Hormone may Worsten Nighttime Asthma

Hormone May WorsenNighttime Asthma

Individuals with nocturnal asthmaneed to worry about melatonin,

a naturally occurring hormone thathelps regulate the body's

circadian rhythms. So suggest theresults of a study published in

the Journal of Allergy andClinical Immunology (September 2003).

Participants in the study included 7with nocturnal asthma, 13 with

nonnocturnal asthma, and 11 withoutasthma. While the participants

slept, the researchers took bloodsamples from them every

2 hours. The investigators alsomeasured lung function before the

patients went to bed and again afterthey woke up.

The results showed that the patientswith nocturnal asthma

had the highest levels of melatoninand the biggest drop in lung

function. Among those with nocturnalasthma, levels of melatonin

were an average of 68 pg/mL,compared with 61 pg/mL for

patients with nonnocturnal asthmaand 54 pg/mL for patients

without asthma. Lung functiondropped by an average of 19% in

nocturnal asthma patients, comparedwith 5% in patients with

nonnocturnal asthma. In nonasthmapatients, lung function increased

by ~2%.

"These findings raise concern thathigh melatonin levels may

play a role in making asthma worseat night, and therefore people

with asthma should avoid takingsupplemental melatonin,"

advised study author RandSutherland, MD, an assistant professor

of medicine at the National JewishMedical Center in Denver.