Diurnal variation in peak expiratory flow rates of healthy young adults

Abstract

Diurnal variability in peak expiratory flow (PEF) was studied in 34 healthy, non-smoking adult males in the age group between 18-26 years. The PEFR (L/min.) was measured with mini Wright's peak flow meter for five times in a day, on waking, 9-11,14-16,18-20 hours and at bedtime. The diurnal variability was observed as lowest PEF values at waking in morning, a progressive rise with peak at 18 hours in evening and a small decrease at bedtime. Diurnal variation for individual subject was calculated by using amplitude percent mean (A%M) and was 4.11+/-1.21. We conclude that a definite pattern of diurnal variation in PEF is seen in healthy population and its knowledge is important meaningful interpretation of PEF recordings in disease condition.