AID-specific recommendations are listed alphabetically by company.

Beta Bionics iLet Bionic Pancreas

The iLet insulin-only Bionic Pancreas system’s glucose targets can be set to 6.1 (lower), 6.7 (usual) or 7.2 mmol/l (higher). Unlike other AID systems, the iLet is initialised based only on bodyweight and does not require discrete CHO input for meals; instead, users employ a qualitative approach to meals indicating if meal sizes are ‘Usual for me’, ‘More’ or ‘Less’. The system delivers ~75% of the estimated insulin needs for a meal immediately and will automatically increase or decrease additional basal or correction insulin dosing in the postprandial period as needed. Correction doses are provided by the system and the user cannot override it to give a manual dose of insulin. In this AID system, IOB is estimated using a fixed model of insulin absorption into the blood and clearance from the blood that considers all correction boluses and meal boluses. IOB is computed every 5 min based on an assumed peak time of insulin in the blood after administration (tmax) of 65 min. Unlike most other AID systems, the duration of insulin action cannot be adjusted by the user.

Evidence on glucose management around PA with the iLet system

To date, the iLet system has been tested only in clinical trials of physically active youth and adults with type 1 diabetes, with no formal evaluation of how it performs during and after PA [35, 36]. Nonetheless, several exercise studies on earlier system designs, including dual-hormone (i.e. glucagon and insulin) configurations, have been conducted [37,38,39]. Therefore, recommendations (Fig. 2) are given based primarily on studies from other AID systems with considerations on how the iLet system may be adjusted for PA (all recommendations are level D).

Fig. 2

Recommendations for use of the iLet Bionic Pancreas system to manage glucose outcomes during PA. Consider insulin delivery suspension with or without disconnecting the iLet system 30 min prior to activity to help mitigate hypoglycaemia risk. If ingesting undeclared CHO and disconnecting the iLet before activity, ensure that the device is already suspended and disconnected prior to CHO ingestion. The prandial bolus insulin dose can be reduced only by ‘underestimating’ CHO (i.e. entering a smaller meal size). SG, sensor glucose. Glucose values: 6.1 mmol/l = 110 mg/dl, 6.7 mmol/l = 120 mg/dl, 7.0 mmol/l = 126 mg/dl, 7.2 mmol/l = 130 mg/dl, 8.3 mmol/l = 150 mg/dl. See ESM 1 for version of this figure with glucose concentrations in mg/dl. This figure is available as part of a downloadable slideset

Recommendations for glucose management around PA with the iLet system

The iLet system currently does not have a feature to allow a higher glucose target to be set prior to PA to help reduce the risk of hypoglycaemia during an activity. However, if using a glucose target of 6.1 or 6.7 mmol/l as the ‘usual target’, one option for PA may be to switch the glucose target to 7.2 mmol/l, ideally 1–2 h before the activity (consensus D). Users must remember to return the glucose target back to the usual target following PA. The prandial bolus insulin dose can be reduced for a pre-exercise meal bolus only by entering a smaller meal size into the device (i.e. select ‘Less’ rather than ‘Usual for me’), which effectively reduces the bolus insulin dose by 50%.

One other point to consider is whether to leave the iLet connected during PA or whether it should be suspended with or without disconnecting the pump during some PA where the risk for hypoglycaemia is elevated. This approach may need to be personalised to the individual and the PA type and intensity (consensus D). Without the current option of setting a glucose target >7.2 mmol/l, in instances of increased hypoglycaemia risk, key strategies for this AID system around PA include (1) frequent checking and monitoring of real-time CGM values and trends pre, during and post exercise; (2) having fast-acting CHO readily available to prevent or treat hypoglycaemia; and (3) aiming to limit the amount of CHO on board before PA when possible, to avoid increases in automated insulin delivery (consensus D). For individuals aiming to consume uncovered CHO before PA, one strategy is to consume CHO after suspending and disconnecting the iLet system, to avoid increases in automated insulin delivery (consensus D).

CamDiab mylife CamAPS FX

The mylife CamAPS FX system allows a glucose target between 4.4 and 11.0 mmol/l to be set, with a default target of 5.8 mmol/l. Insulin delivery using auto-modulated insulin release based on the algorithm and manual correction doses is possible in auto-mode but is not recommended unless following an infusion set occlusion or similar.

In this system, any bolus insulin given through the bolus calculator (correction or meal related) counts towards IOB (displayed as ‘Active Insulin’). The active insulin time that is displayed to the user can be set between 2 and 8 h; however, the real active insulin time used by the algorithm is subject to adaptive learning and is automatically adjusted. Basal rate or algorithm-directed insulin delivery does not count towards IOB, and the programmed duration of insulin action does not affect the algorithm-directed insulin delivery. A realistic view of IOB can be visualised by turning the mobile phone to landscape (horizontal mode), which allows the last bolus dosing and pharmacokinetic profile of the basal rate of insulin delivery to be seen.

Two additional features are available in the mylife CamAPS FX system: the ‘Ease-off’ mode, which delivers less insulin, raises the glucose target and suspends insulin delivery if glucose levels are <7.0 mmol/l; and the ‘Boost’ mode, which increases the algorithm responsiveness to higher glucose levels by up to ~35% while maintaining the same glucose target.

Evidence on glucose management during PA with the mylife CamAPS FX system

Previous studies performed in children and adolescents with type 1 diabetes using the mylife CamAPS FX system demonstrated that use of the Ease-off mode for PA resulted in safe glucose levels during PA [31, 34]. Specifically, increasing the glucose target to 8.3 mmol/l and simultaneously starting the Ease-off mode 2 h before maximum cardiopulmonary exercise testing resulted in stable glucose levels in young people with type 1 diabetes (start 10.7±3.1 mmol/l vs end 10.5±3.1 mmol/l; p=0.69) [34]. In a ski camp study performed in children and adolescents with type 1 diabetes, it was also shown that starting the Ease-off mode 2 h before exercise was suitable for avoiding hypoglycaemia [31].

Recommendations for glucose management around PA with the mylife CamAPS FX system

To reduce the risk of hypoglycaemia during activity, we suggest setting the Ease-off mode and/or increasing the glucose target 1–2 h before PA [31, 34] (C); this may be especially relevant in instances of high IOB or during aerobic exercise [40] (D). We recommend using the Boost mode if an increase in glucose is expected during PA [8] (D) (e.g. during high-intensity sprinting in the fasted state [41] (D)). If deemed useful by the user, caregiver or healthcare professional, both the Ease-off and the Boost mode can be pre-programmed in this system to automatically start and end at a predefined time when PA is expected, as described in Fig. 3.

Fig. 3

Illustration of how to set a new personal glucose target and how to set the Ease-off (now or later) mode when using the mylife CamAPS FX system. See ESM 1 for version of this figure with glucose concentrations in mg/dl. This figure is available as part of a downloadable slideset

For unplanned, low- to moderate-intensity PA, where a decrease in glucose levels is expected and the glucose level is already in a reasonable target range for PA (e.g. 5.0–7.0 mmol/l), the Ease-off mode and/or a higher glucose target should be set immediately, followed by consumption of 10–20 g of CHO at exercise onset [7, 42] (D). The suggestion is to announce this meal or snack as ‘hypoglycaemia treatment’ in the ‘Add meal’ function and not as a regular meal, otherwise the system will likely deliver insulin [31, 34] (C). As with any AID system, more CHO can be consumed during prolonged PA based on observed glucose trends and for performance reasons [43]. In contrast, for instances where a rise in glucose levels is expected during PA (e.g. during high-intensity PA in the overnight fasted state) [41], we recommend starting the Boost mode with the regular or lower glucose target at the onset of PA to help limit activity-related hyperglycaemia. We advise not starting the Boost mode well in advance of the onset of the activity, as this might result in pre-exercise hypoglycaemia (consensus D).

As the Ease-off and Boost modes contribute to a lesser extent to the algorithmic learning, these modes may be considered for individuals who perform more irregular PA (consensus D). For individuals who exercise more regularly with respect to specific days and times (e.g. Mon, Wed, Fri and Sun at ~17:00), one option may be to set a specific glucose target depending on the time of day and type of PA that is typically performed, as described in Fig. 3(consensus D). For example, when glucose levels are expected to decrease during PA, consider setting a glucose target ≥8.3 mmol/l ~2 h before activity. We also recommend that users set an individualised glucose target for PA when they are using either the Ease-off mode (i.e. higher glucose target) or the Boost mode (i.e. lower glucose target) to help achieve their desired glucose level [34] (D). All recommended adaptations concerning the Ease-off and Boost modes, as well as glucose targets, are provided in Fig. 4.

Fig. 4

Recommendations for use of the mylife CamAPS FX system to manage glucose outcomes during PA. Insulin delivery suspension with or without disconnection for prolonged periods (up to 120 min) may be required under some circumstances (e.g. swimming, diving, contact sports), although it is generally not recommended for most activities. SG, sensor glucose. Glucose values: 4.4 mmol/l = 80 mg/dl, 5.6 mmol/l = 100 mg/dl, 6.7 mmol/l = 120 mg/dl, 7.0 mmol/l = 126 mg/dl, 8.3 mmol/l = 150 mg/dl. See ESM 1 for version of this figure with glucose concentrations in mg/dl. This figure is available as part of a downloadable slideset

Diabeloop Generation 1

The Generation 1 (DBLG1) system’s default glucose target is 6.1 mmol/l, but the glucose target can be set between 5.6 and 7.2 mmol/l. The low glucose threshold when insulin delivery is stopped can be set between 3.3 and 4.7 mmol/l and the algorithm hyperglycaemia threshold is 10.0 mmol/l. The aggressiveness of insulin delivery of the DBLG1 system can be modified to deliver 59–147% of the typical basal rate when glucose is between 3.9 and 10.0 mmol/l. When sensor glucose is >10.0 mmol/l, the automated correction bolus can be set to deliver within the range of 43–186% of the typical automated correction bolus dose. The prandial insulin dose can also be set to deliver insulin in the range of 50–200% for breakfast, lunch and dinner. These functions may be used to adapt the prandial insulin dose for post-meal activity; however, this needs to be discussed, individualised and, in some cases, modified with support from the healthcare professional team.

In this system, IOB (displayed as ‘Active Insulin’), as shown in the interface, corresponds to the IOB provided by regulation, including any insulin source confirmed by the pump (basal rate and bolus insulin).

Evidence on glucose management during PA with the DBLG1 system

In a post hoc analysis of an RCT, glycaemic outcomes were compared between days with and days without PA in 56 adults with type 1 diabetes using the DBLG1 system for 12 weeks [44]. Participants announced PA at least 30 min before exercise, which reduced insulin delivery, and, if necessary, a certain amount of CHO was also recommended by the system to avoid hypoglycaemia. Time below range (<3.0 mmol/l; TBR<3.0) was not significantly different between days with and days without PA, independent of exercise duration and intensity (2.0±1.5% vs 2.2±1.1%; p>0.05). Ingested CHO as a preventative strategy against hypoglycaemia as recommended by the system were significantly higher on days with PA (41.1±35.5 vs 21.8±28.5 g/day; p<0.001), and the AID insulin dose was significantly lower on days with PA (31.5±10.5 vs 34.0±10.5 U/day; p<0.001). The time above range (>10.0 mmol/l; TAR>10.0) was 28.7±9.3% on days with PA compared with 26.8±8.6% on days without PA (p=0.017). Time in range (3.9–10.0 mmol/l; TIR3.9–10.0) was 69.1±8.2% on days with PA vs 70.9±8.2% on days without PA (p=0.017). The coefficient of variation in glucose was higher on days with PA than days without (32.0±3.7% vs 30.9±3.7%; p=0.019), indicating increased glycaemic variability on exercise days.

Another study performed in adults with type 1 diabetes showed that the DBLG1 system was superior to open-loop insulin delivery with respect to TIR3.9–10.0 and TAR>10.0 when the ‘Physical Activity’ mode was set 30 min before the start of activity [45].

Recommendations for glucose management around PA with the DBLG1 system

The Physical Activity mode can be used to decrease the risk of hypoglycaemia during PA (Fig. 5). In this mode, the glucose target and hypoglycaemia threshold are increased by 3.9 mmol/l, which reduces the aggressiveness of insulin delivery. When the Physical Activity mode is used, the PA intensity can be set to low, moderate or intense and the planned duration of PA can be set. Both the duration and intensity are considered as a matrix, with coefficients modulating the insulin basal rate, corrective bolus or meal bolus. Another feature of the DBLG1 system is the ‘ZEN’ mode, which increases the glucose target by an increment that is between 0.6 and 2.2 mmol/l for a period of 1–8 h [8] (D).

Fig. 5

Illustration of how to start, stop and modify/delete the Physical Activity mode in the DBLG1 system. See ESM 1 for version of this figure with glucose concentrations in mg/dl. This figure is available as part of a downloadable slideset

We recommend starting Physical Activity mode at least 30 min before PA, as the DBLG1 system suggests consuming a specific amount of CHO to avoid hypoglycaemia [44] (C). However, it is also beneficial to start Physical Activity mode earlier (e.g. between 1 and 2 h before the start of PA), as this has been shown to reduce the risk of hypoglycaemia (Fig. 6) [31, 46] (D). When PA is announced more than 1 h before the start of the activity, the target glucose is increased by 3.9 mmol/l and the system aims to raise blood glucose prior to the start of PA. However, if glucose levels are <8.9 mmol/l 15 min before the start of PA, a specific CHO intake is recommended by the system. When PA is announced closer to the start of the activity, the system only provides a recommendation for CHO intake 15 min before PA if glucose is <8.9 mmol/l.

Fig. 6

Recommendations for use of the DBLG1 system to manage glucose outcomes during PA. Insulin delivery suspension with or without disconnection for prolonged periods (up to 120 min) may be required under some circumstances (e.g. swimming, diving, contact sports), although it is generally not recommended for most activities, as several of these strategies cannot be implemented and/or require modification. SG, sensor glucose. Glucose values: 5.6 mmol/l = 100 mg/dl, 6.1 mmol/l = 110 mg/dl, 6.7 mmol/l = 120 mg/dl, 7.0 mmol/l = 126 mg/dl. See ESM 1 for version of this figure with glucose concentrations in mg/dl. This figure is available as part of a downloadable slideset

Furthermore, the DBLG1 system automatically reduces the basal rate of insulin delivery for 16 h after Physical Activity mode is enabled to help mitigate the risk of post-exercise hypoglycaemia caused by increased insulin sensitivity. Physical Activity mode also allows the user to name and save the PA session (e.g. football) and provide the duration and intensity (e.g. low, moderate, intense). Fig. 6 provides recommendations for managing glucose levels during PA using the DBLG1 system.

Insulet Omnipod 5

The Omnipod 5 system is a tubeless AID system [8, 47] that uses SmartAdjust technology to predict glucose values 60 min in advance and dynamically adjusts basal insulin delivery every 5 min. SmartAdjust targets glucose levels between 6.1 and 8.3 mmol/l, with levels set by the user, caregiver or healthcare professional. Different targets can be programmed for different hours of the day. With each Pod change, usually occurring at least every 72 h, the Omnipod 5 system automatically calculates an adaptive basal rate based on a fading memory of insulin requirements over 6 days. Furthermore, Omnipod 5 is a waterproof patch pump (i.e. Pod) that can provide users with increased flexibility in daily activities, in particular, with water-based activities [48].

In this system, the IOB is the sum of the correction IOB (insulin remaining in the body from previous correction doses), meal IOB (insulin remaining in the body from previous meal boluses) and Omnipod 5 software IOB (i.e. all insulin delivered by the system). IOB is mainly determined by the ‘Duration of Insulin Action’ setting, which ranges from 2 to 6 h. Furthermore, the ‘Reverse Correction’ feature deducts the IOB from the bolus calculation when the current glucose value is below the target glucose value [47].

Evidence on glucose management during PA with the Omnipod 5 system

In the pivotal trial of the Omnipod 5 system, an exercise study was conducted in 59 adults with type 1 diabetes. Participants underwent three, 60 min moderate-intensity treadmill exercise sessions in which (1) the ‘Activity’ feature (higher glucose target) was set 30 min prior to exercise; (2) the Activity feature was set 60 min prior to exercise; and (3) usual automated insulin delivery was continued with no adjustment made for exercise [49]. Not surprisingly, at the start of exercise in sessions (1) and (2), insulin delivery was lower and glucose was higher with use of the Activity feature than with usual automated insulin delivery.

Recommendations for glucose management around PA with the Omnipod 5 system

For PA, the higher glucose target in the Omnipod 5 system is 8.3 mmol/l. This target attenuates automated insulin delivery and can be programmed to last from 1 to 24 h [6]. For activities that lead to an increased risk of hypoglycaemia, the recommendation with this system is to set the Activity feature 1–2 h before PA until the end of the activity (Fig. 7).

Fig. 7

Illustration of how to set and cancel the Activity feature on the Omnipod 5 system. See ESM 1 for version of this figure with glucose concentrations in mg/dl. This figure is available as part of a downloadable slideset

If the usual glucose target is set to 6.7, 7.2, 7.8 or 8.3 mmol/l, and glucose is expected to increase during PA (e.g. fasted, high-intensity PA), we recommend lowering the usual glucose target to 6.1 mmol/l prior to the onset of PA and resuming the usual glucose target after the PA event (consensus D) (Fig. 8). With Omnipod 5, up to eight different targets can be programmed throughout the day, so there is some flexibility around what glucose target is set and when. Therefore, for school-aged children, higher glucose targets can be leveraged to account for usual after-school sports by setting the target higher 1–2 h prior to the scheduled activity until the end of the activity (consensus D).

Fig. 8

Recommendations for use of the Omnipod 5 system to manage glucose outcomes during PA. SG, sensor glucose. Glucose values: 6.1 mmol/l = 110 mg/dl, 6.7 mmol/l = 120 mg/dl, 7.0 mmol/l = 126 mg/dl. See ESM 1 for version of this figure with glucose concentrations in mg/dl. This figure is available as part of a downloadable slideset

A more general consideration for healthcare professionals is how the ‘Reverse Correction’ feature might impact insulin delivery at the meal before PA. With the Reverse Correction feature on, the prandial bolus dose will be reduced if the pre-meal glucose level is below target. If this feature is combined with a manual prandial bolus insulin reduction initiated by the user (e.g. 25–33% reduction) prior to activity, then glucose will likely rise and result in automated insulin delivery by the system, thereby increasing hypoglycaemia risk during PA. To date, there are no published studies to support specific guidance on using Reverse Correction around PA.

If PA is planned <2 h following a meal and a drop in glucose is anticipated, a 25–33% reduction in prandial bolus insulin is generally recommended [26, 50] (C). Another option is to turn the Reverse Correction feature off when applying a prandial bolus insulin reduction before PA (consensus D). For the meal prior to the onset of PA, the bolus insulin amount on the Omnipod 5 system can be reduced by either (1) entering fewer CHO into the system than the amount being consumed or (2) decreasing the recommended bolus insulin amount by 25% up to 100% (i.e. no bolus) [8]. Importantly, research trials on the amount and timing of prandial bolus insulin reductions before PA in children and adults with type 1 diabetes using Omnipod 5 are not currently available. Fig. 8 provides recommendations for managing glucose levels during PA using the Omnipod 5 system.

Medtronic MiniMed 780G

The MiniMed 780G system using SmartGuard technology can set glucose targets of 5.5, 6.1, 6.7 and 8.3 mmol/l (‘Temp Target’, exercise mode). One of the major safety features of the Temp Target is the prevention of automatic bolus correction doses in response to rising glucose levels from ingestion of CHO immediately before or during PA. Without this feature, there is likely to be a significant increase in IOB during PA when CHO are given, which can result in a recurrent cycle of hypoglycaemic episodes. The auto-correction bolus, when enabled, automatically delivers bolus insulin doses when the algorithm has been delivering auto-basal insulin at the maximum insulin limit, the sensor glucose value is >6.7 mmol/l and the calculated correction bolus is >10% of the maximum insulin limit. Furthermore, the auto-correction bolus can be switched off in the SmartGuard settings. When SmartGuard technology is used for calculating the bolus insulin dose for CHO, the dose suggestion is increased or decreased based on the actual glucose value and the total IOB.

The IOB (displayed as ‘Active Insulin’) accounts for bolus insulin, including meal boluses, manual correction boluses and automatic correction boluses. Basal insulin, either from a pre-programmed basal rate or from SmartGuard auto-basal insulin delivery, is excluded from active insulin. The displayed IOB is affected by the Active Insulin time settings (2–8 h, adjustable). Active Insulin is also used in the calculation of correction boluses (both manual and automated).

Evidence on glucose management during PA with the MiniMed 780G system

The Medtronic MiniMed AID systems are suitable for use during PA in people with type 1 diabetes and are the systems with the largest body of published literature related to PA [7]. In a trial of ten adults with type 1 diabetes, it was shown that transitioning from open-loop systems to the MiniMed 780G system did not significantly alter glucose levels during and after 45 min of moderate-intensity exercise [51].

McCarthy et al demonstrated in adults with type 1 diabetes that glucose levels may be optimised during exercise when using the MiniMed 780G system by reducing the pre-exercise prandial bolus insulin dose by 25% for meals consumed up to 90 min before exercise [26]. This study also showed that increasing the glucose target at the onset of exercise or 45 min prior to the start of exercise was less effective for avoiding hypoglycaemia than setting a higher glucose target 90 min before exercise when prandial insulin was reduced by 25%. In a study of youth with type 1 diabetes using the MiniMed 780G system, it was determined that, independent of the type of insulin used (faster-acting insulin aspart vs standard insulin aspart), exercise was safe, with a TBR (<3.9 mmol/l glucose) of 2.8% vs 2.5%, respectively, when the Temp Target was set at least 1 h before exercise [27].

In a preliminary, controlled, in-clinic research study by Lee et al, TIR3.9–10.0 was 100% for 45 min of high-intensity exercise or moderate-intensity exercise when the Temp Target on the MiniMed 670G system was started 2 h prior to the start of exercise in adults with type 1 diabetes who also had impaired awareness of hypoglycaemia [46]. Use of the MiniMed advanced hybrid closed-loop (AHCL) system with different insulins (faster-acting insulin aspart and insulin aspart) did not significantly alter the risk of nocturnal hypoglycaemia on exercise days compared with non-exercise days [33, 52]. Furthermore, when comparing different types of exercise (high-intensity exercise, resistance exercise, moderate-intensity exercise), there were no differences in glycaemic outcomes [46,