Manchester Intermittent Diet in Gestational Diabetes Acceptability Study (MIDDAS-GDM): a two-arm randomised feasibility protocol trial of an intermittent low-energy diet (ILED) in women with gestational diabetes and obesity in Greater Manchester

INTRODUCTION

The prevalence of gestational diabetes mellitus (GDM) is rising in the UK and is associated with maternal and neonatal complications. National Institute for Health and Care Excellence guidance advises first-line management with healthy eating and physical activity which is only moderately effective for achieving glycaemic targets. Approximately 30% of women require medication with metformin and/or insulin. There is currently no strong evidence base for any particular dietary regimen to improve outcomes in GDM. Intermittent low-energy diets (ILEDs) are associated with improved glycaemic control and reduced insulin resistance in type 2 diabetes and could be a viable option in the management of GDM. This study aims to test the safety, feasibility and acceptability of an ILED intervention among women with GDM compared with best National Health Service (NHS) care.

METHOD AND ANALYSIS

We aim to recruit 48 women with GDM diagnosed between 24 and 30 weeks gestation from antenatal clinics at Wythenshawe and St Mary's hospitals, Manchester Foundation Trust, over 13 months starting in November 2022. Participants will be randomised (1:1) to ILED (2 low-energy diet days/week of 1000 kcal and 5 days/week of the best NHS care healthy diet and physical activity advice) or best NHS care 7 days/week until delivery of their baby. Primary outcomes include uptake and retention of participants to the trial and adherence to both dietary interventions. Safety outcomes will include birth weight, gestational age at delivery, neonatal hypoglycaemic episodes requiring intervention, neonatal hyperbilirubinaemia, admission to special care baby unit or neonatal intensive care unit, stillbirths, the percentage of women with hypoglycaemic episodes requiring third-party assistance, and significant maternal ketonaemia (defined as ≥1.0 mmol/L). Secondary outcomes will assess the fidelity of delivery of the interventions, and qualitative analysis of participant and healthcare professionals' experiences of the diet. Exploratory outcomes include the number of women requiring metformin and/or insulin.

ETHICS AND DISSEMINATION

Ethical approval has been granted by the Cambridge East Research Ethics Committee (22/EE/0119). Findings will be disseminated via publication in peer-reviewed journals, conference presentations and shared with diabetes charitable bodies and organisations in the UK, such as Diabetes UK and the Association of British Clinical Diabetologists.

TRIAL REGISTRATION NUMBER

NCT05344066.

Manchester Intermittent and Daily diet Type 1 Diabetes App Study (MIDDAS-Type 1): protocol for a randomised feasibility trial of an intermittent and continuous low-energy diet in patients with type 1 diabetes and overweight and obesity

INTRODUCTION

Rising levels of overweight and obesity among people with type 1 diabetes (T1D) contribute to insulin resistance, dyslipidaemia, retinopathy, cardiometabolic complications and psychological morbidity. Continuous low-energy diets (CLED) providing approximately 800 kcal (3347 kJ)/day can produce significant weight loss in type 2 diabetes, and intermittent low-energy diets (ILED) may be an alternative. The Manchester Intermittent and Daily diet Type 1 Diabetes App Study (MIDDAS-Type 1) aims to assess the safety, acceptability and feasibility of remotely delivered ILED and CLED programmes for people with T1D and overweight and obesity.

METHODS AND ANALYSIS

Twelve participants with T1D and body mass index ≥27.5 kg/m² (≥25 kg/m² in high-risk ethnic minorities) recruited from an National Health Service (NHS) trust and research register in England will be randomised to a remotely delivered CLED (n=6) or ILED (n=6) for 12 weeks. The CLED includes a daily Optifast 850 kcal (3556 kJ) 75 g carbohydrate formula diet. The ILED includes 2 days/week of Optifast and 5 days of a portion-controlled Mediterranean diet (170-250 g carbohydrate/day). Both groups will receive matched high-frequency remote support from a dietitian, nurse and psychologist via telephone and/or the Oviva app. The primary outcome will assess safety (occurrence of severe hypoglycaemia, ketonaemia, ketoacidosis and time above and below target blood glucose). Secondary outcomes include study uptake, retention, dietary adherence, acceptability, intervention delivery fidelity and potential efficacy in relation to change in weight, insulin requirements, glycated haemoglobin, lipids, insulin resistance (estimated glucose disposal rate) and quality of life. Participants will be invited for optional repeat measurements at 52 weeks.

ETHICS AND DISSEMINATION

The trial protocol (V4.0/08.06.2022) was granted ethical approval by Cambridge East Research Ethics Committee (Ref: 21/EE/0014). The study will inform progression to a full-scale randomised controlled trial to test the efficacy of these programmes for patients with T1D and overweight and obesity.

TRIAL REGISTRATION NUMBER

NCT04674384; Pre-results.

Intermittently Scanned Continuous Glucose Monitoring for Type 1 Diabetes

BACKGROUND

In persons with type 1 diabetes and high glycated hemoglobin levels, the benefits of intermittently scanned continuous glucose monitoring with optional alarms for high and low blood glucose levels are uncertain.

METHODS

In a parallel-group, multicenter, randomized, controlled trial involving participants with type 1 diabetes and glycated hemoglobin levels between 7.5% and 11.0%, we investigated the efficacy of intermittently scanned continuous glucose monitoring as compared with participant monitoring of blood glucose levels with fingerstick testing. The primary outcome was the glycated hemoglobin level at 24 weeks, analyzed according to the intention-to-treat principle. Key secondary outcomes included sensor data, participant-reported outcome measures, and safety.

RESULTS

A total of 156 participants were randomly assigned, in a 1:1 ratio, to undergo intermittently scanned continuous glucose monitoring (the intervention group, 78 participants) or to monitor their own blood glucose levels with fingerstick testing (the usual-care group, 78 participants). At baseline, the mean (±SD) age of the participants was 44±15 years, and the mean duration of diabetes was 21±13 years; 44% of the participants were women. The mean baseline glycated hemoglobin level was 8.7±0.9% in the intervention group and 8.5±0.8% in the usual-care group; these levels decreased to 7.9±0.8% and 8.3±0.9%, respectively, at 24 weeks (adjusted mean between-group difference, -0.5 percentage points; 95% confidence interval [CI], -0.7 to -0.3; P<0.001). The time per day that the glucose level was in the target range was 9.0 percentage points (95% CI, 4.7 to 13.3) higher or 130 minutes (95% CI, 68 to 192) longer in the intervention group than in the usual-care group, and the time spent in a hypoglycemic state (blood glucose level, <70 mg per deciliter [<3.9 mmol per liter]) was 3.0 percentage points (95% CI, 1.4 to 4.5) lower or 43 minutes (95% CI, 20 to 65) shorter in the intervention group. Two participants in the usual-care group had an episode of severe hypoglycemia, and 1 participant in the intervention group had a skin reaction to the sensor.

CONCLUSIONS

Among participants with type 1 diabetes and high glycated hemoglobin levels, the use of intermittently scanned continuous glucose monitoring with optional alarms for high and low blood glucose levels resulted in significantly lower glycated hemoglobin levels than levels monitored by fingerstick testing. (Funded by Diabetes UK and others; FLASH-UK ClinicalTrials.gov number, NCT03815006.).

Impact of COVID-19 lockdown on flash and real-time glucose sensor users with type 1 diabetes in England

AIMS

People with type 1 diabetes (T1D) face the daily task of implementing self-management strategies to achieve their glycaemic goals. The UK COVID-19 lockdown has had an impact on day-to-day behaviour, which may affect diabetes self-management and outcomes. We assessed whether sensor-based outcomes pre- and during lockdown periods were different in a cohort of glucose sensor users with T1D.

METHODS

Data were collected from Freestyle Libre (FSL) or Dexcom G6 sensor users who remotely shared their data with the diabetes clinic web platform. Sensor metrics according to international consensus were analysed and compared between pre-lockdown period and 2 and 3 weeks into lockdown (periods 1 and 2).

RESULTS

Two hundred and sixty-nine T1D patients (baseline HbA1c 57 ± 14 mmol/mol) were identified as FSL (n = 190) or Dexcom G6 (n = 79) users. In patients with sensor use > 70% (N = 223), compared to pre-lockdown period percentage TIR 3.9-10 mM (TIR) significantly increased during period 1 (59.6 ± 18.2 vs. 57.5 ± 17.2%, p = 0.002) and period 2 (59.3 ± 18.3 vs. 57.5 ± 17.2%, p = 0.035). The proportion of patients achieving TIR ≥ 70% increased from 23.3% pre-lockdown to 27.8% in period 1 and 30.5% in period 2. A higher proportion also achieved the recommended time below and above range, and coefficient of variation in periods 1 and 2. Dexcom G6 users had significantly lower % time below range (< 3.9 mM) compared to FSL users during both lockdown periods (period 1: Dexcom G6 vs. FSL: 1.8% vs. 4%; period 2: 1.4% vs. 4%, p < 0.005 for both periods).

CONCLUSION

Sensor-based glycaemic outcomes in people with T1D in the current cohort improved during COVID-19 lockdown, which may be associated with positive changes in self-management strategies. Further work is required to evaluate long-term sustainability and support.

Use of Factory-Calibrated Real-time Continuous Glucose Monitoring Improves Time in Target and HbA1c in a Multiethnic Cohort of Adolescents and Young Adults With Type 1 Diabetes: The MILLENNIALS Study

OBJECTIVE

International type 1 diabetes registries have shown that HbA_1c levels are highest in young people with type 1 diabetes; however, improving their glycemic control remains a challenge. We propose that use of the factory-calibrated Dexcom G6 CGM system would improve glycemic control in this cohort.

RESEARCH DESIGN AND METHODS

We conducted a randomized crossover trial in young people with type 1 diabetes (16-24 years old) comparing the Dexcom G6 CGM system and self-monitoring of blood glucose (SMBG). Participants were assigned to the interventions in random order during two 8-week study periods. During SMBG, blinded continuous glucose monitoring (CGM) was worn by each participant for 10 days at the start, week 4, and week 7 of the control period. HbA_1c measurements were drawn after enrollment and before and after each treatment period. The primary outcome was time in range 70-180 mg/dL.

RESULTS

Time in range was significantly higher during CGM compared with control (35.7 ± 13.5% vs. 24.6 ± 9.3%; mean difference 11.1% [95% CI 7.0-15.2]; P < 0.001). CGM use reduced mean sensor glucose (219.7 ± 37.6 mg/dL vs. 251.9 ± 36.3 mg/dL; mean difference -32.2 mg/dL [95% CI -44.5 to -20.0]; P < 0.001) and time above range (61.7 ± 15.1% vs. 73.6 ± 10.4%; mean difference 11.9% [95% CI -16.4 to -7.4]; P < 0.001). HbA_1c level was reduced by 0.76% (95% CI -1.1 to -0.4) (-8.5 mmol/mol [95% CI -12.4 to -4.6]; P < 0.001). Times spent below range (<70 mg/dL and <54 mg/dL) were low and comparable during both study periods. Sensor wear was 84% during the CGM period.

CONCLUSIONS

CGM use in young people with type 1 diabetes improves time in target and HbA_1c levels compared with SMBG.