| 1. |
- Manini, T. M., et al.
(författare)
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Identification of Sarcopenia Components That Discriminate Slow Walking Speed: A Pooled Data Analysis
- 2020
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Ingår i: Journal of the American Geriatrics Society. - : Wiley. - 0002-8614 .- 1532-5415. ; 68:7, s. 1419-1428
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND The Sarcopenia Definitions and Outcomes Consortium (SDOC) sought to identify cut points for muscle strength and body composition measures derived from dual-energy x-ray absorptiometry (DXA) that discriminate older adults with slow walking speed. This article presents the core analyses used to guide the SDOC position statements. DESIGN Cross-sectional data analyses of pooled data. SETTING University-based research assessment centers. PARTICIPANTS Community-dwelling men (n = 13,652) and women: (n = 5,115) with information on lean mass by DXA, grip strength (GR), and walking speed. MEASUREMENTS Thirty-five candidate sarcopenia variables were entered into sex-stratified classification and regression tree (CART) models to agnostically choose variables and cut points that discriminate slow walkers (<0.80 m/s). Models with alternative walking speed outcomes were also evaluated (<0.60 and <1.0 m/s and walking speed treated continuously). RESULTS CART models identified GR/body mass index (GRBMI) and GR/total body fat (GRTBF) as the primary discriminating variables for slowness in men and women, respectively. Men with GRBMI of 1.05 kg/kg/m(2)or less were approximately four times more likely to be slow walkers than those with GRBMI of greater than 1.05 kg/kg/m(2). Women with GRTBF of less than 0.65 kg/kg were twice as likely to be slow walkers than women with GRTBF of 0.65 kg/kg or greater. Models with alternative walking speed outcomes selected only functions of GR as primary discriminators of slowness in both men and women. DXA-derived lean mass measures did not consistently discriminate slow walkers. CONCLUSION GR with and without adjustments for body size and composition consistently discriminated older adults with slowness. CART models did not select DXA-based lean mass as a primary discriminator of slowness. These results were presented to an SDOC Consensus Panel, who used them and other information to develop the SDOC Position Statements.
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| 2. |
- Grosicki, Gregory J., et al.
(författare)
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Circulating Interleukin-6 is Associated with Skeletal Muscle Strength, Quality, and Functional Adaptation with Exercise Training in Mobility-Limited Older Adults
- 2020
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Ingår i: Journal of Frailty & Aging. - : EDITIONS SERDI. - 2260-1341 .- 2273-4309. ; 9:1, s. 57-63
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Tidskriftsartikel (refereegranskat)abstract
- Background: Human aging is characterized by a chronic, low-grade inflammation suspected to contribute to reductions in skeletal muscle size, strength, and function. Inflammatory cytokines, such as interleukin-6 (IL-6), may play a role in the reduced skeletal muscle adaptive response seen in older individuals.Objectives: To investigate relationships between circulating IL-6, skeletal muscle health and exercise adaptation in mobility-limited older adults.Design: Randomized controlled trial.Setting: Exercise laboratory on the Health Sciences campus of an urban university.Participants: 99 mobility-limited (Short Physical Performance Battery (SPPB) <= 9) older adults.Intervention: 6-month structured physical activity with or without a protein and vitamin D nutritional supplement.Measurements: Circulating IL-6, skeletal muscle size, composition (percent normal density muscle tissue), strength, power, and specific force (strength/CSA) as well as physical function (gait speed, stair climb time, SPPB-score) were measured pre- and post-intervention.Results: At baseline, Spearman's correlations demonstrated an inverse relationship (P<0.05) between circulating IL-6 and thigh muscle composition (r = -0.201), strength (r = -0.311), power (r = -0.210), and specific force (r = -0.248), and positive association between IL-6 and stair climb time (r = 0.256; P<0.05). Although the training program did not affect circulating IL-6 levels (P=0.69), reductions in IL-6 were associated with gait speed improvements (r = -0.487; P<0.05) in "higher" IL-6 individuals (>1.36 pg/ml). Moreover, baseline IL-6 was inversely associated (P<0.05) with gains in appendicular lean mass and improvements in SPPB score (r = -0.211 and -0.237, respectively).Conclusions: These findings implicate age-related increases in circulating IL-6 as an important contributor to declines in skeletal muscle strength, quality, function, and training-mediated adaptation. Given the pervasive nature of inflammation among older adults, novel therapeutic strategies to reduce IL-6 as a means of preserving skeletal muscle health are enticing.
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| 3. |
- Yeap, B. B., et al.
(författare)
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Androgens in men study (AIMS): Protocol for meta-analyses of individual participant data investigating associations of androgens with health outcomes in men
- 2020
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Ingår i: BMJ Open. - : BMJ. - 2044-6055. ; 10:5
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Tidskriftsartikel (refereegranskat)abstract
- Introduction This study aims to clarify the role(s) of endogenous sex hormones to influence health outcomes in men, specifically to define the associations of plasma testosterone with incidence of cardiovascular events, cancer, dementia and mortality risk, and to identify factors predicting testosterone concentrations. Data will be accrued from at least three Australian, two European and four North American population-based cohorts involving approximately 20 000 men. Methods and analysis Eligible studies include prospective cohort studies with baseline testosterone concentrations measured using mass spectrometry and 5 years of follow-up data on incident cardiovascular events, mortality, cancer diagnoses or deaths, new-onset dementia or decline in cognitive function recorded. Data for men, who were not taking androgens or drugs suppressing testosterone production, metabolism or action; and had no prior orchidectomy, are eligible. Systematic literature searches were conducted from 14 June 2019 to 31 December 2019, with no date range set for searches. Aggregate level data will be sought where individual participant data (IPD) are not available. One-stage IPD random-effects meta-analyses will be performed, using linear mixed models, generalised linear mixed models and either stratified or frailty-augmented Cox regression models. Heterogeneity in estimates from different studies will be quantified and bias investigated using funnel plots. Effect size estimates will be presented in forest plots and non-negligible heterogeneity and bias investigated using subgroup or meta-regression analyses. Ethics and dissemination Ethics approvals obtained for each of the participating cohorts state that participants have consented to have their data collected and used for research purposes. The Androgens In Men Study has been assessed as exempt from ethics review by the Human Ethics office at the University of Western Australia (file reference number RA/4/20/5014). Each of the component studies had obtained ethics approvals; please refer to respective component studies for details. Research findings will be disseminated to the scientific and broader community via the publication of four research articles, with each involving a separate set of IPD meta-analyses (articles will investigate different, distinct outcomes), at scientific conferences and meetings of relevant professional societies. Collaborating cohort studies will disseminate findings to study participants and local communities. PROSPERO registration number CRD42019139668. © Author(s) (or their employer(s)) 2020. Re-use permitted under CC BY. Published by BMJ.
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| 4. |
- Eriksson, Anna-Lena, 1971, et al.
(författare)
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Genetic Determinants of Circulating Estrogen Levels and Evidence of a Causal Effect of Estradiol on Bone Density in Men.
- 2018
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Ingår i: Journal of Clinical Endocrinology and Metabolism. - : The Endocrine Society. - 0021-972X .- 1945-7197. ; 103:3, s. 991-1004
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Tidskriftsartikel (refereegranskat)abstract
- Serum estradiol (E2) and estrone (E1) levels exhibit substantial heritability.To investigate the genetic regulation of serum E2 and E1 in men.Genome-wide association study in 11,097 men of European origin from nine epidemiological cohorts.Genetic determinants of serum E2 and E1 levels.Variants in/near CYP19A1 demonstrated the strongest evidence for association with E2, resolving to three independent signals. Two additional independent signals were found on the X chromosome; FAMily with sequence similarity 9, member B (FAM9B), rs5934505 (P = 3.4 × 10-8) and Xq27.3, rs5951794 (P = 3.1 × 10-10). E1 signals were found in CYP19A1 (rs2899472, P = 5.5 × 10-23), in Tripartite motif containing 4 (TRIM4; rs17277546, P = 5.8 × 10-14), and CYP11B1/B2 (rs10093796, P = 1.2 × 10-8). E2 signals in CYP19A1 and FAM9B were associated with bone mineral density (BMD). Mendelian randomization analysis suggested a causal effect of serum E2 on BMD in men. A 1 pg/mL genetically increased E2 was associated with a 0.048 standard deviation increase in lumbar spine BMD (P = 2.8 × 10-12). In men and women combined, CYP19A1 alleles associated with higher E2 levels were associated with lower degrees of insulin resistance.Our findings confirm that CYP19A1 is an important genetic regulator of E2 and E1 levels and strengthen the causal importance of E2 for bone health in men. We also report two independent loci on the X-chromosome for E2, and one locus each in TRIM4 and CYP11B1/B2, for E1.
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| 5. |
- Fielding, R. A., et al.
(författare)
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Effect of structured physical activity and nutritional supplementation on physical function in mobility-limited older adults : Results from the VIVE2 randomized trial
- 2017
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Ingår i: The Journal of Nutrition, Health & Aging. - : Springer Science and Business Media LLC. - 1279-7707 .- 1760-4788. ; 21:9, s. 936-942
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Tidskriftsartikel (refereegranskat)abstract
- The interactions between nutritional supplementation and physical activity on changes in physical function among older adults remain unclear. The primary objective of this study was to examine the impact of nutritional supplementation plus structured physical activity on 400M walk capacity in mobility-limited older adults across two sites (Boston, USA and Stockholm, Sweden). All subjects participated in a physical activity program (3x/week for 24 weeks), involving walking, strength, balance, and flexibility exercises. Subjects were randomized to a daily nutritional supplement (150kcal, 20g whey protein, 800 IU vitamin D) or placebo (30kcal, non-nutritive). Participants were recruited from urban communities at 2 field centers in Boston MA USA and Stockholm SWE. Mobility-limited (Short Physical Performance Battery (SPPB) ae9) and vitamin D insufficient (serum 25(OH) D 9 - 24 ng/ml) older adults were recruited for this study. Primary outcome was gait speed assessed by the 400M walk. Results: 149 subjects were randomized into the study (mean age=77.5 +/- 5.4; female=46.3%; mean SPPB= 7.9 +/- 1.2; mean 25(OH)D=18.7 +/- 6.4 ng/ml). Adherence across supplement and placebo groups was similar (86% and 88%, respectively), and was also similar across groups for the physical activity intervention (75% and 72%, respectively). Both groups demonstrated an improvement in gait speed with no significant difference between those who received the nutritional supplement compared to the placebo (0.071 and 0.108 m/s, respectively (p=0.06)). Similar effects in physical function were observed using the SPPB. Serum 25(OH)D increased in supplemented group compared to placebo 7.4 ng/ml versus 1.3 ng/ml respectively. Results suggest improved gait speed following physical activity program with no further improvement with added nutritional supplementation.
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| 6. |
- von Berens, Åsa, et al.
(författare)
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Physical performance and serum 25(OH)vitamin D status in community dwelling old mobility limited adults : A cross-sectional study
- 2018
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Ingår i: The Journal of Nutrition, Health & Aging. - : Springer Science and Business Media LLC. - 1279-7707 .- 1760-4788. ; 22:1, s. 1-7
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Tidskriftsartikel (refereegranskat)abstract
- Objectives:To examine the potential association between serum 25(OH) vitamin D and theperformance on the Short Physical Performance Battery (SPPB) including the sub-components; five repeatedchair stands test, 4 meters walk test and balance in older mobility-limited community-dwelling men and women.Design:A cross sectional study was performed in American and Swedish subjects who were examined forpotential participation in a combined exercise and nutrition intervention trial. Logistic regression analysis andlinear regression analyses were performed to evaluate the association for 25(OH)D with the overall score onthe SBBP, chair stand, gait speed and balance.Participants:Community-dwelling (mean age 77.6 ± 5.3 years)mobility limited American (n=494) and Swedish (n=116) females (59%) and males.Measurements:The SPPB(0-12 points) includes chair stand (s), gait speed (m/s) and a balance test. Mobility limitation i.e., SPPB score ≤9 was an inclusion criterion. A blood sample was obtained to measure serum 25(OH)vitamin D concentrations.Results:No clear association of 25(OH)D with SPPB scores was detected either when 25(OH)D was assessedas a continuous variable or when categorized according to serum concentrations of <50, 50-75 or <75 nmol/L.However, when analyzing the relationship between 25(OH)D and seconds to perform the chair stands, asignificant quadratic relationship was observed. Thus, at serum levels of 25(OH)D above 74 nmol/L, higherconcentrations appeared to be advantageous for the chair stand test, whereas for serum levels below 74 nmol/Lthis association was not observed.Conclusion: This cross- sectional study lacked clear association betweenserum 25(OH)D and physical performance in mobility limited adults. A potentially interesting observation wasthat at higher serum levels of 25(OH)D a better performance on the chair stand test was indicated.
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