The goal of the NHALES Study is to help scientists understand how bacteria and other factors in the environment affect people who have moderate to severe asthma. Individuals who are unable to receive adequate asthma treatment currently are encouraged to join NHALES, which also offers free doctor visits and asthma medications to study participants.
All NHALES visits will take place at the NIEHS Clinical Research Unit (CRU) in Research Triangle Park, North Carolina, and volunteers will be compensated for their time. Participants will have approximately 12 CRU visits over the course of the 5-year study.
During the visits, NHALES team members will talk to you about your medical history, collect samples from you (blood, sputum, house dust, saliva, urine, stool), ask you to complete questionnaires about your asthma, and conduct breathing tests and a physical exam. A small group of eligible participants will be invited to take part in a small sub-study that will examine the inside of the lungs using a procedure called bronchoscopy.
NHALES participants who experience asthma difficulties may come to the CRU and receive health care and medications at no cost.
- Males and females, aged 18-60
- Females should not be pregnant or breastfeeding at the start of the study, but may still participate if they become pregnant during the study
- Nonsmokers that are not exposed to significant amounts of secondhand smoke
- Must have clinical evidence of moderate-severe atopic asthma:
- Self-reported symptoms suggestive of asthma (such as wheezing, chest tightness, shortness of breath, cough nocturnal symptoms) within the past year and;
- A positive methacholine test confirming diagnosis [provocative concentration causing a 20% fall in forced expiratory volume in 1 second (PC20 FEV1) < 16 mg/mL for participants on inhaled corticosteroids and <8 mg/mL for participants not on inhaled corticosteroids] or postbronchodilator FEV1 with at least 12% or 200 mL increase in FEV1 or forced volume vital capacity (FVC) on bronchodilator challenge and;
- No other diagnosis that could explain symptoms.
- No history of chronic obstructive pulmonary disease, emphysema, cystic fibrosis (CF), pulmonary fibrosis, non-CF bronchiectasis, sarcoidosis, unstable angina, or pulmonary hypertension
- Not allergic to methacholine
- Able to provide your own transportation to clinic visits
- Able to present a valid government issued form of identification for entry to the NIEHS campus
- Able to receive asthma treatment medication(s) via mail
- Willingness to comply with instructions regarding medication regimen, diet, and life style as directed by the investigator that are required per protocol
- Access to a vacuum cleaner with a detachable hose component