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| 2. |
- Díaz, Miguel, Högskoleadjunkt, et al.
(författare)
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The effects of resveratrol on aging vessels
- 2016
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Ingår i: Experimental Gerontology. - : Elsevier. - 0531-5565 .- 1873-6815. ; 85:1, s. 41-47
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Forskningsöversikt (refereegranskat)
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| 3. |
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| 4. |
- Grande, Giulia, et al.
(författare)
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Measuring gait speed to better identify prodromal dementia
- 2019
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Ingår i: Experimental Gerontology. - : Elsevier BV. - 0531-5565 .- 1873-6815. ; 124
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Forskningsöversikt (refereegranskat)abstract
- Slow gait speed has been shown to predict incident dementia and cognitive decline in older individuals. We aimed to summarize the evidence concerning the association of slow gait speed with cognitive decline and dementia, and discuss the possible shared pathways leading to cognitive and motor impairments, under the unifying hypothesis that body and mind are intimately connected. This is a scoping review supported by a systematic search of the literature, performed on PubMed and Web of Science. Longitudinal studies providing information on the role of gait speed in the prediction of cognitive decline and dementia in cognitively intact people and in those with initial cognitive impairment were eligible. Of 39 studies selected, including overall 57,456 participants, 33 reported a significant association between gait speed and cognitive outcomes, including dementia. Neurodegenerative pathology and cerebrovascular burden may damage cerebral areas involved in both cognitive functions and motor control. At the same time, systemic conditions, characterized by higher cardiorespiratory, and metabolic and inflammatory burden, can affect a number of organs and systems involved in motor functions, including the brain, having ultimately an impact on cognition. The interplay of body and mind seems relevant during the development of cognitive decline and dementia. The measurement of gait speed may improve the detection of prodromal dementia and cognitive impairment in individuals with and without initial cognitive deficits. The potential applicability of such a measure in both clinical and research settings points at the importance of expanding our knowledge about the common underlying mechanisms of cognitive and motor decline.
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| 5. |
- Hvid, Lars G., et al.
(författare)
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Myosin content of single muscle fibers following short-term disuse and active recovery in young and old healthy men
- 2017
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Ingår i: Experimental Gerontology. - : Elsevier BV. - 0531-5565 .- 1873-6815. ; 87:Part A, s. 100-107
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Tidskriftsartikel (refereegranskat)abstract
- Short-term disuse and subsequent recovery affect whole muscle and single myofiber contractile function in young and old. While the loss and recovery of single myofiber specific force (SF) following disuse and rehabilitation has been shown to correlate with alterations in myosin concentrations in young, it is unknown whether similar relationships exist in old. Therefore, the purpose of the present study was to examine the effect of 14 days lower limb disuse followed by 28 days of active recovery on single muscle fiber myosin content in old (68 yrs) and young (24 yrs) recreationally physically active healthy men. Following disuse, myosin content decreased (p < 0.05) in MHC 1 (young − 28%, old − 19%) and 2a fibers (young − 23%, old − 32%). In old, myosin content decreased more (p < 0.05) in MHC 2a vs 1 fibers. Following recovery, myosin content increased (p < 0.05) and returned to pre-disuse levels for both young and old in both fiber types, with MHC 2a fibers demonstrating an overshooting in young (+ 31%, p < 0.05) but not old. Strong correlations were observed between myosin content and single fiber SF in both young and old, with greater slope steepness in MHC 2a vs 1 fibers indicating an enhanced intrinsic contractile capacity of MHC 2a fibers. In conclusion, adaptive changes in myofiber myosin content appear to occur rapidly following brief periods of disuse (2 wks) and after subsequent active recovery (4 wks) in young and old, which contribute to alterations in contractile function at the single muscle fiber level. Changes in myosin content appear to occur independently of age, while influenced by fiber type (MHC isoform) in young but not old.
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| 6. |
- Hvid, Lars G., et al.
(författare)
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Plasticity in central neural drive with short-term disuse and recovery - effects on muscle strength and influence of aging
- 2018
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Ingår i: Experimental Gerontology. - : Elsevier BV. - 0531-5565 .- 1873-6815. ; 106, s. 145-153
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Tidskriftsartikel (refereegranskat)abstract
- While short-term disuse negatively affects mechanical muscle function (e.g. isometric muscle strength) little is known of the relative contribution of adaptions in central neural drive and peripheral muscle contractility. The present study investigated the relative contribution of adaptations in central neural drive and peripheral muscle contractility on changes in isometric muscle strength following short-term unilateral disuse (4 days, knee brace) and subsequent active recovery (7 days, one session of resistance training) in young (n = 11, 24 yrs) and old healthy men (n = 11, 67 yrs). Maximal isometric knee extensor strength (MVC) (isokinetic dynamometer), voluntary muscle activation (superimposed twitch technique), and electrically evoked muscle twitch force (single and doublet twitch stimulation) were assessed prior to and after disuse, and after recovery. Following disuse, relative decreases in MVC did not differ statistically between old (16.4 ± 3.7%, p < 0.05) and young (−9.7 ± 2.9%, p < 0.05) (mean ± SE), whereas voluntary muscle activation decreased more (p < 0.05) in old (−8.4 ± 3.5%, p < 0.05) compared to young (−1.1 ± 1.0%, ns) as did peak single (−25.8 ± 6.6%, p < 0.05 vs −7.6 ± 3.3%, p < 0.05) and doublet twitch force (−23.2 ± 5.5%, p < 0.05 vs −2.0 ± 2.6%, ns). All parameters were restored in young following 7 days recovery, whereas MVC and peak twitch force remained suppressed in old. Regression analysis revealed that disuse-induced changes in MVC relied more on changes in single twitch force in young (p < 0.05) and more on changes in voluntary muscle activation in old (p < 0.05), whereas recovery-induced changes in MVC mainly were explained by gains in voluntary muscle activation in both young and old. Altogether, the present data demonstrate that plasticity in voluntary muscle activation (~central neural drive) is a dominant mechanism affecting short-term disuse- and recovery-induced changes in muscle strength in older adults.
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| 8. |
- Karlsson, Mikael, et al.
(författare)
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Ability to predict resting energy expenditure with six equations compared to indirect calorimetry in octogenarian men
- 2017
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Ingår i: Experimental Gerontology. - : PERGAMON-ELSEVIER SCIENCE LTD. - 0531-5565 .- 1873-6815. ; 92, s. 52-55
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Tidskriftsartikel (refereegranskat)abstract
- The accuracy of predictive equations for calculating resting energy expenditure (REE) in elderly people has been questioned. Aging is associated with progressive declines in REE, which partly is explained by loss of fat free mass (FFM). Against this background we aimed to identify the most accurate predictive equation for REE in octogenarian men, taking body composition into account and using indirect calorimetry as reference value. REE was measured in 22 men (mean age 82.6 +/- 0.3 years) and compared with six predictive equations: two based on FFM and four based on body weight, height and/or age. FFM was derived from Dual-energy X-ray absorptiometry analyses. Spearman's rank correlations showed a moderate to high positive monotonic correlation (r = 0.62 to 0.79) between measured and calculated REE (all p < 0.005).The mean calculated REE was significantly different from measured REE for all equations except Mifflin-St Jeor. A calculated REE within 10% of measured REE was considered acceptable and the equations of Mifflin-St Jeor, WHO and Harris-Benedict captured 64%, 50% and 45% of the participant, respectively. The Mifflin-St Jeor equation had the lowest root mean square error (138 kcal), followed by the equation by Harris-Benedict (189 kcal) and WHO (220 kcal). The equations from Luhrmann, Henry and Cunningham predicted REE rather poorly in our study subjects, with e.g. <40% of the individuals within 10% of measured REE. Our results indicate that the Mifflin-St Jeor equation (using FFM) is the most accurate equation estimating REE in these octogenarian men. Harris-Benedict or WHO equations are potential alternatives if information on FFM is unavailable, although their accuracy on an individual level is limited.
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| 9. |
- Klepsatel, Peter, et al.
(författare)
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Crowding of Drosophila larvae affects lifespan and other life-history traits via reduced availability of dietary yeast
- 2018
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Ingår i: Experimental Gerontology. - : Elsevier BV. - 0531-5565 .- 1873-6815. ; 110, s. 298-308
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Tidskriftsartikel (refereegranskat)abstract
- Conditions experienced during development have often long-lasting effects persisting into adulthood. In Drosophila, it is well-documented that larval crowding influences fitness-related traits such as body size, starvation resistance and lifespan. However, the underlying mechanism of this phenomenon is not well understood. Here, we show that the effects of increased larval density on life-history traits can be explained by decreased yeast availability in the diet during development. Yeast-poor larval diet alters various life-history traits and mimics the effects of larval crowding. In particular, reduced amount of yeast in larval diet prolongs developmental time, reduces body size, increases body fat content and starvation resistance, and prolongs Drosophila lifespan. Conversely, the effects of larval crowding can be rescued by increasing the concentration of the dietary yeast in the diet during development. Altogether, our results show that the well-known effects of larval crowding on life-history traits are mainly caused by the reduced availability of dietary yeasts due to increased larval competition.
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| 10. |
- Lind, Martin I., et al.
(författare)
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Rapamycin additively extends lifespan in short- and long-lived lines of the nematode Caenorhabditis remanei
- 2017
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Ingår i: Experimental Gerontology. - : Elsevier BV. - 0531-5565 .- 1873-6815. ; 90, s. 79-82
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Tidskriftsartikel (refereegranskat)abstract
- Despite tremendous progress in finding genes that, when manipulated, affects lifespan, little is known about the genetics underlying natural variation in lifespan. While segregating genetic variants for lifespan has been notoriously difficult to find in genome-wide association studies (GWAS), a complementary approach is to manipulate key genetic pathways in lines that differ in lifespan. If these candidate pathways are down regulated in long-lived lines, these lines can be predicted to respond less to pharmaceutical down-regulation of these pathways than short-lived lines. Experimental studies have identified the nutrient-sensing pathway TOR as a key regulator of lifespan in model organisms, and this pathway can effectively be down regulated using the drug rapamycin, which extends lifespan in all tested species. We expose short-and long-lived lines of the nematode Caenorhabditis remanei to rapamycin, and investigate if long-lived lines, which are hypothesized to already have down-regulated TOR signaling, respond less to rapamycin. We found no interaction between line and rapamycin treatment, since rapamycin extended lifespan independent of the intrinsic lifespan of the lines. This shows that rapamycin is equally effective on long and short-lived lines, and suggests that the evolution of long life may involve more factors that down-regulation of TOR.
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