Comparison of body composition and respiratory muscle strength in children and adolescents

Abstract

The evaluation of respiratory muscle strength is widely used in pediatric intensive care units, determining the chance for success or failure of extubation until the monitoring of ambulatory patients with neuromuscular diseases and respiratory diseases. There are reports that body composition and pubertal stage can be determining factors in respiratory muscle strength, because the amount of lean mass can change the strength of skeletal muscles, including respiratory muscles. As above this means the composition, amount of lean mass, and pubertal stage may explain the change in respiratory muscle strength in children and adolescents, in addition to age and gender. Objectives: To correlate the strength of respiratory muscles (maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP)) with body composition (lean) and pubertal stage in children and adolescents. There will be a cross-sectional study in healthy individuals from public high schools of Sao Paulo city. Inclusion criteria: individuals between 6 and 18 years without cardiopulmonary disease, acute or chronic absence of neuromuscular dysfunction, spirometry within the limits of normality. Exclusion criteria: physical activity more than twice a week, unable to perform the maneuvers. Bioimpedance equipment is Quantum BIA-101Q RJL brand-101TM (Detroit, MI) tetrapolar. The volunteer is positioned supine, taking care to keep the upper and lower members away from the body at approximately 30 °, from the midline. Lean body mass is obtained from the following equation: lean mass = 2.38 + (0.58 E2 / R) + (0.23 x PCT), where E2: height squared, R: resistance and PCT: bodyweight total. The evaluation of respiratory muscle strength will be made by the manometer with a scale ranging from ± 300 cmH2O (Gerar ®, São Paulo - Brazil), which will be connected to a plastic breathing tube and mouthpiece. Acceptable maneuvers are those without leakage of air between the lips, with maximum supporting pressure by at least one second, and reproducible, ie, varying less than or equal to 10% of the highest value. The staging of sexual maturation will be done by evaluation of breast and pubic hair in females and genital and pubic hair in males. The breasts and male genitalia are assessed on the size, shape, and characteristics, and pubic hair by its characteristics, amount, and distribution, according to the Turner scale. (AU)