Equações preditivas e valores de normalidade para pressões respiratórias máximas na infância e adolescência

Effects of aerobic interval training on glucose tolerance in children and adolescents with cystic fibrosis: a randomized trial protocol

BACKGROUND

Individuals with cystic fibrosis (CF) may develop CF-related diabetes (CFDR). This comorbidity is related to a poorer quality of life, microvascular complications, a decline in lung function, and an increase in exacerbations, as well as delayed growth and puberty. Evidence exists that physical exercise contributes to glycemic control in individuals with non-CF-related diabetes. This exercise is usually continuous with moderate intensity and long duration, which can cause muscle dyspnea and fatigue in CF individuals. Aerobic interval training (AIT) emerges as a safe and effective alternative for treating these individuals. The objective of this study is to evaluate the effects of AIT on glucose tolerance in children and adolescents with CF.

METHODS

This study will be a two-arm, prospectively registered, randomized controlled trial with blind assessors and twenty 6- to 18-year-old individuals with cystic fibrosis (CF) from two different Brazilian states. People with CF will be randomly allocated to either the experimental or control group using block randomization, stratified by puberty stage,. Participants from both groups will receive an educational intervention and will be asked to continue their usual daily treatment for the full duration of the study. Those in the experimental group will perform AIT on a cycle ergometer at home three times a week, for 8 consecutive weeks. The sample characterization will include an assessment of puberty stage, socioeconomic status, dyspnea, and anthropometry. The primary outcome will be the change in glucose tolerance, while the secondary outcomes will include lung function, exercise tolerance, respiratory muscle strength, quality of life, and CF exacerbations. All outcomes will be assessed at baseline, week 9, and week 17.

DISCUSSION

This is the first study to evaluate the effects of AIT on glucose tolerance in children and adolescents with CF. This study will serve as a basis for guiding clinical practice and decision-making in treating glucose intolerance and CF-related diabetes (CFRD) in children and adolescents with CF.

TRIAL REGISTRATION

ClinicalTrials.gov Protocol Registration System: NCT03653949. Registered on August 31, 2018.

Predictive equations for maximal respiratory pressures of children aged 7-10

•

Predictive equations allow comparisons between children with or without changes in respiratory muscle strength.

•

Predictive equations facilitate the monitoring and control of physical therapy interventions.

•

Age and biometric measurements had little influence on the values of maximal respiratory pressures.

Background

Measurements of respiratory muscle strength are widely used for assessment in children; however, clearly defined predictive equations for the Brazilian pediatric population have yet to be established.

Objective

To determine the prediction equations for maximal respiratory pressures in healthy children.

Method

Cross-sectional observational study with normal-weight students aged 7–10 years (n = 399, 198 boys) with health attested by the (International Study of Asthma and Allergies in Childhood) questionnaire and medical history. Biometric data were evaluated (weight, height, and body mass index) as predictors. Spirometry and maximal expiratory pressure values were measured according to the recommendations of the American Thoracic Society. To verify data normality, the Shapiro–Wilk test was applied, and Pearson's test was used to verify the correlation between variables. The models were developed using simple linear regression and multivariate analyses. For all tests, the significance level was p < 0.05.

Results

Boys showed higher values of maximal respiratory pressures than girls, both increasing with age. For boys, these values had moderate correlation with age, weight, and height and weak correlation with body mass index. For girls, maximum inspiratory pressure had a weak correlation with age and moderate correlation with biometric data. Maximum expiratory pressure had a moderate correlation with age and biometric measures. The best predictive models were found in boys: Log(MIP) = 1.577 + 0.006 × weight (kg) (R²_aj = 14.1%) and Log(MEP) = 1.282 + 0.409 × height (m) (R²_aj = 13.9%); and for girls: Log(MIP) = 1.548 + 0.006 × weight (kg) (R²_aj = 15.0%) and Log(MEP) = 1.524 + 0.012 × age (years) + 0.005 × weight (kg) (R²_aj = 21.6%).

Conclusion

Prediction equations for maximal respiratory pressures were developed for boys and girls. The biometric measurements were shown to have a weak influence on the results.

Comparação dos valores medidos e previstos de pressões respiratórias máximas em escolares saudáveis

A Força Muscular Respiratória é uma ferramenta capaz de diagnosticar diferentes desordens. As equações de referência até hoje descritas consideram diferentes populações e metodologias. Entretanto, não há consenso quanto a qual equação é ideal para se utilizar. O objetivo deste estudo foi comparar e correlacionar valores medidos de pressões respiratórias máximas com aqueles previstos por equações descritas na literatura. A amostra foi de 90 indivíduos saudáveis de 6 a 12 anos. Foram realizadas antropometria, espirometria e manovacuometria. A comparação dos valores medidos e previstos diferiu significativamente, apresentando pressão inspiratória máxima (PImáx) média (80,65±26,78), no sexo masculino, maior que a prevista por Wilson et al. (67,40±5,65; p<0,001) e Schmidt et al. (70,69±21,70; p<0,05). Pressão expiratória máxima (PEmáx) masculina média (84,35±23,16) foi menor que a prevista por Domènech-Clar et al. (92,25±16,90; p<0,01) e maior que a prevista por Schmidt et al. (72,78±13,62; p<0,001). Pressão inspiratória máxima feminina média (76,14±26,08) foi maior que a prevista por Wilson et al. (57,96±6,04; p<0,001), Schmidt et al. (68,54±7,08; p<0,01) e Domènech-Clar et al. (67,61±11,17; p<0,01). Pressão expiratória máxima feminina média (74,55±20,05) foi maior que a prevista por Wilson et al. (66,65±9,55; p<0,001) e menor que a prevista por Domènech-Clar et al. (81,16±14,37; p<0,01). As correlações entre valores medidos e previstos foram de baixa a média magnitude (variação entre r=0,1 e 0,5), sendo significativas para o sexo masculino quando a PImáx foi correlacionada à prevista por Wilson et al. (p<0,01) e Domènech-Clar et al. (p<0,05). Já para o sexo feminino, ambas as correlações foram significativas (PImáx p<0,01; PEmáx p<0,05). Concluiu-se que as equações não conseguiram predizer os valores de pressões respiratórias máximas, reforçando a necessidade de novas equações de força muscular respiratória.