OBJECTIVE: To accurately measure human energy metabolism with high temporal resolution, a respiratory gas analysis system was designed using a breath-by-breath approach. METHODS: Firstly, indirect calorimetry was employed in respiratory gas analysis to measure the respiratory flow and concentration signals in real-time. Secondly, oxygen consumption QO2 and carbon dioxide production QCO2 were calculated through respiratory characteristic alignment and respiratory signal segmentation. Finally, metabolic indexes were calculated according to the Weir formula. Furthermore, a controlled trial was formulated for validation comparisons with the MGC ULTIMA SYSTEM PFX CARDIO2. RESULTS: The results indicate that the data points of metabolic indexes measured by this system all fall within the confidence interval when compared with those of the MGC. CONCLUSION The system has high consistency with the MGC measurement results. Thus, the system can accurately measure metabolism in real-time and provide data support for clinical nutrition assessment and therapy.
Humans ; Energy Metabolism ; Breath Tests/instrumentation* ; Calorimetry, Indirect/instrumentation* ; Equipment Design

Radiotherapy uses high-energy X-rays or other particles to destroy cancer cells and medical practitioners have used this approach extensively for cancer treatment (Hachadorian et al., 2020). However, it is accompanied by risks because it seriously harms normal cells while killing cancer cells. The side effects can lower cancer patients' quality of life and are very unpredictable due to individual differences (Bentzen, 2006). Therefore, it is essential to assess a patient's body damage after radiotherapy to formulate an individualized recovery treatment plan. Exhaled volatile organic compounds (VOCs) can be changed by radiotherapy and thus used for medical diagnosis (Vaks et al., 2012). During treatment, high-energy X-rays can induce apoptosis; meanwhile, cell membranes are damaged due to lipid peroxidation, converting unsaturated fatty acids into volatile metabolites (Losada-Barreiro and Bravo-Díaz, 2017). At the same time, radiotherapy oxidizes water, resulting in reactive oxygen species (ROS) that can increase the epithelial permeability of pulmonary alveoli, enabling the respiratory system to exhale volatile metabolites (Davidovich et al., 2013; Popa et al., 2020). These exhaled VOCs can be used to monitor body damage caused by radiotherapy.
Breath Tests/methods* ; Exhalation ; Humans ; Quality of Life ; Respiratory System/chemistry* ; Volatile Organic Compounds/analysis*

OBJECTIVES: To study the association of fractional exhaled nitric oxide (FeNO) and nasal nitric oxide (nNO) with asthma control and their value in the diagnosis of allergic rhinitis in children. METHODS: A total of 186 children aged 5-12 years, who attended the outpatient service of the Department of Respiration, Shanghai Children's Hospital due to bronchial asthma and/or allergic rhinitis or who underwent physical examination, were enrolled as subjects, with 52 children in the asthma group, 60 children in the asthma+allergic rhinitis group, 36 children in the allergic rhinitis group, and 38 children in the control group. FeNO, nNO, and pulmonary function were compared between groups. RESULTS: The asthma+allergic rhinitis, asthma, and allergic rhinitis groups had a significantly higher level of FeNO than the control group (P<0.05). The asthma+allergic rhinitis and allergic rhinitis groups had a significantly higher level of nNO than the asthma and control groups (P<0.05). The uncontrolled asthma and partially controlled asthma groups had significantly higher levels of FeNO and nNO than the completely controlled asthma group (P<0.05). The receiver operating characteristic (ROC) curve analysis showed that nNO had an area under the ROC curve of 0.91, with a sensitivity of 80.0% and a specificity of 89.5% in the diagnosis of allergic rhinitis in children with asthma (P<0.05). CONCLUSIONS The combined measurement of nNO and FeNO can be used to evaluate the control of asthma, and the measurement of nNO can help with the diagnosis of allergic rhinitis in children with bronchial asthma.
Asthma/diagnosis* ; Breath Tests ; Child ; Child, Preschool ; China ; Fractional Exhaled Nitric Oxide Testing ; Humans ; Nitric Oxide/analysis* ; Rhinitis, Allergic/diagnosis*

Lung cancer is a leading cause of cancer-related morbidity and mortality globally, which is the biggest menace to the health and life of the population. Screening and early detection of lung cancer are effective in reducing its mortality, and the measurement of volatile organic compounds (VOCs) has become a promising clinical means for early detection, course detection and prognosis management of lung cancer, with advantages of rapid speed, non-invasiveness and convenience. Now, a variety of VOCs collection ways and analysis methods have emerged at home and abroad. This report summarized three aspects, including VOCs collection, multiple methods of analysis and progress in the diagnosis and treatment of lung cancer. At last, we discussed the limitations and prospects of VOCs analysis.
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Breath Tests ; Early Detection of Cancer ; Humans ; Lung Neoplasms/diagnosis* ; Volatile Organic Compounds

OBJECTIVES: To study the association between milk consumption and lactose malabsorption in Indonesian children aged 3-12 years. METHODS: This cross sectional study was conducted in randomly selected presumed healthy children with good nutritional status aged 3-12 years in Central Jakarta, Indonesia ( RESULTS: The prevalence of lactose malabsorption in children aged 3-5 years and children aged 6-12 years was 20.8% (15/72) and 35.3% (36/102), respectively. There was no association between milk or milk product consumption and lactose malabsorption ( CONCLUSIONS There is no association between milk consumption and lactose malabsorption in Indonesian children aged 3-12 years, suggesting that genetic predisposition may be more important than adaptive mechanisms to lactose consumption.
Animals ; Breath Tests ; Child ; Cross-Sectional Studies ; Humans ; Indonesia/epidemiology* ; Lactose Intolerance/epidemiology* ; Milk

Asthma, Occupational ; Breath Tests ; Exhalation ; Humans ; Lung ; Nitric Oxide ; ROC Curve

breath test.RESULTS: In first-line treatment, eradication rate was 78.5% (106/135) and 78.6% (114/143) in the 7-day and 14-day treatment in per-protocol (PP) analysis (P = 0.805). In intention-to-treat (ITT) analysis, eradication rate was 64.0% (114/178) and 66.0% (126/191), respectively (P = 0.924). There was no significant difference in drug compliance (81.5% vs. 84.3%, P = 0.320). In second-line therapy, eradication rate was not significantly different in both treatments of PP analysis (91.7% [33/36] vs. 100% [45/45], P = 0.084). In the ITT analysis, eradication rate was 79.6% (35/44) and 90.4% (47/52), respectively (P = 0.080). Drug compliances were not significantly different between the two groups (95.5% vs. 98.1%, P = 0.728).CONCLUSION: PPI-based STT for H. pylori is not efficient as a first-line therapy both in 7 days and 14 days in Korea. Although bismuth-containing quadruple therapy for 14 days as a second line therapy tend to show higher eradication rate compared to 7-day therapy, this should be elucidated by further larger scaled studies.TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02487511]]>
Anti-Bacterial Agents ; Breath Tests ; Compliance ; Drug Resistance ; Helicobacter pylori ; Helicobacter ; Humans ; Korea ; Proton Pump Inhibitors ; Proton Pumps ; Stomach Neoplasms ; Treatment Outcome

BACKGROUND/AIMS: This study aimed to identify the demographic and clinical factors associated with positive breath-test results and to assess the relationship between hydrogen and methane production in patients with suspected irritable bowel syndrome (IBS).METHODS: The demographic and clinical factors of 268 patients with suspected IBS, who had undergone a lactulose breath test, were analyzed.RESULTS: Of 268 patients included in this study, 143 (53.4%) were females. The median age and BMI of the patients was 58.0 years (range, 18.0–80.0 years) and 22.5 kg/m² (range, 14.4–34.3 kg/m²), respectively. A weak positive correlation was observed between the BMI and baseline hydrogen level (rho=0.134, p=0.031). Women were significantly more likely to show a ≥20 ppm increase in hydrogen within 90 min (early hydrogen increase, p=0.049), a ≥10 ppm increase in methane within 90 min (early methane increase, p=0.001), and a ≥10 ppm increase in methane between 90 min and 180 min (late methane increase, p=0.002) compared to men. The baseline hydrogen level was related to the baseline methane level (rho=0.592, p<0.001) and the maximal hydrogen level within 90 min was related to maximal methane level within 90 min (rho=0.721, p<0.001). Patients with an early hydrogen increase (43.8%) were more likely to show a positive result for an early methane increase compared to patients without an early increase in hydrogen (0%, p<0.001).CONCLUSIONS: Women were associated with high rates of positive lactulose breath-test results. In addition, methane production was correlated with hydrogen production.
Breath Tests ; Female ; Humans ; Hydrogen ; Irritable Bowel Syndrome ; Lactulose ; Male ; Methane ; Sex Characteristics

OBJECTIVE: To study the clinical value of combined measurement of fractional exhaled nitric oxide (FeNO) and nasal fractional exhaled nitric oxide (FnNO) and its correlation with the level of asthma control. METHODS: A total of 120 children who were diagnosed with asthma from January to June, 2018 and were in the chronic persistent stage were enrolled as subjects. The childhood asthma control test (C-ACT) was performed for all the 120 children. According to the C-ACT score, these children were divided into 4 groups: complete control group with a C-ACT score of >23, partial control group with a C-ACT score of 20-23, and uncontrolled group with a C-ACT score of ≤19 (n=40 each). According to the presence or absence of allergic rhinitis, they were divided into 2 groups: non-rhinitis group with 55 children and rhinitis group with 65 children. A total of 40 children who underwent physical examination during the same period of time were enrolled as the control group. FeNO and FnNO levels were measured for all the 120 children. RESULTS: The uncontrolled group had the highest level of FeNO, followed by the partial control group and the complete control group (P<0.05). The uncontrolled and partial control groups had a significantly higher level of FeNO than the control group (P<0.05). The uncontrolled and partial control groups had a significantly higher level of FnNO than the complete control and control groups (P<0.05). The rhinitis group had significantly higher FeNO and FnNO levels than the non-rhinitis group (P<0.05). CONCLUSIONS FeNO can be used to assess the level of asthma control in children, and its combination with FnNO may be useful for the evaluation of the degree of inflammation in the upper and lower airways and provide a basis for the combined treatment of the upper and lower airways.
Asthma ; Breath Tests ; Humans ; Nitric Oxide ; Rhinitis, Allergic

OBJECTIVE: To explore the predictive significance of exhaled breath temperature (EBT) for airway inflammation changes in children with asthma. METHODS: A total of 60 children with asthma who met the inclusion criteria at the first visit were chosen as the asthma group, and 60 healthy children were selected as the control group. The EBT level was measured by the latest third-generation product (X-halo). The Childhood Asthma Control Test (C-ACT) score was recorded. EBT level and C-ACT score were compared between the asthma and control groups. At the subsequent visit one month later, the children were divided into well-controlled, partially-controlled, and uncontrolled groups according to their C-ACT scores. The EBT level and the FeNO level of the three groups were measured. EBT level and C-ACT score were compared among the three groups. The correlation between EBT and FeNO was analyzed. The data of initial diagnosis were reviewed, the EBT level and C-ACT score at the first visit were compared among the three groups, and the differences in EBT level and C-ACT score among the three groups at the second and first visits were evaluated. RESULTS: At the first visit, the asthma group had a significantly higher EBT and a significantly lower C-ACT score compared with the control group (P<0.05). At the time of the subsequent visit, there was a significant difference in EBT level between the three groups, i.e., uncontrolled group > partially-controlled group > well-controlled group (P<0.05), and there was also a significant difference in C-ACT score between the three groups, i.e., well-controlled group > partially-controlled group > uncontrolled group (P<0.05). There were no significant differences in EBT level and C-ACT score at the first visit between the three groups. From the first visit to the subsequent visit, EBT level was significantly decreased in the well-controlled group (P<0.05), but significantly increased in both partially-controlled group uncontrolled groups (P<0.05); C-ACT score was significantly increased in the well-controlled and partially-controlled groups (P<0.05), but significantly decreased in the uncontrolled group (P<0.05). EBT and FeNO levels at the subsequent visit were positively correlated with each other in the uncontrolled group (P<0.05). CONCLUSIONS EBT has predictive significance for the changes in airway inflammation in children with asthma.
Asthma ; Breath Tests ; Child ; Humans ; Inflammation ; Nitric Oxide ; Temperature