Table 1.
Standard bolus delivered with meal | Standard bolus delivered before meal | Over-bolus delivered with meal | No bolus delivered with meal | |
---|---|---|---|---|
Number of participants | 42 | 40 | 40 | 46 |
Number of breakfasts | 51 | 40 | 40 | 46 |
Meal and insulin delivery characteristics | ||||
Meal size (g of CHO) | 68 (60, 78) | 67 (58, 75) | 63 (51, 75) | 50 (50, 50) |
Normalized meal size (g of CHO/kg of body weight) | 1.00 (0.99, 1.00) | 1.00 (0.98, 1.00) | 0.99 (0.95, 1.00) | 0.74 (0.64, 0.93) |
Minutes from bolus to start of meal | 0 (−2, +1) | −15 (−16, −14) | +1 (−1, +1) | — |
Meal bolus size (U) | 6.0 (5.2, 8.8) | 6.0 (4.8, 9.5) | 7.4 (6.0, 10.4) | — |
Normalized meal bolus size (unitless)a | 0.96 (0.94, 0.97) | 0.96 (0.95, 0.97) | 1.24 (1.22, 1.26) | — |
Cumulative basal insulin delivery at 4 h (% of open-loop basal) | 103% (77%, 154%) | 118% (72%, 147%) | 80% (53%, 110%) | 204% (173%, 251%) |
Cumulative basal plus bolus insulin delivery at 4 h (U)b | 10.4 (7.8, 13.3) | 11.5 (9.7, 13.8) | 11.9 (9.3, 14.6) | 8.8 (7.3, 11.1) |
Glycemic outcomes | ||||
Metrics at start of meal | ||||
Baseline glucosec | 124 (98, 174) | 148 (124, 180) | 125 (111, 142) | 125 (115, 144) |
Metrics over 4 h | ||||
Number of YSI measurements | 11 (11, 11) | 11 (11, 11) | 11 (11, 11) | 11 (11, 11) |
% of meals with a YSI value | ||||
≤60 mg/dL | 0 | 1 (3%) | 2 (5%) | 0 |
≤70 mg/dL | 2 (4%) | 3 (8%) | 2 (5%) | 0 |
>180 mg/dL | 43 (84%) | 35 (88%) | 31 (78%) | 44 (96%) |
>250 mg/dL | 28 (55%) | 20 (50%) | 10 (25%) | 37 (80%) |
>300 mg/dL | 15 (29%) | 12 (30%) | 5 (13%) | 19 (41%) |
>400 mg/dL | 1 (2%) | 0 | 2 (5%) | 0 |
% of YSI values | ||||
≤70 mg/dL | 0% (0%, 0%) | 0% (0%, 0%) | 0% (0%, 0%) | 0% (0%, 0%) |
71–180 mg/dL | 27% (9%, 64%) | 27% (10%, 55%) | 55% (30%, 85%) | 18% (9%, 27%) |
>180 mg/dL | 73% (36%, 91%) | 73% (43%, 90%) | 41% (9%, 70%) | 82% (73%, 91%) |
Mean glucose (mg/dL) | 204 (159, 249) | 203 (164, 250) | 168 (150, 205) | 231 (208, 245) |
Glucose CV | 22% (15%, 25%) | 21% (16%, 25%) | 18% (15%, 26%) | 21% (17%, 25%) |
Nadir (mg/dL) | 124 (98, 167) | 133 (97, 176) | 114 (101, 138) | 139 (121, 151) |
Peak (mg/dL) | 261 (206, 319) | 250 (217, 307) | 220 (182, 249) | 287 (263, 313) |
Excursion (peak minus baseline)c | 121 (70, 171) | 105 (60, 130) | 102 (67, 134) | 156 (123, 180) |
Area under the curve 180 (mg/dL/min)d | 34 (6, 69) | 29 (9, 72) | 13 (0, 29) | 56 (37, 70) |
% meals with a Hypoglycemia red light | 9 (18%) | 5 (13%) | 8 (20%) | 3 (7%) |
Hypoglycemic treatment interventionse | 0 | 1 (3%) | 1 (3%) | 0 |
Hyperglycemic treatment interventionse | 1 (2%) | 0 | 2 (5%) | 0 |
Metrics at 4 h | ||||
Glucose at 4 h | 175 (134, 213) | 174 (138, 205) | 143 (109, 174) | 201 (161, 226) |
% of meals with a YSI value at 4 h | ||||
≤60 mg/dL | 0 | 0 | 1 (3%) | 0 |
≤70 mg/dL | 0 | 0 | 1 (3%) | 0 |
71–180 mg/dL | 27 (53%) | 22 (55%) | 31 (78%) | 16 (35%) |
>180 mg/dL | 24 (47%) | 18 (45%) | 8 (20%) | 30 (65%) |
>250 mg/dL | 5 (10%) | 4 (10%) | 2 (5%) | 5 (11%) |
>300 mg/dL | 2 (4%) | 0 | 2 (5%) | 1 (2%) |
>400 mg/dL | 0 | 0 | 0 | 0 |
Data are median (25th, 75th percentiles) values or n (%) as indicated.
BolusNORM=(bolusACTUAL×carbohydrate ratio)/meal size.
Includes the meal boluses, correction boluses, and insulin delivered by the controller.
Eleven baseline YSI values and excursions were missing (three with standard bolus delivered with meal, two with standard bolus delivered before meal, three with over-bolus delivered with meal, and three with no bolus delivered with meal).
Area under the curve calculated for each meal and divided by the time.
Hypoglycemic treatments preceded by a red light were not counted as an intervention, and YSI values were not imputed.
CHO, carbohydrate; CV, coefficient of variation.