Effects of low- and high-intensity physical exercise on physical and cognitive function in older persons with dementia: a randomized controlled trial.

BACKGROUND: Potential moderators such as exercise intensity or apolipoprotein-E4 (ApoE4) carriership may determine the magnitude of exercise effects on physical and cognitive functions in patients with dementia (PwD). We determined the effects of a 24-week aerobic and strength training program with a low- and high-intensity phase on physical and cognitive function. METHODS: In an assessor-blinded randomized trial, 91 PwD (all-cause dementia, recruited from daycare and residential care facilities, age 82.3 ± 7.0 years, 59 women, Mini-Mental State Examination 20.2 ± 4.4) were allocated to the exercise or control group. In the exercise group, PwD participated in a walking and lower limb strength training program with 12 weeks low- and 12 weeks high-intensity training offered three times/week. Attention-matched control participants performed flexibility exercises and recreational activities. We assessed adherence, compliance, and exercise intensity for each session. We assessed physical (endurance, gait speed, mobility, balance, leg strength) and cognitive (verbal memory, visual memory, executive function, inhibitory control, psychomotor speed) functions with performance-based tests at baseline and after 6, 12, 18, 24, and 36 weeks (follow-up). ApoE4 carriership was determined post-intervention. RESULTS: Sixty-nine PwD were analyzed. Their mean attendance was ~ 60% during the study period. There were no significant effects of the exercise vs. control intervention on endurance, mobility, balance, and leg strength in favor of the exercise group (Cohen's d = 0.13-0.18). Gait speed significantly improved with ~ 0.05 m/s after the high-intensity phase for exercise participants (Cohen's d = 0.41) but declined at follow-up. There were no significant effects of the exercise vs. control intervention on any of the cognitive measures (Cohen's d ~ - 0.04). ApoE4 carriership did not significantly moderate exercise effects on physical or cognitive function. CONCLUSIONS: Exercise was superior to control activities for gait speed in our sample of PwD. However, the training effect provided no protection for mobility loss after detraining (follow-up). There were no beneficial effects of the exercise vs. control group on cognitive function. Exercise intensity moderated the effects of exercise on gait speed. ApoE4 carriership moderated the effect of exercise on global cognition only (trend level). TRIAL REGISTRATION: Netherlands Trial Register, NTR5035. Registered on 2 March 2015.

Burrowing as a novel voluntary strength training method for mice: A comparison of various voluntary strength or resistance exercise methods.

BACKGROUND: Voluntary strength training methods for rodents are necessary to investigate the effects of strength training on cognition and the brain. However, few voluntary methods are available. NEW METHOD: The current study tested functional and muscular effects of two novel voluntary strength training methods, burrowing (digging a substrate out of a tube) and unloaded tower climbing, in male C57Bl6 mice. To compare these two novel methods with existing exercise methods, resistance running and (non-resistance) running were included. Motor coordination, grip strength and muscle fatigue were measured at baseline, halfway through and near the end of a fourteen week exercise intervention. Endurance was measured by an incremental treadmill test after twelve weeks. RESULTS: Both burrowing and resistance running improved forelimb grip strength as compared to controls. Running and resistance running increased endurance in the treadmill test and improved motor skills as measured by the balance beam test. Post-mortem tissue analyses revealed that running and resistance running induced Soleus muscle hypertrophy and reduced epididymal fat mass. Tower climbing elicited no functional or muscular changes. COMPARISON WITH EXISTING METHODS: As a voluntary strength exercise method, burrowing avoids the confounding effects of stress and positive reinforcers elicited in forced strength exercise methods. Compared to voluntary resistance running, burrowing likely reduces the contribution of aerobic exercise components. CONCLUSIONS: Burrowing qualifies as a suitable voluntary strength training method in mice. Furthermore, resistance running shares features of strength training and endurance (aerobic) exercise and should be considered a multi-modal aerobic-strength exercise method in mice.

Relationship between drug burden and physical and cognitive functions in a sample of nursing home patients with dementia.

PURPOSE: The Drug Burden Index (DBI) is a tool to quantify the anticholinergic and sedative load of drugs. Establishing functional correlates of the DBI could optimize drug prescribing in patients with dementia. In this cross-sectional study, we determined the relationship between DBI and cognitive and physical functions in a sample of patients with dementia. METHODS: Using performance-based tests, we measured physical and cognitive functions in 140 nursing home patients aged over 70 with all-cause dementia. We also determined anticholinergic DBI (AChDBI) and sedative DBI (SDBI) separately and in combination as total drug burden (TDB). RESULTS: Nearly one half of patients (48%) used at least one DBI-contributing drug. In 33% of the patients, drug burden was moderate (0 < TDB < 1) whereas in 15%, drug burden was high (TDB ≥ 1). Multivariate models yielded no associations between TDB, AChDBI, and SDBI, and physical or cognitive function (all p > 0.05). CONCLUSIONS: A lack of association between drug burden and physical or cognitive function in this sample of patients with dementia could imply that drug prescribing is more optimal for patients with dementia compared with healthy older populations. However, such an interpretation of the data warrants scrutiny as several dementia-related factors may confound the results of the study.

[Pain and physical (in)activity in relation to cognition and behaviour in dementia]. / Pijn en bewegen in relatie tot cognitie en gedrag bij dementie.

Older persons with dementia may become confronted with a decline in the level of physical activity. Indeed, a positive relationship between physical activity and cognition has been demonstrated. Although the causality of this relationship needs to be confirmed in advanced dementia, particularly animal experimental studies show the possible negative influence of restrained physical activity on behavior of patients with dementia. Patients with dementia, who get immobilized because of agitation and restlessness, may show an increase in these two symptoms. Another cause for reduced physical activity or inactivity may be the experience of pain. Pain experience may even increase in dementia by neuropathological changes in the central nervous system. There is an increasing (inter)national interest for the development of a more reliable assessment and treatment of pain, for the causality of the relationship between pain and physical (in)activity, and for the causality of the relationship between physical (in)activity and cognition in dementia. In the present paper, the various topics will be addressed in this order.

Motor imagery: the relation between age and imagery capacity.

The imagination of motor actions forms not only a theoretical challenge for cognitive neuroscience but may also be seen as a novel therapeutic tool in neurological rehabilitation, in that it can be used for relearning motor control after damage to the motor system. However, since the majority of rehabilitation patients consist of older individuals it is relevant to know whether the capacity of mental imaging is compromised by age. Scores on the vividness of movement imagery questionnaire were obtained for 333 participants, divided in three age groups. Results showed that elderly participants were slightly worse in motor imagery capacity than younger participants, particularly in relation to motor imagery from an internal (first person) perspective. Furthermore, a possible relation between the level of physical activities and motor imagery capacity is discussed.

[Is the Activities-specific Balance Confidence Scale suitable for Dutch older persons living in the community?]. / Is de Activities-specific Balance Confidence Scale geschikt voor het meten van valangst bij Nederlandse niet-geïnstitutionaliseerde ouderen?

BACKGROUND: In ageing populations fear of falling is an important issue. International studies and collaborations require scales suitable to more cultures. Scales developed in one culture require adaptation and additional investigation of psychometric properties for use in other countries. OBJECTIVE: To investigate the psychometric properties of a Dutch version of the Activities-specific Balance Confidence scale (ABC-NL) and whether adding questions about complex/dual tasks improves the discriminatory power. METHOD: Subjects were 106 men and 140 women aged 65-92 years. Measures were the 16-item ABC-NL and seven additional more complex items, fall history, general and physical self-efficacy, a functional reach test and a balance platform test. RESULTS: The ABC-NL had a weak ceiling effect. Internal consistency (Cronbachs alpha) was high. The relationship between ABC-NL and physical self-efficacy was significantly stronger than between the ABC-NL and general self-efficacy. Relationships with performance-based measures of balance were moderate. Differences between fallers and non-fallers and between activity avoiders and non-avoiders were significant. Adding questions about complex tasks hardly improved discriminatory power, reliability and validity. CONCLUSION: Psychometric properties of the ABC-NL were satisfactory. Further research is needed for use in high-functioning older persons.

Is de Activities-specific Balance Confidence Scale geschikt voor het meten van valangst bij Nederlandse niet-geïnstitutionaliseerde ouderen?

Is the Activities-specific Balance Confidence Scale suitable for Dutch older persons living in the community? Background: In ageing populations fear of falling is an important issue. International studies and collaborations require scales suitable to more cultures. Scales developed in one culture require adaptation and additional investigation of psychometric properties for use in other countries.Objective: To investigate the psychometric properties of a Dutch version of the Activities-specific Balance Confidence scale (ABC-NL) and whether adding questions about complex/dual tasks improves the discriminatory power.Method: Subjects were 106 men and 140 women aged 65-92 years. Measures were the 16-item ABC-NL and seven additional more complex items, fall history, general and physical self-efficacy, a functional reach test and a balance platform test.Results: The ABC-NL had a weak ceiling effect. Internal consistency (Cronbachs alpha) was high. The relationship between ABC-NL and physical self-efficacy was significantly stronger than between the ABC-NL and general self-efficacy. Relationships with performance-based measures of balance were moderate. Differences between fallers and non-fallers and between activity avoiders and non-avoiders were significant. Adding questions about complex tasks hardly improved discriminatory power, reliability and validity.Conclusion: Psychometric properties of the ABC-NL were satisfactory. Further research is needed for use in high-functioning older persons.