Cyclical Changes of Peak Expiratory Flow Rate in Healthy Young Females

Menstrual cycle is a natural physiological process of female during reproductive age group. Changes of estrogen and progesterone in different phases of menstrual cycle play a crucial role in respiratory functioning. Hence, this study was designed to estimate the change of peak expiratory flow rate (PEFR) in different phases of menstrual cycle. This study included 73 healthy young females of age group of 20-25 years. All participants were in the range of normal body mass index. Weighing machine VIRGO Model no 9811 B was used for the estimation of body weight. The machine was standardized by a known 20 kg weight material. The height of the subject was measured by stadiometer and expressed in meter. PEFR was recorded by Mini Wright's peak flow meter. PEFR recording was done between 3[sup.rd] and 4[sup.th] days of cycle for menstrual phase, between 10[sup.th] and 12[sup.th] days of cycle for proliferative phase, and between 21[sup.st] and 25[sup.th] days of cycle for secretory phase. The PEFR in menstrual, proliferative, and secretory phases of menstrual cycle was 310 ± 43, 347 ± 52, and 377 ± 47 L/min, and these variations were found to be significant with P < 0.0001. Post hoc analysis of PEFR between the groups showed P value between Group I-II, II-III, and III-I was 0.019, 0.048, and < 0.0001, respectively (I - menstrual phase, II - proliferative phase, and III - secretory phase). This study observed that the PEFR in secretory phase is highest, followed by proliferative phase then menstrual phase.