Mealtime injection of bolus insulin is critical for maintaining good glycemic control in patients with type 1 diabetes (T1D). It has previously been shown in a real-world setting that patients using connected pens had fewer missed mealtime injections of bolus doses as well as improved time-in-range (TIR) compared to baseline. This subgroup post-hoc study examined the effect of using connected pens on timing of bolus doses in adults and the relationship between timing of the insulin dose and glycemic variability. In a non-interventional study, conducted at 12 Swedish diabetes clinics, connected pens with bolus and/or basal insulin were prescribed to adults with T1D. Injection- and continuous glucose monitoring (CGM) data were collected at routine clinic visits. CGM data were also uploaded at home. These data were used by healthcare providers (HCPs) and patients during visits at the clinic. Meals were subsequently detected based on the CGM signals using the clinically validated Glucose Rate Increase Detector algorithm. A bolus dose given 60-120 minutes after the estimated start of the meal was defined as a late-bolus dose. In total 96 patients with 2238 days of acceptable CGM coverage (≥ 70%) were included in the analysis. The mean number of late-bolus doses decreased from 0.32 per day (95% CI [0.26;0.39]) at baseline to 0.18 per day [0.13;0.27] at follow-up, corresponding to a 42% reduction (p = 0.005). A significant correlation between the timing of the bolus dose and the coefficient of variation (CV) of the CGM signal was found; each 10-minute delay of the bolus dose was associated with an increase of 0.5% CV (p < 0.0001) on average. This study confirms that timely injection of bolus doses relative to meals is correlated with a more stable glycemic control. Also, the results indicate that timely bolus dosing can be a challenge in everyday life but that data from connected pens may help support patient behavior through improved interaction with HCP.
J.H. Jendle: Advisory Panel; Self; Abbott, AstraZeneca, Boehringer Ingelheim International GmbH, Eli Lilly and Company, Medtronic, Novo Nordisk A/S, Sanofi. Research Support; Self; Novo Nordisk A/S. Speaker’s Bureau; Self; AstraZeneca, Boehringer Ingelheim International GmbH, Eli Lilly and Company, Novo Nordisk A/S, Sanofi. N.V. Hartvig: Employee; Self; Novo Nordisk A/S. A. Kaas: Employee; Self; Novo Nordisk A/S. Stock/Shareholder; Self; Novo Nordisk A/S. J. Moller: Employee; Self; Novo Nordisk A/S. Stock/Shareholder; Self; Novo Nordisk A/S. A.M. Mårdby: Employee; Self; Novo Nordisk A/S. Stock/Shareholder; Self; Novo Nordisk A/S. S. Catrina: None.