Normative Data of Maximal Respiratory Pressures in Adult Population of the Himalayan Region: A Cross-sectional Study

Introduction: Measurement of Maximal Static Respiratory Pressures (MSRP) is a non invasive tool to determine global respiratory muscle strength. The unique lifestyle factors in the Himalayan region, prompted the need for establishing normative values. Aim: To establish the typical maximum respiratory pressures in the Himalayan region and, secondarily, to develop a predictive equation based on the normative data collected. Materials and Methods: A cross-sectional observational study was conducted at the Department of Respiratory Medicine, Himalayan Institute of Medical Sciences, Swami Rama Himalayan University, Dehradun, Uttarakhand, India. A total of 101 non smokers (78 males, 23 females) aged from 19-70 years were selected after initial screening by a questionnaire and spirometry from the attendants of patients attending Himalayan Hospital from July 2000 to May 2022. Sustained Nasal Inspiratory Pressure (SNIP), Maximal Expiratory Pressure (MEP), and Maximal Inspiratory Pressure (MIP) values were measured using Micro Respiratory Pressure Meter (RPM) following the American Thoracic Society Technical Statement (ATS) standard protocol. The prediction model for the Maximal Respiratory Pressure (MRP) was obtained using regression analysis. Height, age, weight, and Body Mass Index (BMI) were included as variables in the calculations. The statistical analysis was conducted using the Statistical Package for Social Sciences (SPSS) program for Windows (Version 22.0). Results: There was a statistically significant difference observed in MIP among males 91.77±29.41 cmH2 O and females 65.26±19.55 cmH2 O and in MEP among males 86.37±26.96 cmH2 O and females 56.04±18.29 cmH2 O. Both MIP and MEP averages were more in males than in females. In the present study, there was no significant relationship between height, weight, BMI, and respiratory pressure in females. There was no significant relationship between MIP and MEP plus height, age, weight, or BMI. Weight (r-value=0.24), age (r-value=0.27), and BMI (r-value=0.27) all had a significant association in men. Conclusion: Based on these findings, it can be concluded that there are gender-based disparities in MRP in the Himalayan population, with males exhibiting higher average values than females. Additionally, while there was no significant correlation between anthropometric factors and respiratory pressures in females, in males, weight, age, and BMI showed significant associations with these respiratory parameters.