Gray-Donald K, Carrey Z, Martin J G
Montreal Chest Institute Research Centre, Meakins-Christie Laboratories, Que.
Clin Invest Med. 1998 Jun;21(3):135-41.
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.
Prospective study.
A total of 18 patients (14 men, 4 women) aged 46 to 83 with severe, stable COPD.
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.
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.
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.
比较体重过轻与体重正常的慢性阻塞性肺疾病（COPD）患者在标准餐后的通气反应、摄氧量和呼吸困难感，以研究饮食诱导产热导致的呼吸困难增加是否会改变饮食习惯。COPD患者体重减轻会对健康产生不利影响，但其体重减轻的原因尚不清楚。
前瞻性研究。
共18例年龄在46至83岁之间的重度、稳定期COPD患者（14例男性，4例女性）。
在摄入一顿2.5兆焦耳（600千卡）的均衡流食前15分钟以及餐后四个15分钟间隔时段，测量每分通气量（VE）、潮气量（VT）、呼吸频率、摄氧量（VO2）、二氧化碳排出量（VCO2）和呼吸困难感（使用Borg量表）。
所有受试者的VE、VT、VO2和VCO2均增加。校正体表面积后，体重过轻和体重正常的COPD受试者这些指标的餐后最大变化无差异。两组间呼吸功（11名受试者测量）无差异，报告呼吸困难加重的受试者数量也无差异。
由于体重正常和体重过轻的患者在VE、VO2、VCO2和感知到的呼吸困难增加方面无差异，这表明进餐时的呼吸困难不太可能导致食物摄入量减少。
