Department of Biological Science and Technology, National Chiao Tung University, No. 1001, Ta Hsueh Rd., Hsinchu City 300, Taiwan. Division of Nephrology, Department of Internal Medicine, National Taiwan University Hospital Hsin-Chu Branch, No. 25, Ln. 442, Sec. 1, Jingguo Rd., Hsinchu City 300, Taiwan.
J Breath Res. 2020 Apr 28;14(3):036002. doi: 10.1088/1752-7163/ab728b.
Previous studies have shown that breath ammonia (breath-NH) concentration is associated with blood urea nitrogen (BUN) levels. However, interindividual variations in breath-NH concentrations were observed. Thus, the present study aimed to assess the effect of oral cavity conditions on breath-NH concentration and to validate whether the measurement of breath-NH concentration is feasible in clinical settings. A total of 125 individuals, including patients with stage 3 to 5 chronic kidney disease (CKD3-5), those on dialysis, and healthy participants, were recruited. A nanostructured sensor was used to detect breath-NH concentrations. Pre- and post-gargling as well as pre- and post-hemodialysis (HD) breath-NH, salivary pH, and salivary urea levels were measured. Breath-NH, salivary urea, salivary pH, and BUN levels were positively correlated to each other. Breath-NH concentrations were associated with BUN levels (r = 0.43, p < 0.001) and were significantly higher in CKD3-5 (p < 0.005) and dialysis patients (p < 0.001) than in healthy participants. Higher correlation coefficients were noted between breath-NH concentrations and BUN levels during follow-up (r = 0.59-0.94, p < 0.05). When the cutoff value of breath-NH was set at 523.65 ppb, its sensitivity and specificity in predicting CKD (BUN level >24 mg dl) were 87.6% and 80.9%, respectively. Breath-NH concentrations decreased after HD (p < 0.001) and immediately after gargling (p < 0.01). Breath-NH concentration, which was affected by gargling, was correlated to BUN level. The measurement of breath-NH concentration using the nanostructured device may be used as a tool for CKD detection and personalized point-of-care for CKD and dialysis patients. The current study had a small sample size. Thus, further studies with a larger cohort must be conducted to validate the effect of oral factors on breath-NH concentration and to validate the benefit of breath-NH measurement.
先前的研究表明，呼吸氨（breath-NH）浓度与血尿素氮（BUN）水平有关。然而，观察到呼吸-NH 浓度存在个体间差异。因此，本研究旨在评估口腔状况对呼吸-NH 浓度的影响，并验证在临床环境中测量呼吸-NH 浓度是否可行。共招募了 125 名个体，包括慢性肾脏病（CKD）3-5 期患者、透析患者和健康参与者。使用纳米结构传感器检测呼吸-NH 浓度。测量了预漱口和后漱口、预透析和后透析（HD）的呼吸-NH、唾液 pH 值和唾液尿素水平。呼吸-NH、唾液尿素、唾液 pH 值和 BUN 水平彼此呈正相关。呼吸-NH 浓度与 BUN 水平相关（r=0.43，p<0.001），在 CKD3-5 期（p<0.005）和透析患者（p<0.001）中明显高于健康参与者。在随访期间，呼吸-NH 浓度与 BUN 水平之间的相关性更高（r=0.59-0.94，p<0.05）。当呼吸-NH 的截止值设定为 523.65 ppb 时，其预测 CKD（BUN 水平>24 mg dl）的灵敏度和特异性分别为 87.6%和 80.9%。HD 后（p<0.001）和漱口后（p<0.01）呼吸-NH 浓度降低。受漱口影响的呼吸-NH 浓度与 BUN 水平相关。使用纳米结构设备测量呼吸-NH 浓度可作为 CKD 检测工具和 CKD 和透析患者的个性化即时护理工具。本研究样本量较小。因此，必须进行更大队列的进一步研究，以验证口腔因素对呼吸-NH 浓度的影响，并验证呼吸-NH 测量的益处。
