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| 2. |
- Boussard, Annika, et al.
(författare)
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The link between relative brain size and cognitive ageing in female guppies (Poecilia reticulata) artificially selected for variation in brain size
- 2021
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Ingår i: Experimental Gerontology. - : Elsevier BV. - 0531-5565 .- 1873-6815. ; 146
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Tidskriftsartikel (refereegranskat)abstract
- Cognitive ageing is the general process when certain mental skills gradually deteriorate with age. Across species, there is a pattern of a slower brain structure degradation rate in large-brained species. Hence, having a larger brain might buffer the impact of cognitive ageing and positively affect survival at older age. However, few studies have investigated the link between relative brain size and cognitive ageing at the intraspecific level. In particular, experimental data on how brain size affects brain function also into higher age is largely missing. We used 288 female guppies (Poecilia reticulata), artificially selected for large and small relative brain size, to investigate variation in colour discrimination and behavioural flexibility, at 4-6, 12 and 24 months of age. These ages are particularly interesting since they cover the life span from sexual maturation until maximal life length under natural conditions. We found no evidence for a slower cognitive ageing rate in large-brained females in neither initial colour discrimination nor reversal learning. Behavioural flexibility was predicted by large relative brain size in the youngest group, but the effect of brain size disappeared with increasing age. This result suggests that cognitive ageing rate is faster in large-brained female guppies, potentially due to the faster ageing and shorter lifespan in the large-brained selection lines. It also means that cognition levels align across different brain sizes with older age. We conclude that there are cognitive consequences of ageing that vary with relative brain size in advanced learning abilities, whereas fundamental aspects of learning can be maintained throughout the ecologically relevant life span.
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| 3. |
- Edholm, Peter, 1977-, et al.
(författare)
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Muscle mass and aerobic capacity in older women : Impact of regular exercise at middle age
- 2021
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Ingår i: Experimental Gerontology. - : Elsevier. - 0531-5565 .- 1873-6815. ; 147
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The impact of regular exercise habits at middle-age on muscle mass and function at old age remains inconclusive. While regular exercise likely represents a primary source of health-enhancing physical activity (PA), the physical demand of occupation needs to be considered. Additionally, PA level at old age should be taken into account in order to elucidate true associations between past exercise behaviors and muscle mass and function at old age. Therefore, the aim of the study was to examine the impact of regular exercise habits during middle age years on muscle mass and physical function at old age, while considering occupation and objectively assessed PA level at old age.METHODS: Self-reported leisure-time PA during middle age years [35-65 years] and present accelerometer-derived PA level were assessed in a population of community-dwelling older women (65-70 years; n = 112). Participants who accumulated at least 600 MET-min of PA per week during middle age years were classified as physically active. Skeletal muscle mass index (SMI), aerobic fitness and maximal isometric arm and leg strength were determined. Analyses of differences in muscle mass and physical function between physically active and inactive at middle age were adjusted by present PA, adiposity level, and the physical demand of former occupation (sedentary vs manual).RESULTS: Participants accumulating at least 600 MET-min of exercise-related activities during middle-age years had higher aerobic fitness (P < 0.01) and SMI (P < 0.05) at old age compared to their less active peers. Notably, these beneficial impacts were driven by exercise habits during late middle-age period [50 to 65 years], and remained significant after further adjustment by the physical demand of former occupation and present PA behavior at old age. Finally, middle-age engagement in exercise-related activities had no influence on maximal arm and leg isometric strength at old age.CONCLUSION: Our findings highlight the importance of engaging in regular PA of at least moderate intensity during middle age years in order to promote benefits at the level of muscle mass and aerobic fitness. This clearly supports the potential of PA in delaying aerobic capacity impairment and the occurrence of clinically manifest sarcopenia at old age.
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| 4. |
- Gylling, Anne Theil, et al.
(författare)
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The influence of prolonged strength training upon muscle and fat in healthy and chronically diseased older adults
- 2020
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Ingår i: Experimental Gerontology. - : Elsevier. - 0531-5565 .- 1873-6815. ; 136
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Tidskriftsartikel (refereegranskat)abstract
- Background: Physical muscle function and brain hippocampus size declines with age, accelerating after the age of 60. Strength training over a few months improves physical function, but less is known about how long-term strength training affects physical function and hippocampus volume. Therefore, we aimed to investigate the effect of 1-year strength training of two different intensities upon muscle mass, function, and hippocampus volume in retirement-age individuals.Methods: In this multidisciplinary randomized controlled trial (clinicaltrials.gov: NCT02123641), participants were allocated to either a) supervised, heavy resistance training (HRT, n = 149, 3/wk), b) moderate intensity resistance training (MIT, n = 154, 3/wk) or c) non-exercise activities (CON, n = 148). 451 participants were randomized (62-70 yrs., women 61%, approximate to 80% with a chronic medical disease) and 419 were included in the intention-to-treat analysis (n = 143, 144 and 132; HRT, MIT and CON). Changes in muscle power (primary outcome), strength and size, physical function, body composition, hippocampus volume and physical/mental well-being were analyzed.Findings: Of the participants (HRT + MIT), 83% completed training at least 2/week. Leg extensor power was unchanged in all groups, but strength training had a positive effect on isometric knee extensor strength in both groups, whereas an increased muscle mass, cross-sectional area of vastus lateralis muscle, a decreased whole-body fat percentage, visceral fat content and an improved mental health (SF-36) occurred in HRT only. Further, chair-stand performance improved in all groups, whereas hippocampus volume decreased in all groups over time with no influence of strength training.Interpretation: Together, the results indicate that leg extensor power did not respond to long-term supervised strength training, but this type of training in a mixed group of healthy and chronically diseased elderly individuals can be implemented with good compliance and induces consistent changes in physiological parameters of muscle strength, muscle mass and abdominal fat.
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| 5. |
- Hoogendijk, Emiel O., et al.
(författare)
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Gait speed as predictor of transition into cognitive impairment: Findings from three longitudinal studies on aging
- 2020
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Ingår i: Experimental Gerontology. - : Elsevier BV. - 0531-5565 .- 1873-6815. ; 129
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Tidskriftsartikel (refereegranskat)abstract
- © 2019 The Authors Objectives: Very few studies looking at slow gait speed as early marker of cognitive decline investigated the competing risk of death. The current study examines associations between slow gait speed and transitions between cognitive states and death in later life. Methods: We performed a coordinated analysis of three longitudinal studies with 9 to 25 years of follow-up. Data were used from older adults participating in H70 (Sweden; n = 441; aged ≥70 years), InCHIANTI (Italy; n = 955; aged ≥65 years), and LASA (the Netherlands; n = 2824; aged ≥55 years). Cognitive states were distinguished using the Mini-Mental State Examination. Slow gait speed was defined as the lowest sex-specific quintile at baseline. Multistate models were performed, adjusted for age, sex and education. Results: Most effect estimates pointed in the same direction, with slow gait speed predicting forward transitions. In two cohort studies, slow gait speed predicted transitioning from mild to severe cognitive impairment (InCHIANTI: HR = 2.08, 95%CI = 1.40–3.07; LASA: HR = 1.33, 95%CI = 1.01–1.75) and transitioning from a cognitively healthy state to death (H70: HR = 3.30, 95%CI = 1.74–6.28; LASA: HR = 1.70, 95%CI = 1.30–2.21). Conclusions: Screening for slow gait speed may be useful for identifying older adults at risk of adverse outcomes such as cognitive decline and death. However, once in the stage of more advanced cognitive impairment, slow gait speed does not seem to predict transitioning to death anymore.
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| 6. |
- Lagunas-Rangel, Francisco Alejandro
(författare)
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Deciphering the whale's secrets to have a long life
- 2021
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Ingår i: Experimental Gerontology. - : Elsevier. - 0531-5565 .- 1873-6815. ; 151
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Forskningsöversikt (refereegranskat)abstract
- Whales are marine creatures known for their enormous size and that live in all the oceans on earth. One of the oldest known organisms is bowhead whales, which can survive up to 200 years, and similarly, other species of whales have shown a remarkable long lifespan. In addition to this, whales are highly resistant to cancer, a disease that is strongly related to aging and the accumulation of damage over time. These two characteristics make whales an interesting model to study and that can provide us with a track both to delay aging and to avoid pathologies associated with it, such as cancer. In the present work, we try to analyze different aspects of whales such as metabolism, hematological and biochemical characteristics, and properties of their genome and transcriptome in order to elucidate possible molecular mechanisms that evolution has provided to these aquatic mammals.
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| 7. |
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| 8. |
- Picca, Anna, et al.
(författare)
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Mitophagy : At the heart of mitochondrial quality control in cardiac aging and frailty
- 2021
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Ingår i: Experimental Gerontology. - : Elsevier BV. - 0531-5565 .- 1873-6815. ; 153
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Tidskriftsartikel (refereegranskat)abstract
- Cardiovascular disease is highly prevalent among older adults and poses a huge burden on morbidity, disability, and mortality. The age-related increased vulnerability of the cardiovascular system towards stressors is a pathophysiological trait of cardiovascular disease. This has been associated with a progressive deterioration of blood vessels and decline in heart function during aging. Cardiomyocytes rely mostly on oxidative metabolism for deploying their activities and mitochondrial metabolism is crucial to this purpose. Dysmorphic, inefficient, and oxidant-producing mitochondria have been identified in aged cardiomyocytes in association with cardiac structural and functional alterations. These aberrant organelles are thought to arise from inefficient mitochondrial quality control, which has therefore been place in the spotlight as a relevant mechanism of cardiac aging. As a result of alterations in mitochondrial quality control and redox dyshomeostasis, mitochondrial damage accumulates and contributes to cardiac frailty. Herein, we discuss the contribution of defective mitochondrial quality control pathways to cardiac frailty. Emerging findings pointing towards the exploitation of these pathways as therapeutic targets against cardiac aging and cardiovascular disease will also be illustrated.
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| 9. |
- Schnitzer, Barbara Maria, 1992, et al.
(författare)
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The effect of stress on biophysical characteristics of misfolded protein aggregates in living Saccharomyces cerevisiae cells
- 2022
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Ingår i: Experimental Gerontology. - : Elsevier BV. - 1873-6815 .- 0531-5565. ; 162
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Forskningsöversikt (refereegranskat)abstract
- Aggregation of misfolded or damaged proteins is often attributed to numerous metabolic and neurodegenerative disorders. To reveal underlying mechanisms and cellular responses, it is crucial to investigate protein aggregate dynamics in cells. Here, we used super-resolution single-molecule microscopy to obtain biophysical characteristics of individual aggregates of a model misfolded protein ∆ssCPY* labelled with GFP. We demonstrated that oxidative and hyperosmotic stress lead to increased aggregate stoichiometries but not necessarily the total number of aggregates. Moreover, our data suggest the importance of the thioredoxin peroxidase Tsa1 for the controlled sequestering and clearance of aggregates upon both conditions. Our work provides novel insights into the understanding of the cellular response to stress via revealing the dynamical properties of stress-induced protein aggregates.
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| 10. |
- Skoglund, Elisabeth, et al.
(författare)
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Functional improvements to 6 months of physical activity are not related to changes in size or density of multiple lower-extremity muscles in mobility-limited older individuals
- 2022
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Ingår i: Experimental Gerontology. - : Elsevier BV. - 0531-5565 .- 1873-6815. ; 157
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Tidskriftsartikel (refereegranskat)abstract
- Older adults are encouraged to engage in multicomponent physical activity, which includes aerobic and muscle-strengthening activities. The current work is an extension of the Vitality, Independence, and Vigor in the Elderly 2 (VIVE2) study - a 6-month multicenter, randomized, placebo-controlled trial of physical activity and nutritional supplementation in community dwelling 70-year-old seniors. Here, we examined whether the magnitude of changes in muscle size and quality differed between major lower-extremity muscle groups and related these changes to functional outcomes. We also examined whether daily vitamin-D-enriched protein supplementation could augment the response to structured physical activity. Forty-nine men and women (77 ± 5 yrs) performed brisk walking, muscle-strengthening exercises for the lower limbs, and balance training 3 times weekly for 6 months. Participants were randomized to daily intake of a nutritional supplement (20 g whey protein + 800 IU vitamin D), or a placebo. Muscle cross-sectional area (CSA) and radiological attenuation (RA) were assessed in 8 different muscle groups using single-slice CT scans of the hip, thigh, and calf at baseline and after the intervention. Walking speed and performance in the Short Physical Performance Battery (SPPB) were also measured. For both CSA and RA, there were muscle group × time interactions (P < 0.01). Significant increases in CSA were observed in 2 of the 8 muscles studied, namely the knee extensors (1.9%) and the hip adductors (2.8%). For RA, increases were observed in 4 of 8 muscle groups, namely the hip flexors (1.1 HU), hip adductors (0.9 HU), knee extensors (1.2 HU), and ankle dorsiflexors (0.8 HU). No additive effect of nutritional supplementation was observed. While walking speed (13%) and SPPB performance (38%) improved markedly, multivariate analysis showed that these changes were not associated with the changes in muscle CSA and RA after the intervention. We conclude that this type of multicomponent physical activity program results in significant improvements in physical function despite relatively small changes in muscle size and quality of some, but not all, of the measured lower extremity muscles involved in locomotion.
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