Analysis of Prevalence, Magnitude, and Timing of the Dawn Phenomenon in Type 1 Diabetes—Descriptive Analysis of Two Insulin Pump Trials
Bibliographic record
Abstract
To better understand the dawn phenomenon in type 1 diabetes, we sought to determine its prevalence, timing and magnitude in studies specifically designed to assess insulin pump basal requirements. Thirty-three participants from two insulin pump studies were analyzed. Twenty were obtained from a methodologically-ideal semi-automated basal analysis trial in which basal rates were determined from repeated fasting tests (the derivation set) and 13 from an artificial pancreas trial in which duration of fasting was variable (the validation set). Prevalence was determined for the total cohort and the individual trials using the standard definition of an increase in insulin exceeding 20% and lasting 90 minutes or more. Among cases, time of onset and percent change in the magnitude of basal delivery was determined. Seventeen of the 33 (52%) participants experienced the dawn phenomenon [11 of 20 (55%) in the derivation set, 6 of 13 (46%) in the validation set]. Time of onset was 3:00 am [IQR; 3:00, 4:15 am] in the derivation set and 3:00 am [3:00, 4:00 am] in the validation set. The magnitude of the dawn phenomenon was a 58.1% [28.8, 110.6%] increase in insulin requirements in the derivation set and 65.5% [45.6%, 87.4%] in the validation set. The dawn phenomenon occurs in approximately half of patients with type 1 diabetes, when present it has predictable timing of onset (generally 3am), and has substantial but highly variable magnitude. These findings imply that optimization of glycemic control requires clinical emphasis on fasted overnight basal insulin assessment. Disclosure I. Ostrovski: None. L. Lovblom: None. D. Scarr: None. A. Weisman: None. A. Orszag: None. E. D'Aoust: None. A. Haidar: Consultant; Self; Eli Lilly and Company. Research Support; Self; AgaMatrix, Medtronic MiniMed, Inc. R. Rabasa-Lhoret: Consultant; Self; Abbott, Amgen Inc.. Other Relationship; Self; Animas Corporation. Consultant; Self; AstraZeneca, Boehringer Ingelheim Pharmaceuticals, Inc.. Research Support; Self; Diabetes Canada, Canadian Institutes of Health Research. Other Relationship; Self; Eli Lilly and Company. Consultant; Self; Janssen Pharmaceuticals, Inc.. Research Support; Self; JDRF. Consultant; Self; Medtronic. Other Relationship; Self; Merck & Co., Inc., Novo Nordisk Inc., Sanofi-Aventis. Advisory Panel; Self; Sanofi US. Research Support; Self; National Institutes of Health, Cystic Fibrosis Canada, Société Francophone du Diabéte. L. Legault: Advisory Panel; Self; Insulet Corporation. Research Support; Self; Merck & Co., Inc., Sanofi. Advisory Panel; Self; Medtronic. Other Relationship; Self; Eli Lilly and Company. B.A. Perkins: Advisory Panel; Self; Boehringer Ingelheim GmbH. Research Support; Self; Boehringer Ingelheim GmbH, Novo Nordisk Inc.. Advisory Panel; Self; Novo Nordisk Inc., Abbott. Speaker's Bureau; Self; Abbott, Janssen Pharmaceuticals, Inc.. Advisory Panel; Self; Insulet Corporation. Speaker's Bureau; Self; Insulet Corporation, Dexcom, Inc..
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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 | 0.024 | 0.053 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.002 | 0.002 |
| Bibliometrics | 0.002 | 0.003 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.002 | 0.001 |
| Open science | 0.001 | 0.001 |
| 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".