scholarly journals Chronological age, biological age, and individual variation in the stress response in the European starling: A follow-up study

Author(s):  
Annie Gott ◽  
Clare Andrews ◽  
Maria Larriva Hormigos ◽  
Karen Spencer ◽  
Melissa Bateson ◽  
...  

The responsiveness of the avian stress system declines with age. A recently published study of European starlings (Sturnus vulgaris) found that a marker of biological age predicted stress responsiveness even in individuals of the same chronological age. Specifically, birds that had experienced greater developmental telomere attrition showed a lower peak corticosterone response to an acute stressor, and more rapid recovery of corticosterone levels towards baseline. Here, we performed a follow-up study using the same capture-restraint-handling stressor in a separate cohort of 27 starlings. Unlike the original study, we measured the response at two different age points (4 and 18 months). We did not replicate the associations with developmental telomere attrition observed in the previous study at either age point. However, a meta-analysis of the present results combined with those of the earlier study still lent some support to the conclusions of the earlier paper. Estimates of familial influence on stress responsiveness differed across the two age points. We found little evidence of individual consistency in stress responsiveness between 4 and 18 months. Peak corticosterone was significantly lower at the second age point than the first, though interpretation of this as age-related decline is problematic due to the samples having been analysed at different times.

2018 ◽  
Author(s):  
Annie Gott ◽  
Clare Andrews ◽  
Maria Larriva Hormigos ◽  
Karen Spencer ◽  
Melissa Bateson ◽  
...  

The responsiveness of the avian stress system declines with age. A recently published study of European starlings (Sturnus vulgaris) found that a marker of biological age predicted stress responsiveness even in individuals of the same chronological age. Specifically, birds that had experienced greater developmental telomere attrition showed a lower peak corticosterone response to an acute stressor, and more rapid recovery of corticosterone levels towards baseline. Here, we performed a follow-up study using the same capture-restraint-handling stressor in a separate cohort of 27 starlings. Unlike the original study, we measured the response at two different age points (4 and 18 months). We did not replicate the associations with developmental telomere attrition observed in the previous study at either age point. However, a meta-analysis of the present results combined with those of the earlier study still lent some support to the conclusions of the earlier paper. Estimates of familial influence on stress responsiveness differed across the two age points. We found little evidence of individual consistency in stress responsiveness between 4 and 18 months. Peak corticosterone was significantly lower at the second age point than the first, though interpretation of this as age-related decline is problematic due to the samples having been analysed at different times.


PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5842 ◽  
Author(s):  
Annie Gott ◽  
Clare Andrews ◽  
Maria Larriva Hormigos ◽  
Karen Spencer ◽  
Melissa Bateson ◽  
...  

The strength of the avian stress response declines with age. A recently published study of European starlings (Sturnus vulgaris) found that a marker of biological age predicted the strength of the stress response even in individuals of the same chronological age. Specifically, birds that had experienced greater developmental telomere attrition (DTA) showed a lower peak corticosterone (CORT) response to an acute stressor, and more rapid recovery of CORT levels towards baseline. Here, we performed a follow-up study using the same capture-handling-restraint stressor in a separate cohort of starlings that had been subjected to a developmental manipulation of food availability and begging effort. We measured the CORT response at two different age points (4 and 18 months). Our data suggest a decline in the strength of the CORT response with chronological age: peak CORT was lower at the second age point, and there was relatively more reduction in CORT between 15 and 30 min. Individual consistency between the two age points was low, but there were modest familial effects on baseline and peak CORT. The manipulation of begging effort affected the stress response (specifically, the reduction in CORT between 15 and 30 min) in an age-dependent manner. However, we did not replicate the associations with DTA observed in the earlier study. We meta-analysed the data from the present and the earlier study combined, and found some support for the conclusions of the earlier paper.


2019 ◽  
Vol 6 (6) ◽  
pp. 190420 ◽  
Author(s):  
Melissa Bateson ◽  
Abraham Aviv ◽  
Laila Bendix ◽  
Athanase Benetos ◽  
Yoav Ben-Shlomo ◽  
...  

Smoking is associated with shorter leucocyte telomere length (LTL), a biomarker of increased morbidity and reduced longevity. This association is widely interpreted as evidence that smoking causes accelerated LTL attrition in adulthood, but the evidence for this is inconsistent. We analysed the association between smoking and LTL dynamics in 18 longitudinal cohorts. The dataset included data from 12 579 adults (4678 current smokers and 7901 non-smokers) over a mean follow-up interval of 8.6 years. Meta-analysis confirmed a cross-sectional difference in LTL between smokers and non-smokers, with mean LTL 84.61 bp shorter in smokers (95% CI: 22.62 to 146.61). However, LTL attrition was only 0.51 bp yr −1 faster in smokers than in non-smokers (95% CI: −2.09 to 1.08), a difference that equates to only 1.32% of the estimated age-related loss of 38.33 bp yr −1 . Assuming a linear effect of smoking, 167 years of smoking would be required to generate the observed cross-sectional difference in LTL. Therefore, the difference in LTL between smokers and non-smokers is extremely unlikely to be explained by a linear, causal effect of smoking. Selective adoption, whereby individuals with short telomeres are more likely to start smoking, needs to be considered as a more plausible explanation for the observed pattern of telomere dynamics.


2017 ◽  
Vol 4 (9) ◽  
pp. 171208 ◽  
Author(s):  
Clare Andrews ◽  
Daniel Nettle ◽  
Maria Larriva ◽  
Robert Gillespie ◽  
Sophie Reichert ◽  
...  

The acute stress response functions to prioritize behavioural and physiological processes that maximize survival in the face of immediate threat. There is variation between individuals in the strength of the adult stress response that is of interest in both evolutionary biology and medicine. Age is an established source of this variation—stress responsiveness diminishes with increasing age in a range of species—but unexplained variation remains. Since individuals of the same chronological age may differ markedly in their pace of biological ageing, we asked whether biological age—measured here via erythrocyte telomere length—predicts variation in stress responsiveness in adult animals of the same chronological age. We studied two cohorts of European starlings in which we had previously manipulated the rate of biological ageing by experimentally altering the competition experienced by chicks in the fortnight following hatching. We predicted that individuals with greater developmental telomere attrition, and hence greater biological age, would show an attenuated corticosterone (CORT) response to an acute stressor when tested as adults. In both cohorts, we found that birds with greater developmental telomere attrition had lower peak CORT levels and a more negative change in CORT levels between 15 and 30 min following stress exposure. Our results, therefore, provide strong evidence that a measure of biological age explains individual variation in stress responsiveness: birds that were biologically older were less stress responsive. Our results provide a novel explanation for the phenomenon of developmental programming of the stress response: observed changes in stress physiology as a result of exposure to early-life adversity may reflect changes in ageing.


Author(s):  
Justus G. Garweg ◽  
Christin Gerhardt

Abstract Purpose To assess disease stability (absence of intra- and/or subretinal fluid) and the portion of eyes being capable to extend their treatment interval to ≥ 12 weeks in exudative age-related macular degeneration (AMD). Methods A systematic literature search was performed in NCBI, PubMed, CENTRAL, and ClinicalTrials.gov to identify clinical studies reporting treatment outcomes for ranibizumab, aflibercept, and brolucizumab in exudative AMD under a treat-and-extend protocol and a follow-up of ≥ 12 months. Weighted mean differences and subgroup comparisons were used to integrate the different studies. Results This meta-analysis refers to 29 published series, including 27 independent samples and 5629 patients. In the pooled group, disease stability was reported in 62.9% and 56.0%, respectively, after 12 and 24 months of treatment, whereas treatment intervals were extended to ≥ 12 weeks in 37.7% and 42.6%, respectively. Ranibizumab, aflibercept, and brolucizumab differed regarding their potential to achieve disease stability (56.3%, 64.5%, and 71.5% after 12, and 50.0%, 52.7% and 75.7% after 24 months; p = < 0.001) and to allow an interval extension to ≥ 12 weeks (28.6%, 34.2%, and 53.3% after 12, and 34.2%, 47.7%, and 41.7% after 24 months; p = < 0.001). Conclusion The portion of eyes achieving disease stability regressed in the second year, whereas the portion of eyes under a ≥ 12-week interval increased. This discrepancy may reflect the challenges in balancing between under-treatment and a reduced treatment burden.


Stroke ◽  
2017 ◽  
Vol 48 (suppl_1) ◽  
Author(s):  
Jordi Jimenez-Conde ◽  
Carolina Soriano-Tarraga ◽  
Eva Giralt-Steinhauer ◽  
Marina Mola ◽  
Rosa Vivanco-Hidalgo ◽  
...  

Background: Stroke has a great impact in functional status of patients, although there are substantial interindividual differences in recovery capacity. Apart from stroke severity, age is considered an important predictor of outcome after stroke, but aging is not only due to chronological age. There are age-related DNA-methylation changes in multiple CpG sites across the genome that can be used to estimate the biological age (b-Age), and we seek to analyze the impact of this b-Age in recovery after an ischemic stroke. Methods: We include 600 individuals with acute ischemic stroke assessed in Hospital del Mar (Barcelona). Demographic and clinical data such as chronological age (c-Age), vascular risk factors, NIHSS at admission, recanalization treatment (rtPA or endovascular treatment), previous modified Rankin scale (p-mRS) and 3 months post stroke functional status (3-mRS) were registered. Biological age (b-Age) was estimated with Hannumm algorithm, based on DNA methylation in 71 CpGs. Results: The bivariate analyses for association with 3-mRS showed a significant results of NIHSS, c-Age, b-Age, p-mRS, and current smoking (all with p<0.001). Recanalization treatment showed no significant differences in bivariate analysis. In multivariate ordinal models, b-Age kept its significance (p=0.025) nullifying c-Age (p=0.84). Initial NIHSS, p-mRS and recanalization treatment kept also significant results (p<0.001). Conclusions: Biological Age, estimated by DNA methylation, is an independent predictor of stroke prognosis, irrespective to chronological age. "Healthy aging” affects the capacity of recovering after an ischemic stroke.


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