Tony Mets

The feasibility of whole body vibration in institutionalised elderly persons and its influence on muscle performance, balance and mobility: a randomised controlled trial [ISRCTN62535013]

BackgroundFatigue or lack of interest can reduce the feasibility of intensive physical exercise in nursing home residents. Low-volume exercise interventions with similar training effects might be an alternative. The aim of this randomised controlled trial was to investigate the feasibility of Whole Body Vibration (WBV) in institutionalised elderly, and its impact on functional capacity and muscle performance.MethodsTwenty-four nursing home residents (15 female, 9 male; mean age 77.5 ± 11.0 years) were randomised (stratification for age, gender and ADL-category) to 6 weeks static WBV exercise (WBV+, N = 13) or control (only static exercise; N = 11). Outcome measures were exercise compliance, timed up-and-go, Tinetti-test, back scratch, chair sit-and-reach, handgrip strength and linear isokinetic leg extension.ResultsAt baseline, WBV+ and control groups were similar for all outcome variables. Twenty-one participants completed the program and attended respectively 96% and 86% of the exercise sessions for the WBV+ and control groups. Training-induced changes in timed up-and-go and Tinetti-test were better for WBV+ compared to control (p = 0.029 for timed up-and-go, p = 0.001 and p = 0.002 for Tinetti body balance and total score respectively). In an alternative analysis (Worst Rank Score & Last Observation Carried Forward) the differences in change remained significant on the Tinetti body balance and total score. No other significant differences in change between both groups were observed.ConclusionIn nursing home residents with limited functional dependency, six weeks static WBV exercise is feasible, and is beneficial for balance and mobility. The supplementary benefit of WBV on muscle performance compared to classic exercise remains to be explored further.

Chronic low-grade inflammation and age-related sarcopenia.

Purpose of reviewAge-related chronic low-grade inflammatory profile (CLIP) has been recognized as an important causative factor for sarcopenia. Here, we report the recent evidence concerning CLIP and sarcopenia. Recent findingsTwenty-one studies were included (12 observational, five interventional studies and four randomized controlled trials). Observational studies strengthen the association between CLIP and sarcopenia in cross-sectional and longitudinal designs. Interleukin (IL)-6 and tumour necrosis factor-&agr; are the most reported inflammatory parameters. Biopsy studies confirm the role of oxidative mechanisms, protein kinase B and nuclear factor kappa-light-chain-enhancer of activated B cells pathways and implicate stress response mechanisms and heat shock protein. Adipose tissue as source of inflammatory cytokines remains unclear and correction for fat mass is advisable in new research. Exercise interventions (both aerobic and resistance training) demonstrate beneficial effects on CLIP even in the absence of decreases in weight, BMI or fat mass. IL-6 is also released during exercise, in hormone-like fashion unrelated to inflammation, and exercise-induced IL-6 changes require careful interpretation. Soy supplementation in one study showed no influence on CLIP and no recent pharmacological trials were retrieved. SummaryAssociations between CLIP and sarcopenia are observed quite consistently and underlying mechanisms become apparent. Exercise remains the mainstay intervention to lower CLIP and counter sarcopenia. More research is warranted to unravel the exact dose–response relationship.

Motivators and barriers for physical activity in the oldest old: A systematic review

Worldwide, people engage insufficiently in physical activity, particularly subjects aged 80 years and over. For optimal life-style campaigns, knowledge of motivators and barriers for physical activity is mandatory. Given their specific needs, it is conceivable that these would be different for the oldest old compared to younger subjects. Pubmed, Web of Science and Psychinfo were systematically screened for articles reporting motivators and barriers for physical activity. Papers were excluded if data regarding elderly aged >79 years were absent. Forty-four relevant articles were included, involving a total of 28,583 subjects. Sixty one motivators and 59 barriers for physical activity in the elderly were identified, including those who are relevant for persons aged 80 years and over. Based on the results of our literature review, we recommend that when promoting physical activity in the oldest old, special attention is paid to the health benefits of physical activity, to the subjects fears, individual preferences and social support, and to constraints related to the physical environment. However, no studies were found exclusively describing people aged 80 years and over, and future research is necessary to differentiate the barriers or motivators that are specific for the oldest old from those of younger elderly.

The six-minute walk test in community dwelling elderly: influence of health status.

BackgroundThe 6 minutes walk test (6MWT) is a useful assessment instrument for the exercise capacity of elderly persons. The impact of the health status on the 6MWT-distance in elderly, however, remains unclear, reducing its value in clinical settings. The objective of this study was to investigate to what extent the 6MWT-distance in community dwelling elderly is determined by health conditions.MethodsOne hundred and fifty-six community dwelling elderly people (53 male, 103 female) were assessed for health status and performed the 6MWT. After clinical evaluation, electrocardiography and laboratory examination participants were categorized into a stratified six-level classification system according to their health status, going from A (completely healthy) to D (signs of active disease at the moment of examination).ResultsThe mean 6MWT-distance was 603 m (SD = 178). The 6MWT-distance decreased significantly with increasing age (ANOVA p = 0.0001) and with worsening health status (ANCOVA, corrected for age p < 0.001).A multiple linear regression model with health status, age and gender as independent variables explained 31% of the 6MWT-distance variability. Anthropometrical measures (stature, weight and BMI) did not significantly improve the prediction model. A significant relationship between 6MWT-distance and stature was only present in category A (completely healthy).ConclusionsSignificant differences in 6MWT-distance are observed according to health status in community-dwelling elderly persons. The proposed health categorizing system for elderly people is able to distinguish persons with lower physical exercise capacity and can be useful when advising physical trainers for seniors.

In vitro aging of human bone marrow derived stromal cells

We have studied the in vitro cellular aging process in human bone marrow derived stromal cells. Two cell types, here called type I and type II, can be distinguished in the primary cell population. During subcultivation, resulting in aging in vitro, the type I cells gradually disappear, whereas the type II cells form an increasing fraction of the population. This observation is confirmed by cloning experiments, revealing that type I cells act as progenitor cells, giving rise to non-dividing type II cells. These results are best explained by the terminal differentiation theory as proposed by Martin et al.

Handgrip performance in relation to self-perceived fatigue, physical functioning and circulating IL-6 in elderly persons without inflammation

BackgroundLow grip strength is recognized as one of the characteristics of frailty, as are systemic inflammation and the sensation of fatigue. Contrary to maximal grip strength, the physical resistance of the muscles to fatigue is not often included in the clinical evaluation of elderly patients. The aim of this study was to investigate if the grip strength and the resistance of the handgrip muscles to fatigue are related to self-perceived fatigue, physical functioning and circulating IL-6 in independently living elderly persons.MethodsForty elderly subjects (15 female and 25 male, mean age 75 ± 5 years) were assessed for maximal grip strength, as well as for fatigue resistance and grip work (respectively time and work delivered until grip strength drops to 50% of its maximum during sustained contraction), self perceived fatigue (VAS-Fatigue, Mob-Tiredness scale and the energy & fatigue items of the WHOQOL-100), self rated physical functioning (domain of physical functioning on the MOS short-form) and circulating IL-6. Relationships between handgrip performance and the other outcome measures were assessed.ResultsIn the male participants, fatigue resistance was negatively related to actual sensation of fatigue (VAS-F, p < .05) and positively to circulating IL-6 (p < .05). When corrected for body weight, the relations of fatigue resistance with self-perceived fatigue became stronger and also apparent in the female. Grip strength and grip work were significantly related with several items of self-perceived fatigue and with physical functioning. These relations became more visible by means of higher correlation coefficients when grip strength and grip work were corrected for body weight.ConclusionWell functioning elderly subjects presenting less handmuscle fatigue resistance and weaker grip strength are more fatigued, experience more tiredness during daily activities and are more bothered by fatigue sensations. Body weight seems to play an important role in the relation of muscle performance to fatigue perception. Elderly patients complaining from fatigue should be physically assessed, both evaluating maximal grip strength and fatigue resistance, allowing the calculation of grip work, which integrates both parameters. Grip work might best reflect the functional capacity resulting from the development of a certain strength level in relation to the time it can be maintained.

Reliability and clinical correlates of 3D-accelerometry based gait analysis outcomes according to age and fall-risk

PURPOSE To investigate the reliability of a 3D-accelerometry based gait analysis, and its correlates with clinical status and fall-risk. METHODS Forty elderly subjects presenting with increased fall-risk (OFR), 41 elderly controls (OC) and 40 young controls (aged 80.6±5.4, 79.1±4.9 and 21.6±1.4 years respectively) underwent three gait evaluations (two assessors in random order) each containing two walks of 18 m with a DynaPort MiniMod accelerometer on the pelvis. Intra- and inter-observer reliability of gait speed, step-time asymmetry, mediolateral and craniocaudal step and stride regularity were determined by ICC and CV of standard error of measurement (CV(SEM)). Relationships with cognition (MMSE), dependency, grip strength, muscle endurance, and fall-risk (fall-history, timed-get-up-and-go and Tinetti-test) were analysed in elderly participants. RESULTS Reliability for single walk was low (ICC<0.70, 11%<CV(SEM)<23%), except for mediolateral step regularity (0.70≤ICC<0.80) and gait speed (ICC>0.80, CV(SEM)<7%), but high (ICC>0.70, 4%<CV(SEM)<20%) when based on the mean of two walks; except for step-time asymmetry (42%<CV(SEM)<77%). Compared to OC, OFR showed significantly (p<0.05) slower gait speed, and worse step and stride regularity. Gait speed, step-time asymmetry, step and stride regularity related significantly (p<0.05) with several functional outcomes. Besides gait speed (1.158 m/s, 78% sensitivity and 78% specificity), none of the gait features showed sufficient discriminative capacity according to fall-risk. CONCLUSIONS In all participants together, 3D-accelerometry based gait speed and regularity showed high reliability when based on two walks of 18 m. Relationships with functional characteristics support the validity of gait variability features in elderly persons. More fundamental and prospective research is necessary to clarify their clinical value.

Reaction Times and Performance Variability in Normal Aging, Mild Cognitive Impairment, and Alzheimer's Disease:

This study evaluated whether reaction times (RT) and performance variability are potential markers for the early detection of Alzheimers disease (AD). Cognitively healthy elderly (n = 218), persons with amnestic MCI (a-MCI) (n = 29) and patients with AD (n = 50) were examined with RT tasks with increasing complexity, subdividing RT into a decision and a movement component. Persons with cognitive deterioration demonstrated more intra-individual variability and more slowing than cognitively healthy elderly. The slowing in AD affects both the cognitive and the motor component, while performance variability mainly affects the cognitive component of the RT. Although in a-MCI not all differences reached statistical significance, primarily the cognitive component of the RT is affected in a-MCI. Intra-individual variability and RT of the complex tasks are the best predictors for a-MCI and AD status, respectively. We conclude that performance variability can be regarded as a useful preclinical marker for AD.

Elevated serum heat-shock protein 70 levels in patients with acute infection: use of an optimized enzyme-linked immunosorbent assay.

Heat‐shock proteins (Hsps) are highly conserved throughout evolution and evoke great interest both in basic biology and in medicine. They are expressed in small quantities under normal conditions, and their expression can be strongly induced by several stressors. Although their action is basically intracellular, it is now obvious that these proteins can be released into the extracellular environment from viable cells. In this study, the human Hsp 70 serum concentrations were determined using an optimized, cost‐effective enzyme‐linked immunosorbent assay (ELISA). The average intra‐assay variation was 6%, whereas the average interassay variation was 9%. The sensitivity of the assay was 10 ng/ml, and spiking experiments showed recoveries between 101 and 109%. As an application of the technique, we have investigated the serum levels of human Hsp 70 in patients with infection and in healthy subjects. Our data show significantly higher levels of Hsp 70 (P  = 0.003) in patients compared to control subjects. Positive correlations were noticed between the serum levels of Hsp 70 and various markers of inflammation (IL‐6; r = 0.579, P = 0.009, TNF‐α; r  = 0.552, P  = 0.012, IL‐10; r  = 0.361, P = 0.002). We conclude that Hsp 70 is involved in inflammation of infectious origin. The interindividual variation in the serum concentration of Hsp 70 precludes the use of serum Hsp 70 levels to distinguish patients from healthy subjects.

Drug-induced orthostatic hypotension in the elderly: avoiding its onset.

SummaryThe prevalence of orthostatic hypotension in the elderly is reported to be 5 to 33%. This high prevalence contributes to the risk of syncope and falls in old age.Drugs are a major cause of postural hypotension. Changes in pharmacokinetics and pharmacodynamics occur with aging in relation to many drugs, resulting in delayed elimination and increased bioavailability. Therefore, drugs with an antihypertensive action (diuretics, calcium antagonists, β-blockers, ACE inhibitors, α1-blockers, and centrally acting antihypertensives) have a more pronounced effect in the elderly. Nitrates, antiparkinsonian drugs, antidepressants and antipsychotics all cause hypotension as a known adverse effect.When assessing orthostatic hypotension in the elderly, drug treatment should always be reviewed. Whenever possible, antihypertensive drugs should be discontinued, and the dosages of essential drugs should be reduced.