Lifestyle factors and risk of dementia: Dubbo Study of the elderly

Physical activity and the maintenance of cognitive function

Experimental studies suggest that physical activity or exercise can prevent or delay the onset of age-related cognitive impairment or dementia. Several epidemiologic studies have attempted to address this issue by using widely varying definitions of physical activity as well as differing methods to assess cognitive function or dementia. Despite the variability in study design, longitudinal studies report that the risk of dementia, cognitive impairment, cognitive decline, and Alzheimer's disease is lower among persons engaging in high levels of physical activity, relative to those engaging in low levels of physical activity. There is also evidence of a dose-response relationship between physical activity and preservation of cognitive function, even though small increases in physical activity from a sedentary state can reap comparatively large incremental benefits. Reductions in the relative risk of vascular dementia associated with physical activity were weaker and more variable. Although many studies had a follow-up duration of around 5 years, at least one study has found evidence that exercise in midlife reduces the risk of dementia in late life. How interactions between physical activity and the APOE e4 allele affect the risk of cognitive impairment is inconsistent. The available epidemiologic studies support the concept that physical activity might prevent or delay the onset of cognitive decline. Whether that effect will translate into a reduction in the prevalence of dementia is unknown.

Epidemiological studies of the effect of stroke on incident dementia: a systematic review

BACKGROUND AND PURPOSE

Stroke is implicated in the incidence of dementia, and the risk of poststroke dementia is well characterized, but the excess risk of dementia in those with stroke compared with those without stroke is not well known.

METHODS

We conducted a systematic review of the excess risk of incident dementia conferred by stroke. Studies of the risk of incident dementia in the population with stroke compared with the population without stroke were identified and compared.

RESULTS

Sixteen studies were identified with all but one conducted in a community setting. A history of stroke doubles the risk of incident dementia in the older population. This increase is not explained by demographic or cardiovascular risk factors or by prestroke cognitive decline. The excess risk of incident dementia diminishes with time after stroke and may be higher in those without an APOE epsilon4 allele. There is no excess risk of incident dementia in those aged >85 years with a history of stroke compared to those aged >85 years without stroke.

CONCLUSIONS

The effect of stroke on dementia incidence in the population is not explained by common risk factors. At this time of population aging and increased stroke survival, more research is needed to determine to what extent efforts to reduce the incidence of stroke will affect the incidence of dementia.

The healthy steps study: a randomized controlled trial of a pedometer-based green prescription for older adults. Trial protocol

BACKGROUND

Graded health benefits of physical activity have been demonstrated for the reduction of coronary heart disease, some cancers, and type-2 diabetes, and for injury reduction and improvements in mental health. Older adults are particularly at risk of physical inactivity, and would greatly benefit from successful targeted physical activity interventions.

METHODS/DESIGN

The Healthy Steps study is a 12-month randomized controlled trial comparing the efficacy of a pedometer-based Green Prescription with the conventional time-based Green Prescription in increasing and maintaining physical activity levels in low-active adults over 65 years of age. The Green Prescription interventions involve a primary care physical activity prescription with 3 follow-up telephone counselling sessions delivered by trained physical activity counsellors over 3 months. Those in the pedometer group received a pedometer and counselling based around increasing steps that can be monitored on the pedometer, while those in the standard Green Prescription group received counselling using time-based goals. Baseline, 3 month (end of intervention), and 12 month measures were assessed in face-to-face home visits with outcomes measures being physical activity (Auckland Heart Study Physical Activity Questionnaire), quality of life (SF-36 and EQ-5D), depressive symptoms (Geriatric Depression Scale), blood pressure, weight status, functional status (gait speed, chair stands, and tandem balance test) and falls and adverse events (self-report). Utilisation of health services was assessed for the economic evaluation carried out alongside this trial. As well, a process evaluation of the interventions and an examination of barriers and motives for physical activity in the sample were conducted. The perceptions of primary care physicians in relation to delivering physical activity counselling were also assessed.

DISCUSSION

The findings from the Healthy Steps trial are due in late 2009. If successful in improving physical activity in older adults, the pedometer-based Green Prescription could assist in reducing utilisation of health services and improve cardiovascular health and reduction of risk for a range of non-communicable lifestyles diseases.

TRIAL REGISTRATION

Australian and New Zealand Clinical Trials Registry ACTRN012606000023550.

Alcohol consumption as a risk factor for dementia and cognitive decline: meta-analysis of prospective studies

The relationships between alcohol consumption and dementia and cognitive decline were investigated in a systematic review including meta-analyses of 15 prospective studies. Follow-ups ranged from 2 to 8 years. Meta-analyses were conducted on samples including 14,646 participants evaluated for Alzheimer disease (AD), 10,225 participants evaluated for vascular dementia (VaD), and 11,875 followed for any type of dementia (Any dementia). The pooled relative risks (RRs) of AD, VaD, and Any dementia for light to moderate drinkers compared with nondrinkers were 0.72 (95% CI = 0.61-0.86), 0.75 (95% CI = 0.57-0.98), and 0.74 (95% CI = 0.61-0.91), respectively. When the more generally classified "drinkers," were compared with "nondrinkers," they had a reduced risk of AD (RR = 0.66, 95% CI = 0.47-0.94) and Any dementia (RR = 0.53, 95% CI = 0.53-0.82) but not cognitive decline. There were not enough data to examine VaD risk among "drinkers." Those classified as heavy drinkers did not have an increased risk of Any dementia compared with nondrinkers, but this may reflect sampling bias. Our results suggest that alcohol drinkers in late life have reduced risk of dementia. It is unclear whether this reflects selection effects in cohort studies commencing in late life, a protective effect of alcohol consumption throughout adulthood, or a specific benefit of alcohol in late life.

Physical Leisure Activities and their Role in Preventing Dementia: A Systematic Review

BACKGROUND

Identifying protective factors or effective prevention strategies for dementia would result in considerable benefits by prolonging quality of life and reducing social burden. Current data suggests that participation in physical leisure activities may lower the risk of dementia by improving cognitive reserves.

OBJECTIVE

The objective of this review was to determine the best available evidence in relation to physical leisure activities in preventing dementia among older adults.

INCLUSION CRITERIA

Types of studies Randomised controlled trials (RCTs) and other experimental designs were considered for inclusion into the review. In the absence of clinical trials, other study designs such as cohort, case controlled and cross-sectional were considered. Only articles published in the English language were included with no publication date restriction.Types of participants Participants of interest were adults aged 60 and older with or without a clinical diagnosis of dementia, living in the community or residential care setting.Types of intervention This review considered studies that evaluated the effectiveness of any physical leisure activity in the prevention of dementia. Physical activities included gardening, playing sports, exercises, sightseeing and any other activities that required active movement of the body.Types of outcome measures The review considered studies that indicated the presence or absence of dementia as determined by cognitive function tests, mental examination scores, DSM classification (Diagnostic and Statistical Manual of Mental Disorders), and other valid dementia diagnostic tools.

SEARCH STRATEGY

A search for published and unpublished literature in the English language was conducted using all major electronic databases. There was no publication date restriction. A three-step search strategy was developed using MeSH terminology and keywords to ensure that all material relevant to the review was captured.

CRITICAL APPRAISAL

The methodological quality of included studies was assessed by two reviewers, who appraised each study independently, using standardised Joanna Briggs Institute (JBI) critical appraisal tools.

DATA EXTRACTION AND SYNTHESIS

Data was extracted from the studies that were identified as meeting the criteria for methodological quality using the standard JBI data extraction tools. Due to the heterogeneity of populations and interventions, results are presented in narrative form.

RESULTS

Seventeen longitudinal studies were included in the review. Studies were grouped by stage of adult life participation when interventions were undertaken i.e. early-middle adulthood and late life. The evidence regarding the relationship between participation in physical activities during midlife and later life and the prevention of dementia was equivocal. The majority of studies showed limited benefits in engaging in physical activities and results indicated that some activities might be more beneficial than others.

IMPLICATIONS FOR PRACTICE

IMPLICATIONS FOR RESEARCH.

Alcohol, dementia and cognitive decline in the elderly: a systematic review

BACKGROUND

dementia and cognitive decline have been linked to cardiovascular risk. Alcohol has known negative effects in large quantities but may be protective for the cardiovascular system in smaller amounts. Effect of alcohol intake may be greater in the elderly and may impact on cognition.

METHODS

to evaluate the evidence for any relationship between incident cognitive decline or dementia in the elderly and alcohol consumption, a systematic review and meta-analyses were carried out. Criteria for inclusion were longitudinal studies of subjects aged >or=65, with primary outcomes of incident dementia/cognitive decline.

RESULTS

23 studies were identified (20 epidemiological cohort, three retrospective matched case-control nested in a cohort). Meta-analyses suggest that small amounts of alcohol may be protective against dementia (random effects model, risk ratio [RR] 0.63; 95% CI 0.53-0.75) and Alzheimer's disease (RR 0.57; 0.44-0.74) but not for vascular dementia (RR 0.82; 0.50-1.35) or cognitive decline (RR 0.89; 0.67-1.17) However, studies varied, with differing lengths of follow up, measurement of alcohol intake, inclusion of true abstainers and assessment of potential confounders.

CONCLUSIONS

because of the heterogeneity in the data these findings should be interpreted with caution. However, there is some evidence to suggest that limited alcohol intake in earlier adult life may be protective against incident dementia later.

Effects of indoor gardening on sleep, agitation, and cognition in dementia patients--a pilot study

OBJECTIVE

A pilot study was performed to examine the efficacy of indoor gardening on sleep, agitation and cognition of dementia patients.

METHOD

Twenty-three institutionalized dementia patients who had sleep disturbance and/or agitation participated in a 5-week study protocol of 1 week of baseline and 4 weeks of treatment. The study design was a one group repeated measures study. For the first and fifth week of the study period, sleep patterns, agitation, and cognition were evaluated using a sleep diary, Modified Cohen-Mansfield Agitation Inventory and revised Hasegawa Dementia Scale respectively.

RESULTS

Significant improvement in wake after sleep onset, nap, nocturnal sleep time, and nocturnal sleep efficiency was identified. On the contrary sleep onset time, wake-up time, total sleep time did not change after indoor gardening. Agitation and cognition score was significantly improved.

CONCLUSION

Indoor gardening was found to be effective for sleep, agitation, and cognition of dementia patients. Randomized controlled studies of larger sample size are needed to confirm treatment effect.

Atividade física e estado de saúde mental de idosos

OBJETIVO: Avaliar a associação entre nível de atividade física e o estado de saúde mental de pessoas idosas. MÉTODOS: Inquérito de base populacional com amostragem probabilística, incluindo 875 idosos da cidade de Florianópolis, Santa Catarina, em 2002. Foram aplicados os questionários: Internacional de Atividades Físicas e Brazil Old Age Schedule. Os problemas de saúde mental avaliados foram depressão e demência, além da prática de atividade física total (lazer, ocupação, deslocamentos e serviços domésticos). Após análises descritivas e bivariadas, realizou-se análise ajustada por meio de regressão logística, com ajuste para os fatores de atividade física total, atividade de lazer, escores de depressão e demência. RESULTADOS: Verificou-se associação estatisticamente significativa e inversa de demência e depressão com atividade física total e atividade física no lazer. A odds ratio ajustada para demência entre os sujeitos sedentários para atividade física total comparada à dos ativos foi de 2,74 (IC 95%: 1,85; 4,08), enquanto o respectivo valor para depressão foi de 2,38 (IC 95%: 1,70; 3,33). CONCLUSÕES: Os resultados reforçam a importância de estilo de vida ativo para prevenção de problemas de saúde mental de idosos. Infere-se que a atividade física tem conseguido reduzir e/ou atrasar os riscos de demência, embora não se possa afirmar que a atividade física evita a demência.

Delaying dementia and nursing home placement: the Dubbo study of elderly Australians over a 14-year follow-up

In order to capture the "longevity dividend," modifiable risk factors for a diagnosis of dementia and nursing home placement were examined in a longitudinal study of an elderly cohort living in Dubbo, New South Wales, Australia. One thousand two-hundred thirty-three men and 1572 women 60 years and older living in the community were examined in 1988 and followed to 2002 for diagnosis of dementia and nursing home placement. There were 244 (8.7%) nursing home placements and 44% of these placements were primarily due to dementia, but dementia was a secondary diagnosis in another 20% of cases. In a proportional hazards model for dementia, any intake of alcohol predicted a 34% lower risk, and daily gardening a 36% lower risk. Daily walking predicted a 38% lower risk of dementia in men, but there was no significant prediction in women. The lowest tertile of peak expiratory flow predicted an 84% higher risk of dementia, the upper tertile of depression score predicted a 50% higher risk. The Cox proportional hazards model for nursing home placement, showed placement increased significantly with age, urinary incontinence, impaired peak expiratory flow, physical disability, and depression. The hazard of placement was significantly reduced by alcohol intake and female gender. Socioeconomic factors were not significant. Similar risk factors for dementia and nursing home placement indicate that the continuation of moderate alcohol intake, the maintenance of physical activity, especially daily gardening, and improvement of respiratory function, and the treatment of depression are recommended targets for interventions to delay or prevent major negative late-life experiences.