Ilia Ostrovski1, Leif E Lovblom1, Daniel Scarr1, Alanna Weisman1, Nancy Cardinez1, Andrej Orszag1, C Marcelo Falappa1, Émilie D'Aoust2, Ahmad Haidar3, Rémi Rabasa-Lhoret4, Laurent Legault5, Bruce A Perkins6. 1. Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada. 2. Institut de recherches Cliniques de Montréal, Montréal, Québec, Canada. 3. Department of Biomedical Engineering, Faculty of Medicine, McGill University, Montréal, Québec, Canada; Research Institute of McGill University Health Centre, Montréal, Québec, Canada. 4. Institut de recherches Cliniques de Montréal, Montréal, Québec, Canada; Division of Experimental Medicine, McGill University, Montréal, Québec, Canada; Nutrition Department, Faculty of Medicine, Université de Montréal, Montréal, Québec, Canada; Montreal Diabetes Research Centre, Montréal, Québec, Canada. 5. Montreal Children's Hospital, McGill University Health Centre, Montréal, Québec, Canada. 6. Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada; Division of Endocrinology and Metabolism, Department of Medicine, University of Toronto, Toronto, Ontario, Canada. Electronic address: bruce.perkins@sinaihealthsystem.ca.
Abstract
OBJECTIVES: 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 basal insulin requirements in patients using insulin pumps. METHODS: Thirty-three participants from 2 sensor-augmented insulin pump studies were analyzed. Twenty participants were obtained from a methodologically ideal semiautomated 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 "confirmation" set). Prevalence was determined for the total cohort and for individual trials using the standard definition of an increase in insulin exceeding 20% and lasting ≥90 minutes. Among cases, time of onset and percent change in the magnitude of basal delivery were determined. RESULTS: Seventeen participants (52%) experienced the dawn phenomenon (11 of 20 [55%] in the derivation set and 6 of 13 [46%] in the confirmation set). Time of onset was 3 AM (interquartile range [IQR], 3 to 4:15 AM) in the derivation set and 3 AM (IQR, 3 to 4 AM) in the confirmation set. The magnitude of the dawn phenomenon was a 58.1% (IQR, 28.8% to 110.6%) increase in insulin requirements in the derivation set and 65.5% (IQR, 45.6% to 87.4%) in the confirmation set. CONCLUSIONS: The dawn phenomenon occurs in approximately half of patients with type 1 diabetes; when present, it has predictable timing of onset (generally 3 AM) and a substantial, but highly variable, magnitude. These findings imply that optimization of glycemic control requires clinical emphasis on fasted overnight basal insulin assessment.
OBJECTIVES: 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 basal insulin requirements in patients using insulin pumps. METHODS: Thirty-three participants from 2 sensor-augmented insulin pump studies were analyzed. Twenty participants were obtained from a methodologically ideal semiautomated 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 "confirmation" set). Prevalence was determined for the total cohort and for individual trials using the standard definition of an increase in insulin exceeding 20% and lasting ≥90 minutes. Among cases, time of onset and percent change in the magnitude of basal delivery were determined. RESULTS: Seventeen participants (52%) experienced the dawn phenomenon (11 of 20 [55%] in the derivation set and 6 of 13 [46%] in the confirmation set). Time of onset was 3 AM (interquartile range [IQR], 3 to 4:15 AM) in the derivation set and 3 AM (IQR, 3 to 4 AM) in the confirmation set. The magnitude of the dawn phenomenon was a 58.1% (IQR, 28.8% to 110.6%) increase in insulin requirements in the derivation set and 65.5% (IQR, 45.6% to 87.4%) in the confirmation set. CONCLUSIONS: The dawn phenomenon occurs in approximately half of patients with type 1 diabetes; when present, it has predictable timing of onset (generally 3 AM) and a substantial, but highly variable, magnitude. These findings imply that optimization of glycemic control requires clinical emphasis on fasted overnight basal insulin assessment.
Keywords:
dawn phenomenon; diabète de type 1; distribution d'insuline; insulin delivery; insulin pump therapy; phénomène de l'aube; thérapie par pompe à insuline; type 1 diabetes
Authors: Olivia McCarthy; Rachel Deere; Max L Eckstein; Jason Pitt; Ben Wellman; Stephen C Bain; Othmar Moser; Richard M Bracken Journal: Front Public Health Date: 2021-01-07