165 research outputs found
Familial longevity is marked by lower diurnal salivary cortisol levels: the leiden longevity study
No full textBackground
Reported findings are inconsistent whether hypothalamic-pituitary-adrenal (HPA) signaling becomes hyperactive with increasing age, resulting in increasing levels of cortisol. Our previous research strongly suggests that offspring from long-lived families are biologically younger. In this study we assessed whether these offspring have a lower HPA axis activity, as measured by lower levels of cortisol and higher cortisol feedback sensitivity.
Methods
Salivary cortisol levels were measured at four time points within the first hour upon awakening and at two time points in the evening in a cohort comprising 149 offspring and 154 partners from the Leiden Longevity Study. A dexamethasone suppression test was performed as a measure of cortisol feedback sensitivity. Age, gender and body mass index, smoking and disease history (type 2 diabetes and hypertension) were considered as possible confounding factors.
Results
Salivary cortisol secretion was lower in offspring compared to partners in the morning (Area Under the Curve = 15.6 versus 17.1 nmol/L, respectively; p = 0.048) and in the evening (Area Under the Curve = 3.32 versus 3.82 nmol/L, respectively; p = 0.024). Salivary cortisol levels were not different after dexamethasone (0.5 mg) suppression between offspring and partners (4.82 versus 5.26 nmol/L, respectively; p = 0.28).
Conclusion
Offspring of nonagenarian siblings are marked by a lower HPA axis activity (reflected by lower diurnal salivary cortisol levels), but not by a difference in cortisol feedback sensitivity. Further in-depth studies aimed at characterizing the HPA axis in offspring and partners are needed.On behalf of the Leiden Longevity Study grou
Genetic influences on exercise participation in 37.051 twin pairs from seven countries
No full textBackground A sedentary lifestyle remains a major threat to health in contemporary societies. To get more insight in the relative contribution of genetic and environmental influences on individual differences in exercise participation, twin samples from seven countries participating in the GenomEUtwin project were used. Methodology Self-reported data on leisure time exercise behavior from Australia, Denmark, Finland, Norway, the Netherlands, Sweden and United Kingdom were used to create a comparable index of exercise participation in each country (60 minutes weekly at a minimum intensity of four metabolic equivalents). Principal Findings Modest geographical variation in exercise participation was revealed in 85,198 subjects, aged 19–40 years. Modeling of monozygotic and dizygotic twin resemblance showed that genetic effects play an important role in explaining individual differences in exercise participation in each country. Shared environmental effects played no role except for Norwegian males. Heritability of exercise participation in males and females was similar and ranged from 48% to 71% (excluding Norwegian males). Conclusions Genetic variation is important in individual exercise behavior and may involve genes influencing the acute mood effects of exercise, high exercise ability, high weight loss ability, and personality. This collaborative study suggests that attempts to find genes influencing exercise participation can pool exercise data across multiple countries and different instrument
A whole-genome scan for 24-hour respiration rate: a major locus at 10q26 influences respiration during sleep.
No full textIdentification of heart rate-associated loci and their effects on cardiac conduction and rhythm disorders
No full textElevated resting heart rate is associated with greater risk of cardiovascular disease and mortality. In a 2-stage meta-analysis of genome-wide association studies in up to 181,171 individuals, we identified 14 new loci associated with heart rate and confirmed associations with all 7 previously established loci. Experimental downregulation of gene expression in Drosophila melanogaster and Danio rerio identified 20 genes at 11 loci that are relevant for heart rate regulation and highlight a role for genes involved in signal transmission, embryonic cardiac development and the pathophysiology of dilated cardiomyopathy, congenital heart failure and/or sudden cardiac death. In addition, genetic susceptibility to increased heart rate is associated with altered cardiac conduction and reduced risk of sick sinus syndrome, and both heart rate-increasing and heart rate-decreasing variants associate with risk of atrial fibrillation. Our findings provide fresh insights into the mechanisms regulating heart rate and identify new therapeutic targets
Environmental Influences on Children's Physical Activity: Quantitative Estimates Using a Twin Design
No full textBackground: Twin studies offer a 'natural experiment' that can estimate the magnitude of environmental and genetic effects on a target phenotype. We hypothesised that fidgetiness and enjoyment of activity would be heritable but that objectively-measured daily activity would show a strong shared environmental effect.Methodology/Principal Findings: In a sample of 9-12 year-old same-sex twin pairs ( 234 individuals; 57 MZ, 60 DZ pairs) we assessed three dimensions of physical activity: i) objectively-measured physical activity using accelerometry, ii) 'fidgetiness' using a standard psychometric scale, and iii) enjoyment of physical activity from both parent ratings and children's self-reports. Shared environment effects explained the majority (73%) of the variance in objectively-measured total physical activity (95% confidence intervals (CI): 0.63-0.81) with a smaller unshared environmental effect (27%; CI: 0.19-0.37) and no significant genetic effect. In contrast, fidgetiness was primarily under genetic control, with additive genetic effects explaining 75% (CI: 62-84%) of the variance, as was parent's report of children's enjoyment of low 74% (CI: 61-82%), medium 80% (CI: 71-86%), and high impact activity (85%; CI: 78-90%), and children's expressed activity preferences (60%, CI: 42-72%).Conclusions: Consistent with our hypothesis, the shared environment was the dominant influence on children's day-to-day activity levels. This finding gives a strong impetus to research into the specific environmental characteristics influencing children's activity, and supports the value of interventions focused on home or school environments
Reproducibility of functional connectivity and graph measures based on the Phase Lag Index (PLI) and weighted Phase Lag Index (wPLI) derived from high resolution EEG
No full textFunctional connectivity (FC) and graph measures provide powerful means to analyze complex networks. The current study determines the inter-subject-variability using the coefficient of variation (CoV) and long-term test-retest-reliability (TRT) using the intra-class correlation coefficient (ICC) in 44 healthy subjects with 35 having a follow-up at years 1 and 2. FC was estimated from 256-channel-EEG by the phase-lag-index (PLI) and weighted PLI (wPLI) during an eyes-closed resting state condition. PLI quantifies the asymmetry of the distribution of instantaneous phase differences of two time-series and signifies, whether a consistent non-zero phase lag exists. WPLI extends the PLI by additionally accounting for the magnitude of the phase difference. Signal-space global and regional PLI/wPLI and weighted first-order graph measures, i.e. normalized clustering coefficient (gamma), normalized average path length (lambda), and the small-world-index (SWI) were calculated for theta-, alpha1-, alpha2- and beta-frequency bands. Inter-subject variability of global PLI was low to moderate over frequency bands (0.1
Filosofía de las ecologías humanas y de las energías sustentables
No full textIlustraciones, mapas, gráficasspa:La humanidad actualmente sufre de grandes problemas que la agobian significativamente, no solo problemas de la especie, sino problemas del medio ambiente donde vivimos, debido al manejo incorrecto que se le ha dado a los recursos naturales del planeta, el consumo desmedido de éstos y la incapacidad actual que tiene la humanidad para renovar los recursos naturales necesarios para la supervivencia; Además de que estos factores confluyen con un tipo de comportamiento autocrático que se ha ido fraguando en una parte importante de la sociedad actual en general, en principio por algún tipo de carácter que se ha privilegiado en una parte bastante considerable de ella, que La ha llevado a ser extremadamente individualista y la ha llevado a dejar de reconocer y alejarse de los compromisos sociales genuinamente adquiridos en el modo de vida actual, que se rige por los estatutos civiles, como bien argumenta Rousseau cuando expone algunas de las razones por las que sucede. este hecho. Por ello, se pretende hacer un recuento de algunos problemas que afectan a nuestra sociedad actual, mostrando sus orígenes y las soluciones que la humanidad ha tratado de darles a lo largo de su historia, pero también se propone una posible solución a esta crisis, la cual ha sus raíces en la cuestión ambiental, pero también social, política y por ende moral, además de que también ha estado ligada a la cuestión económica. Sin embargo, a través de propuestas políticas, sociales, morales, científicas y tecnológicas, se plantea una forma posible de vivir en una sociedad más justa y armónica, tanto con los demás como con el medio ambiente, a través de una forma de ver la vida y hacer uso de las tecnologías actuales que están inmediatamente disponibles para la sociedad. la humanidad para solucionar la crisis ambiental que vive actualmente, la cual la tiene al borde de una extinción inminente.eng:Humanity is currently suffering from major problems which significantly overwhelm it, not only problems of the species, but problems of the environment where we live, due to the incorrect management that has been given to the natural resources of the planet, the excessive consumption of these and the current inability that humanity has to renew the natural resources necessary for survival; In addition to the fact that these factors converge with a type of autocratic behavior that has been forged in a significant part of today's society in general, in principle due to some type of character that has been privileged in a fairly considerable part of it, which It has led her to be extremely individualistic and has led her to stop recognizing and move away from genuinely acquired social commitments in the current way of life, which is governed by civil statutes, as Rousseau well argues when he presents some of the reasons why which happens this fact. For this reason, it is intended to make a recount of some problems that affect our current society, showing their origins and solutions that humanity has tried to give them throughout its history, but also a possible solution to this crisis is proposed, the which has its roots in the environmental issue, but also social, political and therefore moral, besides that it has also been linked to the economic issue. However, through political, social, moral, scientific and technological proposals, a possible way of living in a more just and harmonious society, both with others and with the environment, is proposed through a way of seeing life and making use of current technologies that are immediately available to society. humanity to solve the environmental crisis that it is currently experiencing, which has it on the brink of imminent extinction.RESUMEN / FILOSOFÍA DE LAS ECOLOGÍAS HUMANAS Y DE LAS ENERGÍAS SUSTENTABLES / CAPÍTULO I: INTRODUCCIÓN / CAPÍTULO II: CONTRACTUALISMO Y TEORÍA SOCIAL: MEDIACIÓN HOMBRE Y NATURALEZA / CAPÍTULO III: PERSPECTIVAS DE UNA RELACIÓN CON LA NATURALEZA DESDE EL ENFOQUE DE LA FILOSOFÍA DE LAS ECOLOGÍAS HUMANAS / CAPÍTULO IV: FILOSOFÍA DE LAS ECOLOGÍAS HUMANAS Y SU RELACIÓN CON LAS ENERGÍAS RENOVABLES / ORÍGENES DEL CONCEPTO SOSTENIBILIDAD: / CAPÍTULO V: FILOSOFÍA DE LA CIENCIA Y LA TECNOLOGÍA / JUSTIFICACIÓN DE LA TRANSICIÓN ENERGÉTICA: ¿POR QUÉ LOS PANELES SOLARES? / HISTORIA DE LAS CELDAS SOLARES Y DEL EFECTO FOTOVOLTAICO27 FORMULACIÓN ANALÍTICA / Filosofía de Las Ecologías Humanas y de Las Energías Sustentables VI EFICIENCIA DE LOS PANELES SOLARES / CAPÍTULO VI: TRÁNSITO DE LA SOSTENIBILIDAD A LA SUSTENTABILIDAD / CONCEPTO DE SOSTENIBILIDAD / RASTREO HISTÓRICO DEL CONCEPTO DE SOSTENIBILIDAD: / LA SUSTENTABILIDAD COMO OPTIMIZACIÓN DE LA SOSTENIBILIDAD / CAPÍTULO VII: CONCLUSIONES / VIII: BIBLIOGRAFÍA CONSULTADAUniversitarioProfesional en Filosofía y Letrasfilosofía de la ciencia y la tecnologí
alfa-Amylase as a reliable and convenient measure of sympathetic activity: don’t start salivating just yet!
No full textRecent years have seen a growing interest in salivary α-amylase (sAA) as a non-invasive marker for sympathetic nervous system (SNS) activity. Saliva offers many advantages as a biomarker fluid and sAA is one of its most plentiful components. sAA is a digestive enzyme that breaks down starch, which provides a simple means of quantification by measuring its enzymatic activity. This commentary will address a number of common misconceptions and methodological issues that surround the use of sAA as a marker of SNS activity and limit its utility in biobehavioral research. The usefulness of sAA as an SNS marker is undermined by the fact that the parasympathetic nerves also play a significant role in sAA release. Local parasympathetic nerves regulate sAA activity via: (1) α-amylase release from glands that are solely or mainly parasympathetically innervated; (2) via synergistic sympathetic-parasympathetic effects on protein secretion (known as ‘augmented secretion’); and (3) via effects on salivary flow rate. Regarding methodology, we discuss why it is problematic: (1) to ignore the contribution of salivary flow rate; (2) to use absorbent materials for saliva collection, and; (3) to stimulate saliva secretion by chewing. While these methodological problems can be addressed by using standardized and timed collection of unstimulated saliva, the physiological regulation of sAA secretion presents less resolvable issues. We conclude that at present there is insufficient support for the use and interpretation of sAA activity as a valid and reliable measure of SNS activity
Meta-analysis identifies 13 new loci associated with waist-hip ratio and reveals sexual dimorphism in the genetic basis of fat distribution
No full textWaist-hip ratio (WHR) is a measure of body fat distribution and a predictor of metabolic consequences independent of overall adiposity. WHR is heritable, but few genetic variants influencing this trait have been identified. We conducted a meta-analysis of 32 genome-wide association studies for WHR adjusted for body mass index (comprising up to 77,167 participants), following up 16 loci in an additional 29 studies (comprising up to 113,636 subjects). We identified 13 new loci in or near RSPO3, VEGFA, TBX15-WARS2, NFE2L3, GRB14, DNM3-PIGC, ITPR2-SSPN, LY86, HOXC13, ADAMTS9, ZNRF3-KREMEN1, NISCH-STAB1 and CPEB4 (P = 1.9 × 10⁻⁹ to P = 1.8 × 10⁻⁴⁰) and the known signal at LYPLAL1. Seven of these loci exhibited marked sexual dimorphism, all with a stronger effect on WHR in women than men (P for sex difference = 1.9 × 10⁻³ to P = 1.2 × 10⁻¹³). These findings provide evidence for multiple loci that modulate body fat distribution independent of overall adiposity and reveal strong gene-by-sex interactions
Bivariate genetic modelling of the response to an oral glucose tolerance challenge: A gene x environment interaction approach
No full textAIMS/HYPOTHESIS: Twin and family studies have shown the importance of genetic factors influencing fasting and 2 h glucose and insulin levels. However, the genetics of the physiological response to a glucose load has not been thoroughly investigated. METHODS: We studied 580 monozygotic and 1,937 dizygotic British female twins from the Twins UK Registry. The effects of genetic and environmental factors on fasting and 2 h glucose and insulin levels were estimated using univariate genetic modelling. Bivariate model fitting was used to investigate the glucose and insulin responses to a glucose load, i.e. an OGTT. RESULTS: The genetic effect on fasting and 2 h glucose and insulin levels ranged between 40% and 56% after adjustment for age and BMI. Exposure to a glucose load resulted in the emergence of novel genetic effects on 2 h glucose independent of the fasting level, accounting for about 55% of its heritability. For 2 h insulin, the effect of the same genes that already influenced fasting insulin was amplified by about 30%. CONCLUSIONS/INTERPRETATION: Exposure to a glucose challenge uncovers new genetic variance for glucose and amplifies the effects of genes that already influence the fasting insulin level. Finding the genes acting on 2 h glucose independently of fasting glucose may offer new aetiological insight into the risk of cardiovascular events and death from all causes
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