Development of Minimally Invasive 13C-Glucose Breath Test to Examine Different Dietary Therapies in Patients with Glycogen Storage Disorders
Bibliographic record
Abstract
The objectives of the current study were: 1) to establish the use of ,13C-Glucose Breath Test (,13C-GBT) and its oxidation to ,13CO2 as a minimally invasive technique to examine in vivo glucose oxidation in healthy adults, and 2) to measure the utilization of uncooked cornstarch (UCCS) and Glycosade® in patients with glycogen storage disease type Ia (GSD-Ia) and healthy controls using ,13C-GBT, based on the natural enrichment of ,13C in UCCS and Glycosade®. Experiment 1- Ten healthy adults (22 – 33y) underwent ,13C-GBT protocols twice as a proof-of-principle, once without oral isotope dose (only D-glucose 75 g/d) and once with isotope (D-glucose 75 g/d + U-,13C-glucose 75 mg/d). Breath samples were collected at baseline and every 20 min for 240 min to measure ,13CO2. Experiment 2- Two patients (12 and 28y) with GSD-Ia and five healthy controls (10 – 32y) underwent ,13C-GBT protocols twice. Subjects received UCCS or Glycosade® orally (based on their current prescribed dose 42 – 100 g) after a 4 hour fast according to GSD-Ia fasting tolerance. Breath samples were collected at baseline and every 30 min for 240 min. ,13CO2 oxidation of glucose from UCCS and Glycosade® were measured using an isotope ratio mass spectrometer and compared using a paired t-test. Blood glucose was measured using a glucometer hourly to test hypoglycemia (≤3.4 mmol/L). Results 1- The mean rate of ,13CO2 in all healthy adults from D-glucose without U-,13C-glucose 0.435 ± 0.162 was significantly lower than the mean rate of ,13CO2 in the same group with U-,13C-glucose 3.518 ± 0.988. The peak occurred at 200 minutes in all healthy adults without and with U-,13C-glucose. Results 2- Glucose oxidation from Glycosade® was lower than glucose oxidation from UCCS in the 12y GSD-Ia. Glucose oxidation from UCCS and Glycosade® remained the same in the 28y GSD-Ia. However, oxidation of glucose by the 28y GSD-Ia for both starches displayed a higher rate, compared to age matched controls. Our results show that the minimally invasive,13C-GBT test over 4 hours can be useful to examine glucose metabolism from various exogenous carbohydrate sources in GSD. Future studies are needed to use ,13C-GBT in response to different doses to determine optimal glucose management in GSD patients. Saudi Arabian Cultural Bureau, Ottawa and BC Children's Hospital Research Institute.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".