Reducing the Risk or Delaying the Onset of Dementia

The population on the island of Ireland is ageing. Given that ageing is the biggest risk factor for dementia, both jurisdictions face a substantial rise in the number of people with dementia in the coming decades. This puts dementia risk reduction at the heart of policy in NI and ROI and makes continued research and awareness in the area a key priority. While age, gender and genetics play a role in the development of dementia, an increasing body of evidence has emerged in the international literature to highlight the role of modifiable risk and protective factors in exacerbating or reducing an individual’s risk of developing dementia in later life. Between 2010 and 2014, the published articles from the island of Ireland on reducing the risk or delaying the onset of dementia are limited to a focus on the effects of education, employment and retirement age on the age of onset of Alzheimer’s disease, prevention of dementia among specific groups at risk of developing dementia (i.e. people with affective disorders) and prevention of very rare forms of dementia (i.e. variant CJD), whilst another study on secondary prevention highlights the importance and possibility of minimising the health impact of frailty in people with dementia. 

Correlates of frailty In Alzheimer’s Disease and Mild Cognitive Impairment

NI MHAOLAIN, A., GALLAGHER, D., CROSBY, L., RYAN, D., LACEY, L., COEN, R., BRUCE, I., WALSH, J.B., CUNNINGHAM, C., LAWLOR, B.A.
Age and Ageing, 40(5)
2011

Ni Mhaolain et al. (2011) examine the relationship between frailty and a range of domains including age, comorbidity, course of illness, cognitive impairment, functional limitations and abnormalities of behaviour in a group of patients with AD and MCI.

The study found that 51% of the patients were robust or not-frail, with 49% at an intermediate or complete stage of frailty.  It suggests that escalating frailty is positively associated with increasing number of medical comorbidities and advancing age rather than being a marker of cognitive decline and severity of illness. The study suggests that optimising the management of co-morbid illness in people with dementia may play a role in minimizing the health impact of frailty in this group. 

Cost-effectiveness of prion filtration of red blood cells to reduce the risk of transfusion-transmitted variant Creutzfeldt-Jakob disease in the Republic of Ireland

TELJEUR, C., FLATTERY, M., HARRINGTON, P., O’NEILL, M., MORAN, P.S., MURPHY, L., RYAN, M.
Transfusion, 52(November)
2012

This study by Telijeur et al.

(2012) evaluated the cost-effectiveness of implementing a policy of prion filtration of red blood cells in ROI, based on a literature review on efficacy and safety of prion filters, a cost effectiveness analysis and analysis of two models of prion filtration. It concluded that the introduction of prion filtration for all transfusion recipients was not cost-effective by traditional standards of cost-effectiveness, whilst acknowledging that factors other than cost-effectiveness may influence the decision on whether or not to implement a policy of prion filtration of red blood cells in ROI.  

Lithium and prevention of cognitive impairment

ABIDAN, Z., COONEY, C., JACKSON, D., FREYNE, A.
Irish Journal of Psychological Medicine
2014

A retrospective study by Abidan et al. (2014) was undertaken in the context of increased interest in the neuro-protective effects of lithium and studies suggesting lithium may have a protective role in dementia.

Covering the period 1998 to 2007, it involved 29 patients attending a lithium treatment clinic who had been commenced on lithium treatment for affective disorders such as depression, bipolar disorder and schizoaffective disorder. The study reported that no new cases of dementia developed over a mean follow-up period of 38 months. Given the limitations, the authors tentatively suggest that lithium may have a protective effect against cognitive decline in people with affective disorder and in those with concurrent affective disorder and cognitive impairment.

Very rare and unusual causes account for about 5% of cases of dementia.  Variant CJD, a human prion disease, is one of the rarer causes of dementia, caused when meat from cattle infected with bovine spongiform encephalopathy (BSE) is eaten. It typically affects younger adults. ROI has the second highest rate of vCJD in the world, with four cases reported to date. To complement existing measures adopted to contain the risk of vCJD transmission from transfusion of blood or blood products originating from subclinical carriers of the disease, prion-removing filters have been developed to reduce the risk of vCJD transmission. 

Education, occupation and retirement age effects on the age of onset of Alzheimer’s disease

LUPTON, M.K., STAHL., D., ARCHER, N., FOY, C., POPPE, M., LOVESTONE, S., HOLLINGSWORTH, P., WILLIAMS, J., OWEN, M.J., DOWZELL, K., ABRAHAM., R., SIMS, R., BRAYNE, C., RUBINSZTEIN, D., GILL., M., LAWLOR, B.A., LYNCH, A., POWELL., J.F
International journal of geriatric psychiatry
2010

This study by Lupton et al. (2010) is based on data from a sample of 1,320 people with probably Alzheimer’s disease from the UK and the ROI, who were primarily recruited to investigate candidate genes that may increase susceptibility to Alzheimer’s disease.

Data was analysed (using multiple regression analysis) to determine the effects of early life education, midlife employment and later life age of retirement on the age of onset of Alzheimer’s disease. This study found no effect of education or employment on the age of onset of Alzheimer’s disease, but found a significant effect of a later retirement age in delaying the onset of Alzheimer’s disease.