Dose Estimation for Studies of Acute Respiratory Effects

NCT ID: NCT00005362

Last Updated: 2016-05-13

Basic Information

• Recruitment Status: COMPLETED
• Study Classification: OBSERVATIONAL
• Study Start Date: 1992-09-30
• Study Completion Date: 1995-08-31

Brief Summary

To modify and expand an existing pharmacokinetic model for nasal dose as well as to develop a new model to estimate tracheobronchial dose of an active agent for each subject in a study of acute respiratory health effects.

Detailed Description

BACKGROUND:

Epidemiologic analysis of acute, reversible respiratory health effects is uncommonly performed, yet these are important health outcomes because acute responses by the respiratory defense system appear to represent one end of the continuum toward progressive, chronic and potentially disabling physiologic changes. Repeatable epidemiologic studies of dose-response relationships necessitate accurate measures of 'dose'. However, in occupational and environmental settings, exposure to a toxin is seldom found at identical concentrations and/or particle sizes among persons with the same activity patterns. In addition, air concentration does not account for factors such as clearance or metabolism which may alter the biologically effective tissue dose. These factors cause the target tissue dose of the toxin to vary greatly despite exposure to similar air concentrations.

DESIGN NARRATIVE:

The results of these toxicokinetic models were individual measures of tissue dose used in a 2-stage epidemiologic analysis which placed special emphasis on the definition of individual dose-response curves for exposure to an irritant dust, sodium borate, and the reversible effects of peak expiratory flow and irritant symptoms. A primary advantage of the two stage epidemiologic approach was that it permitted particular attention to be focused on the factors which determined the sensitivity (threshold) and reactivity (slope) for an individual. The use of tissue dose estimates were also compared to simple exposure measurements in the epidemiologic analysis to evaluate the efficacy of using dosimetric methods in epidemiologic studies.

The study completion date listed in this record was obtained from the "End Date" entered in the Protocol Registration and Results System (PRS) record.

Conditions

Lung Diseases

Eligibility Criteria

Inclusion Criteria

No eligibility criteria

• Maximum Eligible Age: 100 Years
• Eligible Sex: MALE
• Accepts Healthy Volunteers: No

Sponsors

National Heart, Lung, and Blood Institute (NHLBI)

NIH

Sponsor Role: lead

References

Woskie SR, Eisen EE, Wegman DH, Hu X, Kriebel D. Worker sensitivity and reactivity: indicators of worker susceptibility to nasal irritation. Am J Ind Med. 1998 Dec;34(6):614-22. doi: 10.1002/(sici)1097-0274(199812)34:63.0.co;2-s.

Reference Type: BACKGROUND

PMID: 9816420 (View on PubMed)

Other Identifiers

R01HL048853

Identifier Type: NIH

Identifier Source: secondary_id

View Link

4249

Identifier Type: -

Identifier Source: org_study_id