A randomized clinical trial comparing breakfast and bedtime administration of insulin glargine in children and adolescents with type 1 diabetes.

Background: Insulin glargine provides effective glycemic control when administered at bedtime in adults.
Objective: This study aims to investigate whether insulin glargine is equally effective if administered in the morning or at bedtime in combination with preprandial anologue insulin.
Methods: Twenty-eight patients that have been treated with an intensified insulin regimen for at least one year were randomized to insulin glargine injection at breakfast (06:00-09:00) (12 patients) or bedtime (21:00-24:00) (16 patients), plus meal-time anologue insulin in the two groups. Glucose data from each day were analyzed at four different times: between 9:00 and 21:00 (t1), between 21:00 and 24:00 (t2), between 24:00 and 04:00 (t3),04:00 and 09:00 (t4) by the Minimed continuous glucose monitoring system.
Results: Baseline characteristics were similar in the two groups. The sensor values were lower before breakfast in the bedtime group (180.5 ± 49.0 vs 223.8 ± 47.3 mg/dl, p=0.03). There were 13.7 events.patient (-1).day(-1) in the bedtime group and 6.9 events.patient (-1).day(-1) in the breakfast group in which glucose levels fell below 60 mg/dl (p=0.3). There were 121.6 events.patient (-1).day(-1) in the bedtime group and 162.4 events.patient (-1).day(-1) in the breakfast group in which glucose levels exceeded 180 mg/dl (p=0.05). Nighttime hypoglycemia only reached to a statistical significance between the two groups between 24:00 and 04:00. There were no significant correlations between the duration of nocturnal hypoglycemia, age, duration of diabetes, gender and HbA1c levels.
Conclusion: Breakfast group is hyperglycemic during the day and hyperglycemia starts in the morning at 04:00. There is no significant difference in the frequency or duration of hypo/hyper glycemia during the day and night irrespective of the timing of glargine injection except pre-breakfast levels are significantly better in the bedtime group and hypoglycemia occurs between midnight and 04:00 in the bedtime group.