Postprandial dyspnea and malnutrition in patients with chronic obstructive pulmonary disease.

OBJECTIVE

To compare ventilatory response, oxygen uptake and sense of dyspnea of underweight versus normal-weight patients with chronic obstructive pulmonary disease (COPD) after a standard meal, in order to investigate whether an increase in dyspnea due to diet-induced thermogenesis might lead to altered eating habits. Weight loss in patients with COPD leads to adverse health effects, but the reasons for this loss are not well understood.

DESIGN

Prospective study.

PARTICIPANTS

A total of 18 patients (14 men, 4 women) aged 46 to 83 with severe, stable COPD.

OUTCOME MEASURES

Minute ventilation (VE), tidal volume (VT), frequency of breathing, oxygen uptake (VO2), carbon dioxide excretion (VCO2) and sense of dyspnea (using the Borg scale) were measured 15 minutes before a 2.5-MJ (600-kcal) balanced liquid meal and at four 15-minute intervals after the meal.

RESULTS

Increases in VE, VT, VO2 and VCO2 were observed for all subjects. Corrected for body surface area, the maximum postprandial changes in these indicators did not differ between the underweight and the normal-weight subjects with COPD. Work of breathing (measured in 11 subjects) did not differ between the 2 groups, nor did the number of subjects reporting increased dyspnea.

CONCLUSIONS

Since the increases in VE, VO2, VCO2 and perceived dyspnea did not differ between the normal-weight and underweight patients, this indicates that dyspnea at mealtimes is not likely to lead to decreased food intake.