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.