Does Minimed 780G™ Insulin Pump System Affect Energy and Nutrient Intake?: Long-Term Follow-up Study

Automated insulin delivery (AID) systems, such as the Minimed 780G™, have shown promise in improving glycemic control and quality of life for individuals with type 1 diabetes (T1D). The International Society of Pediatric and Adolescent Diabetes (ISPAD) recommends AID systems for all youth with T1D. While these systems adjust insulin delivery based on real-time glucose data, users still need to manually input carbohydrate intake for optimal postprandial glucose management. Effective nutrition management is crucial for T1D, with ISPAD guidelines recommending a macronutrient distribution of approximately 40-50% carbohydrates, less than 35% fat (with saturated fat under 10%), and 15-25% protein. Prior to this study, there was limited real-world data on the impact of AID systems on actual food intake patterns. Anecdotal evidence suggested some users had unrealistic expectations about the system's ability to compensate for poor dietary choices, leading to the hypothesis that AID might influence energy and nutrient intake, potentially increasing fat intake. This study aimed to investigate this hypothesis by evaluating energy and nutrient intake using 3-day food diaries at baseline, 3 months, and 6 months after initiating Minimed 780G™ use. Several studies have examined the impact of continuous glucose monitoring (CGM) and/or insulin pump use on nutrient intake, but limited data existed on the effects of AID systems specifically. This study sought to fill this gap by providing real-world data on the influence of AID on the macronutrient and fiber intake of children and adolescents with T1D.

Existing research demonstrates that AID systems significantly improve glycemic control compared to traditional methods in clinical trials involving diverse age groups and diabetes durations. Real-world data is increasingly available, offering insights into AID acceptance and performance. However, while studies show improvements in glycemic outcomes, they often lack data on the effects on food intake. Studies assessing the impact of CGM and/or pump use on nutrient intake have yielded mixed results, emphasizing the need for further investigation specifically focused on AID systems and real-world dietary habits of T1D individuals.

This 6-month prospective follow-up study included 29 children, adolescents, and young adults with T1D (aged 5-22 years, 48.3% female) who transitioned to using the Minimed 780G™ AID system between November 2021 and May 2022. Participants underwent a training session before using the system in manual mode for several days (3 days for sensor-augmented pump users, 10 days for MDI users), before initiating the auto mode. Anthropometric measurements (height, weight, BMI) were collected, and standard deviation scores (SDS) were calculated. Dietary intake was assessed using 3-day food diaries (two weekdays and one weekend day) at baseline and at months 3 and 6 after AID initiation. Two dieticians reviewed the diaries for accuracy and consistency. Glycemic parameters (HbA1c, time in range (TIR), time below range (TBR), time above range (TAR), coefficient of variation (CV), glucose management indicator (GMI)) were obtained from the MiniMed 780G™ data uploaded to CareLink™. Statistical analysis was performed using SPSS version 25.0, with independent t-tests or Mann-Whitney tests for group comparisons and repeated-measures ANOVA or Friedman tests for repeated measures. Correlation analyses explored relationships between macronutrient intake and glycemic metrics. Post-hoc power analysis was also conducted.

The mean age of participants was 12.7 ± 4.3 years, with a median diabetes duration of 2.2 years and a mean HbA1c of 6.9 ± 1.2%. At baseline, the mean carbohydrate, protein, and fat intake (energy %) were 49.1 ± 4.5, 17.8 ± 2.3, and 33.0 ± 3.9, respectively. These values remained consistent throughout the follow-up period, showing no statistically significant changes in macronutrient intake after transitioning to the Minimed 780G™ system. However, low fiber intake (<14 g/1000 kcal) and high saturated fat intake (>10 energy %) were observed at baseline and throughout follow-up. The median auto-correction bolus ratio increased significantly from 14.0% at the start of auto mode to 19.0% at month 6 (p < 0.05). A negative correlation existed between auto-correction boluses and TIR at both months 3 (r = -0.747, p < 0.01) and 6 (r = -0.395, p < 0.05). Interestingly, the amount of carbohydrates announced to the pump was statistically higher than that recorded in food diaries at months 3 and 6, suggesting potential underreporting or attempts to compensate for hyperglycemia. Glycemic parameters improved after switching to the AID system, with median TIR increasing from 79.0% to 81.0% and GMI decreasing from 6.6 to 6.5 (both p<0.05).

This study's findings suggest that the use of the Minimed 780G™ AID system does not significantly alter energy and macronutrient intake in children, adolescents, and young adults with T1D in a real-world setting. Despite the improved glycemic control observed with AID, the participants consistently exhibited low fiber and high saturated fat consumption, highlighting the persistent need for nutritional counseling and education. The negative correlation between auto-correction boluses and TIR emphasizes the importance of accurate carbohydrate counting, even with advanced technology. The discrepancy between reported and actual carbohydrate intake underscores the need for diligent monitoring and patient education to prevent manipulation of the system to compensate for poor dietary choices. The observed improvements in glycemic control are significant, but the modest improvement in TIR may reflect the already relatively well-controlled glycemia in the participants before AID initiation.

The Minimed 780G™ AID system improves glycemic control in T1D patients without altering their overall energy and macronutrient intake. However, dietary habits, particularly low fiber and high saturated fat consumption, remain a concern. Continued nutritional education and monitoring are crucial for minimizing cardiovascular disease risks in this population. Future research with a larger sample size and inclusion of physical activity data is warranted to further strengthen these findings.

The main limitation of this study is the relatively small sample size (n=29), which might limit the generalizability of the results. Another limitation is the lack of physical activity data, which could influence energy and nutrient intake. The reliance on 3-day food diaries for dietary assessment might also introduce some degree of recall bias. Future studies with a larger sample size and more comprehensive data collection are recommended.