摘要目的 利用自主搭建的基于光腔衰荡光谱(CRDS)技术的呼吸丙酮分析仪准确快速地获取大量糖尿病患者的呼吸丙酮数据.方法 用不同体积分数的标准丙酮气体验证仪器的线性响应;通过呼吸气体分析的金标准气质联用色谱(GC-MS)测得结果与CRDS呼吸丙酮分析仪测得结果的对比测试来验证仪器的准确性.利用该仪器测量30例健康志愿者和260例2型糖尿病(T2D)患者空腹、早餐后2h、午餐后2h和晚餐后2h状态下的917个呼出气体样本.结果 CRDS呼吸丙酮分析仪对不同体积分数的丙酮有非常好的线性响应(R=1,P＜0.05);其与GC-MS对比测试结果的拟合系数R=0.98,表明该仪器的测量结果与金标准相符.260例T2D患者呼吸丙酮体积分数在0.0～10.6×10-6范围内,30例健康志愿者呼吸丙酮体积分数在(0.1～2.0)×10-6之间.260例T2D患者平均呼吸丙酮体积分数((1.5±1.1)×10-6)是30例健康志愿者的平均呼吸丙酮体积分数((1.1±0.5)×10-6)的1.4倍.260例T2D患者空腹、早餐后2h、午餐后2h和晚餐后2h状态下的平均呼吸丙酮体积分数((1.6±1.2)×10-6,(1.4±1.0)×10-6,(1.4±0.9)×10-6,(1.4±1.2)×10-6)均高于30例健康志愿者((1.3±0.3)×10-6,(1.0±0.6)×10-6,(1.0±0.6)×10-6,(1.1±0.4)×10-6).未观察到呼吸丙酮与血糖显著的相关性.结论 经GC-MS验证后的CRDS呼吸丙酮分析仪可用于实时在线的呼吸丙酮测量.T2D患者具有较高的呼吸丙酮体积分数.糖尿病患者呼吸丙酮体积分数与其生理参数的定量关系还需大样本临床研究.

abstractsObjective To conduct breath test with a relatively large number of subjects for new data regarding breath acetone in diabetes using a high accuracy and high data throughput breath acetone analyzer based on the cavity ringdown spectroscopy (CRDS) technique.Methods The CRDS breath analyzer was validated by standard acetone gas samples with various concentrations and golden standard gas chromatography-mass spectrometry (GC-MS).A total of 917 breath samples from 260 type 2 diabetic (T2D) patients and 30 healthy individuals were collected under each of 4 different conditions: fasting, 2 h post-breakfast, 2 h post-lunch, and 2 h post-dinner, and the samples were tested by the breath analyzer.Results The linear fitting curve of standard acetone samples with various concentration had good linearity (R=1, P＜0.05).The linear fitting of the results of GC-MS and CRDS was 0.98, suggesting that the obtained acetone concentrations using both methods were consistent.For the 260 T2D subjects, the exhaled breath acetone concentrations ranged from 0.0 to 10.6×10-6, while for the 30 healthy subjects, the breath acetone concentration ranged from 0.1 × 10-6 to 2.0× 10-6.The mean breath acetone concentration of the 260 T2D subjects was (1.5±1.l)× 10-6, which was 1.4 times of(1.1±0.5)×10-6 for the 30 healthy subjects.The mean breath acetone concentrations under the 4 conditions for the 260 T2D subjects ((1.6±1.2)×10-6, (1.4±1.0)×10-6~, (1.4±0.9)×10-6, and (1.4±1.2)× 10-6) were higher than that of the 30 healthy subjects ((1.3±0.3)×10-6, (1.0±0.6)×10-6, (1.0±0.6)×10-6, and (1.1±0.4)×10-6), respectively.No correlation was found between the breath acetone concentration and the blood glucose level of the T2D subjects and the healthy individuals.Conclusions The GC-MS validation confirms that the CRDS breath acetone analyzer is a reliable instrument for fast response and on-line breath acetone measurement.An elevated mean breath acetone concentration exists in T2D subjects.The relationship between breath acetone level and physiological parameters needs to be further investigated.