Menoufia Medical Journal

ORIGINAL ARTICLE
Year
: 2015  |  Volume : 28  |  Issue : 3  |  Page : 734--736

Respiratory reserve capacity in the proliferative phase of the menstrual cycle with reference to obesity


Amrith Pakkala1, Chitradurga Palaiah Ganashree2, Thippeswamy Raghavendra3,  
1 Department of Physiology, PES Institute of Medical Sciences and Research, Kuppam, India
2 Department of Physiology, Basaveshwara Medical College, Chitradurga, Karnataka, India
3 Department of Anesthesiology, Basaveshwara Medical College, Chitradurga, Karnataka, India

Correspondence Address:
Amrith Pakkala
No. 40, SM Road 1 st cross, T. Dasarahalli, 560 057 Bengaluru, Karnataka
India

Abstract

Background The role of estrogen in pulmonary function test (PFT) is well known in the normal course of the menstrual cycle. A significant increase in both progesterone (37%) and estradiol (13.5%) was observed in exercising women in previous studies, whereas no change in plasma follicle stimulating hormone and luteinizing hormone was observed. Therefore, this study was intended to see the limitations of the pulmonary system in adaptability to exercise in the proliferative phase of the menstrual cycle in obese and nonobese women. Participants and methods Healthy young women aged between 19 and 25 years and in the proliferative phase of their menstrual cycle leading a sedentary lifestyle were considered in the study group. Ten women in each group were studied on the basis of their BMI. They underwent treadmill exercise testing and computerized spirometry for assessment of their dynamic lung functions. Results It was observed that exercise per se does not cause a statistically significant change in dynamic lung function parameters - maximum mid expiratory flow (MMEF), peak expiratory flow rate, and mid expiratory flow 25-75% - in either of the groups. Conclusion This finding supports the hypothesis that the respiratory system is not normally the most limiting factor in the delivery of oxygen even under the predominant influence of estrogen in the proliferative phase, which is further accentuated by exercise, and obesity, at least borderline, does not have much influence on respiratory system adaptability.



How to cite this article:
Pakkala A, Ganashree CP, Raghavendra T. Respiratory reserve capacity in the proliferative phase of the menstrual cycle with reference to obesity.Menoufia Med J 2015;28:734-736


How to cite this URL:
Pakkala A, Ganashree CP, Raghavendra T. Respiratory reserve capacity in the proliferative phase of the menstrual cycle with reference to obesity. Menoufia Med J [serial online] 2015 [cited 2022 May 27 ];28:734-736
Available from: http://www.mmj.eg.net/text.asp?2015/28/3/734/165820


Full Text

 Introduction



The role of hormones in the healthy pulmonary system in delivering oxygen to meet the demands of various degrees of exercise has been a matter of debate. There are conflicting reports that the respiratory system is not normally the most limiting factor in the delivery of oxygen to the muscles during maximal muscle aerobic metabolism, whereas others do not subscribe to this. Within this context it is appropriate to study the effect of the proliferative phase of the menstrual cycle on ventilatory functions after exercise in obese individuals compared with nonobese individuals.

Mechanical constraints on exercise hyperpnea have been studied as a factor limiting performance in endurance athletes [1]. Others have considered the absence of structural adaptability to physical training as one of the 'weaknesses' inherent in the response of the healthy pulmonary system to exercise [2].

Ventilatory functions are an important part of functional diagnostics [3], aiding the selection and optimization of training and early diagnosis of sports pathology. Assessment of the exercise response of dynamic lung functions in the healthy pulmonary system in the obese and the nonobese may help augment the existing information, especially in a special group of individuals.

 Participants and methods



The present study was conducted as a part of cardiopulmonary efficiency studies on two groups of women - nonobese (n = 10) and obese (n = 10) - who were comparable in age and sex. Ethical clearance for the study was obtained from institutional ethical committee.

Informed consent was obtained and clinical examination was carried out to rule out any underlying disease. Healthy young women aged between 19 and 25 years who lead a sedentary lifestyle were considered in the study group. Obesity was determined by means of BMI. They were not involved in any regular exercise program. Smoking, clinical evidence of anemia, obesity, and involvement of cardiorespiratory system was considered as exclusion criteria. Menstrual history was ascertained to confirm the proliferative phase of the menstrual cycle.

Details of the treadmill exercise test and computerized spirometry were explained to the participants.

The treadmill was set to an elevation of 7°. The safety key was put in place and the mains were switched ON. The participant was made to stand on the belt and support the arms by the side in the arm support provided. The 'ON' switch was pressed to start the motor. The 'FAST' switch was pressed to increase the speed gradually up to 5 km/h, and the participant was instructed to run at this speed until a heart rate between 125 and 170 beats/min was recorded on the LCD display. A steady heart rate for a given workload is indicated by a variation of not more than 5 beats/min. On attaining this heart rate, the speed was gradually reduced by pressing the SLOW switch, and the machine was switched OFF.

The spirolyser was switched ON, participants' details were entered, and the vital capacity (VC) key was pressed and kept ready. The participants were suitably instructed about the test maneuver. Elevation was continued at 7°. They were asked to run until exhaustion and to stop only when they felt unable to continue running.

With the participant on the belt, the treadmill was switched ON and the FAST key was pressed. The speed was gradually increased to 10 km/h. When the participant could no longer continue running, the speed was gradually reduced and the treadmill was switched OFF.

Dynamic lung functions were measured in both groups before the exercise was evaluated following standard procedure of spirometry using a computerized spirometer (Spl-95, France International Medical Company, Lyon, France). All participants underwent maximal exercise testing to VO 2 max levels on a motorized treadmill.

After exercise, the assessment of dynamic lung functions was repeated. All these set of recordings were carried out on both the obese as well as the nonobese groups.

Statistical analysis

Statistical analysis was performed using paired Student's t-test for comparing parameters within the group before and after exercise testing and the unpaired t-test for comparing the two groups of participants.

In view of the less number of participants included in the study, a P-value less than 0.01 was considered as significant.

 Results



It is clear from [Table 1] that the study group is obese from the significantly higher BMI values.{Table 1}

On comparing the dynamic lung functions in the two groups from [Table 2] and [Table 3], there was no statistically significant change before and after the exercise.{Table 2}{Table 3}

 Discussion



Considerable information can be obtained by studying the exercise response of dynamic lung functions in untrained and trained participants.

Intragroup comparison is helpful in noting the exercise response and intergroup comparison in evaluating adaptations of the respiratory system to training.

On comparing the anthropometric data of the two study groups it is clear that participants with matched age and sex have no statistically significant difference in height. BMI determined the obesity status.

VO 2 max values were not significantly different in the two groups. This observation is expected in view of the similar sedentary lifestyle of the two groups and adaptability of both the pulmonary system and the cardiovascular system. VO 2 max is an objective index of the functional capacity of the body's ability to generate power.

Forced vital capacity (FVC) is the volume expired with the greatest force and speed from the total lung capacity (TLC), and forced expiratory volume in 1st second (FEV 1 ) is that expired during the first second during the same maneuver. The FEV 1 was initially used as an indirect method of estimating its predecessor as the principal pulmonary function test, the maximal breathing capacity [4].

On comparing the response of exercise within the two study groups and between them, there was no statistically significant difference in FVC and FEV 1 under any condition.

A normal FEV 1 /FVC ratio is observed always.

Another way of evaluating forced expiration is by measuring both expiratory flow and the volume expired. The maximum flow can be measured from a flow-volume curve and is represented as the peak expiratory flow rate. The peak flow occurs at high lung volumes and is effort dependent. Flow at lower lung volumes is effort independent. It depends on the elastic recoil pressure of the lungs and the resistance of the airways upstream or distal to the point at which dynamic compression occurs. For measurements of flow at low lung volumes, mid expiratory flow (25-75%) is often used as indices of peripheral or small airway resistance [5].

[Table 2] and [Table 3] show that exercise per se does not cause a statistically significant change in dynamic lung function parameters - MMEF, peak expiratory flow rate, or mid expiratory flow 25-75% - in either of the groups. This finding supports the hypothesis that the respiratory system is not normally the most limiting factor in the delivery of oxygen.

Thirty minutes of exercise at 74% of VO 2 was found to cause a significant increase in both progesterone (37%) and estradiol (13.5%), whereas no change in plasma follicle stimulating hormone and luteinizing hormone was observed in exercising women [6]; others have confirmed these findings. This finding supports the hypothesis that the respiratory system is not normally the most limiting factor in the delivery of oxygen even under the predominant influence of estrogen in the proliferative phase, which is further accentuated by exercise, and obesity, at least borderline, does not have much influence on respiratory system adaptability. The deleterious effect of weight gain is, to a large extent, reversible. Improvement in pulmonary mechanics is the great advantage gained by obese patients upon losing weight [7].

 Acknowledgements



Conflicts of interest

None declared.

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