Level of Physical Exercise Capacity, Respiratory Muscle Strength and Peak Expiratory Flow Rate in Healthy Adolescents.

ABSTRACT

Introduction: The maturation of respiratory system in children leads to changes in value of respiratory parameters like peak expiratory flow rate (PEFR), maximum inspiratory pressure (MIP), maximum expiratory pressure (MEP), and 6-minute walk distance (6MWD). Accurate analysis and clinical decisionmaking in disease state require reference values for different ages. The current study was undertaken to study pulmonary function and exercise capacity in children and adolescents. Materials and methods: After obtaining Institutional Ethical approval and parental informed consent, 262 subjects aged 9 to 15 years were recruited for the study. They were divided into two age groups, i.e., preadolescent (9-12 years) and early adolescent (13-15 years). Demographic details including age, sex, height, weight, and body mass index (BMI) were noted. Physical activity rating (PAR) scale was used to denote physical activity levels. Peak expiratory flow rate was measured using standard Mini-bell peak flow meter (PFM). The parameters MIP and MEP was measured using micro respiratory pressure meter, and 6-minute walk test (6MWT) was performed as per American Thoracic Society (ATS) guidelines. Results: A significant difference was noted between the two groups in PEFR, MIP, MEP, and 6MWD (p = 0.00). Age showed a strong positive correlation with PEFR (r = 0.613, p = 0.000), MIP (r = 0.676, p = 0.000), and MEP (r = 0.658, p = 0.00) whereas showed a strong negative correlation with 6MWD (r = -0.605, p = 0.00). Height showed a strong positive correlation with MEP (r = 0.720, p = 0.000) whereas a strong negative correlation with 6MWD (r = -0.42, p = 0.00). Weight showed a weak negative correlation with 6MWD (r = -0.328, p = 0.00). Gender difference was noticeable in 6MWD and PEFR (p = 0.00) but not in MIP (p = 0.45) and MEP (p = 0.44). Almost 22.10% of early adolescents were overweight compared to only 7.7% seen in preadolescent group. Conclusion: PEFR and respiratory muscle strength was higher in early adolescents as compared to pre-adolescents. However, exercise capacity reflected by 6 MWD was found to be lower in early adolescents in comparison to pre-adolescents. These findings could be used while interpreting the outcome measures utilized while treating patients and for goal setting in cardiopulmonary rehabilitation in clinical practice.