Frequency of the apolipoprotein E epsilon 4 allele in a case-control study of early onset Parkinson's disease.

OBJECTIVES: It has been suggested that Parkinson's disease and Alzheimer's disease may share a common or at least overlapping aetiology. The prevalence of dementia among cases of Parkinson's disease is known to be greater than expected in the general population. The frequency of the apolipoprotein epsilon 4 allele in a large case-control study of early onset Parkinson's disease has been examined. METHODS: 215 patients and 212 population based controls were recruited from the Republic of Ireland between 1992 and 1994. Cases had to have disease onset at 55 years or younger and be born after 1925. RESULTS: The frequency of the epsilon 4 allele was almost identical between cases of Parkinson's disease (14.6%) and healthy controls (13.3%). There was no relation between epsilon 4 status and disease onset, disease duration, Hoehn and Yahr score, and disease progression. The frequency of the epsilon 4 allele was not increased among 10 patients with Parkinson's disease with dementia (10.0%) compared with the other patients without dementia (14.8%). There was no association between epsilon 4 allele status and either a history of smoking, family history of dementia, or Parkinson's disease, or being born in a rural area. The odds ratio for the ApoE epsilon 4 allele associated with Parkinson's disease was 1.10 (95% confidence interval (95% CI) 0.68-1.79), adjusting for age group, sex, and residential status. The pooled odds ratio from a meta-analysis of six studies of ApoE epsilon 4 status and Parkinson's disease was 0.94 (95% CI 0.69-1.27). CONCLUSIONS: The results from our study as well as the pooled meta-analysis exclude any important role for ApoE epsilon 4 status in the development of Parkinson's disease. Our results similarly do not support its role either in dementia associated with Parkinson's disease or disease prognosis.

The effects of caring for a spouse with Parkinson's disease on social, psychological and physical well-being.

BACKGROUND: Several previous studies have examined the health of carers, but they have usually focused on elderly subjects and have often not had representative control samples. AIM: To determine whether caring for a partner with Parkinson's disease is associated with a worsening social, psychological and physical well-being than people with partners who do not suffer with Parkinson's disease. METHOD: One hundred and fifty-four carer spouses of subjects with Parkinson's disease, and 124 non-carer spouses of randomly selected population controls recruited from a national case-control study of early-onset Parkinson's disease in the Republic of Ireland, between 1992-1994, were studied. Outcome was measured along three dimensions: social functioning, assessed by the frequency of social contacts, outings and holidays; psychological well-being, measured by the General Health Questionnaire; and physical health, measured by the career's use of medical services, medications and episodes of chronic illness. RESULTS: Carer spouses were less likely to get out of the house once a week at least (odds ratio 1.79, 95% confidence intervals 1.00-3.20) or to have had a holiday in the last year (odds ratio 1.71, 95% confidence intervals 1.01-2.90). Contact with friends and neighbours decreased with increasing care provision. For spouses providing a lot of care, there was an almost fivefold increase in psychiatric morbidity (odds ratio 4.86, 95% confidence intervals 1.5-15.9) after adjusting for other variables. Most of the medical outcomes were less favourable among carers, but only the use of tranquilizers (odds ratio 3.73, 95% confidence intervals 1.18-11.8) and episodes of chronic illness (odds ratio 2.96, 95% confidence intervals 1.27-6.94) were significant. CONCLUSIONS: Overall, career spouses have slightly worse social, psychological and physical profiles. For social outcomes, increasing care provision is associated with fewer contacts, outings and holidays. For psychological and physical measures, carers providing a lot of care experience worse health. These results have implications for targeting appropriate interventions.

The epidemiology of Parkinson's disease in the Republic of Ireland: observations from routine data sources.

Routine data sources can provide clues to the temporal and geographical patterns of Parkinson's disease. Mortality trends show divergent age specific rates, with decreasing mortality for younger age-groups and increasing mortality for older age-groups. Cohort analysis showed a pattern consistent with the hypothesis that Parkinson's disease may have increased after the encephalitis lethargica pandemic. Hospital admission data suggest a rural excess of cases. The interpretation of this finding is complicated by the role of a variety of potential biases. Research is needed to examine urban-rural differences and environmental risk factors.