Pulmonology · Medical Literature
Effects of extra training with active cycle of breathing technique relative to whole-body breathing exercise in older adults with stable COPD.
Abstract
To examine the effects of extra training with active cycle of breathing technique (ACBT) as compared to whole-body breathing exercise (WBBE) in older adults with stable chronic obstructive pulmonary disease (COPD). Fifty-one participants with stable COPD were randomly assigned into experimental group undergoing extra training of ACBT plus WBBE (n = 25), and control group undergoing WBBE only (n = 26), 30 minutes daily for 3 months. Lung function including forced expiratory volume in one second (FEV1), FEV1 in percentage of predicted value (FEV1%) and FEV1/forced vital capacity (FVC) ratio; exercise capacity (six-minute walk test distance, 6MWD); dyspnea symptoms (modified Medical Research Council, mMRC dyspnea scale score and Dyspnoea-12-Chinese/D-12-C scale score); and quality of life in terms of COPD Assessment Test (CAT) score before and after intervention were evaluated. Significantly higher FEV1 (1.82L versus 1.76L, p < 0.05) was found for the experimental group, with no significant differences in FEV1% and FEV1/FVC ratio. Significantly larger 6MWD (359.72m versus 340.18m, p < 0.001), significantly lower D-12-C scores (11.47 versus 13.55, p < 0.001), and significantly lower CAT scores (2.95 versus 3.98, p < 0.001) were observed in the experimental group relative to the control group. Our findings suggested that ACBT in conjunction with WBBE could be effective complementary approaches for improving lung function and exercise capacity, reducing dyspnea symptoms, and enhancing quality of life in older adults with stable COPD. Future studies may explore how ACBT and WBBE could be optimized in training frequency, intensity, and duration specifically for older adults.
Clinical relevance
In older adults with stable COPD, does the addition of active cycle of breathing technique (ACBT) to whole-body breathing exercise (WBBE) produce superior improvements in lung function, exercise capacity, dyspnea, and quality of life compared with WBBE alone? __SNAPSHOT__ {"studyDesign":"Randomized controlled trial (parallel-group, two-arm)","setting":"Not reported in abstract; study focused on older adults with stable COPD, specifically noted to be especially prevalent in China; institutional setting not specified","sampleSize":"n=51 (experimental [ACBT+WBBE]: n=25; control [WBBE only]: n=26)","population":"Older adults with stable COPD; mean GOLD stage 1.48 (experimental) vs. 1.92 (control) — difference did not reach statistical significance. Specific age range, sex distribution, baseline comorbidities, and GOLD staging eligibility criteria not reported in the abstract.","intervention":"ACBT plus WBBE: one 30-minute session of ACBT training and one 30-minute session of WBBE training daily (sessions separated by at least 30 minutes of rest) for approximately 90 days","comparator":"WBBE only: one 30-minute session of WBBE training daily for approximately 90 days","primaryOutcome":"Not formally designated as a single primary endpoint in the abstract; outcomes evaluated included FEV1, FEV1%, FEV1/FVC ratio (lung function); 6-minute walk test distance (6MWD; exercise capacity); mMRC dyspnea scale score and Dyspnoea-12-Chinese (D-12-C) score (dyspnea); and COPD Assessment Test (CAT) score (quality of life), assessed before and after intervention","followUp":"Approximately 90 days (3 months); no post-intervention surveillance period reported","fundingSource":"Not reported"}
Key findings
The experimental group (ACBT+WBBE) demonstrated significantly higher post-intervention FEV1 compared with the control group (WBBE only) (1.82 L vs. 1.76 L; p<0.05); however, FEV1% predicted and FEV1/FVC ratio did not differ significantly between groups. The absolute between-group difference in FEV1 of 0.06 L is below conventionally accepted minimal clinically important difference (MCID) thresholds for FEV1 in COPD (~100 mL). On exercise capacity, the experimental group achieved a significantly greater 6MWD (359.72 m vs. 340.18 m; p<0.001), representing a between-group difference of approximately 19.5 m (calculated). Notably, both groups exceeded the MCID for 6MWD of 35 m — the experimental group improved by approximately 49.4 m and the control group by approximately 38.6 m from baseline — indicating that the between-group difference of ~19.5 m (calculated) did not itself reach the MCID. The experimental group had significantly lower D-12-C dyspnea scores (11.47 vs. 13.55; p<0.001) and significantly lower CAT scores (2.95 vs. 3.98; p<0.001). The mMRC dyspnea scale did not differ significantly between groups. Confidence intervals for all comparisons were not reported. No adverse events were described in the abstract. Moderate positive correlations were observed between FEV1 and 6MWD, and moderate negative correlations between these measures and D-12-C/CAT scores.
Practice implications
This small RCT provides preliminary evidence that adding ACBT to a WBBE regimen in older adults with stable COPD may confer statistically significant incremental benefits in dyspnea perception (D-12-C), disease-specific quality of life (CAT), and exercise capacity (6MWD), and a marginal spirometric benefit (FEV1 only). However, several important caveats limit translational confidence. First, the between-group FEV1 difference of 0.06 L and the between-group 6MWD difference of ~19.5 m both fall below established MCIDs, raising concerns about whether observed statistically significant improvements reflect clinically meaningful change at the individual patient level. Both groups independently achieved clinically meaningful 6MWD improvements exceeding the 35-m MCID. Second, no single pre-specified primary outcome was designated, increasing the risk of type I error from multiple comparisons. Third, a baseline imbalance in GOLD stage severity (mean 1.48 [experimental] vs. 1.92 [control]) was not statistically significant but may have biased results in favor of the intervention group. Fourth, participant blinding was not feasible, introducing performance bias particularly for patient-reported outcomes such as D-12-C and CAT. Fifth, the study enrolled GOLD stages approximately 1–2, predominantly mild-to-moderate disease; findings may not generalize to patients with severe or very severe COPD. Sixth, the sample was drawn from a Chinese older adult population, limiting generalizability to other ethnic, demographic, or healthcare settings. Overall, while consistent with biological plausibility and prior ACBT literature, these findings are best regarded as hypothesis-generating. NOTE: This interpretation is based solely on the published abstract; full-text review may reveal additional methodological details, sensitivity analyses, or adjusted models not captured here. __LIMITATIONS__ Small sample size (n=51) with no reported a priori power calculation in the abstract, raising risk of both underpowering and spurious significance across multiple outcomes,No single designated primary endpoint, increasing multiple comparison risk without apparent statistical correction,Baseline GOLD stage imbalance (mean 1.48 vs. 1.92) between groups, not statistically significant but potentially confounding — particularly for lung function outcomes,Participant blinding not feasible for an exercise intervention; performance and detection bias likely for patient-reported outcomes (D-12-C, mMRC, CAT),Outcome assessor blinding status not reported in abstract,Between-group differences in FEV1 (~0.06 L) and 6MWD (~19.5 m, calculated) fall below established MCIDs, limiting the clinical significance of statistically significant findings,Short intervention duration (90 days) and no post-intervention follow-up; durability of benefits unknown,Mechanism of benefit not directly examined — unclear whether observed differences are attributable to complementary respiratory vs. non-respiratory muscle effects or simply to additional total exercise dose,Population restricted to older adults with stable, predominantly mild-to-moderate COPD in China; generalizability to other severity stages, younger populations, or different healthcare systems is limited,Funding source, adherence monitoring, and dropout rates not reported in abstract,No reporting of confidence intervals, limiting precision assessment of all effect estimates __BOTTOM_LINE_CATEGORY__ promising_but_preliminary __BOTTOM_LINE__ In this small RCT, adding ACBT to WBBE in older adults with stable, predominantly mild-to-moderate COPD produced statistically significant improvements in dyspnea (D-12-C), quality of life (CAT), 6MWD, and FEV1 compared with WBBE alone; however, between-group differences in FEV1 and 6MWD fell below established MCIDs, and performance bias in patient-reported outcomes cannot be excluded. Both groups independently achieved clinically meaningful improvements in exercise capacity exceeding the 35-m 6MWD MCID. These findings are hypothesis-generating and insufficient to change current practice; larger, adequately powered trials with pre-specified primary endpoints, assessor blinding, and longer follow-up are needed before ACBT can be routinely recommended as an add-on to structured breathing exercise programs.