Moderate-to-vigorous physical activity modifies the relationship between sedentary time and sarcopenia: the Tromsø Study 2015–2016

Background: Sarcopenia is an age-related muscle disease primarily characterized by reductions in muscle strength that increases the risk of falls, fractures, cognitive impairment, and mortality. Exercise is currently preferred in prevention and treatment, but it is unknown how different habitual physical activity and sedentary behaviour patterns associate with sarcopenia status. The purpose of the present study was to compare associations of these patterns with probable sarcopenia in older adults. Methods: In 3653 community-dwelling participants (51% women) aged 60–84 years from the seventh survey of the Tromsø Study, we assessed objective physical activity and sedentary behaviour collected over 8 days (ActiGraph wGT3X-BT Accelerometer), grip strength (Jamar+ Digital Dynamometer), five-repetition chair stands, and self-reported disease. We combined tertiles of sedentary (SED) time and moderate-to-vigorous physical activity (MVPA) to create nine different activity profiles (SEDHIGH, SEDMOD, and SEDLOW combined with MVPAHIGH, MVPAMOD, or MVPALOW). Multiple logistic regression models were used to examine how these profiles associated with probable sarcopenia, defined by low handgrip strength and/or slow chair stands time according to the revised European Working Group on Sarcopenia in Older People criteria. Results: Probable sarcopenia was present in 227 (6.2%) participants. Men with probable sarcopenia had on average 35.3 min more SED time and 20 min less MVPA compared with participants without sarcopenia (P HIGH–MVPALOW reference activity profile (714.2 min SED/day and 10.4 min MVPA/day), the SEDHIGH–MVPAMOD profile (697.1 min SED/day and 31.5 min MVPA/day) had significantly lower odds ratio (OR) for probable sarcopenia (OR 0.17, 95% confidence interval [CI] 0.08–0.35), while the SEDLOW–MVPALOW profile (482.9 min SED/day and 11.0 min MVPA/day) did not (OR 0.72, 95% CI 0.47–1.11). These findings were not influenced by age, sex, smoking, or self-reported diseases, and higher levels of MVPA did not further decrease ORs for probable sarcopenia. Conclusions: Older adults who achieve moderate amounts of MVPA have reduced odds for probable sarcopenia, even when they have high sedentary time. Those with low sedentary time did not have reduced odds for probable sarcopenia when they also had low amounts of MVPA. These findings need confirmation in longitudinal studies but suggest that interventions for preventing sarcopenia should prioritize increasing MVPA over reducing sedentary behaviour

Synergies, Strengths and Challenges: Findings on Community Capability from a Systematic Health Systems Research Literature Review

Background: Community capability is the combined influence of a community’s social systems and collective resources that can address community problems and broaden community opportunities. We frame it as consisting of three domains that together support community empowerment: what communities have; how communities act; and for whom communities act. We sought to further understand these domains through a secondary analysis of a previous systematic review on community participation in health systems interventions in low and middle income countries (LMICs). Methods: We searched for journal articles published between 2000 and 2012 related to the concepts of “community”, “capability/participation”, “health systems research” and “LMIC.” We identified 64 with rich accounts of community participation involving service delivery and governance in health systems research for thematic analysis following the three domains framing community capability. Results: When considering what communities have, articles reported external linkages as the most frequently gained resource, especially when partnerships resulted in more community power over the intervention. In contrast, financial assets were the least mentioned, despite their importance for sustainability. With how communities act, articles discussed challenges of ensuring inclusive participation and detailed strategies to improve inclusiveness. Very little was reported about strengthening community cohesiveness and collective efficacy despite their importance in community initiatives. When reviewing for whom communities act, the importance of strong local leadership was mentioned frequently, while conflict resolution strategies and skills were rarely discussed. Synergies were found across these elements of community capability, with tangible success in one area leading to positive changes in another. Access to information and opportunities to develop skills were crucial to community participation, critical thinking, problem solving and ownership. Although there are many quantitative scales measuring community capability, health systems research engaged with community participation has rarely made use of these tools or the concepts informing them. Overall, the amount of information related to elements of community capability reported by these articles was low and often of poor quality. Conclusions: Strengthening community capability is critical to ensuring that community participation leads to genuine empowerment. Our simpler framework to define community capability may help researchers better recognize, support and assess it

The unsupported upper limb exercise test in people without disabilities: assessing the within-day test–retest reliability and the effects of age and gender

Purpose: To estimate the within-day test–retest reliability and standard error of measurement (SEM) of the unsupported upper limb exercise test (UULEX) in adults without disabilities and to determine the effects of age and gender on performance of the UULEX. Method: A cross-sectional study was conducted with 100 adults without disabilities (44 men, mean age 44.2 [SD 26] y; 56 women, mean age 38.1 [SD 24.1] y). Participants performed three UULEX tests to establish within-day reliability, measured using an intra-class correlation coefficient (ICC) model 2 (two-way random effects) with a single rater (ICC[2,1]) and SEM. The effects of age and gender were examined using two-factor mixed-design analysis of variance (ANOVA) and one-way repeated-measures ANOVA. For analysis purposes, four sub-groups were created: younger adults, older adults, men, and women. Results: Excellent within-day reliability and a small SEM were found in the four sub-groups (younger adults: ICC[2,1]=0.88; 95% CI: 0.82, 0.92; SEM∼40 s; older adults: ICC[2,1]=0.82; 95% CI: 0.72, 0.90; SEM∼50 s; men: ICC[2,1]=0.93; 95% CI: 0.88, 0.96; SEM∼30 s; women: ICC[2,1]=0.85; 95% CI: 0.78, 0.91; SEM∼45 s). Younger adults took, on average, 308.24 seconds longer than older adults to perform the test; older adults performed significantly better on the third test (p0.05). Conclusion: The within-day test–retest reliability and SEM values of the UULEX may be used to define the magnitude of the error obtained with repeated measures. One UULEX test seems to be adequate for younger adults to achieve reliable results, whereas three tests seem to be needed for older adults.Objectif : évaluer la fiabilité d'un test-retest en une même journée et l'erreur type de mesure (ETM) du test d'exercice des membres supérieurs sans appui (UULEX) chez des adultes sans incapacités et déterminer les effets de l'âge et du sexe sur leur exécution. Méthodologie : les chercheurs ont réalisé une étude transversale auprès de 100 adultes sans incapacités (44 hommes, d'un âge moyen de 44,2 ans [ÉT 26], et 56 femmes, d'un âge moyen de 38,1 ans [ÉT 24,1]). Les participants ont effectué trois UULEX pour établir la fiabilité du test-retest en une même journée, mesurés à l'aide du modèle 2 de coefficient de corrélation intraclasse (ICC, effets aléatoires bilatéraux) comportant un ICC(2,1) et une ETM à un seul évaluateur. Les chercheurs ont examiné les effets de l'âge et du sexe à l'aide d'une analyse de variance bifactorielle à mesures mixtes et d'une analyse de variance unifactorielle à mesures répétées. Pour les besoins de l'analyse, les chercheurs ont créé quatre sous-groupes: jeunes adultes, adultes plus âgés, hommes et femmes. Résultats : les quatre sous-groupes affichaient une excellente fiabilité en une même journée et une petite ETM (jeunes adultes: ICC[2,1]=0,88 [IC 95% : 0,82, 0,92] et ETM∼40 secondes; adultes plus âgés : ICC[2,1]=0,82 [IC 95 % : 0,72, 0,90] et ETM∼50 secondes; hommes: ICC[2,1]=0,93 [IC 95% : 0,88, 0,96] et ETM∼30 secondes; femmes: ICC[2,1]=0,85 [IC 95 % : 0,78, 0,91] et ETM∼45 secondes). En moyenne, les jeunes adultes ont effectué le test pendant 308,24 secondes de plus que les adultes plus âgés; ceux-ci ont obtenu un résultat nettement meilleur au troisième test (p0,05). Conclusion : il est possible d'utiliser la fiabilité de test-retest en une même journée et les valeurs d'ETM de l'UULEX pour définir l'importance de l'erreur obtenue lors de mesures répétées. Un UULEX semble suffire pour que les jeunes adultes obtiennent des résultats fiables, tandis que trois tests semblent nécessaires chez les adultes plus âgés

Adiposity and grip strength as long-term predictors of objectively measured physical activity in 93 015 adults: the UK Biobank study

BACKGROUND/OBJECTIVES: Fatness and fitness are associated with physical activity (PA) but less is known about the prospective associations of adiposity and muscle strength with PA. This study aimed to determine longitudinal associations of body mass index (BMI), waist circumference (WC) and grip strength (GS) with objectively measured PA. SUBJECTS/METHODS: Data are from the UK Biobank study. At baseline (2006-2010), BMI, WC and GS were objectively measured. At follow-up (2013-2015), a sub-sample of 93 015 participants (52 161 women) wore a tri-axial accelerometer on the dominant wrist for 7 days. Linear regression was performed to investigate longitudinal associations of standardised BMI, WC and GS at baseline with moderate-to-vigorous PA (MVPA) and acceleration after a median 5.7-years follow-up (interquartile range: 4.9-6.5 years). RESULTS: Linear regression revealed strong inverse associations for BMI and WC, and positive associations for GS with follow-up PA; in women, MVPA ranges from lowest to highest quintiles of GS were 42-48 min day(-1) in severely obese (BMI⩾35 kg m(-)(2)), 52-57 min day(-1) in obese (30⩽BMI<35 kg m(-)(2)), 61-65 min day(-1) in overweight (25⩽BMI<30 kg m(-)(2)) and 69-75 min day(-1) in normal weight (18.5⩽BMI<25 kg m(-2)). Follow-up MVPA was also lower in the lowest GS quintile (42-69 min day(-1)) compared with the highest GS quintile (48-75 min day(-1)) across BMI categories in women. The pattern of these associations was generally consistent for men, and in analyses using WC and mean acceleration as exposure and outcome, respectively. CONCLUSIONS: More pronounced obesity and poor strength at baseline independently predict lower activity levels at follow-up. Interventions and policies should aim to improve body composition and muscle strength to promote active living.International Journal of Obesity advance online publication, 6 June 2017; doi:10.1038/ijo.2017.122.This work was supported by the UK Medical Research Council (MC_UU_12015/3), a PhD studentship from MedImmune (to TW), and an Intermediate Basic Science Research Fellowship of British Heart Foundation (FS/12/58/29709 to KW). No financial disclosures were reported by the authors of this paper. This research has been conducted using the UK Biobank Resource under Application Numbers 262 and 12885

Positron analysis of defects in metals

New methods are discussed to improve defect analysis. The first method employs mapping of two shape parameters, S and W, of the positron annihilation photopeak. It is demonstrated that the combined use of S and W allows to a better discrimination of defects. The other method is based on background suppression and resolution improvement by the use of two detectors in coincidence. This opens possibilities for characterizing defects by element specific contributions to the momentum distribution of the annihilating e(+)e(-) pair, Examples are given of vacancies in Al-nitride precipitates in iron and manganese oxide precipitates in silver