Parkinson Disease, Secondary Clinical Trial
Official title:
Study on the Relationship Between Environmental and Occupational Exposure to Metals and Parkinson's Disease
The Department of Experimental Medicine - Section of Hygiene, Occupational Medicine, Forensic Medicine of the Second University of Naples, the Section of Neurology of the Second University of Naples and the Mediterranean Neurological Institute NEUROMED, IRCCS are involved in the realization of a research project aimed at studying the correlation between environmental and occupational exposure to metals (copper, iron and manganese) and Parkinson disease in order to increase the knowledge of these possible risk factors and highlight an eventual predictive-diagnostic meaning of possible discrepancies in the content of these elements; secondly the collected data could be used for assessing the association (odd ratio-OR) between pathologies and different risk factors (for example smoking habits, professional exposure and so on).
During the selection of the sample it is essential to consider all the variables that could
provoke an alteration in the levels of the indicators examined in the biological fluids
investigated.
The adoption of strict criteria for inclusion and exclusion, which differ from metal to
metal, is therefore necessary to establish the presence / absence of possible confounding
factors that could affect the analysis or interpretation of the data.
It is to be noted also that the number of required participants in a study of MB must be
sufficiently large to allow an adequate statistical analysis: the more limited the group of
subjects included in the study is, the broader the variability of the data due to
inter-individual and methodological differences.
In light of this, some variables, such as age and sex, will be firstly neglected and other
potential confounding factors will be considered such as, for example, smoking habits.
Based on the purpose of the research project, the following criteria for exclusion will be
considered:
- diseases that may interfere with toxicokinetics of the analyzed metals;
- pharmacological therapy;
- habit-forming additives consumption (excessive alcohol consumption);
- altered physiological states (pregnancy, strenuous physical exercise, recent meal,
stress, psychological disorders);
On the contrary, the basic criteria for inclusion in the study are:
- age: subjects of working age, between 18 and 65 years;
- diagnosis of Parkinson's disease (using the criteria of the "London Brain Bank")
Regarding the criteria of partition or stratification of the subjects, the type and number
of the possible partitions are conditioned by the sample size; indeed it is essential to
ensure a sufficient number of cases (and if possible a similar number of cases) in the
various layers to have correct statistical results. It was recommended that the minimum
number of subjects per layer must be equal to 80.
In order to collect all the necessary information for the inclusion of subjects in the study
and the subsequent stratification of the data, an anonymous questionnaire was realized and
administered to each recruited subject.
The questionnaire deals with the environment and the lifestyle and work habits of every
participant and it consists of multiple choice questions and free response questions and is
divided into macro areas: identification data for data processing; place of residence;
professional activity; extraprofessional activities; eating habits; habit-forming additives
consumption; medical history.
Each question will be transformed into a "continue" or "categorical" variable in order to be
able to build and constantly update a database summarizing the collected data and allowing
the statistical analysis of the results.
Each subject enrolled will be also asked to sign a consent form, which states that he or she
voluntarily take part to the study, after being informed about the purpose of the study and
the analysis of both biological samples and personal data.
The guarantee of anonymity for people recruited for this study is provided by an anonymous
questionnaire which do not contain personal data, which are collected only in the consent
form, separately from the questionnaire.
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Observational Model: Case Control, Time Perspective: Retrospective