Chronic Respiratory Symptoms, Skin Test Results, and Lung Function as Predictors of Peak Flow Variability

Abstract

We examined how chronic respiratory symptoms, reported in a questionnaire, and results of skin prick tests and spirometry predicted variability in peak expiratory flow (PEF) among 6-12-yr-old children (n = 1,854). After characterization with skin tests and spirometry, children were followed for 2-3 mo during the winter of 1993-1994. Peak expiratory flow was measured daily in the morning and evenings. Children with asthmatic symptoms (wheeze and/or attacks of shortness of breath with wheeze in the past 12 mo and/or ever doctor diagnosed asthma) had a greater variation in PEF than children with dry nocturnal cough as their only chronic respiratory symptom. Similarly, doctor-diagnosed asthma was associated with a greater variation in PEF, also among children with asthmatic symptoms. Peak flow variability increased with an increasing number of symptoms reported in the questionnaire. Atopy, positive skin test reactions to house dust mite and cat and lowered level (as % of predicted) in FEV1 and in MMEF were also associated with an increased variation in PEF. All the differences were observed in both diurnal and day-to-day variation in PEF. In conclusion, chronic respiratory symptoms reported in a questionnaire, spirometric lung function and skin prick test results among asthmatic children predicted variation in PEF measured during a 2-3 mo follow-up. The difference in morning PEF coefficient of variation (CV) between children with asthmatic symptoms and children with cough only was somewhat bigger in girls than in boys. The effect of atopy on morning PEF CV was somewhat bigger in young than in older children.

Daily variations in air pollution and respiratory health in a multicentre study: the PEACE project. Pollution Effects on Asthmatic Children in Europe

“…To evaluate unmeasured differences between urban and suburban locations, a dummy indicator for location was included in the regression models. Children who were selected only on the basis of a positive answer to the nightly dry cough question had a lower prevalence of lower respiratory symptoms, upper respiratory symptoms and phlegm than children selected on asthma symptoms [14] and reacted differently to air pollution in the Finnish panels [15]. Thus, the reaction of a panel to air pollution might be influenced by panel composition.…”

Reproducibility of home spirometry in children with newly diagnosed asthma

“…1,2 In children, diurnal variation in PEF correlates significantly with asthma symptoms and bronchial hyperresponsiveness. 3,4 Although diurnal variation in PEF is considered useful in the diagnosis and treatment of asthma and also in large epidemiological studies in children, 5 measurement of this variable is not regarded as sensitive enough to distinguish children with mild asthma from those without asthma. 6,7 Many basic questions concerning the validity of monitoring pulmonary function at home remain unanswered.…”

Respiratory medications and sleep

“…It is known that even normal subjects demonstrate diurnal variation in peak expiratory flow (PEF), but an exaggerated response is seen in patients with nocturnal asthma [1]. Additional factors may include gastroesophageal reflux, airway cooling, and allergen exposure [2][3][4]. Obesity has also been associated with increased PEF variability [5].…”