The aim of this work was to study the environmental and genetic factors for Parkinson???s disease (PD) in Chinese and Australian. Using a case-control method, environmental factors for PD were studied in a Chinese population (n=528) in Hong Kong. Current smoking (OR=0.437; p=0.013) and infrequent tea drinking (OR=1.51; p=0.02) were found to be protective factors, whereas family history and pesticide exposure during farming in females were found to be risk factors in the univariate analysis. In the multivariate analysis, current smoking reached borderline significance at the 5% level and the variables, years exposed to pesticides and family history were significant at the 10% level. Similarly, a case-control study involving 534 subjects was conducted in Australia. A positive family history was the strongest risk factor (OR=3.4; p<0.001). In addition, rural residency was found to be another risk factor (OR=1.8; p<0.001). Hypertension, stroke and well water ingestion were inversely correlated with PD (OR=0.2; p<0.001, OR=0.2; p<0.001 and OR=0.7; p<0.03 respectively). When genetic factors were examined in the Chinese population, no association to PD were found for the polymorphisms of the following candidate genes: CYP-2D6 debrisoquine hydroxyalse gene, dopamine transporter gene and monamine oxidase B (MAOB) gene. Furthermore, the Ala53Thr and Ala30Pro mutations of the alpha-synuclein gene were not found amongst this large Chinese population, indicating that variations of this gene are probably rare in Chinese. When candidate genes were studied amongst Caucasian Australians, the poor metaboliser genotype of CYP-2D6 was found to be weaky associated with PD (OR=1.36) in a meta-analysis. The length of the GT repeat alleles of MAOB gene were found to be significantly associated with PD (>188 base pair and 186 base pair) while angiotensin converting enzyme gene polymorphism was not found to be associated with PD. A pilot study was then conducted in Randwick, New South Wales to find out the latest prevalence of PD as well as putative risk factors in a random population. A validation study was carried out for a screening tool (questionnaire) for PD, which was then used for the main study. A total of 730 subjects were involved (527 in the community and 203 in institutions). The survey found that PD prevalence was between 3.6% and 4.9% (higher in aged care facilities). The putative risk factors positively identified were ???family history???(p<0.01) and ???exposure to chemicals at work or in surrounding environment??? (p<0.05). The age adjusted prevalence rate of PD revealed at least 42.5 % increase in the disease compared to 1966. We conclude that there may be an increase in the disease in Australia due to aging and other risk factors.
| Identifer | oai:union.ndltd.org:ADTP/215796 |
| Date | January 2000 |
| Creators | Chan, Daniel Kam Yin, School of Physiology & Pharmacology, UNSW |
| Publisher | Awarded by:University of New South Wales. School of Physiology & Pharmacology |
| Source Sets | Australiasian Digital Theses Program |
| Language | English |
| Detected Language | English |
| Rights | Copyright DANIEL KAM YIN CHAN, http://unsworks.unsw.edu.au/copyright |
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