Preserved muscle metaboreflex in chronic obstructive pulmonary disease

The objective of this study was to measure the magnitude of the muscle metaboreflex in people with chronic obstructive pulmonary disease (COPD) compared with healthy controls and to assess the relationships between disease severity, exercise capacity, and the magnitude of the muscle metaboreflex. Nine people with mild-to-severe COPD and 11 age- and gender-matched healthy controls performed isometric handgrip exercise (IHG), followed by postexercise circulatory occlusion (PECO) while hemodynamic changes were measured. Continuous measures of heart rate, arterial pressure, leg blood flow, leg vascular resistance, and total peripheral resistance were obtained. Participants then performed a cycle test to exhaustion. Heart rate, blood pressure, and blood flow responses during IHG and PECO were similar between the COPD group and healthy controls (p > 0.05). There was no association between disease severity or exercise capacity and the magnitude of the muscle metaboreflex. We observed a preserved muscle metaboreflex in mild-to-severe COPD, suggesting the metaboreflex is not a contributing factor to the development of exercise intolerance in this population.