Abstract

One of the attributes of CSII (continuous subcutaneous insulin infusion) is its ability to tailor prandial insulin delivery to the composition of a meal and anticipated glycemic effects. The dual-wave bolus (DWB) is a tool implemented in contemporary insulin pumps that delivers a combination of an instant insulin bolus followed by a square bolus (SB) infused over several hours. We assessed the effectiveness of DWB in 56 adult patients with type 1 diabetes (T1DM) who were on continuous subcutaneous insulin infusion via insulin pump for at least 2 years. We divided patients into frequent (DWB+, n = 32) and infrequent (DWB-, n = 24) DWB users (>20% vs. <20% of daily bolus dose delivered as SB). CSII implementation resulted in a decrease of adjusted HbA1c level by 0.80% (95% CI 0.67-0.93, P < 0.0001) and adjusted mean glycemia by 18.4 mg/dl (95% CI 15.3-21.4, P < 0.0001) in the whole cohort within the first year of observation. It was sustained in the second year, but without further improvement. Frequent DWB use was associated with male sex (59% vs. 17%, p = 0.001) and shorter duration of T1DM (3.4 vs. 11.3 yrs, p < 0.0001), but not with patients' age (25.7 vs. 27.0 years, P = 0.6). DWB+ patients improved their HbA1c by 0.45% more (95% CI 0.20-0.71, P = 0.0009) than DWB- individuals. In conclusion, DWB might be a tool potentially helping to improve glycemic control in T1DM adult users of insulin pumps. Male patients and those with a shorter duration of diabetes seem to use it more willingly.