Neuromuscular and acute symptoms responses to progressive elastic resistance exercise in patients with chronic obstructive pulmonary disease:Cross-sectional study

BACKGROUND: Quadriceps muscle training is a key part in the rehabilitation of chronic obstructive pulmonary disease (COPD) patients. However, exercise intensity prescription and progression with the typically used elastic bands is challenging. We aimed to evaluate neuromuscular, acute symptoms and cardiorespiratory responses (heart rate and dyspnea) during progressive elastic resistance exercise in patients with COPD. METHODS: Fourteen patients diagnosed with moderate-very severe COPD performed knee extensions at different elastic resistance levels (i.e., colors). The neuromuscular activity was recorded using surface electromyography for the rectus femoris, vastus lateralis and vastus medialis, together with rate of perceived exertion, perceived quadriceps fatigue, dyspnea, oxygen saturation and heart rate. RESULTS: For the vastus lateralis and rectus femoris, increase of muscle activity was evident from a two-level increment when using the red color. For the vastus medialis, there were no muscle activity progressions. Dyspnea, quadriceps fatigue and especially rate of perceived exertion increased in a dose-response fashion and were correlated with the resistance level and muscle activity at the three muscles. CONCLUSION: Heavy elastic resistance exercise is feasible in COPD patients without excessive dyspnea and a stable cardiorespiratory response. In general, at least two elastic resistance increments are needed to enhance muscle activity for the vastus lateralis and rectus femoris, while there is no increase for the vastus medialis. These results may help to individualize exercise dosing during elastic resistance training in patients with COPD

Physical activity in children and adolescents with cystic fibrosis: A systematic review and meta-analysis

Background Exercise and physical activity (PA) are essential components of the care of cystic fibrosis (CF) patients. Lower PA levels have been associated with worse pulmonary function, aerobic fitness, glycemic control, and bone mineral density. Most people with CF do not engage in the recommended amounts of PA. Objective To determine the level of PA in children and adolescents with CF. Methods A systematic review with meta-analysis was conducted without language restrictions in five databases. Were included studies that analyzed PA measured by objective and subjective instruments in children and adolescents with CF. Two independent reviewers analyzed the studies, extracted the data, and assessed the quality of evidence. The risk of bias of the included studies was assessed with the National Heart, Lung, and Blood Institute's risk-of-bias tool. Results Of the 1535 reports returned by the initial search, 20 articles reporting on 785 patients were included in the data synthesis. The forest plot showed that the CF group had a similar moderate-to-vigorous PA (MVPA) (mean difference, -7.79; 95% CI, -15.65 to 0.08 min/d;P = .05) and sedentary time (mean difference, -50.81; 95%CI, -109.96 to 8.35 min/d;P = .09) to the control group. Conclusion Children and adolescents with CF have a similar MVPA and sedentary time compared to controls. There are many options, subjective and objective, for assessing PA in this population. Optimal tool selection should guarantee more valid results.Universidad de Chil

Agreement between clinical and non-clinical digital manometer for assessing maximal respiratory pressures in healthy subjects.

Measurement of respiratory muscles strength such as maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP) are used to detect, diagnose and treat respiratory weakness. However, devices used for these measurements are not widely available and are costly. Currently, the use of a digital manometer is recommended. In industry, several inexpensive devices are available, but these have not been validated for clinical use. Our objective was to determine the agreement between maximal respiratory pressures obtained with a clinical digital manometer and that with a non-clinical digital manometer in healthy volunteers. We assessed the height, weight, lung function, MIP, and MEP of healthy volunteers. To compare pressures obtained by each type of digital manometer, a parallel approach configuration was used. The agreement was measured with the Intraclass Coefficient Correlation (ICC) and the Bland-Altman plot. Twenty-seven participants (14 men) were recruited with a median age of 22 (range: 21-23) years. Each participant underwent three measurements to give a total of 81 measurements. The mean MIPs were 90.8 ± 26.4 (SEM 2.9) and 91.1 ± 26.4 (SEM 2.9) cmH2O for the clinical and non-clinical digital manometers, respectively. The mean MEPs were 113.8 ± 40.4 (SEM 4.5) and 114.5 ± 40.5 (SEM 4.5) cmH2O for the clinical and non-clinical digital manometers, respectively. We obtained an ICC of 0.998 (IC 0.997-0.999) for MIP and 0.999 (IC 0.998-0.999) for MEP. There is a high agreement in the values obtained for MIP and MEP between clinical and non-clinical digital manometers in healthy volunteers. Further validation at lower pressures and safety profiling among human subjects is needed

Development of a small panel of SNPs to infer ancestry in chileans that distinguishes Aymara and Mapuche components

Background Current South American populations trace their origins mainly to three continental ancestries, i.e. European, Amerindian and African. Individual variation in relative proportions of each of these ancestries may be confounded with socio-economic factors due to population stratification. Therefore, ancestry is a potential confounder variable that should be considered in epidemiologic studies and in public health plans. However, there are few studies that have assessed the ancestry of the current admixed Chilean population. This is partly due to the high cost of genome-scale technologies commonly used to estimate ancestry. In this study we have designed a small panel of SNPs to accurately assess ancestry in the largest sampling to date of the Chilean mestizo population (n = 3349) from eight cities. Our panel is also able to distinguish between the two main Amerindian components of Chileans: Aymara from the north and Mapuche from the south. Results A panel of 150 ancestry-informative markers (AIMs) of SNP type was selected to maximize ancestry informativeness and genome coverage. Of these, 147 were successfully genotyped by KASPar assays in 2843 samples, with an average missing rate of 0.012, and a 0.95 concordance with microarray data. The ancestries estimated with the panel of AIMs had relative high correlations (0.88 for European, 0.91 for Amerindian, 0.70 for Aymara, and 0.68 for Mapuche components) with those obtained with AXIOM LAT1 array. The country's average ancestry was 0.53 +/- 0.14 European, 0.04 +/- 0.04 African, and 0.42 +/- 0.14 Amerindian, disaggregated into 0.18 +/- 0.15 Aymara and 0.25 +/- 0.13 Mapuche. However, Mapuche ancestry was highest in the south (40.03%) and Aymara in the north (35.61%) as expected from the historical location of these ethnic groups. We make our results available through an online app and demonstrate how it can be used to adjust for ancestry when testing association between incidence of a disease and nongenetic risk factors. Conclusions We have conducted the most extensive sampling, across many different cities, of current Chilean population. Ancestry varied significantly by latitude and human development. The panel of AIMs is available to the community for estimating ancestry at low cost in Chileans and other populations with similar ancestry.FONDEF D10I1007 D10E100