Determine the Relationship Between Circadian Rhythms and Nocturnal Asthma
Asthma is a disease that affects the lungs. Symptoms include repeated episodes of wheezing, breathlessness, chest tightness, and nighttime or early morning coughing. Some people with asthma experience worse symptoms at night, which is known as nocturnal asthma (NA). The reason for the decline in lung function at night in some asthmatics is not well understood, but it may be linked to the human biological clock, which controls daily activity and sleep rhythms. To determine whether differences in biological clocks relate to worsening nocturnal lung function, this study will evaluate the circadian rhythms of people with NA, people with non-nocturnal asthma, and healthy people.
|Study Design:||Observational Model: Case Control
Time Perspective: Prospective
|Official Title:||Circadian Rhythms and Nocturnal Asthma|
- Spirometry [ Time Frame: Measured during the 28-hour constant routine testing ] [ Designated as safety issue: No ]
- Cortisol, melatonin, exhaled nitric oxide, inflammatory cytokine levels, clock gene expression, and heart rate variability [ Time Frame: Measured during the 28-hour constant routine testing ] [ Designated as safety issue: No ]
|Study Start Date:||January 2009|
|Study Completion Date:||December 2011|
|Primary Completion Date:||December 2011 (Final data collection date for primary outcome measure)|
Healthy participants without asthma
2 Non-nocturnal asthma
Participants with non-nocturnal asthma
3 Nocturnal asthma
Participants with nocturnal asthma
Nocturnal worsening of asthma, frequently called NA, is a common problem among some people with asthma and one that leads to increased morbidity and mortality. It is still unknown why lung function worsens at night in some asthmatics and not others. There is a possible relationship between NA, biological clocks, and circadian rhythms, but more research is needed to understand this relationship. Although the diurnal nature of NA has been shown repeatedly in studies, circadian rhythms have not yet been implicated as a related factor. This study will examine the pathophysiology of NA as it relates to circadian biology and will specifically explore physiological and molecular aspects.
This study will include people with asthma, people with NA, and healthy people. Potential participants will attend a screening visit to assess general health and severity of asthma, if present. They will also complete 2 weeks of diary recordings of their daily symptoms and airway function.
Eligible participants will then attend two study visits. The first study visit will last 1 hour and may include a methacholine challenge and bronchodilator testing, both of which will measure lung function. For 2 weeks before the second study visit, participants will keep records of their sleep patterns. The second study visit will be a hospital stay that will last for 2.5 days. While in the hospital, participants will undergo periodic blood draws and lung function testing. During waking hours, participants will remain quietly awake. During the first night, participants will be monitored while they sleep. During the second night, participants will stay awake for 28 hours, which will continue into the third day. Then, on the third day, participants will sleep for 8 hours while again being monitored. Upon waking, participants will be given a regular meal and discharged.
Please refer to this study by its ClinicalTrials.gov identifier: NCT00891189
|United States, Illinois|
|Chicago, Illinois, United States, 60611|
|Principal Investigator:||Brandon S. Lu, MD, MS||Northwestern University|