Diurnal variation of peak expiratory flow rate in healthy young adults: A gender-based study

Abstract

Background: Peak expiratory flow rate (PEFR) variability follows a diurnal rhythmic pattern in healthy people as well as in asthmatics. A number of studies are there on diurnal variation of PEFR in asthmatics. However, there are fewer studies on diurnal variation in PEFR in young adult male and female in Indian population. Objective: To find out diurnal PEFR variability in young male and female separately in Indian population. Materials and Methods: Sixty-three male and 40 female medical students of age 18–24 years were recruited for this study as the participants. After proper training, PEFR recording of the participants was taken at 6–7 am, 9–10 am, 1–2 pm, 5–6 pm, and 10–11 pm by Mini-Wright peak flow meter. Recording was done by students themselves in guidance of principal investigator. Data analysis was done by unpaired t-test and one-way ANOVA. Diurnal variation of each participant was calculated by two indices, i.e., amplitude percent mean (A%M) and standard deviation percent mean (SD%M). Results: There was a significant difference in PEFR at different time periods in both male and female (P = 0.000) which shows lowest at morning followed by progressive rise in day, highest at evening, and again fall at bedtime. A%M between male and female was found significant (P = 0.019), but SD%M between male and female was not significant (P = 0.105). Conclusion: Our study provides the reference data of diurnal variation of PEFR in male and female which further will be helpful in diagnosis and monitoring of bronchial asthma patients.