação Momentânea Ecológica , Postura , Local de Trabalho , Exercício Físico , Fadiga/prevenção & controleRESUMO
A growing body of research is exploring the potential added health benefits of exercise when performed outdoors in nature versus indoors. This systematic review aimed to compare the effects of exercise in outdoor environments versus indoor environments on psychological health, physical health, and physical activity behaviour. We searched nine databases from inception to March 2021 for English language, peer-reviewed articles: MEDLINE, Embase, PubMed, Scopus, Web of Science, CINAHL, SportsDiscus, GreenFile, and CENTRAL. We included randomized and non-randomized trials that compared multiple bouts of exercise in outdoor versus indoor environments, and that assessed at least one outcome related to physical health, psychological health, or physical activity behaviour. Due to minimal outcome overlap and a paucity of studies, we performed a narrative synthesis. We identified 10 eligible trials, including 7 randomized controlled trials, and a total of 343 participants. Participant demographics, exercise protocols, and outcomes varied widely. In the 10 eligible studies, a total of 99 comparisons were made between outdoor and indoor exercise; all 25 statistically significant comparisons favoured outdoor exercise. Interpretation of findings was hindered by an overall high risk of bias, unclear reporting, and high outcome heterogeneity. There is limited evidence for added health or behaviour benefits of outdoor exercise versus indoor exercise. Rigorous randomized controlled trials are needed with larger samples and clear reporting.
Assuntos
Exercício Físico , Atividade Motora , Humanos , Saúde MentalRESUMO
With an increasing number of children attending regular early childhood education and care (ECEC), this setting presents an opportunity to develop physical activity habits and movement skills of children. These behaviours play an important role in the development and well-being of children. In 2017, an Active Play Standard was introduced in British Columbia, Canada, to mandate practices related to physical activity, screen time and movement skill development in licensed ECEC. A capacity-building initiative including training and online resources was released alongside these guidelines to support implementation. The purpose of this study was to qualitatively examine the barriers and facilitators ECEC practitioners faced in implementing the standard, and to explore the role of the capacity-building initiative. Data were collected via semi-structured telephone interviews with educators (n = 23). Data were coded using thematic analysis and sorted into three major themes influencing provision of physical activity opportunities: attributes and impact of the Active Play standard and capacity-building workshop, characteristics of providers and characteristics of ECEC settings. Future studies should consider targeting factors including organizational culture and climate, and provider capacity to provide physical activity and fundamental movement skill programming, and support for facility level policies and collaborative planning processes that create a positive physical activity culture.
Assuntos
Cuidado da Criança , Creches , Criança , Pré-Escolar , Humanos , Colúmbia Britânica , Exercício Físico , Saúde da CriançaRESUMO
Physical activity may play a role in promoting or preventing substance use among youth. The purpose of this study was to examine the association between different types of physical activity [i.e., non-competitive school sport, competitive school sport, outside of school sport and minutes of moderate to vigorous physical activity (MVPA) per day] and substance use (i.e., current smoking, e-cigarette, cannabis, binge drinking) among Canadian youth. Interaction effects between physical activity and school connectedness were also examined. Using data from the COMPASS study (2018-19; n = 73,672), four multi-level logistic regression models were developed to investigate whether physical activity lessened or worsened the odds of (1) smoking; (2) e-cigarette use; (3) cannabis use; and (4) binge drinking. Models were stratified by gender to reflect the inherent differences between genders. Models were adjusted for demographic factors and other covariates. Sport participation was consistently associated with substance use, whereas less evidence was found for meeting MVPA guidelines. Non-competitive school sport lessened the odds of cannabis use for males and females. However, non-competitive school sport only lessened the odds of e-cigarette use for females but increased the odds of binge drinking for males. Participation in competitive school sport lessened the odds of cigarette smoking but increased the odds of e-cigarette use and binge drinking for males and females. Outside of school sport lessened the odds of cigarette smoking and cannabis use but increased the odds of e-cigarette use and binge drinking for males and females. A significant moderation effect was found for males participating in sport outside of school and meeting MVPA guidelines who were at a lower risk of e-cigarette use in the presence of high levels of school connectedness. Our study provides evidence for further consideration and provision of extracurricular activities, specifically non-competitive sport, in protecting against substance use. Caution is required in claiming that sport participation or physical activity, in general, is negatively associated with substance use among youth.
Assuntos
Consumo Excessivo de Bebidas Alcoólicas , Sistemas Eletrônicos de Liberação de Nicotina , Transtornos Relacionados ao Uso de Substâncias , Adolescente , Feminino , Humanos , Masculino , Consumo Excessivo de Bebidas Alcoólicas/epidemiologia , Canadá/epidemiologia , Instituições Acadêmicas , Exercício Físico , Transtornos Relacionados ao Uso de Substâncias/epidemiologiaRESUMO
[This corrects the article DOI: 10.1007/s42761-022-00112-x.].
RESUMO
Sleep is an important process that can influence and be influenced by daily events and emotions. We examined the bidirectional relationships between sleep, daily events, and emotions with a daily diary method completed by 181 mothers (M age = 41.91, SD = 5.06). They answered morning and evening questionnaires for 1 week at three different points in time separated by nine months each, 21 days in total. Measures of sleep quality and emotional experiences each morning were assessed, and they reported on their best and worst experience of the day, peak emotional responses to these events, and affect in the evening. Sleep behavior, including total sleep time and sleep efficiency, was objectively quantified using wrist actigraphy. Multilevel modeling analyses showed that longer sleep duration and better subjective quality predicted greater positive emotions and lower negative emotions upon waking, and lower levels of peak perceived stressfulness, but not peak positivity ratings. Daily experiences did not predict sleep duration. Conversely, negative affect in the evening and greater peak perceived stressfulness during the day predicted worse sleep quality that night, whereas positive affect and positive events were not related to sleep. Although correlational, these findings suggest that good sleep can improve waking affect and help mitigate the impact of stressful experiences but does not amplify responses to the positive events of the day. In turn, daily perceived stress reactivity impairs sleep quality. These novel findings show stronger bidirectional relationships between sleep with daily stress, than sleep with daily positivity. Supplementary Information: The online version contains supplementary material available at 10.1007/s42761-022-00112-x.
RESUMO
BACKGROUND: Previous research suggests that there is a bidirectional relationship between incidental affect (i.e., how people feel in day-to-day life) and physical activity behavior. However, many inconsistencies exist in the body of work due to the lag interval between affect and physical activity measurements. PURPOSE: Using a novel continuous-time analysis paradigm, we examined the temporal specificity underlying the dynamic relationship between positive and negative incidental affective states and moderate-to-vigorous physical activity (MVPA). METHODS: A community sample of adults (n = 126, Mage = 27.71, 51.6% Male) completed a 14-day ambulatory assessment protocol measuring momentary positive and negative incidental affect six times a day while wearing a physical activity monitor (Fitbit). Hierarchical Bayesian continuous-time structural equation modeling was used to elucidate the underlying dynamics of the relationship between incidental affective states and MVPA. RESULTS: Based on the continuous-time cross-effects, positive and negative incidental affect predicted subsequent MVPA. Furthermore, engaging in MVPA predicted subsequent positive and negative incidental affect. Incidental affective states had a greater relative influence on predicting subsequent MVPA compared to the reciprocal relationship. Analysis of the discrete-time coefficients suggests that cross-lagged effects increase as the time interval between measurements increase, peaking at about 8 h between measurement occasions before beginning to dissipate. CONCLUSIONS: The results provide support for a recursive relationship between incidental affective states and MVPA, which is particularly strong at 7-9 hr time intervals. Future research designs should consider these medium-term dynamics, for both theory development and intervention.
Assuntos
Exercício Físico , Monitores de Aptidão Física , Adulto , Humanos , Masculino , Feminino , Teorema de Bayes , Exercício Físico/psicologia , EmoçõesRESUMO
Mitochondria contain their own genome that can be released in multiple biofluids such as blood and cerebrospinal fluid, as cell-free mitochondrial DNA (cf-mtDNA). In clinical studies, blood cf-mtDNA predicts mortality and higher cf-mtDNA levels are associated with mental and physical stress. However, the dynamics of cf-mtDNA has not been defined, and whether it can be measured non-invasively like other neuroendocrine markers in saliva has not been examined. Here we report cf-mtDNA in human saliva and establish its natural within-person dynamic behavior across multiple weeks. In a small proof-of-principle cohort of healthy adults, we first develop an approach to rapidly quantify salivary cf-mtDNA without DNA isolation, and demonstrate the existence of salivary cf-mtDNA. We then deploy this approach to perform an intensive repeated-measures analysis of two healthy men studied at 4 daily timepoints over 53-60 consecutive days (n = 212-220 observations each) with parallel measures of steroid hormones, self-reported daily mood, and health-related behaviors. Salivary cf-mtDNA exhibited a robust awakening response reaching up to two orders of magnitude 30-45 min after awakening, varied from day-to-day, and moderately correlated with the cortisol awakening response. In exploratory analyses, no consistent association with self-reported daily mood/health-related behaviors were found, although this requires further examination in future studies. Dynamic variation in cf-mtDNA was inversely related with salivary interleukin 6 (IL-6), inconsistent with a pro-inflammatory effect of salivary cf-mtDNA. The highly dynamic behavior of salivary cf-mtDNA opens the door to non-invasive studies examining the relevance of mtDNA signaling in relation to human health.
Assuntos
Ácidos Nucleicos Livres , Saliva , Adulto , DNA Mitocondrial , Humanos , Hidrocortisona/análise , Masculino , Mitocôndrias/genética , Saliva/químicaRESUMO
OBJECTIVE: To examine whether premenopausal reproductive age, as indicated by serum antimüllerian hormone (AMH), is associated with leukocyte aging biomarkers. DESIGN: Prospective cohort analysis. SETTING: The Coronary Artery Risk Development in Young Adults study, a population-based study of Black and White adults from four US communities (Birmingham, AL; Chicago, IL; Minneapolis, MN; Oakland, CA). PATIENT(S): Premenopausal women with serum AMH measures at examination year 15 as well as leukocyte aging markers. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Telomere length, mitochondrial deoxyribonucleic acid (mtDNA) copy number, and intrinsic and extrinsic epigenetic age acceleration (EAA) at examination years 15, 20, and 25 as well as change between examination years. RESULT(S): Women were 40.2 (standard deviation, 3.7) years of age at examination year 15 when the AMH and initial measures of telomere length and mtDNA copy number (n = 386) were obtained and EAA occurred. After adjustment for chronological age, race, and smoking history, AMH quartile at examination year 15 was not associated with telomere length at examination years 15 and 25 or telomere length change between these years, mtDNA copy number at examination years 15 and 25 or change between these years, or intrinsic EAA at examination years 15 and 20 or change between these years. Women in the second AMH quartile had faster extrinsic EAA than women in the lowest AMH quartile (ß-coefficient, 1.84; 95% confidence interval, 0.20-3.49). CONCLUSION(S): In a population-based cohort, AMH did not have associations with leukocyte telomere length, mtDNA copy number, or intrinsic EAA.