Alterations in circadian rhythms of melatonin and cortisol in patients with bronchial asthma.

AIM

To investigate the possible relationships between alterations in circadian rhythm of melatonin, cortisol and bronchial asthma.

METHODS

Salivary melatonin and cortisol were measured simultaneously by radioimmunoassay in 10 mild intermittent or persistent patients, 11 moderate-to-severe persistent asthma patients, and 15 control subjects. Twelve salivary samples were collected in a series during a 24-h period in each subject.

RESULTS

The results showed overall lower levels of salivary melatonin in asthma patients compared with control subject (P<0.01). The amplitude, peak-level, and baseline of salivary melatonin were significantly lower in mild intermittent or persistent (P<0.01, P<0.05) and moderate-to-severe persistent asthma patients (P<0.01) compared with control group. The 24-h mean level of salivary cortisol was greatly lower and the acrophase was markedly delayed in patients with mild intermittent or persistent asthma (P<0.01) and moderate-to-severe persistent asthma (P< 0.05, P<0.01) compared with control subject.

CONCLUSION

Disordered circadian rhythms of salivary melatonin and cortisol were found in asthma patients, which may be involved in the pathogenesis of bronchial asthma.