Showing papers on "Breath test published in 2014"

Methanogens, Methane and Gastrointestinal Motility

Abstract: Anaerobic fermentation of the undigested polysaccharide fraction of carbohydrates produces hydrogen in the intestine which is the substrate for methane production by intestinal methanogens. Hydrogen and methane are excreted in the flatus and in breath giving the opportunity to indirectly measure their production using breath testing. Although methane is detected in 30%-50% of the healthy adult population worldwide, its production has been epidemiologically and clinically associated with constipation related diseases, like constipation predominant irritable bowel syndrome and chronic constipation. While a causa- tive relation is not proven yet, there is strong evidence from animal studies that methane delays intestinal transit, possibly act- ing as a neuromuscular transmitter. This evidence is further supported by the universal finding that methane production (measured by breath test) is associated with delayed transit time in clinical studies. There is also preliminary evidence that anti- biotic reduction of methanogens (as evidenced by reduced methane production) predicts the clinical response in terms of symptomatic improvement in patients with constipation predominant irritable bowel syndrome. However, we have not identi- fied yet the mechanism of action of methane on intestinal motility, and since methane production does not account for all constipation associated cases, there is need for high quality clinical trials to examine methane as a biomarker for the diagnosis or as a biomarker that predicts antibiotic treatment response in patients with constipation related disorders.

Sobriety Monitoring System

Abstract: A system and method of monitoring sobriety using a hand-held breath testing device that, on receipt of a user's breath, generates a breath test signal comprising substance content data and user identification data, and wirelessly transmits the breath test signal to a breath test signal receiving station. The breath test signal includes substance content data and user identification data. The substance content data includes at least one of: a blood alcohol level and a narcotics presence. The user identification data includes compressed image data. The signal receiving station is monitored by a supervisor who is able to intervene should the substance level be greater than a predetermined threshold, or should the user identification data no match with a reference user identification data.

Detecting active pulmonary tuberculosis with a breath test using nanomaterial-based sensors

Abstract: To the Editor: Detecting active tuberculosis (TB) remains a major global public health challenge [1] The tuberculin skin test does not distinguish latent from active TB [2] The interferon-γ release assays have similar limitations [3] Acid-fast bacilli staining of sputum has a high false-negative rate (up to 50%) [4] Nucleic acid amplification tests (NAATs), such as GeneXpert MTB/RIF (Cepheid, Sunnyvale, CA, USA), are accurate but require a good infrastructure and the necessity to obtain a good quality sputum sample, which is often unobtainable in more than a third of HIV-infected persons [5, 6] Given these unmet needs, we explored the use of a novel, rapid, simple and inexpensive point-of-care test for the diagnosis of TB [7] The approach is based on the detection of volatile organic compounds (VOCs) that are emitted from infected cells and released in exhaled breath [8, 9] Using gas chromatography linked with mass spectrometry, researchers have previously reported identification of TB-related VOCs in the exhaled breath, though there has been low accuracy in detection (80–85%) [10] In this study, we explore the possibility of active TB detection via the analysis of exhaled breath using a novel technology of organically modified nanomaterial-based sensors Such cross-reactive sensors are highly sensitive to the collective changes in the VOCs spectrum [8] Therefore, we designed a case–control study, in which breath and sputum sampling was performed in 210 adult participants, after informed consent, at three sites in Cape Town, South Africa, between November 2011 and March 2012 The study population consisted of two main subgroups The first subgroup included those in …

Expiratory flow rate, breath hold and anatomic dead space influence electronic nose ability to detect lung cancer

Abstract: Background Electronic noses are composites of nanosensor arrays. Numerous studies showed their potential to detect lung cancer from breath samples by analysing exhaled volatile compound pattern (“breathprint”). Expiratory flow rate, breath hold and inclusion of anatomic dead space may influence the exhaled levels of some volatile compounds; however it has not been fully addressed how these factors affect electronic nose data. Therefore, the aim of the study was to investigate these effects.

Small Intestinal Bacterial Overgrowth in Gastroparesis

Abstract: To determine symptoms of small intestinal bacterial overgrowth (SIBO) in gastroparesis patients. Patients undergoing LBT (lactulose breath test) for evaluation of SIBO were included. LBT was considered positive on the basis of three conventional criteria: (1) hydrogen level increase >20 ppm above baseline by 90 min (H2@90min); (2) dual hydrogen peaks (>10 ppm increase over baseline before second peak >20 ppm (DPHBT); and (3) breath methane increase of >20 ppm above baseline by 90 min. Results of gastric emptying scintigraphy (GES) were recorded. Patients completed the Patient Assessment of Upper Gastrointestinal Disorders-Symptom Severity Index. Of 740 patients who underwent LBT from December 2009 to August 2011, 471 underwent GES, with 201 having delayed GES. Of patients with delayed GES who underwent LBT 87 % were female, 23 % diabetic, 49 % used gastric acid suppressants, 29 % used opiate analgesics, 35 % used pro-motility medications, and 27 % had a history of gastrointestinal surgery. Overall, 79 (39 %) patients with gastroparesis had evidence of SIBO by LBT: 30 (15 %) had positive H2@90min, 53 (26 %) positive DPHBT, and 6 (3 %) positive breath methane test. In gastroparesis patients with positive H2@90min, there was increased severity of bloating (3.80 ± 0.20 vs 3.29 ± 0.12; P = 0.02), early satiety (3.57 ± 0.27 vs 3.05 ± 0.13; P = 0.045), and postprandial fullness (4.20 ± 0.18 vs 3.52 ± 0.12; P < 0.01) compared with negative H2@90min patients. No significant difference in symptom severity was seen between positive and negative DPHBT gastroparesis patients. In our cohort, 39 % of gastroparesis patients tested positive for SIBO by LBT. Positive H2@90min testing by LBT was associated with increased symptoms of bloating and excessive fullness during and after meals.

Comparison of breath gases, including acetone, with blood glucose and blood ketones in children and adolescents with type 1 diabetes

Abstract: Previous studies have suggested that breath gases may be related to simultaneous blood glucose and blood ketone levels in adults with type 2 and type 1 diabetes. The aims of this study were to investigate these relationships in children and young people with type 1 diabetes in order to assess the efficacy of a simple breath test as a non-invasive means of diabetes management. Gases were collected in breath bags and measurements were compared with capillary blood glucose and ketone levels taken at the same time on a single visit to a routine hospital clinic in 113 subjects (59 male, age 7 years 11 months-18 years 3 months) with type 1 diabetes. The patients were well-controlled with relatively low concentrations of the blood ketone measured (β hydroxybutyrate, 0-0.4 mmol l(-1)). Breath acetone levels were found to increase with blood β hydroxybutyrate levels and a significant relationship was found between the two (Spearman's rank correlation ρ = 0.364, p < 10(-4)). A weak positive relationship was found between blood glucose and breath acetone (ρ = 0.16, p = 0.1), but led to the conclusion that single breath measurements of acetone do not provide a good measure of blood glucose levels in this cohort. This result suggests a potential to develop breath gas analysis to provide an alternative to blood testing for ketone measurement, for example to assist with the management of type 1 diabetes.

Breath tests and irritable bowel syndrome

Abstract: Breath tests are non-invasive tests and can detect H₂ and CH₄ gases which are produced by bacterial fermentation of unabsorbed intestinal carbohydrate and are excreted in the breath. These tests are used in the diagnosis of carbohydrate malabsorption, small intestinal bacterial overgrowth, and for measuring the orocecal transit time. Malabsorption of carbohydrates is a key trigger of irritable bowel syndrome (IBS)-type symptoms such as diarrhea and/or constipation, bloating, excess flatulence, headaches and lack of energy. Abdominal bloating is a common nonspecific symptom which can negatively impact quality of life. It may reflect dietary imbalance, such as excess fiber intake, or may be a manifestation of IBS. However, bloating may also represent small intestinal bacterial overgrowth. Patients with persistent symptoms of abdominal bloating and distension despite dietary interventions should be referred for H₂ breath testing to determine the presence or absence of bacterial overgrowth. If bacterial overgrowth is identified, patients are typically treated with antibiotics. Evaluation of IBS generally includes testing of other disorders that cause similar symptoms. Carbohydrate malabsorption (lactose, fructose, sorbitol) can cause abdominal fullness, bloating, nausea, abdominal pain, flatulence, and diarrhea, which are similar to the symptoms of IBS. However, it is unclear if these digestive disorders contribute to or cause the symptoms of IBS. Research studies show that a proper diagnosis and effective dietary intervention significantly reduces the severity and frequency of gastrointestinal symptoms in IBS. Thus, diagnosis of malabsorption of these carbohydrates in IBS using a breath test is very important to guide the clinician in the proper treatment of IBS patients.

Rapid point-of-care breath test for biomarkers of breast cancer and abnormal mammograms.

Abstract: Background Previous studies have reported volatile organic compounds (VOCs) in breath as biomarkers of breast cancer and abnormal mammograms, apparently resulting from increased oxidative stress and cytochrome p450 induction. We evaluated a six-minute point-of-care breath test for VOC biomarkers in women screened for breast cancer at centers in the USA and the Netherlands.

Breath analysis in real time by mass spectrometry in chronic obstructive pulmonary disease.

Abstract: Background: It has been suggested that exhaled breath contains relevant information on health status Objectives: We hypothe

Motility Abnormalities in Irritable Bowel Syndrome

Abstract: Background/Aims: The intestinal pathophysiology in irritable bowel syndrome (IBS) is largely unknown. The lactulose breath test has been used to identify small bowel bacterial overgrowth in these patients. Methods: We studied intestinal transit in patients with IBS using of the SmartPill® (SP) wireless pH/pressure recording capsule and performed lactulose breath tests to look for physiologic abnormalities. Results: A total of 35/46 (76%) of the IBS patients had prolonged gastric emptying times. Constipation-predominant disease was associated with prolonged gut transit times. The mean hours ± SD for colonic transit time in the constipation group was 71.7 ± 61.1 (n = 13) compared with 22.5 ± 14.9 (n = 14) for diarrhea-predominant and 26.4 ± 21.5 (n = 20) for mixed clinical subtype (p = 0.0010). No correlation between small bowel transit time and abnormal breath hydrogen or methane excretion in the 46 combined patients with IBS was seen. Conclusions: Delayed gastric emptying was identified in IBS and in some patients may contribute to at least a component of their symptoms. Constipation-predominant IBS is associated with prolonged gut transit times. Otherwise, transit abnormalities do not appear to be important in IBS. Intestinal transit did not correlate with breath test results.

Unclear abdominal discomfort: pivotal role of carbohydrate malabsorption.

Abstract: BACKGROUND/AIMS Carbohydrate malabsorption is frequent in patients with functional gastrointestinal disorders and in healthy volunteers and can cause gastrointestinal symptoms mimicking irritable bowel syndrome (IBS). The aim of this study was to investigate the prevalence of symptomatic lactose and fructose malabsorption in a large population of patients with IBS-like symptoms based on Rome II criteria. METHODS Patients with unclear abdominal discomfort (n = 2,390) underwent lactose (50 g) and fructose (50 g) hydrogen (H2) breath tests and depending on the results further testing with 25 g fructose or 50 g glucose, or upper endoscopy with duodenal biopsies. Additionally, this population was investigated regarding the prevalence of small intestinal bacterial overgrowth (SIBO) based on glucose breath test and celiac disease. RESULTS Of the 2,390 patients with IBS-like symptoms, 848 (35%) were symptomatic lactose malabsorbers and 1,531 (64%) sympto-matic fructose malabsorbers. A combined symptomatic carbohydrate malabsorption was found in 587 (25%) patients. Severe fructose malabsorbers (pathologic 25 g fructose test) exhaled significantly higher H2 concentrations in the 50 g test than pa-tients with negative 25 g fructose test (P < 0.001). Out of 460/659 patients with early significant H2 increase in the lactose and fructose test who underwent a glucose breath test, 88 patients had positive results indicative of SIBO and they were sig-nificantly older than patients with negative test result (P < 0.01). Celiac disease was found in 1/161 patients by upper endoscopy. CONCLUSIONS Carbohydrate malabsorption is a frequent but underestimated condition in patients with IBS-like symptoms although diagnosis can be easily confirmed by H2 breath testing.

Positive or Negative Fructose Breath Test Results do not Predict Response to Fructose Restricted Diet in Children with Recurrent Abdominal Pain: Results from a Prospective Randomized Trial

Abstract: Objectives: To perform a prospective, blinded, randomized interventional trial in patients with recurrent abdominal pain. The primary endpoint was to determine the abdominal pain intensity after 2 weeks of fructose restricted diet. Secondary endpoints were changes of pain frequency and a secondary symptom score (SSS). Methods: 103 individuals with recurrent abdominal pain for more than 3 months were randomized. 51 patients were allocated to group A (diet) and 52 to group B (no diet). 2 weeks later the patients underwent hydrogen breath test and were assigned to the test positive or negative group to identify patients with fructose malabsorption. Results: 2 weeks after intervention the pain score decreased significantly from a median 5.5 in group A to 4 and did not change significantly in group B (5.3 to 5). In group A both patients with positive and negative breath tests had a significant lower pain score (−2 and −1.75, respectively). Frequency of abdominal pain decreased in both groups but without significant difference, SSS improved only in group A from median 6 to 3.5. Positive breath test was no predicting factor, neither was abdominal pain during the test. Conclusions: Fructose restricted diet in children and adolescents with recurrent abdominal pain may be of benefit to improve both abdominal pain symptoms and other secondary symptoms. Since a negative breath test result does not exclude a positive response to fructose restriction, the hydrogen breath test does not seem to be the appropriate diagnostic mean to predict the response to the diet.

Optimization of volatile markers of lung cancer to exclude interferences of non-malignant disease.

Abstract: Background Breath analysis became promising for noninvasive diagnosis of cancer with sophisticated spectrometry technology introduced. Objective This study aimed to select volatile markers for lung cancer detection, which exclude the influences from non-malignant lung diseases. Methods 171 subjects who were divided into three groups: patients with LC, patients with PNMD and healthy controls were enrolled in our studies as training cohort. The volatile organic compounds (VOCs) in their breath samples were analyzed with solid-phase micro-extraction/gas chromatography/mass spectrometry (SPME-GCMS). Markers were selected by receiver operating characteristic (ROC) curves. After that, 78 subjects with high morbidity of LC were employed as validation cohort. Their breath samples were analyzed by thermal desorption instrument/gas chromatography/mass spectrometry (TD-GCMS). Results Through a series of comparisons among lung cancer patients, pulmonary non-malignant diseases patients, and healthy participants in training cohort, Nonane,5-(2-methyl-)propyl-; phenol,2,6-di-tert-butyl-,4-methyl-; dodecane,2,6,11-trimethyl-; hexadecanal and pentadecane,8-hexyl- were selected as markers for lung cancer diagnosis. Principal component analysis was employ to process data from validation cohort. As results, satisfied distinctions have been obtained with detection of these five selected markers, although the detection method is not identical with that used for training cohort. Conclusions In conclusion, with optimization method described in this paper, breath test could be an effective method for diagnosis of lung cancer and avoid the interference of pulmonary non-malignant diseases.

Symptomatic fructose malabsorption in irritable bowel syndrome: A prospective study.

Abstract: IntroductionFructose can trigger or worsen symptoms in irritable bowel syndrome (IBS) patients. The aim of this study was to determine the prevalence of symptomatic fructose malabsorption in IBS patients and to test whether the patient's characteristics can help to detect a fructose malabsorption.Materials and methodsNinety Rome III IBS patients (predominant diarrhoea (IBS-D): 31%, predominant constipation (IBS-C): 18%, mixed type (IBS-M): 51%) were included prospectively. After exclusion of a small intestinal bacterial overgrowth by a glucose breath test, fructose malabsorption was assessed by a five-hour breath test, with symptom monitoring, after a 25 g load of fructose. An increase of more than 20 ppm of hydrogen (H2) or methane (CH4) levels in the exhaled air led to the diagnosis of malabsorption.ResultsFructose test was abnormal in 20/90 patients among whom only 35% were intolerant, with a simultaneous rise of H2/CH4 levels and the onset of abdominal discomfort or diarrhoea. IBS characteristics were...

Lactose malabsorption testing in daily clinical practice: a critical retrospective analysis and comparison of the hydrogen/methane breath test and genetic test (c/t-13910 polymorphism) results.

Abstract: The aim of this study was to establish a retrospective evaluation and comparison of the hydrogen/methane (H2/CH4) breath test and genetic test (C/T−13910 polymorphism) results in lactose malabsorption testing. In total 263 consecutive patients with suspected lactose malabsorption were included in this study. They underwent the H2/CH4 breath test following the ingestion of 50 g lactose and were tested for the C/T−13910 polymorphism. In total 51 patients (19.4%) had a C/C−13910 genotype, indicating primary lactose malabsorption. Only 19 patients (7.2%) also had a positive H2/CH4 breath test. All in all 136 patients (51.69%) had a C/T−13910 and 76 patients (28.91%) a T/T−13910 genotype, indicating lactase persistence. Four patients (1.5%) with the C/T−13910 genotype and one patient (0.4%) with the T/T−13910 genotype had a positive H2/CH4 breath test result, indicating secondary lactose malabsorption. Cohen's Kappa measuring agreement between the two methods was 0.44. Twenty patients (7.6%) with a positive H2/CH4 peak within 60 minutes after lactose ingestion were classified as patients with lactose-dependent small intestinal bacterial overgrowth (SIBO). In conclusion, only moderate agreement between the breath test and the genetic test was shown. Secondary lactose malabsorption as well as preanalytical limitations of the combined H2/CH4 breath test procedure can cause discrepant results. This trial is registered with K-42-13.

Small intestinal bacterial overgrowth in patients with chronic pancreatitis.

Abstract: Goals To assess the prevalence of small intestinal bacterial overgrowth (SIBO) in chronic pancreatitis (CP), and analyze factors related with SIBO in CP. Background SIBO is to be considered a factor that worsens symptoms and nutritional status in patients with CP. However, the few studies evaluating the rate of SIBO in CP patients used nonuniform and nonstandardized procedures, and reported a wide range of positivity (0% to 92%). Those studies often investigated CP patients with previous resection surgery (cause of SIBO per se). Study CP patients and controls evaluated for SIBO by the H2 glucose breath test with a standard protocol. For CP patients, the relationship between test results, abdominal symptoms, and clinical and biochemical variables was analyzed. Results A total of 43 CP patients and 43 controls were enrolled. Of the CP patients, 8 had advanced disease (defined by M-ANNHEIM index) and none had undergone previous surgery. The glucose breath test positivity rate was higher in the CP patients than in the controls (21% vs. 14%), albeit without a significant difference (P=0.57). Mean fasting H2 excretion and mean H2 excretion at 120 minutes also had a trend toward higher levels in CP patients. There were no clinical differences between CP patients with or without SIBO, but there were nutritional differences for lower levels of vitamin D and higher levels of folate in these patients with SIBO. Conclusions Our findings suggest that SIBO is not uncommon in uncomplicated CP patients. The lack of a significant difference compared with controls might be due to the study being underpowered. SIBO in CP patients does not seem to be related to peculiar clinical features, but it might affect nutritional status.

Dietary herb extract rikkunshi-to ameliorates gastroparesis in Parkinson's disease: a pilot study.

Abstract: Objective: To perform an open trial on the effects of the extract of the dietary herb Rikkunshi-to (RKT) on gastroparesis in Parkinson's disease (PD) patients, using objective parameters given by the 13C-sodium acetate expiration breath test (gastric emptying study). Methods: Twenty patients with PD were enrolled into this study. Eleven patients were male and 9 were female, with the following characteristics (mean ± SD): age, 69.4 ± 8.17 years; disease duration, 4.34 ± 4.03 years; modified Hoehn and Yahr stage, 2.37 ± 0.98, and Unified Parkinson's Disease Rating Scale Part 3 motor score, 16.6 ± 7.37. Fourteen patients came to the clinic due to constipation; 16 patients were taking 288 ± 72 mg/day levodopa/carbidopa, 2 were taking dopamine agonists, and the others were not treated yet. All patients underwent the breath test. Statistical analysis was performed using Student's t test. Results: RKT was well tolerated by all patients and none experienced abdominal pain or other adverse effects, except for its bitter taste. RKT significantly reduced the peak time of the 13C-dose-excess curve (p Conclusion: In this pilot trial, we found a significant shortening of the gastric emptying time after administration of the dietary herb extract RKT in PD patients. Further studies examining both gastric emptying and delayed-on in PD are warranted.

Nizatidine ameliorates gastroparesis in Parkinson's disease: a pilot study.

Abstract: Background The objective of this work was to perform an open trial of the effects of nizatidine (NZT), a selective histamine H2-receptor antagonist and a cholinomimetic, on gastroparesis in Parkinson's disease (PD) patients, using objective parameters given by a gastric emptying study using a 13C-sodium acetate expiration breath test. Methods Twenty patients with PD were enrolled in the study. There were 13 men and 7 women; aged 68.0 ± 7.72 years; disease duration 5.50 ± 3.62 years. All patients underwent the breath test and a gastrointestinal questionnaire before and after 3 months of administration of NZT at 300 mg/day. Statistical analysis was performed by Student t test. Results NZT was well tolerated by all patients and none had abdominal pain or other adverse effects. NZT significantly shortened Tmax (13C) (the peak time of the 13C-dose-excess curve) (P < 0.05). Conclusions Although this is a pilot study, we found a significant shortening of gastric emptying time after administration of NZT in PD patients. © 2013 International Parkinson and Movement Disorder Society

Validity and reliability of the 13C-methionine breath test for the detection of moderate hyperhomocysteinemia in Mexican adults.

Abstract: BACKGROUND Hyperhomocysteinemia (Hhcy) is considered an independent risk factor for vascular diseases and, more recently, for dementia. The methionine loading test (MLT) is useful for diagnosing additional subjects with moderate Hhcy. However, it is a complex and time-consuming procedure. A noninvasive test for the diagnosis of moderate Hhcy is desirable. METHODS The study protocol consisted of three consecutive visits. During the first visit, we performed an MLT to characterize the Hhcy status of 75 healthy adult subjects. For the breath test protocol, we selected a subsample and assigned to the control group 17 subjects with fasting and post-loading homocysteine (Hcy) ≤12 and 42.3 μmol/L after loading. Selected subjects were requested to have a second visit to perform a breath test within 1-4 weeks following the MLT test and received an oral dose of 2.5 mg/kg of 1-13C-methionine dissolved in water. Breath samples were collected at basal, 20, 40, 60, 80, 100 and 120 min (test 1). The same procedure was repeated within 1 week (test 2). RESULTS MLT was useful for diagnosing almost twice the number of individuals with Hhcy (24%) in comparison with the fasting determination alone (13.3%). The 13C-methionine breath test reported a sensitivity of 81.3% and a specificity of 64.7% against the MLT. The coefficient of variation between breath test 1 and breath test 2 was 9.0±5.4%. CONCLUSIONS The 13C-methionine breath test is a valid and reliable method for identifying subjects with moderate Hhcy.

Exhaled breath condensate pH decreases during exercise-induced bronchoconstriction.

Abstract: Background and objective Exercise-induced bronchoconstriction (EIB) is the temporary narrowing of the airways caused by physical exercise. Its exact pathophysiology is unclear; however, acute changes in airways pH may play a role. Exhaled breath condensate (EBC) pH was suggested as a surrogate indicator for airway acid–base status, but its value is also affected by volatile molecules and respiratory droplet dilution. The aim of the study was to assess changes in EBC pH during EIB. Methods Twenty-two asthmatics who reported breathlessness following exercise and 16 healthy individuals participated in the study. Lung function test was performed and exhaled breath samples were collected for pH, dilution factor and volatile compound pattern measurements (Cyranose 320) pre-exercise and at 0, 10, 20 and 30 min after physical exercise challenge. Fractional exhaled nitric oxide was measured before exercise. Results EIB developed in 13 asthmatic subjects. In these participants, but not in the EIB-negative asthmatics (P = 0.51), EBC pH reduced significantly during exercise (P = 0.01). In addition, changes in EBC pH were related to the degree of bronchospasm in the EIB-positive group (P = 0.01, r = 0.68). Exhaled volatile pattern became altered (P 0.05). Conclusions The development of EIB was related to acute changes of EBC pH, which suggest the role of airway pH decrease in the pathophysiology of EIB. Exercise-induced changes in exhaled biomarkers suggest methodological precautions to avoid physical exercise before performing exhaled breath tests.

Sensitivity and specificity of an abbreviated (13)C-mixed triglyceride breath test for measurement of pancreatic exocrine function.

Abstract: Background: A modified 13 C-mixed triglyceride breath test ( 13 C -MTGT) detects moderate pancreatic exocrine insufficiency noninvasively and reliably, but it requires prolonged breath sampling (6 hours (hr)). Objective: We aimed to investigate whether 13 C -MTGT can be abbreviated, to optimize clinical usability. Methods: We analyzed the 13 C-MTGT of 200 consecutive patients, retrospectively. Cumulative 1–5hr 13 C-exhalation values were compared with the standard parameter (6-hr cumulative 13 C-exhalation). We determined the sensitivity and specificity of shortened breath sampling periods, by comparison with the normal values from 10 healthy volunteers, whom also underwent a secretin test to quantitate pancreatic secretion. Moreover, we evaluated the influence of gastric emptying (GE), using a 13 C-octanoic acid breath test in a subset (N ¼117). Results: The 1–5hr cumulative 13 C-exhalation tests correlated highly and significantly with the standard parameter (p <0.0001). Sensitivity for detection of impaired lipolysis was high (� 77%), but the specificity was low (� 38%) for the early measurements. Both parameters were high after 4hrs (88% and 94%, respectively) and 5hrs (98% and 91%, respectively). Multivariate linear correlation analysis confirmed that GE strongly influenced early postprandial 13 C-exhalation during the 13 C-MTGT. Conclusion: Shortening of the 13 C -MTGT from 6 to 4hrs of duration was associated with similar diagnostic accuracy, yet increased clinical usability. The influence of GE on early postprandial results of the 13 C-MTGT precluded further abbreviation of the test.

How accurate are blood (or breath) tests for identifying self-reported heavy drinking among people with alcohol dependence?

Abstract: Aims: Managing patients with alcohol dependence includes assessment for heavy drinking, typically byasking patients. Some recommend biomarkers to detect heavy drinking but evidence of accuracy is limited. Methods: Among people with dependence, we assessed the performance of disialo-carbohydrate-deficient transferrin (%dCDT, ≥1.7%), gamma-glutamyltransferase (GGT, ≥66 U/l), either %dCDT or GGT positive, and breath alcohol (> 0) for identifying 3 self-reported heavy drinking levels: any heavy drinking (≥4 drinks/day or >7 drinks/week for women, ≥5 drinks/day or >14 drinks/week for men), recurrent (≥5 drinks/day on ≥5 days) and persistent heavy drink- ing (≥5 drinks/day on ≥7 consecutive days). Subjects (n=402) with dependence and current heavy drinking were referred to primary care and assessed 6 months later with biomarkers and validated self-reported calendar method assessment of past 30-day alcohol use. Results: The self-reported prevalence of any, recurrent and persistent heavy drinking was 54, 34 and 17%. Sensitivity of %dCDT for detecting any, recurrent and persistent self-reported heavy drinking was 41, 53 and 66%. Specificity was 96, 90 and 84%, respectively. %dCDT had higher sensitivity than GGT and breath test for each alcohol use level but was not adequately sensitive to detect heavy drinking (missing 34-59% of the cases). Either %dCDT or GGT positive improved sensitivity but not to satisfactory levels, and specificity decreased. Neither a breath test nor GGT was sufficiently sensitive (both tests missed 70-80% of cases). Conclusions: Although biomarkers may provide some useful information, their sensitivity is low the incremental value over self-report in clinical settings is questionable.

Effects of exogenous lactase administration on hydrogen breath excretion and intestinal symptoms in patients presenting lactose malabsorption and intolerance.

Abstract: Objective. To establish whether supplementation with a standard oral dose of Beta-Galactosidase affects hydrogen breath excretion in patients presenting with lactose malabsorption. Methods. Ninety-six consecutive patients positive to H2 Lactose Breath Test were enrolled. Mean peak H2 levels, the time to reach the peak H2, the time to reach the cut-off value of 20 ppm, the cumulative breath H2 excretion, the areas under the curve, and a Visual Analogical 10-point Scale for symptoms were calculated. Genotyping of the C/T-13910 variant was carried out. Results. Following the oral administration of Beta-Galactosidase, in 21.88% of the cases, H2 Lactose Breath Test became negative (Group A), while mean peak H2 levels (74.95 ppm versus 7.85), , in 17.71% (Group B) were still positive, with the H2 level 20 ppm above the baseline, but the peak H2 levels were significantly lower than those observed at the baseline test (186.7 ppm versus 66.64), , while in 60.41% (Group C) they were still positive with the peak H2 levels similar to those observed at the baseline test (94.43 versus 81.60 ppm). All 96 individuals tested presented the C/C-13910 genotype nonpersistence. Conclusions. The response to oral administration of Beta-Galactosidase in patients with symptoms of lactose malabsorption presents a significant variability.

Diagnosis, Treatment, and Outcome in Patients with Bleeding Peptic Ulcers and Helicobacter pylori Infections

Abstract: Upper gastrointestinal (UGI) bleeding is the most frequently encountered complication of peptic ulcer disease. Helicobacter pylori (Hp) infection and nonsteroidal anti-inflammatory drug (NSAID) administration are two independent risk factors for UGI bleeding. Therefore, testing for and diagnosing Hp infection are essential for every patient with UGI hemorrhage. The presence of the infection is usually underestimated in cases of bleeding peptic ulcers. A rapid urease test (RUT), with or without histology, is usually the first test performed during endoscopy. If the initial diagnostic test is negative, a delayed 13C-urea breath test (UBT) or serology should be performed. Once an infection is diagnosed, antibiotic treatment is advocated. Sufficient evidence supports the concept that Hp infection eradication can heal the ulcer and reduce the likelihood of rebleeding. With increased awareness of the effects of Hp infection, the etiologies of bleeding peptic ulcers have shifted to NSAID use, old age, and disease comorbidity.

Non-invasive 13C-glucose breath test using residual gas analyzer-mass spectrometry: a novel tool for screening individuals with pre-diabetes and type 2 diabetes.

Abstract: We report, for the first time, the clinical feasibility of a novel residual gas analyzer mass spectrometry (RGA-MS) method for accurate evaluation of the (13)C-glucose breath test ((13)C-GBT) in the diagnosis of pre-diabetes (PD) and type 2 diabetes mellitus (T2D). In T2D or PD, glucose uptake is impaired and results in blunted isotope enriched (13)CO2 production in exhaled breath samples. Using the Receiver operating characteristics (ROC) curve analysis, an optimal diagnostic cut-off point of the (13)CO2/(12)CO2 isotope ratios expressed as the delta-over-baseline (DOB) value, was determined to be δDOB(13)C‰ = 28.81‰ for screening individuals with non-diabetes controls (NDC) and pre-diabetes (PD), corresponding to a sensitivity of 100% and specificity of 94.4%. We also determined another optimal diagnostic cut-off point of δDOB(13)C‰ = 19.88‰ between individuals with PD and T2D, which exhibited 100% sensitivity and 95.5% specificity. Our RGA-MS methodology for the (13)C-GBT also manifested a typical diagnostic positive and negative predictive value of 96% and 100%, respectively. The diagnostic accuracy, precision and validity of the results were also confirmed by high-resolution optical cavity enhanced integrated cavity output spectroscopy (ICOS) measurements. The δDOB(13)C‰ values measured with RGA-MS method, correlated favourably (R(2) = 0.979) with those determined by the laser based ICOS method. Moreover, we observed that the effects of endogenous CO2 production related to basal metabolic rates in individuals were statistically insignificant (p = 0.37 and 0.73) on the diagnostic accuracy. Our findings suggest that the RGA-MS is a valid and sufficiently robust method for the (13)C-GBT which may serve as an alternative non-invasive point-of-care diagnostic tool for routine clinical practices as well as for large-scale diabetes screening purposes in real-time.

13C-mixed triglyceride breath test for evaluation of pancreatic exocrine function in diabetes mellitus.

Abstract: OBJECTIVE The clinical relevance of pancreatic exocrine insufficiency (PEI) in diabetic patients is unclear mostly because established function tests are invasive and expensive or lack sensitivity and specificity. A modified version of the noninvasive 13C-mixed triglyceride breath test (13C-MTGT) has recently been shown to detect moderate PEI reliably in patients with chronic pancreatitis. Its sensitivity and specificity in other patient groups are unknown. We therefore aimed to clarify the significance of this test for patients with diabetes mellitus (DM). METHODS A secretin cerulein test and a modified 13C-MTGT were performed in 14 patients with DM (10 patients with type 1 DM) and 10 healthy volunteers. RESULTS Secretin cerulein test showed significantly lower outputs of amylase, trypsin, and lipase in DM compared with healthy volunteers (P < 0.05). Likewise, 13C-MTGT showed significantly lower maximal and cumulative 13C-exhalation in DM (P < 0.005). Stimulated lipase output correlated with cumulative 13C-exhalation (P < 0.05). However, when compared with normal values, only 2 patients with diabetes had abnormally low lipase output, whereas cumulative 13C-exhalation was pathologically decreased in 8 patients, including those with decreased lipase output. CONCLUSIONS The noninvasive 13C-MTGT can detect mild to moderate PEI in DM. However, the specificity of the 13C-MTGT is low in these patients probably because nonpancreatic mechanisms contribute to decreased intestinal lipolysis.

Remote breath alcohol monitoring

Abstract: A portable handheld wireless breath alcohol monitoring device (RBAM) utilizes facial recognition and automatic retesting if an initial test is positive for alcohol or of an initial facial match is negative. A location fix is captured with each breath test taken by an offender. After each breath test, the breath alcohol content (BrAC), date and time of the breath test, facial image data, and location fix are uploaded through a built-in cellular phone module in the RBAM to a monitoring station. The monitoring station evaluates each breath test and determines if immediate notification to a supervising agency is needed. If so, an email, text message, or page is sent to the supervising agency. RBAM enables the monitoring of lower-risk offenders or offenders who have earned the privilege of a less intrusive alcohol testing and monitoring program.