Background: Several tests may be used to assess exercise intolerance in cystic fibrosis (CF), including the gold standard cardiopulmonary exercise test (CPET) and the Modified Shuttle Test (MST).Objective: To evaluate the use of the MST as a predictor of peak oxygen uptake (VO 2 peak) and to compare VO 2 peak and maximal heart rate (HRmax) obtained in both tests.Methods: Cross-sectional study including individuals with CF aged between 6 and 20 years old. Participants who were unable to perform the tests and/or presented signs of pulmonary exacerbation were excluded. Demographic, anthropometric, clinical and spirometric values were collected. CPET and the MST were performed in two consecutive outpatient visits. HRmax, peripheral oxygen saturation, dyspnea, and VO 2 peak measured and estimated were compared.Results: Twenty-four patients, mean age 15.7 ± 4.2 years and FEV 1 (% predicted) 76.4 ± 23.8, were included. Mean values of HRmax (bpm) and HRmax in percent of predicted (HRmax%) were lower (P = 0.01) in the MST (171.6 ± 14.5 and 87.1 ± 7.5) compared to CPET (180.9 ± 10.0 and 91.9 ± 5.4). However, there was no significant differences between tests in the variation (delta) for HRmax and HRmax% (P = 0.17). A strong correlation (r = 0.79; P < 0.0001) was found between distance achieved (MST) and VO 2 peak (CPET). The regression model to estimate VO 2 peak resulted in the following equation: VO 2 (mL · kg −1 · min −1 ) = 20.301 + 0.019 × MST distance (meters). There was no difference (P = 0.50) between VO 2 peak measured (CPET) and estimated by the equation. Conclusion:The MST may be an alternative method to evaluate exercise capacity and to predict VO 2 peak in children and adolescents with CF.

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Despite the overwhelming evidence supporting the effectiveness of antihypertensive medication, hypertension remains poorly controlled in low and middle-income countries (LMICs). Lifestyle intervention studies reporting effects on blood pressure published from January 1977 to September 2012 were searched on various databases. From the 6211 references identified, 52 were included in the systematic review (12, 024 participants) and 43 were included in the meta-analysis (in total 6779 participants). We calculated and pooled effect sizes in mmHg with random-effects models. We grouped interventions into behavioral counseling (1831 participants), dietary modification (1831 participants), physical activity (1014 participants) and multiple interventions (2103 participants). Subgroup analysis and meta-regression were used to evaluate origins of heterogeneity. Lifestyle interventions significantly lowered blood pressure levels in LMIC populations, including in total 6779 participants. The changes achieved in SBP (95% confidence interval) were: behavioral counseling -5.4 (-10.7, -0.0) mmHg, for dietary modification -3.5 (-5.4, -1.5) mmHg, for physical activity -11.4 (-16.0, -6.7) mmHg and for multiple interventions -6.0 (-8.9, -3.3) mmHg. The heterogeneity was high across studies and the quality was generally low. Subgroup analyses showed smaller samples reporting larger effect sizes; intervention lasting less than 6 months showed larger effect sizes and intention-to-treat analysis showed smaller effect sizes Lifestyle interventions may be of value in preventing and reducing blood pressure in LMICs. Nevertheless, the overall quality and sample size of the studies included were low. Improvements in the size and quality of studies evaluating lifestyle interventions are required.

Objective: To evaluate the exercise capacity of children and adolescents with severe therapy resistant asthma (STRA) aiming to identify its main determinants. Methods: Cross-sectional study including individuals aged 6-18 years with a diagnosis of STRA. Clinical (age and gender), anthropometric (weight, height and body mass index) and disease control data were collected. Lung function (spirometry), cardiopulmonary exercise testing (CPET) and exercise-induced bronchoconstriction (EIB) test were performed. Results: Twenty-four patients aged 11.5 ± 2.6 years were included. The mean forced expiratory volume in one second (FEV 1 ) was 91.3 ± 9.2%. EIB occurred in 54.2% of patients. In CPET, the peak oxygen uptake (VO 2peak ) was 34.1 ± 7.8 mL kg À1 min À1 . A significant correlation between ventilatory reserve and FEV 1 (r ¼ 0.57; p ¼ 0.003) was found. Similarly, there was a significant correlation between CPET and percent of FEV 1 fall in the EIB test for both V E /VO 2 (r ¼ 0.47; p ¼ 0.02) and V E /VCO 2 (r ¼ 0.46; p ¼ 0.02). Patients with FEV 1 <80% had lower ventilatory reserve (p ¼ 0.009). In addition, resting heart rate correlated with VO 2peak (r¼-0.40; p ¼ 0.04), V E /VO 2 (r ¼ 0.46; p ¼ 0.02) and V E /VCO 2 (r ¼ 0.48; p ¼ 0.01). Conclusions: Exercise capacity is impaired in approximately 30% of children and adolescents with STRA. The results indicate that different aspects of aerobic fitness are influenced by distinct determinants, including lung function and EIB.

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Objective: To compare the values of measured maximum heart rate (HRmax) and maximum heart rate estimated by different equations during the cardiopulmonary exercise test (CPET) in obese adolescents.Methods: This is a cross-sectional study. Adolescents aged between 15 and 18 years old, with obesity (BMI Z-score>2.0) were included. Demographic and anthropometric data were collected, followed by CPET, recording HRmax. The highest heart rate reached at peak exercise was considered as HRmax. The comparison between measured and estimated HRmax values was performed using four previous equations. Descriptive statistics and the ANOVA test (Bonferroni post-test) were used.Results: Fifty-nine obese adolescents were included, 44% of them male. The mean age was 16.8±1.2 years old and the BMI (Z-score) was 3.0±0.7. At peak exercise, the mean HRmax (bpm) was 190.0±9.2, the respiratory coefficient was 1.2±0.1, and the VO2max (mL/kg/min) was 26.9±4.5. When comparing the measured values of HRmax with those estimated by the different formulas, the equations “220-age”, “208-0.7 x age” and “207-0.7 x age” were shown to overestimate (p<0.001) the measured HRmax results in obese adolescents. Only the “200-0.48 x age” equation presented similar results (p=0.103) with the values measured in the CPET. Conclusions: The findings of the present study demonstrate that the equation “200-0.48 x age” seems to be more adequate to estimate HRmax in obese adolescents.

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BACKGROUND: Patients with cystic fibrosis develop decreased exercise capacity. However, the main factors responsible for this decline are still unclear. Thus, the objective of this study was to evaluate the factors influencing exercise capacity assessed with the modified shuttle test (MST) in individuals with cystic fibrosis. METHODS: A cross-sectional study was carried out in subjects with a diagnosis of cystic fibrosis who were 6-26 y old and were regularly monitored at 2 cystic fibrosis reference centers in Brazil. Individuals who were unable to perform the tests or who exhibited hemodynamic instability and exacerbation of respiratory symptoms were excluded. Anthropometric, clinical, and genotype data were collected. In addition, lung function and exercise capacity were evaluated with the MST. RESULTS: 73 subjects (mean age 12.2 6 4.9 y and FEV 1 76.8 6 23.3%) were included. The mean distance achieved in the MST was 765 6 258 m (71.6% of predicted). The distance achieved on the MST correlated significantly with age (r 5 0.49, P < .001), body mass index (r 5 0.41, P < .001), resting heart rate (r 5 20.51, P < .001), and FEV 1 (r 5 0.24, P 5 .042). Subjects with FEV 1 > 67% of predicted (P 5 .02) and those with resting heart rate < 100 beats/min (P 5 .01) had a greater exercise capacity. Resting heart rate, age, and FEV 1 (%) were found as significant variables to explain the distance achieved on the MST (R 2 5 0.48, standard error 5 191.0 m). CONCLUSIONS: The main determinants of exercise capacity assessed with the MST in individuals with cystic fibrosis were resting heart rate, age, and lung function.