Reproducibility of isokinetic measures of the knee and ankle muscle strength in community-dwelling older adults without and with Alzheimer's disease.

BACKGROUND: To interpret changes of muscle strength in older adults with Alzheimer's disease (AD), determining the reliability of outcome measures is necessary. Therefore, the purpose of the present study was to investigate the relative and absolute intra-rater reliability of concentric isokinetic measures of the knee and ankle muscle strength in community-dwelling older adults without and with AD in the mild and moderate stages. METHODS: A methodological study was conducted. The participants were submitted to two isokinetic evaluations with an interval of three to seven days. The evaluations consisted of knee extension and flexion at 60°/s (five repetitions) and 180°/s (15 repetitions) and plantar flexion and dorsiflexion of the ankle at 30°/s (five repetitions). The measures of interest were peak torque, average peak torque and total work. The intraclass correlation coefficient two-way mixed model of a single-measure (ICC3,1), standard error of measurement (SEM) and minimal detectable change at the 95% confidence interval (MDC95) were calculated. The ICC3,1 was interpreted based on Munro's classification. Standard error of measurement and MDC95 were analyzed in absolute and relative values (percentage of error [SEM%] and change [MDC95%]). RESULTS: A total of 62 older adults were included and allocated to the three groups: mild-AD (n = 22, 79.9 years, 15 female and seven male), moderate-AD (n = 20, 81.6 years, 15 female and five male) and without-AD (n = 20, 74.3 years, 10 female and seven male). The ICCs3,1 of the measures of knee were high/very high in the three groups (0.71-0.98). The ICCs3,1 of the measures of ankle were high/very high in the mild-AD group (0.78-0.92), moderate/high/very high in the moderate-AD group (0.63-0.93) and high/very high in the group without-AD (0.84-0.97). The measurements of knee extensors at 60°/s, knee extensors (peak torque and total work), with the exception of peak torque in the mild-AD group, and flexors (average peak torque) at 180°/s, and ankle dorsiflexors at 30°/s had the lowest of SEM% and MDC95% in the three groups. CONCLUSION: Concentric isokinetic measures are reliable for the assessment of knee and ankle muscle strength in community-dwelling older adults without and with AD in the mild and moderate stages.

Self-management strategies and multicomponent training to mitigate the effects of the interruption of physical exercise programmes in the pandemic context on functionality, sedentary behaviour, physical capacity, mental health, body composition and quality of life in older adults: a blinded randomized controlled study protocol.

BACKGROUND: Considering the confinement recommended by the World Health Organization due to the pandemic caused by COVID-19, many community physical exercise programmes for older adults have had their activities cancelled. In this context, proposing strategies to recover the possible adverse effects of the confinement period is pertinent. The use of self-management strategies associated with regular physical activity reduces sedentary behaviour and improves physical capacity in older adults. Thus, the purpose of this study was to describe a multicomponent training programme combined with a self-management strategy protocol to mitigate the effects of interruptions in physical exercise programmes on functionality, physical capacity, mental health, body composition and quality of life in older adults. METHODS: This will be a blinded, randomized and controlled clinical trial performed in São Carlos, SP, Brazil. Eighty older adults will be divided into two groups: multicomponent training (Multi) and multicomponent training + self-management strategies (Multi+SM). The intervention will be performed over 16 weeks on three alternate days of every week, with 50-min sessions. The assessment of physical capacity will be performed before the interruption of physical exercise programmes (T0: initial assessment, March 2020), preintervention (T1: immediately after the return of the exercise programme) and postintervention (T2). The assessments of physical activity level, quality of life, mental health, functionality and body composition will be performed at T1 and T2. DISCUSSION: The results from this MC+SM protocol will allow us to contribute clinical support to evaluate the variables analysed and to guide future public health policies with the aim of minimizing the possible deleterious effects arising from the physical exercise interruption periods caused by epidemics and pandemics. TRIAL REGISTRATION: RBR-10zs97gk . Prospectively registered in Brazilian Registry of Clinical Trials (ReBEC) on 17 June 2021. Registry name: Use of self-management strategies combined with multicomponent training to mitigate the effects of social distancing due to COVID-19 on capacity, physical capacity, mental health and quality of life in older adults - A blind, randomized and controlled clinical trial.

Reproducibility of Assessment Tests Addressing Body Structure and Function and Activity in Older Adults With Dementia: A Systematic Review.

OBJECTIVE: The purpose of this study was to analyze the relative and absolute reliability of assessment tests addressing body structure and function and activity in older adults with dementia. METHODS: Medline, Embase, Web of Science, The Cochrane Library, and Scielo were searched from inception until March 2021. Two independent reviewers performed the selection process based on titles, abstracts, and full text. Reliability studies of assessment tests in older adults with dementia were included. Methodological quality of the studies was evaluated using the COnsensus-based Standards for the selection of health Measurement INstruments Risk of Bias checklist. Relative reliability was analyzed using the intraclass correlation coefficient (ICC) interpreted based on Munro classification. Absolute reliability was analyzed using the minimal detectable change (MDC) and standard error of measurement. RESULTS: Fifteen studies involving a total of 560 older adults with dementia were included. Nineteen assessment tests were identified: 13 addressing body structure and function (muscle strength, postural balance, cardiorespiratory fitness) and 6 addressing activity (walking and mobility). Studies determined test-retest and interrater reliability. Fifteen studies evaluated relative reliability using the ICC, with values ranging from no or small correlation to very high correlations. Ten studies evaluated absolute reliability using the MDC or standard error of measurement or both. CONCLUSION: Relative reliability of the assessment tests for body structure and function and activity was high to very high based on ICCs, demonstrating good reproducibility. Regarding absolute reliability, the analysis of the MDC values revealed the need for substantial change to determine that a real change had occurred. Future investigations should consider the type of dementia and standardization of verbal encouragement during the assessment. IMPACT: This review identified the good reproducibility of assessment tests of body structure and function (muscle strength, postural balance, cardiorespiratory fitness) and activity (walking and mobility) domains in older adults with dementia. Clinically important values may differ when older adults with dementia of diverse etiologies are analyzed together and older adults specifically with Alzheimer disease. Identifying the type of dementia, analyzing types of dementia separately, and standardizing verbal commands during the execution of tests is of considerable clinical importance for this population of older adults.

Concomitant Evaluation of Heart Period and QT Interval Variability Spectral Markers to Typify Cardiac Control in Humans and Rats.

The variability of heart period, measured as the time distance between two consecutive QRS complexes from the electrocardiogram (RR), was exploited to infer cardiac vagal control, while the variability of the duration of the electrical activity of the heart, measured as the time interval from Q-wave onset to T-wave end (QT), was proposed as an indirect index of cardiac sympathetic modulation. This study tests the utility of the concomitant evaluation of RR variability (RRV) and QT variability (QTV) markers in typifying cardiac autonomic control of humans under different experimental conditions and of rat groups featuring documented differences in resting sympatho-vagal balance. We considered: (i) 23 healthy young subjects in resting supine position (REST) undergoing head-up tilt at 45° (T45) and 90° (T90) followed by recovery to the supine position; (ii) 9 Wistar (WI) and 14 wild-type Groningen (WT) rats in unstressed conditions, where the WT animals were classified as non-aggressive (non-AGG, n = 9) and aggressive (AGG, n = 5) according to the resident intruder test. In humans, spectral analysis of RRV and QTV was performed over a single stationary sequence of 250 consecutive values. In rats, spectral analysis was iterated over 10-min recordings with a frame length of 250 beats with 80% overlap and the median of the distribution of the spectral markers was extracted. Over RRV and QTV we computed the power in the low frequency (LF, from 0.04 to 0.15 Hz in humans and from 0.2 to 0.75 Hz in rats) band (LFRR and LFQT) and the power in the high frequency (HF, from 0.15 to 0.5 Hz in humans and from 0.75 to 2.5 Hz in rats) band (HFRR and HFQT). In humans the HFRR power was lower during T90 and higher during recovery compared to REST, while the LFQT power was higher during T90. In rats the HFRR power was lower in WT rats compared to WI rats and the LFQT power was higher in AGG than in non-AGG animals. We concluded that RRV and QTV provide complementary information in describing the functioning of vagal and sympathetic limbs of the autonomic nervous system in humans and rats.

Dual-Task Performance: Influence of Frailty, Level of Physical Activity, and Cognition.

BACKGROUND AND PURPOSE: Cognition and level of physical activity have been associated with frailty syndrome. The development of tools that assess deficits related to physical and cognitive frailties simultaneously are of common interest. However, little is known about how much these aspects influence the performance of dual-task tests. Our aims were (a) to verify the influence of frailty syndrome and objectively measured physical activity and cognition on the Timed Up and Go (TUG) test and Timed Up and Go associated with dual-task (TUG-DT) performances; and (b) to compare TUG and TUG-DT performances between older adults who develop frailty syndrome. METHODS: Sixty-four community-dwelling older adults were divided into frail, prefrail, and nonfrail groups, according to frailty phenotype. Assessments included anamnesis, screening of frailty syndrome, cognitive assessment (Addenbrooke's Cognitive Examination), placement of a triaxial accelerometer to assess level of physical activity, and TUG and TUG-DT (TUG associated with a motor-cognitive task of calling a phone number) performances. After 7 days, the accelerometer was removed. A multiple linear regression was applied to identify which independent variables could explain performances in the TUG and TUG-DT. Subsequently, the analysis of covariance test, adjusted for age, cognition, and level of physical activity covariates, was used to compare test performances. RESULTS: There were no differences in cognition between groups. Significant differences in the level of physical activity were found in the frail group. Compared with the frail group, the nonfrail group required less time and fewer steps to complete the TUG. Regarding the TUG-DT, cognition and age influenced the time spent and number of steps, respectively; however, no differences were found between groups. CONCLUSIONS: Frail older adults presented worse performance in the TUG when compared with nonfrail older adults. The dual-task test does not differentiate older adults with frailty syndrome, regardless of cognitive performance.

Exercise training in older adults, what effects on muscle oxygenation? A systematic review.

AIM: To determine the effects of different modality of exercise training programs on muscle oxygenation in older adults. METHODS: Relevant articles were searched in PubMed, Web of Science, Science Direct and Scopus, using the keywords: "Aged" AND "Muscle oxygenation" AND (Exercise OR "Exercise therapy" OR "Exercise Movement Techniques" OR Hydrotherapy), without limitation concerning the publication date. To be included in the full analysis, the study had to be a randomized controlled trial in which older adults participants (mean age: 65 years at least) were submitted to an exercise-training program and muscle oxygenation assessment. RESULTS: The searches resulted in 1238 articles from which 7 met all the inclusion criteria. The trials involved 370 older adults (68.7±1.7years), healthy and with peripheral arterial disease. Studies included resistance and endurance exercises as well as walking sessions. Training sessions were 2-6 time per week, lasted 3-24 months and with different training intensity throughout studies. After a long-term resistance training, healthy older adults showed enhanced muscle oxygen extraction capacity, regulation of vessels and vascular endothelium function; endurance training is reported to improve microvascular blood flow and matching of oxygen delivery to oxygen utilization, muscle oxidative capacity and muscle saturation, and walking sessions results in better muscle oxygen availability and muscle oxygen extraction capacity in older adults with peripheral arterial disease. CONCLUSIONS: This review supports the fact that depending on the clinical status of the participants and the modality, exercise training improves different aspects of the muscle oxygenation in older adults.

Effects of the Addition of a Dual Task to a Supervised Physical Exercise Program on Older Adults' Cognitive Performance.

The purpose of this study was to investigate the effects of the addition of a dual task to multicomponent training on cognition of active older adults. Eighty physically active older adults were divided into an intervention group (IG) and a control group (CG). Both groups performed multicomponent training over 12 weeks. The IG simultaneously performed exercises and cognitive tasks. The Mini-Mental State Examination, the Montreal Cognitive Assessment, and the Clock Drawing Test were used for cognitive assessments. The Timed Up and Go Test associated with a cognitive task was used for dual-task assessment. Significant interactions were not observed between groups in terms of the cognitive variables or the dual-task performance. An interaction was observed only for Timed Up and Go Test performance, which was better in the CG than in the IG. Active older adults showed no improvement in cognition following the addition of the dual task to the multicomponent training.

Effect of hormone replacement therapy on cardiac autonomic modulation.

OBJECTIVE: To investigate the effects of hormone replacement therapy (HRT) on heart rate variability (HRV) in healthy postmenopausal women. METHODS: Two groups were evaluated: group 1 (G1): 20 women not undergoing HRT (60 ± 5.89 years), group 2 (G2): 20 women undergoing HRT (59 ± 5.70 years). The HRTs involved were either conjugated equine estrogen with or without medroxyprogesterone, synthetic estrogen hormone, estradiol associated with norethisterone acetate or isoflavonoids. Electrocardiogram was recorded in the supine position for 10 min. Spectral analysis included low and high frequencies in absolute (LF and HF) and normalized units (LFnu and HFnu), which are predominantly cardiac sympathetic modulation (CSM) and cardiac vagal modulation (CVM) indicators, respectively. The LF/HF ratio was also calculated. Symbolic analysis involved the following indexes: 0V % (CSM indicator), 1V % (CSM and CVM indicators), 2LV % (predominantly CVM indicator) and 2UV % (CVM indicator). Shannon and conditional entropies were also calculated. RESULTS: Spectral analysis demonstrated that HRT affected HRV. LF, LFnu and LF/HF ratio were higher (showing increased CSM), while HFnu was lower (representing decreased CVM) in G2 than in G1. Correlations between complexity indices and HFnu were significant and positive only in G1. INTERPRETATION: Women undergoing HRT presented higher CSM and lower CVM than those who were not. Moreover, the expected positive relationship between CVM and complexity of HRV was found only in control group, thus indicating that CVM in women under therapy drop below a minimal value necessary to the association to become apparent, suggesting an unfavorable cardiac autonomic modulation in spite of HRT.