Reference values for lung function tests. II. Maximal respiratory pressures and voluntary ventilation.

J.A Neder,M.C Lerario,L.E Nery,S Andreoni

doi:10.1590/s0100-879x1999000600007

Abstract

The strength of the respiratory muscles can be evaluated from static measurements (maximal inspiratory and expiratory pressures, MIP and MEP) or inferred from dynamic maneuvers (maximal voluntary ventilation, MVV). Although these data could be suitable for a number of clinical and research applications, no previous studies have provided reference values for such tests using a healthy, randomly selected sample of the adult Brazilian population. With this main purpose, we prospectively evaluated 100 non-smoking subjects (50 males and 50 females), 20 to 80 years old, selected from more than 8,000 individuals. Gender-specific linear prediction equations for MIP, MEP and MVV were developed by multiple regression analysis: age and, secondarily, anthropometric measurements explained up to 56% of the variability of the dependent variables. The most cited previous studies using either Caucasian or non-Caucasian samples systematically underestimated the observed values of MIP (P < 0.05). Interestingly, the self-reported level of regular physical activity and maximum aerobic power correlates strongly with both respiratory and peripheral muscular strength (knee extensor peak torque) (P < 0.01). Our results, therefore, provide a new frame of reference to evaluate the normalcy of some useful indexes of respiratory muscle strength in Brazilian males and females aged 20 to 80.

Highlights

Ventilation plays a key role in the adequacy of the external gas exchange, the ultimate lung function
In addition to the typical demographic and anthropometric variables, this study evaluated the relationship of physical fitness with these indexes of respiratory muscle strength
Height, weight, lean body mass and regular level of physical activity showed a significant positive relationship (Table 2). When these variables were considered in a multiple regression analysis, only gender and age continued to have an independent predictive role for the three dependent variables (Table 3)

Summary

Introduction

Ventilation plays a key role in the adequacy of the external gas exchange, the ultimate lung function. MIP is the greatest subatmospheric pressure that can be generated during inspiration against an occluded airway; MEP is the highest pressure that can be developed during a forceful expiratory effort against an occluded airway, and MVV is the largest volume that can be ventilated during a 10- to 15-s interval with voluntary effort [1] These relatively simple and inexpensive measurements, apart from having a role in the diagnosis and prognosis of a number of neuromuscular and pulmonary disorders, have been associated with health status, physical fitness and even post-surgical and general morbidity-mortality [1,2,3]. In addition to the typical demographic and anthropometric variables, this study evaluated the relationship of physical fitness (aerobic power and the level of regular physical activity) with these indexes of respiratory muscle strength

Methods

Results

Conclusion