Heart rate recovery in asthmastic children and adolescents after clinical field test

BACKGROUND

Inflammation caused by chronic lung disease in childhood may lead to delayed heart rate recovery (HRR) however, there is lack of evidence on HRR in this population. The aim was to assess HRR after functional capacity testing in asthmatic children and adolescents and to compare with severity and disease control.

METHOD

This was a study secondary to a randomized control trial. The modified shuttle test (MST) was performed to assess functional capacity and HRR. This is an externally cadenced test in which the distance walked is the outcome. HRR was assessed after MST and was defined as HR at exercise peak minus HR in the second minute after the end of exercise. Asthma control was assessed by the Asthma Control Test (ACT). Data normality was tested by Shapiro Wilk and the comparison between groups was made by Student's t test or Mann Whitney test for numerical variables, and by Chi-square test for categorical variables. Statistical significance was considered when p < 0.05. SPSS version 20 was used in the analyzes.

RESULTS

The sample included 77 patients diagnosed with asthma (asthma group - AG) who were regularly treated for asthma. Control group (CG) consisted of 44 volunteers considered healthy, matched in age and gender to AG. The median age of CG was 12 (10-14) years and in AG 11 (9-13 years) being classified as mild to moderate asthmatic, and 57% of the sample had controlled asthma by ACT. Distance walked in the CG was 952 ± 286 m and AG 799 ± 313 m, p = 0.001. HRR was more efficient in CG (79 ± 15 bpm) compared to AG (69 ± 12 bpm), p = 0.001. The mild (69 ± 12 beats) and severe (72 ± 15 beats) AG presented worse HRR compared to control group (79 ± 15 bpm), p < 0.05.

CONCLUSIONS

Asthmatic children and adolescents have delayed HRR after modified Shuttle test compared to their peers, suggesting that asthma leads to autonomic nervous system imbalance.

TRIAL REGISTRATION

Registered in Clinical Trials under number NCT02383069 and approved by the Universidade Nove de Julho - UNINOVE Research Ethics Committee, protocol number 738192/2014.

Expanding the Use of Six-Minute Walking Test in Patients with Intermittent Claudication

BACKGROUND

Six-min walking test (6MWT) has been widely in patients with symptomatic peripheral artery disease (PAD) to quantify the walking impairment and the efficacy of different therapeutic interventions. Despite the aforementioned usefulness of 6MWT for PAD, the information provided by this test goes beyond the meters walked. The aim of this study was to describe the relative values of 6MWT and body weight-walking distance product (DW) in patients with symptomatic PAD.

METHODS

Two hundred twenty-seven patients with symptomatic PAD participated in the study. The 6MWT was performed and absolute and claudication distances were obtained. The results of 6MWT were then relativized and expressed as a percentage of a healthy subject. DW was obtained by the product of 6MWT distance by weight. In both sexes, the relative 6MWT ranged from 57% to 64%.

RESULTS

Absolute 6MWT total distance (P < 0.001) was lower in women than in men, whereas the relative 6MWT total distance was similar between sexes (P = 0.398). The absolute and relative 6MWT total distance were similar among age categories (P > 0.072). The DW was higher in men than in women (P < 0.05). In addition, in women, DW was higher in younger group than in other age groups (P < 0.05).

CONCLUSIONS

Patients with symptomatic PAD achieve less than 70% of the distance achieved by an age-matched healthy subject. In patients with symptomatic PAD, the relative values of 6MWT total distance are similar between sexes and among different age groups, whereas DW are influenced by age and sex.

Reference values for spirometry in Brazilian children

Objective:

To generate reference values for spirometry in Brazilian children 3-12 years of age and to compare those values with the values employed in the equations currently in use in Brazil.

Methods:

This study involved healthy children, 3-12 years of age, recruited from 14 centers (primary data) and spirometry results from children with the same characteristics in six databases (secondary data). Reference equations by quantile regressions were generated after log transformation of the spirometric and anthropometric data. Skin color was classified as self-reported by the participants. To determine the suitability of the results obtained, they were compared with those predicted by the equations currently in use in Brazil.

Results:

We included 1,990 individuals from a total of 21 primary and secondary data sources. Of those, 1,059 (53%) were female. Equations for FEV₁, FVC, the FEV₁/FVC ratio, FEF between 25% and 75% of the FVC (FEF_25-75%) and the FEF_25-75%/FVC ratio were generated for white-, black-, and brown-skinned children. The logarithms for height and age, together with skin color, were the best predictors of FEV₁ and FVC. The reference values obtained were significantly higher than those employed in the equations currently in use in Brazil, for predicted values, as well as for the lower limit of normality, particularly in children with self-reported black or brown skin.

Conclusions:

New spirometric equations were generated for Brazilian children 3-12 years of age, in the three skin-color categories defined. The equations currently in use in Brazil seem to underestimate the lung function of Brazilian children 3-12 years of age and should be replaced by the equations proposed in this study.

Patients with asthma have reduced functional capacity and sedentary behavior

OBJECTIVE

The modified shuttle test is a field test that avoids the ceiling effect, and there are no reports of a multidimensional assessment concerning physical activity in asthmatic patients. Thus, the aim was to evaluate functional capacity by MST, additionally to perform a multidimensional assessment as physical activity in daily life, muscle strength, and cytokine levels in children and adolescents with asthma, and to correlate these variables.

METHOD

This cross-sectional study included volunteers aged between 6 and 18 years who were divided into two groups: asthma group (n=43) that received regular treatment and control group (n=24). Functional capacity was evaluated by distance walked during the MST; physical activity in daily life was evaluated using an accelerometer by the number of steps. Quadriceps femoris strength was evaluated by load cell.

RESULTS

Distance walked was lower for the asthma group (790m [222m]) when compared with the control group (950m [240m]; p=0.007); however, the number of steps was similar between the two groups (asthma group: 7743 [3075]; control group: 7181 [3040]; p=0.41), and both groups were classified as sedentary behavior. There was no difference in muscle strength. Tumor necrosis factor-α differed, but interleukin levels were similar between groups. Quadriceps strength was correlated to distance walked (r=0.62; p<0.001) and tumor necrosis factor-α to the number of steps taken (r=-0.54, p=0.005).

CONCLUSION

Children and adolescents undergoing regular asthma treatment showed reduced functional capacity and sedentary behavior. The lower the quadriceps strength, the shorter the distance walked; the higher the tumor necrosis factor-α levels, the lower their daily physical activity levels.

Relationship between gait speed and physical function in patients with symptomatic peripheral artery disease

OBJECTIVE

The aim of the study was to analyze the relationship between gait speed and measurements of physical function in patients with symptomatic peripheral artery disease (PAD).

METHODS

One hundred sixty-nine patients (age 66.6±9.4 years) with symptomatic PAD were recruited. Usual and fast gait speeds were assessed with a 4-meter walk test. Objective (balance, sit-to-stand, handrip strength, and six-minute walk test) and subjective (WIQ - Walking Impairment Questionnaire and WELCH - Walking Estimated-Limitation Calculated by History) measurements of physical function were obtained. Crude and adjusted linear regression analyses were used to confirm significant associations.

RESULTS

Usual and fast gait speeds were significantly correlated with all objective and subjective physical function variables examined (r<0.55, p<0.05). In the multivariate model, usual gait speed was associated with six-minute walking distance (β=0.001, p<0.001), sit-to-stand test score (β=-0.005, p=0.012), and WIQ stairs score (β=0.002, p=0.006) adjusted by age, ankle brachial index, body mass index, and gender. Fast gait speed was associated with six-minute walking distance (β=0.002, p<0.001), WIQ stairs score (β=0.003, p=0.010), and WELCH total score (β=0.004, p=0.026) adjusted by age, ankle brachial index, body mass index, and gender.

CONCLUSION

Usual and fast gait speeds assessed with the 4-meter test were moderately associated with objective and subjective measurements of physical function in symptomatic PAD patients.

Predicted Equation for VO2 Based on a 20-Meter Multistage Shuttle Run Test for Children

This study compared maximum oxygen consumption (VO₂max) on a 20-meter multistage shuttle run test (20-Srt) with a cardiopulmonary exercise test (CPET) to determine a VO₂max prediction equation for a 20-Srt in children aged 6-10 years. Eighty healthy children performed the CPET on a treadmill, while the 20-Srt took place on a sports court. Heart rate (HR) was measured and the expired gases were continuously measured breath-by-breath using a portable gas analyzer. The VO₂max was lower (p<0.05) in CPET than 20-Srt for all, female, and male participants, respectively (46.3±7.9 vs. 48.7±4.6; 42.7±7.8 vs. 46.7±4.8; 49.3±6.8 vs. 50.4±3.9, mL·kg-1·min-1). The standard error estimates were between 3.0 and 3.6 and considered as not clinically relevant if less than 5 mL·kg-1·min-1. The intraclass correlation coefficient between the VO₂ in CPET and in 20-Srt was 0.74 (CI95% 0.55-0.84) and considered moderately reliable. The linear multiple regression excluded sex, body mass index and fat-free mass and retained the maximum speed and age in the predictive equation. The 20-Srt estimates the VO₂max with moderate reliability and the predictive equation was VO₂maxpred=4.302+(maximum speed*5.613)-(age*1.523) for children aged 6-10 years.

Pulmonary function in former very low birth weight preterm infants in the first year of life

BACKGROUND

Pulmonary function in former preterm infants may be compromised during childhood.

OBJECTIVES

To assess pulmonary function in very-low-birth-weight preterm infants at 6-12 months of corrected age and analyze the factors associated with abnormal pulmonary function.

METHODS

Cross-sectional study with preterm infants at 6-12 months of corrected age with birth weight <1500 g. Children with malformations or affected by neuromuscular and respiratory diseases were excluded. Forced expiratory flows were assessed using the chest compression technique, and volumes were measured by total body plethysmography. Pulmonary function parameters in preterm infants were compared to a control group of same-aged children born at term.

RESULTS

We studied 51 preterm and 37 infants born at term. Preterm infants had: gestational age at birth (30.0 ± 2.5 weeks), birth weight (1179 ± 247 g), 27.5% had bronchopulmonary dysplasia, and 45% received mechanical ventilation. Preterm infants had lower median z-scores in comparison to term infants for the following parameters (p < 0.05): FVC (-0.3 vs. 0.7), FEV_0.5 (-0.5 vs. 0.9), FEV_0.5/FVC (-0.6 vs. -0.5), FEF₅₀ (-0.4 vs. 0.9), FEF₇₅ (-0.3 vs. 0.8), FEF₈₅ (-0.1 vs. 0.6) and FEF_25-75 (-0.5 vs. 1.1). No term child had abnormal lung function, compared to 39.2% of preterm infants (p = 0.001). Factors associated with abnormal pulmonary function were lower gestational age at birth, small for gestational age, need for mechanical ventilation and presence of recurrent wheezing.

CONCLUSIONS

Preterms had a high prevalence of abnormal pulmonary function and lower pulmonary function in comparison to term infants. Prematurity, intrauterine growth restriction, respiratory support and recurrent wheezing were associated with abnormal pulmonary function.

Effects of periodontal treatment on exacerbation frequency and lung function in patients with chronic periodontitis: study protocol of a 1-year randomized controlled trial

Background

Chronic obstructive pulmonary disease (COPD) has been associated with periodontal disease (PD), and periodontal treatment (PT) has been connected to reduction of lung disease exacerbations. Bronchiectasis has many clinical similarities with COPD but, although it is also a chronic lung disease, to date it has not been studied with relation to PD. The aim of this study is to evaluate whether PT associated with photodynamic therapy (PDT) reduces the number of exacerbations, improves pulmonary function, periodontal clinical parameters and quality of life after 1 year of periodontal treatment follow-up.

Methods

Bronchiectasis patients will undergo medical anamnesis and periodontal examination. Participants with periodontitis will be divided into two groups and PT will be performed as G1 control group (n = 32) – OHO (oral hygiene orientation) + supragingival treatment + simulation of using photodynamic therapy (PDT); G2 experimental (n = 32) – scaling and root planing + PDT + OHO. Lung function will be assessed both at baseline and after 1 year by spirometry, exacerbation history will be analyzed through clinical records monitoring. Three instruments for quality of life assessment will also be applied – Saint George’s Respiratory Questionnaire and Impact Profile Analysis Oral health (OHIP-14). It is expected that periodontal treatment can improve the analyzed parameters after 1 year.

Discussion

Although only one study evaluates exacerbation in COPD after 1 year of PT, bronchiectasis has not been studied in the dentistry field to date. Trial registration: NCT02514226. Version #1. This study protocol receives grant from FAPESP (São Paulo Research Foundation) #2015/20535-1. First received: July 22, 2015, 1^st version. This protocol has been approved by the Research Ethics Committee of Nove de Julho University.

Bronchodilator response in wheezing infants assessed by the raised volume rapid thoracic compression technique

BACKGROUND

Bronchodilator response (BDR) analyzed by the raised volume rapid thoracic compression (RVRTC) in wheezing infants is not yet well described, although bronchodilators (BD) are routine in the treatment of this population.

OBJECTIVE

To evaluate BDR by RVRTC technique in infants with recurrent wheezing and compare to control group.

METHOD

Cross sectional study, 45 infants, age 56 weeks (38-67 weeks). Two groups: wheezing group (WG: history of recurrent wheezing) and control group (CG). RVRTC was evaluated, FVC, FEV_0.5, FEF₅₀, FEF₇₅, FEF_85, FEF_25-75 were measured. Salbutamol was delivered to infants and RVRTC evaluated again. BDR was determined by the increase greater than two standard deviation from the mean change in the CG.

RESULTS

In WG (n = 32) lung function was worse than in CG (n = 13): FEV_0.5: 0.0(-0.9-0.9z score) vs 0.8(0.2-1.4z score); FEF₅₀: 0.2(-0.3-1.1z score) vs 0.9(0.5-1.4z score); and FEF_25-75: 0.2(-0.5-1.1z score) vs 1.1(0.6-1.6z score), respectively, p < 0.05. Both groups had similar increase after BD. In WG 11 patients (34%) were responder and these had worse lung function compared to nonresponder (n = 21) (p < 0.05). The increase in lung function after BD in responder was higher than in nonresponder: FEV_0.5: 6.5(2.1-7.1%) vs -0.5(-2.5-0.7%), FEF₅₀: 5.1(2.7-11.7%) vs 0.4(-1.1-2.8%), FEF₇₅: 20.7(4.7-23.6%) vs -1.3(-6.4-3.9%), FEF_25-75: 9.9(3.8-16.4%) vs 0.0(-1.5-1.0%), respectively, p < 0.05.

CONCLUSION

34% WG showed BDR measured by the RVRTC. The best variables to detect BDR were FEF₇₅, FEF_25-75 and FEV_0.5. Patients with worse lung function showed better response to BD.

Prevalence and associated factors for asthma in Brazilian and Japanese schoolchildren living in the city of São Paulo, Brazil

OBJECTIVES

Ethnic background interferes on the prevalence of asthma among schoolchildren (4 to 9 years old, SC) born and living in São Paulo, Brazil.

METHODS

International Study of Asthma and Allergy in Childhood (ISAAC)'s written standard and complementary questionnaires were applied to SC (similar socioeconomic status) living in the city of São Paulo: no-Japanese Brazilian (NJB, N = 306) and Japanese Brazilian (third generation, born in Brazil, from Japanese families with no miscegenation, JB, N = 258).

RESULTS

The prevalence of current asthma was significantly higher among NJB in comparison to JB (22.2% vs 14.7%, respectively). To have rhinitis and to exercise less than once/week were risk factors for both groups of children.

CONCLUSION

Although both groups were apparently exposed to the same environment, other cultural differences do not allow us to conclude about the ethnic component having greater influence than the environment in the development of asthma in these individuals.

Reference Equation for Respiratory Pressures in Pediatric Population: A Multicenter Study

Previous studies have proposed only one prediction equation for respiratory muscle strength without taking into consideration differences between ages in pediatric population. In addition, those researches were single-center studies. The objective of this study was to establish reference equations for maximal inspiratory pressure (PImax) and maximal expiratory pressure (PEmax) in children and teenagers. In a multicenter study, 450 healthy volunteers were evaluated (aged 6–18yrs). There were included volunteers with normal lung function. We excluded volunteers who could not perform the tests; participated in physical activity more than twice a week; were born prematurely; smokers; chronic respiratory, cardiologic, and/or neurologic diseases; had acute respiratory disease during the prior three weeks. The volunteers were divided into two groups: Group 6–11 (6–11yrs) and Group 12–18 (12–18yrs). PImax and PEmax were measured according to statement. The mean PImax value was 85.6 (95%IC 83.6–87.6 cmH₂O), and PEmax 84.6 (95%IC 85.5–86.2 cmH₂O). The prediction equations for PImax and PEmax for Group 6–11 were 37.458–0.559 + (age * 3.253) + (BMI * 0.843) + (age * gender * 0.985); and 38.556 + 15.892 + (age * 3.023) + (BMI * 0.579) + (age * gender * 0.881), respectively (R² = 0.34 and 0.31, P<0.001). The equations for Group 12–18 were 92.472 + (gender * 9.894) + 7.103, (R² = 0.27, P = 0.006) for PImax; and 68.113 + (gender * 17.022) + 6.46 + (BMI * 0.927), (R² = 0.34, P<0.0001) for PEmax. This multicenter study determined the respiratory muscle strength prediction equations for children and teenagers.

Effects of a pulmonary rehabilitation program on physical capacity, peripheral muscle function and inflammatory markers in asthmatic children and adolescents: study protocol for a randomized controlled trial

Background

Individuals with chronic lung disease are more susceptible to present reduction in exercise tolerance and muscles strength not only due to pulmonary limitations but also due systemic repercussions of the pulmonary disease.

The aim of this study is to assess the physical capacity, peripheral muscle function, physical activity in daily life, and the inflammatory markers in children and adolescents with asthma after pulmonary rehabilitation program.

Method

This is a study protocol of randomized controlled trial in asthmatic patients between 6 to 18 years old. The assessments will be conducted in three different days and will be performed at the beginning and at the end of the protocol. First visit: quality of life questionnaire, asthma control questionnaire, pre- and post-bronchodilator spirometry (400 μcg salbutamol), inflammatory assessment (blood collection), and cardiopulmonary exercise test on a cycle ergometer to determine aerobic capacity. Second visit: assessment of strength and endurance of the quadriceps femoris and biceps brachii muscles with concomitant electromyography to assess peripheral muscle strength. Third visit: incremental shuttle walk test (ISWT) and accelerometer to evaluate functional capacity and physical activity in daily life during 7 days. Then, the volunteers will be randomized to receive pulmonary rehabilitation program (intervention group) or chest physiotherapy + stretching exercises (control group). Both groups will have a supervised session, twice a week, each session will have 60 minutes duration, with minimum interval of 24 hours, for a period of 8 weeks. Intervention group: aerobic training (35 minutes) intensity between 60 to 80 % of the maximum workload of cardiopulmonary exercise testing or of ISWT; strength muscle training will be applied to the quadriceps femoris, biceps brachii and deltoid muscles (intensity: 40 to 70 % of maximal repetition, 3 x 8 repetition); finally the oral high-frequency oscillation device (Flutter®) will be used for 5 minutes. The control group: oral high-frequency oscillation device (Flutter®) for 10 minutes followed by the stretching of upper and lower limbs for 40 minutes. It is expected to observe the improvement in aerobic capacity, physical activity in daily life, muscle strength and quality of life of patients in the intervention group, and reduction in inflammatory markers.

Trial registration

Clinical Trial Number: NCT02383069. Data of registration: 03/03/2015