Exposure to Neurotoxins as Risk Factors for ALS
|First Received Date ICMJE||June 19, 2006|
|Last Updated Date||April 21, 2017|
|Start Date ICMJE||June 2, 2003|
|Primary Completion Date||Not Provided|
|Current Primary Outcome Measures ICMJE
||Measurement in blood or toenails of genes, proteins, neurotoxicants, and other factors or agents potentially associated with ALS|
|Original Primary Outcome Measures ICMJE||Not Provided|
|Change History||Complete list of historical versions of study NCT00340301 on ClinicalTrials.gov Archive Site|
|Current Secondary Outcome Measures ICMJE||Not Provided|
|Original Secondary Outcome Measures ICMJE||Not Provided|
|Current Other Outcome Measures ICMJE||Not Provided|
|Original Other Outcome Measures ICMJE||Not Provided|
|Brief Title ICMJE||Exposure to Neurotoxins as Risk Factors for ALS|
|Official Title ICMJE||Exposure to Neurotoxins as Risk Factors for ALS: Measurement of Genes, Proteins, Neurotoxicants, and Other Factors Potentially Associated With ALS|
Chemicals called neurotoxins can harm the nervous system. Amyotrophic lateral sclerosis (ALS) is a progressive disease affecting movement. Researchers have studied many possible causes of ALS, including injury, diet, and exposure to chemicals, but these studies were inconclusive.
The purpose of this study was to determine whether exposure to lead or other neurotoxins can contribute to ALS. The study also evaluated lifestyle and dietary patterns. The study was completed in 1994-1996.
One hundred eighty-two participants took part in this study 110 patients with ALS and 72 who did not have ALS. Each completed a questionnaire concerning lifestyle, diet, and residential, job, and medical history. Participants contributed 50 cc of blood, used to measure lead, as well as clippings of their toenails, used to measure mercury and other metals. They then underwent an XRF test (an X-ray procedure) to measure the level of lead in their shinbones and knees. Genes related to ALS or susceptibility to lead exposure were also evaluated.
OBJECTIVES: Stored blood and toenail samples are available from a case-control study of ALS conducted in 1993-1996. The purpose of the initial study was to examine the relationship to ALS of lead and other exposures, including mercury, pesticides, and solvents, as well as genetic susceptibility to these exposures. The protocol was closed in May 1997 (closed protocol #95-007) after recruitment of study subjects ended. The objective of the present proposal is to reopen the protocol to permit measurement in blood or toenails of genes, proteins, neurotoxicants, and other factors or agents potentially associated with ALS, as well as analyses of existing data. The short-term goal is to measure (i) polymorphisms in DNA repair genes; (ii) serum protein profiles; and (iii) serum organochlorine pesticide levels. Other factors may be of interest in the future, for example polymorphisms in other genes or levels of metals in blood or toenails. We also plan (iv) to continue analyses of existing data. Some data analysis will involve combining data from the original ALS study with data from the Harvard Normative Aging Study, a cohort study of World War II verterans that has collected demographic, lifestyle, and medical data as well as information on bone and blood lead levels.
STUDY POPULATION: No new subjects will be recruited for this protocol. The original study involved 110 ALS cases, 31 hospital controls with other neurologic diseases, and 256 population controls, recruited in New England between 1993 and 1996. The population controls were frequency matched to the cases on the basis of age, gender, race, and region within New England.
DESIGN: The original study was a case-control study. Data collection involved an interview collection of blood and toenail samples, and measurement of bone lead using x-ray fluorescence. Stored blood and/or toenail samples are available from 107 ALS cases, 31 hospital controls, and 39 population controls. The present study will use conventional techniques to measure genetic polymorphisms and serum organochlorine levels and newly developed SLDI-TOF technology to evaluate serum protein profiles.
OUTCOME PARAMETERS: The outcome parameter is risk of ALS. Associations with ALS risk will be evaluated for polymorphisms in DNA repair genes; serum protein profiles; and organochlorine pesticide levels in serum.
|Study Type ICMJE||Observational|
|Study Design ICMJE||Observational Model: Case-Control
Time Perspective: Retrospective
|Target Follow-Up Duration||Not Provided|
|Sampling Method||Not Provided|
|Study Population||Not Provided|
|Intervention ICMJE||Not Provided|
|Study Groups/Cohorts||Not Provided|
* Includes publications given by the data provider as well as publications identified by ClinicalTrials.gov Identifier (NCT Number) in Medline.
|Recruitment Status ICMJE||Completed|
|Estimated Enrollment ICMJE||397|
|Completion Date||Not Provided|
|Primary Completion Date||Not Provided|
|Eligibility Criteria ICMJE||
Cases were eligible to participate in the original study if (1) they had received a diagnosis of ALS within 2 years; (2) they lived in New England at least half the year; (3) they spoke English; (4) they were mentally and physically able to participate. The same inclusion criteria were used for controls.
Potential controls were excluded if they had a physician diagnosis of a neurodegenerative disease, polio, post-polio syndrome, or nondiabetic neuropathy.
Pregnant women were excluded from both case and control groups.
|Ages||Child, Adult, Senior|
|Accepts Healthy Volunteers||No|
|Contacts ICMJE||Contact information is only displayed when the study is recruiting subjects|
|Listed Location Countries ICMJE||United States|
|Removed Location Countries|
|NCT Number ICMJE||NCT00340301|
|Other Study ID Numbers ICMJE||999903210
|Has Data Monitoring Committee||Not Provided|
|U.S. FDA-regulated Product||Not Provided|
|Plan to Share Data||Not Provided|
|IPD Description||Not Provided|
|Responsible Party||National Institute of Environmental Health Sciences (NIEHS)|
|Study Sponsor ICMJE||National Institute of Environmental Health Sciences (NIEHS)|
|Collaborators ICMJE||Not Provided|
|Information Provided By||National Institutes of Health Clinical Center (CC)|
|Verification Date||February 7, 2017|
ICMJE Data element required by the International Committee of Medical Journal Editors and the World Health Organization ICTRP