Study of circadian rhythm of tidal breathing lung function and LTE4 in 3～6 years old children with nocturnal asthma

Objective:To observe the circadian rhythm of tidal breathing lung function in 3～6 years old children with nocturnal asthma and the relationship of inflammation mediator leukotriene E4(LTE4)and nocturnal asthmatic children who are 3～6 years old.Methods:The subjects were divided into three groups:nocturnal asthmatic group;non-nocturnal attacksgroup and normal control group.Tidal breathing lung function(TPTEF/Te,VPEF/Ve)was measured at 4:00,9:00,16:00,22:00.Urine was collected at 3:01～6:00,8:01～11:00 and 15:01～18:00.The level of LTE4 was measured by ELISA.Results:In nocturnal asthmatic group tidal breathing lung function(TPTEF/Te,VPEF/Ve)were highest at 16:00 and lowest at 4:00.At 3:01～6:00,the level of LTE4 was significantly higher in nocturnal asthmatic group than in non-nocturnal attacks group and normal controls(P0.01).And in nocturnal asthmatic group the levels of LTE4 at 3:01～6:00 were significantly higher than those of at 8:01～11:00,at 15:01～18:00(P0.05,P0.01).Correlation analysis showed that the level of LTE4 at 3:01～6:00 was negatively correlated to the level of TPTEF/Te at 4:00 in nocturnal asthmatic group(P0.01).The level of LTE4 at 3:01～6:00 was negatively correlated to the level of VPEF/Ve at 4:00 in nocturnal asthmatic group(P0.05),too.Conclusion:In nocturnal asthmatic children who were 3～6 years old,tidal breathing lung function takes on circadian rhythm.LTE4 is a significatnt inflammation mediator in asthma,and may contribute to the nocturnal worsening of asthma.