Seasonal differences of peak expiratory flow rate variability and mediators of allergic inflammation in non‐atopic adolescents

Abstract

Variations in peak expiratory flow (PEF) and serum eosinophil mediators were studied in healthy adolescents. Twenty-five boys and 31 girls, 11-16 years of age (mean age 14.3 years), were selected and investigated during the birch pollen season of 1995; 45 were also investigated during the autumn of the same year. The PEF was measured twice daily and eosinophil mediators in serum and in urine were measured by radioimmunoassay (RIA) once during the birch pollen season and once in autumn. The type values of the daily PEF variation, expressed in amplitude percentage mean, were 6.4 and 3.9%, mean values were 7.35 and 6.74%, and the 95th percentiles were 18 and 14%, during the birch pollen season and autumn, respectively. The 95th percentiles were 41 and 38 microg/l for serum eosinophil cationic protein (s-ECP), 74 and 62 microg/l for serum eosinophil protein X (s-EPX), 987 and 569 microg/l for serum myeloperoxidase (s-MPO), and 165 and 104 microg/mmol for urinary eosinophil protein X/urinary creatinine (u-EPX/u-creatinine), during the birch pollen season and autumn, respectively. The levels of the eosinophil mediators decreased significantly from May (n = 56) to November (n = 45), for s-ECP from a median value of 14 microg/l to 7 microg/l (p= 0.001), for s-EPX from a median value of 28 microg/l to 20 microg/l (p= 0.001), and for the neutrophil mediator, s-MPO, from a median value of 440 g/l to 292 g/l (p< 0.001). The PEF variability decreased significantly (p= 0.037), from spring (n = 55; median 8%, 95% confidence interval [CI] 7.8-10.19) to autumn (n = 44; median 6%, 95% CI 6.1-8.9). A significant correlation was found between the levels of s-ECP and s-EPX (rs = 0.7, p< 0.001), between s-ECP and s-MPO (rs = 0.6, p< 0.001), between s-EPX and s-MPO (rs = 0.4, p< 0.005), and between s-EPX and u-EPX/u-creatinine (rs = 0.6, p< 0.0001), in the birch pollen season (n = 56) and in the autumn (n = 45). There was a positive correlation found in PEF variability between the two seasons (n = 43; rs = 0.5, p= 0.0006). No other correlation was found between PEF variability and any other parameters. The difference in the levels of eosinophil mediators between seasons in non-atopic, healthy children is unexplained. Normal limits for mediators were higher and PEF variability was almost the same as has been reported in adults. When using normal values, seasonal influences should be considered.

Bronchial hyper‐responsiveness predicts the development of mild clinical asthma within 2 yr in school children with hay‐fever

“…In a study on normal levels of PEF variability (16) in non-atopic children, the children were asked to follow the same procedure as in this study, i.e. registered PEF variability during the same 4 wk in the spring and in the autumn (16). In that study we found a similar pronounced PEF variability as we did in these children with hay fever and mild asthma in the year 1992.…”

“…This may be because of those who were asthmatic had got anti-asthmatic medication and some of them had got immunotherapy. In a study on normal levels of PEF variability (16) in non-atopic children, the children were asked to follow the same procedure as in this study, i.e. registered PEF variability during the same 4 wk in the spring and in the autumn (16).…”

Comparative study of seasonal variability in peak expiratory flow rate amongst school children in rural and urban areas

“…15,16 This study findings with poor PEFR values found during summer season amongst children than the winter, were found to be statistically significant (p<0.001) as supported by studies by Debalina Sahoo, Hosne Ara Ferdousi, Składanowski, Manjunath CB and Strachan Paul. 2,13,[17][18][19] Such decreased PEFR values during the summer season of the region (April to June) in both rural and urban children, in the present study were probably attributable to dry and hot climate in this region during this period, with outside temperature rising to 470ºC or more at occasions; thus affecting the respiratory functions along with its ill effects on the other organ body systems too. In a study by Gultyaeva VV which showed that minimum value of respiratory parameters were found in the spring and the maximum--in the autumn.…”

‘EUROPART’. Airborne particles in the indoor environment. A European interdisciplinary review of scientific evidence on associations between exposure to particles in buildings and health effects

“…Taking exposure to common allergens in the non-industrial indoor air as an example, the skin prick test as commonly performed has low sensitivity to detect sensitization (Dreborg, 2001) and a considerable proportion of young people presenting with hay fever do not admit asthma and bronchial hyperresponsiveness even if they actually have it (Mo¨ller et al, 2002). Furthermore, as shown for healthy adolescents, there is seasonal variation in bronchial sensitivity (Ferdousi et al, 2001). Thus, future studies should address these deficiencies and, if they cannot be eliminated, should assess the extent to which the results may be biased.…”