Effect of obesity on constant workrate exercise in hyperinflated men with COPD

Abstract

BackgroundChronic obstructive pulmonary disease (COPD) and a high body mass index (BMI) can both affect pulmonary volumes as well as exercise tolerance, but their combined effect on these outcomes is not well known. The aim of this study was to investigate the effects of increased BMI during constant workrate cycle ergometry in patients with COPD.MethodsMen with COPD and hyperinflation were divided according to World Health Organization BMI classification: 84 normal BMI (NBMI), 130 overweight (OW) and 64 obese (OB). Patients underwent spirometric and lung volumes assessment and an incremental cycling exercise test. This was followed by a constant workrate exercise test (CET) at 75% of peak capacity. Inspiratory capacity and Borg dyspnea scores were measured at baseline, during and at the end of CET.Results and discussionFEV1 % predicted was not different across BMI classes. Total lung capacity and functional residual capacity were significantly lower in OB and OW compared to NBMI patients. Peak VO2 in L·min-1 was significantly higher in OB and OW patients than in NBMI patients. CET time was not different across BMI classes (p = 0.11). Changes in lung volumes and dyspnea during CET were not different between BMI categories.ConclusionsOB and OW patients with COPD had a higher peak VO2 than their lean counterparts. Endurance time, dyspnea and changes in lung volumes during CET were similar between BMI categories.

Antagonistic implications of sarcopenia and abdominal obesity on physical performance in COPD

“…This finding corresponds to previous literature reporting that exercise capacity is preserved or even increased in obese COPD patients during cycling (non-weight bearing exercise) [28,29], except when walking is used as testing modality (weight bearing exercise) [30]. A potential explanation for this functional improvement in advanced COPD might be a lowering effect of obesity on resting and dynamic hyperinflation as established determinant of exercise impairment in COPD [29,31]. Nonetheless, this condition of excessive body weight with a disproportional low muscle mass (i.e.…”

Obesity and Physical Activity in the Daily Life of Patients with COPD

“…Despite obesity being characterized by an increased ventilatory demand and work of breathing, respiratory muscle inefficiency, reduced respiratory compliance, and increased dyspnea [15], the literature show that obese patients with COPD have a better prognosis of the disease and less pronounced airway obstruction than patients with normal BMI [2,4,8]. Moreover, although previous studies have shown that obese patients with COPD have lower functional exercise capacity [6,8], other studies found that obese and overweight patients with COPD have higher peak VO 2 and similar or reduced perception of dyspnea (due to reduced rest and dynamic hyperinflation) than their lean counterparts [16,17]. Explanation for these apparently contradictory findings may be linked to the different characteristics of exercise assessment (walking versus cycling and submaximal versus maximal), among other factors.…”

Does exercise test modality influence dyspnoea perception in obese patients with COPD?

“…However, while field tests indicate reduced walking distance in obese versus normal-weight COPD patients [3,4], physiological studies using cycle ergometry have found that dyspnoea intensity, endurance time and peak oxygen uptake (V9O 2 ) are similar in the two groups when severity of airway obstruction is matched [5,6]. The question therefore arises: does measurement of perceived dyspnoea intensity and exercise performance in obese COPD during cycle ergometry (where leg muscles are selectively stressed [7,8]) accurately reflect the situation during daily activities such as walking?…”