AgroParisTech, Nutrition Physiology and Ingestion Behavior, Paris, France; Vivatech, Paris, France.
Dig Liver Dis. 2013 Sep;45(9):727-32. doi: 10.1016/j.dld.2013.03.015. Epub 2013 Jun 29.
Lactose malabsorption occurs frequently and the variable consequent intolerance may seriously impair quality of life. No reliable and convenient test method is in routine clinical practice. A recent animal study showed that the respiratory quotient changed significantly after ingestion of sucrose and lactose in naturally lactase-deficient rats.
This exploratory study evaluated the relevance of monitoring the respiratory quotient after lactose ingestion to detect malabsorption.
Healthy volunteers were identified and classified lactose absorbers and malabsorbers by a lactose tolerance test (25 g). After an overnight fast, a second lactose challenge was performed to monitor hydrogen excretion and respiratory quotient kinetics over 4h. Participants also completed questionnaires to score and localise their gastrointestinal symptoms.
20 subjects were enrolled (10 per group, 60% males, mean age 34 ± 4 years). Respiratory quotient kinetics were different between absorbers and malabsorbers during the first 100 min after lactose ingestion (p<0.01) and during the initial 30-50 min period. Respiratory quotient was significantly, positively correlated to peak glycaemia (R=0.74) and negatively correlated to hydrogen excretion (R=-0.51) and symptoms score (R=-0.46).
Indirect calorimetry could improve the reliability of lactose malabsorption diagnosis. Studies on larger populations are needed to confirm the validity of this test and propose a simplified measurement.
乳糖吸收不良很常见，由此导致的不同程度的不耐受可能严重影响生活质量。但目前临床上并没有可靠且方便的检测方法。最近的一项动物研究表明，在天然缺乏乳糖酶的大鼠中，摄入蔗糖和乳糖后呼吸商明显改变。
本探索性研究评估了监测乳糖摄入后呼吸商变化来检测吸收不良的相关性。
通过乳糖耐量试验（25 g）鉴定健康志愿者，并将其分为乳糖吸收者和吸收不良者。禁食一夜后，进行第二次乳糖挑战，以监测 4 小时内氢排泄和呼吸商动力学。参与者还完成了问卷，以评分和定位他们的胃肠道症状。
共纳入 20 名受试者（每组 10 名，60%为男性，平均年龄 34 ± 4 岁）。在乳糖摄入后的前 100 分钟（p<0.01）和最初的 30-50 分钟期间，吸收者和吸收不良者的呼吸商动力学不同。呼吸商与峰值血糖呈显著正相关（R=0.74），与氢排泄（R=-0.51）和症状评分（R=-0.46）呈负相关。
间接热量测定法可以提高乳糖吸收不良诊断的可靠性。需要更大规模的人群研究来确认该检测的有效性，并提出简化的测量方法。
