Building Competency in Diabetes Education THE ESSENTIALS

BASAL-BOLUS INSULIN THERAPY | 12-34

Are there differences in types of U100 rapid-acting insulin analogues? Direct comparisons of lispro and aspart kinetics are available. One study suggested that lispro is absorbed slightly more quickly (time to peak: 125 minutes and 150 minutes with lispro and aspart, respectively) and that aspart has a slightly longer duration (17). These differences may not be clinically significant. No significant differences in A1C or hypoglycemic episodes have been observed in randomized trials with the two rapid-acting insulin analogues (lispro and aspart) (64). Both analogues reduce postprandial BG and rates of hypoglycemia in comparison to regular insulin. Insulin lispro and insulin aspart have virtually identical modes of action and advantages over short- acting insulin (65). Minor dose adjustments to basal and/or bolus doses may be required if changing from short to rapid insulin, or vice versa. Glulisine displays faster absorption and onset and shorter duration than regular human insulin and similar intra-subject variability (66). When used in CSII, glulisine performed comparably to insulin aspart in terms of clinical endpoints, including A1C, daily doses, BG profiles and adverse events (catheter occlusion included) (12). Faster-acting insulin aspart, when compared with insulin aspart, has an earlier onset; four minutes versus nine minutes, a higher exposure of action within the first 30 minutes with more than 50% greater insulin action within that first 30 minutes (62). Are there advantages to using rapid-acting analogues vs. short-acting insulin for CSII? The 2018 Guidelines include a specific recommendation favouring the use of rapid-acting analogues in CSII. The rapid onset and decreased variability of rapid-acting analogues allow the meal bolus features of today’s pumps to be used to their fullest advantage and mimic physiologic insulin action more closely. For example: • A bolus calculator recommends a specific dose for each correction or meal bolus using individualized guidelines for carbohydrate: insulin ratios, sensitivity factor, BG target and duration of insulin action. • Meal boluses may be given all at once or customized to deliver insulin over varying periods of time, to match the absorption of foods with various glycemic indexes. • Doses may be given in increments of 0.025 to 0.05 units. A theoretical advantage related to isoelectric properties and less precipitation in pump tubing has been reported for aspart (67). However, Weinzimer et al. compared aspart and lispro in CSII therapy and noted no significant differences between the two analogues (68).