Determinants of physical function in community dwelling old people

Funding Information: The trial is registered at the US National Library of Medicine (No. NCT01074879). Funding Information: This study was part of the IceProQualita project, which was funded by the Icelandic Technology Development Fund (No 071323008), Research Fund of the University of Iceland, a grant from Landspitali University Hospital Research Fund and the Helga Jonsdottir and Sigurlidi Kristjansson Geriatric Research Fund. Publisher Copyright: © 2022, Pacini Editore S.p.A./AU-CNS. All rights reserved.Background. Poor physical function is associated with disability and mortality in old people. Objectives. The aim was to find determinants of physical function in old people. Design. Secondary, cross-sectional analysis. Setting. Community in the Reykjavik, Iceland. Participants. 236 old people (73.7 ± 5.7 years, 58.2% female). Measurements. Timed-up-and-go (TUG), six-minute-walk-for-distance (6MWD), anthropometrics, quadriceps strength, dietary intake, mini-mental-state-examination (MMSE), leisure-time physical activity (LTPA) and blood variables were assessed. Descriptive, bivariate and multivariate statistical analyses were used. Results. There were differences between men and women in energy intake, body composition and muscular strength, but physical function did not differ between men and women. In bivariate analysis, most of the assessed variables correlated with 6MWD and TUG. Stepwise lin-ear models showed that age, body composition, strength, medication, LTPA and MMSE were predictors of physical function but not hematological variables. The association between MMSE and function disappeared when corrected for strength/body weight. Results were similar for both 6MWD and TUG and the strongest predictors in the final models were age and quadriceps strength/body weight. Conclusions. In community dwelling old people, physical function decreases with age. However, it is of clinical relevance that there are modifiable determinants of physical function, in particular strength for a given body weight, LTPA and number of medications, which represent potential targets to maintain physical function in this age group. Our results also indicate that neither cognitive function, nor dietary intake nor blood chemical variables were independently associated with physical function.Peer reviewe

Hemoglobin Concentrations Predict Physical Function After A 12-Week Resistance Exercise Training and Subsequent Changes After 11 Months of Follow-Up Among Community Dwelling Older Adults

Background: Hemoglobin transports oxygen in blood yet its concentrations generally decrease with age. The aim of the study was to examine whether hemoglobin is connected with physical function in older age people. Design: Intervention study. Setting: Community. Participants: Older adults (N=236, 73.7±5.7 years, 58.2% female). Intervention: A 12-week resistance exercise program (3 times/week; 3 sets, 6-8 repetitions at 75-80% of the 1-repetition maximum) was conducted to increase strength and muscle mass of major muscle groups. Measurements: Anthropometrics, muscle strength, timed up and go (TUG in sec), six-minute walking distance (6MWD in m) and blood chemical variables were measured at baseline, endpoint and after 10.7 months followup. The linear regression model was used to examine the association between baseline hemoglobin and physical function outcome. Results: Only about 4% of the participants were anemic. According to calculations baseline hemoglobin was associated with TUG (0.14 to 0.36 sec improvement by 10 g/L increase of hemoglobin) at all-time points, even though this was of borderline significance for baseline (p=0.57) and endpoint (p=0.062). Hemoglobin also predicted endpoint 6 MWD (4.88m), but not at baseline (follow up 6 MWD was not available). Statistical correction for compliance did not influences results. Conclusion: Hemoglobin is positively associated to physical function in community dwelling old aged people. Additionally, we found that baseline hemoglobin is associated to adaptions to 12-week resistance exercise training and changes in physical function during the follow-up.Rannís (No 071323008), Rannsóknarsjóður Háskóla Íslands, Styrkur frá Landspítala Hákólasjúkrahúsi Helga Jonsdottir and Sigurlidi Kristjansson Geriatric Research Fund.Peer Reviewe

BAFFR activates PI3K/AKT signaling in human naive but not in switched memory B cells through direct interactions with B cell antigen receptors.

Binding of BAFF to BAFFR activates in mature B cells PI3K/AKT signaling regulating protein synthesis, metabolic fitness, and survival. In humans, naive and memory B cells express the same levels of BAFFR, but only memory B cells seem to survive without BAFF. Here, we show that BAFF activates PI3K/AKT only in naive B cells and changes the expression of genes regulating migration, proliferation, growth, and survival. BAFF-induced PI3K/AKT activation requires direct interactions between BAFFR and the B cell antigen receptor (BCR) components CD79A and CD79B and is enhanced by the AKT coactivator TCL1A. Compared to memory B cells, naive B cells express more surface BCRs, which interact better with BAFFR than IgG or IgA, thus allowing stronger responses to BAFF. As ablation of BAFFR in naive and memory B cells causes cell death independent of BAFF-induced signaling, BAFFR seems to act also as an intrinsic factor for B cell survival

Telephone conversation impairs sustained visual attention via a central bottleneck

Recent research has shown that holding telephone conversations disrupts one's driving ability. We asked whether this effect could be attributed to a visual attention impairment. In Experiment 1, participants conversed on a telephone or listened to a narrative while engaged in multiple object tracking (MOT), a task requiring sustained visual attention. We found that MOT was disrupted in the telephone conversation condition, relative to single-task MOT performance, but that listening to a narrative had no effect. In Experiment 2, we asked which component of conversation might be interfering with MOT performance. We replicated the conversation and single-task conditions of Experiment 1 and added two conditions in which participants heard a sequence of words over a telephone. In the shadowing condition, participants simply repeated each word in the sequence. In the generation condition, participants were asked to generate a new word based on each word in the sequence. Word generation interfered with MOT performance, but shadowing did not. The data indicate that telephone conversation disrupts attention at a central stage, the act of generating verbal stimuli, rather than at a peripheral stage, such as listening or speaking

Developmental Aspects of Children's Behavior and Safety While Cycling

Objective To examine children's competence while cycling, as demonstrated in mistakes in performance and failure to comply with safety rules. Methods Children in three age groups (8, 10, and 12 years) participated in a realistic yet simulated traffic environment. Results The boys' cycling speed increased steadily with age, while that of the girls increased from 8 to 10 but decreased at age 12. Most children had adequate motor control by age 10, and the youngest compensated for their less developed skills by cycling slowly and braking early at junctions. Serious mistakes, often related to the children's age and gender, consisted of the children failing to stop at signals or stopping too late, especially at short stopping range. Conclusions There are considerable individual differences in children's cycling competence that are related to biological factors, such as age and gender, and psychological factors, such as rule compliance and choice of cycling speed

Monomelic amyotrophy associated with the 7472insC mutation in the mtDNA tRNA Ser(UCN) gene

We describe a 49-year-old male patient who experienced progressive amyotrophy with no sensorial abnormality in the left arm since 45 years of age. The neuromuscular syndrome was identical to that known as Hirayama disease, a rare form of focal lower motor neuron disease affecting the C7-C8-T1 metamers of the spinal cord. Asymmetric neurosensorial hearing loss was present since age 35 in the patient, and was also documented in an elder sister and in the mother. A muscle biopsy showed cytochrome c oxidase (COX) negative fibers but no ragged-red fibers, and mild reduction of COX was confirmed biochemically. The patient was found to have high levels of a known pathogenic mutation of mtDNA, the 7472insC in the gene encoding the tRNA Ser(UCN). Investigation on several family members showed a correlation between mutation load and clinical severity. This is the second report documenting the association of lower motor neurone involvement with a specific mtDNA. \ua9 2004 Elsevier B.V. All rights reserved

Muscular strength and physical function in elderly adults 6-18 months after a 12-week resistance exercise program.

Neðst á síðunni er hægt að nálgast greinina í heild sinni með því að smella á hlekkinn View/OpenBenefits of resistance exercise in elderly people are well documented; however, sustaining these benefits can be difficult and adherence is often poor. Muscular strength and physical function usually decline after a supervised resistance exercise program (REP). We investigated these changes in older adults during an observational follow-up and whether leisure time physical activity (LTPA) or unsupervised resistance exercise (RE) limit these changes.Subjects (N=236, 73.7±5.7 years, 58.2% female) had participated in a supervised 12-week REP. Quadriceps strength and timed-up-and-go performance (TUG) at follow-up were compared to values before and after REP. Multivariate statistics were used to predict changes in strength or function.Two hundred and eleven (90.3%) participants completed REP and 149 (63.1%) completed follow-up (11.4±2.9 months). Quadriceps strength at follow-up decreased significantly compared to after REP (-27N), but was higher than before REP (+30N). TUG did not decrease during follow-up and was better than before REP (-0.9 seconds). LTPA (+38.0N, p<0.001) and RE (+31.6N, p=0.006) predicted strength at follow-up, although they did not completely prevent loss of strength during follow-up. CONCLUSIONS QUADRICEPS STRENGTH DECLINES AFTER A 12-WEEK RESISTANCE EXERCISE PROGRAM IN OLDER ADULTS NEITHER LTPA NOR RE COMPLETELY PREVENTS LOSS OF QUADRICEPS STRENGTH DURING FOLLOW-UP, ALTHOUGH THEY LIMITED THE LOSS TUG DID NOT CHANGE DURING FOLLOW-UP AND WAS BETTER AT FOLLOW-UP THAN BEFORE THE START OF THE RESISTANCE EXERCISE PROGRAM:IceProQualita project, the Icelandic Technology Development Fund (No 071323008), Research Fund of the University of Iceland, Landspitali University Hospital Research Fund, Helga Jonsdottir and Sigurlidi Kristjansson Geriatric Research Fund

Gender, Success, and Drop-Out during a Resistance Exercise Program in Community Dwelling Old Adults

Background. Resistance exercise training can be effective against sarcopenia. We identified predictors of drop-out and compared physical outcomes between men and women after such training. Methods. Subjects (N=236, 73.7±5.7 years) participated in a 12-week resistance exercise program. Outcome variables were measured at baseline and endpoint. Results. Drop-out was 11.9% and not significantly different between genders. Drop-outs were significantly older and had poorer strength and physical function in comparison to completers. Anthropometrics, QoL, and cognitive function were not related to drop-out. According to multivariate analysis, gait speed and physical activity were the strongest predictors of drop-out. After the training, gains in lean mass or appendicular muscle were significantly higher in men than women; however relative gains in appendicular muscle as well as absolute improvements in strength and function were similar in men and women, respectively. Conclusions. Participants who drop out are older, have poorer physical function, and are less physically active. Old women do not drop out more frequently than men and show meaningful improvements in relevant outcomes similar to men after such a training program. The trial is registered at the US National Library of Medicine (NCT01074879)