A randomized trial in 39 stable COPD patients found that eight weeks of 30 inspiratory breaths twice daily at the highest tolerable intensity shifted heart-rate variability toward greater parasympathetic activity and improved six-minute walk distance and health scores versus control. The trial was small, lacked sham training, and did not measure long-term cardiac events or exacerbations.
Key findings
- Training-group high-frequency HRV rose from 36.99±17.51% to 46.84±15.33% (p
Why this matters globally
If replicated, the simple device-based program could expand rehabilitation options where center-based pulmonary rehabilitation is difficult to access, but should not replace comprehensive rehabilitation.
Thai researcher contribution
Mahidol, Chiang Mai, and Mae Fah Luang researchers combined vascular physiology, physical therapy, and respiratory medicine to test a practical intervention in Thai patients.
Limitations to consider
Only 39 were randomized and 37 completed. Without a sham device, participants were not blinded and symptom scores are vulnerable to expectancy bias. The abstract omits adherence, adverse events, and multiplicity handling. HRV is a surrogate and eight weeks cannot address exacerbations, hospitalization, or mortality.