Timing of Meal Insulin and Its Relation to Adherence to Therapy in Type 1 Diabetes.

The purpose of this study is to examine timing of meal insulin and further determine whether an association exists between timing of meal insulin and missed meal insulin doses. The cohort included 4768 T1D Exchange clinic registry participants <26 years with type 1 diabetes ≥1 year. Chi-square tests, t-tests, and regression were used to assess the relationship between participant characteristics and timing of meal insulin and missed meal doses, respectively. Timing of meal insulin and association with missed meal doses was analyzed using logistic regression. In all, 21% reported administering insulin several minutes before, 44% immediately before, 10% during, and 24% after meal. Participants who gave insulin prior to a meal had significantly lower HbA1c than those who gave insulin during or after meal (8.4% ± 1.5% vs 8.8% ± 1.6%, adjusted P < .001), but no significant association was observed regarding DKA events. Those who reported missing ≥1 insulin dose per week had higher HbA1c (9.8% ± 1.9% vs 8.3% ± 1.3%, adjusted P < .001) and were more likely to experience at least one DKA event (9% vs 5%, adjusted P = .001) compared with those who rarely missed a meal insulin dose. Participants who reported administering insulin during or after a meal were more likely to report missing ≥1 meal insulin dose per week compared with those who administered insulin before a meal (28% vs 14%, adjusted P < .001). Premeal insulin was associated with lower HbA1c and fewer missed meal insulin doses. Providers may use this information to discuss the benefits of premeal insulin on glycemic control and adherence to therapy.