Design and rationale of the IN CONTROL trial: the effects of real-time continuous glucose monitoring on glycemia and quality of life in patients with type 1 diabetes mellitus and impaired awareness of hypoglycemia

Use of Patient-Reported Outcomes for Assessing Diabetes Outcomes

The treatment of diabetes can be complex and overwhelming for patients as it demands persistent attention to lifestyle management, adherence to medications, monitoring of side effects of drugs, and management of devices for glucose monitoring and/or insulin infusion. Therefore, understanding patient-reported outcomes (PROs) that provide direct insight into the patient's experience with diabetes is crucial for optimizing diabetes management.This review provides an overview of commonly used PRO questionnaires that assess different aspects of diabetes management.

Epidemiology and risk factors of hypoglycemia in subjects with type 1 diabetes in Brazil: a cross-sectional, multicenter study

Objective

The aim of this study was to investigate the factors associated with hypoglycemia and severe hypoglycemia (SH) in individuals with type 1 diabetes mellitus (T1D) in Brazil.

Materials and Methods

This multicenter, cross-sectional study was conducted between August 2011 and August 2014 across 10 Brazilian cities. The data were obtained from 1,760 individuals with T1D. Sociodemographic and clinical characteristics related to hypoglycemic events in the previous 4 weeks were evaluated.

Results

Of 1,760 individuals evaluated, 1,319 (74.9%) reported at least one episode of hypoglycemia in the previous 4 weeks. The main factors associated with hypoglycemia were lower hemoglobin A1c (HbA1c) level, better adherence to self-monitoring of blood glucose (SMBG), and higher education level. Episodes of SH were reported by 251 (19%) individuals who, compared with subjects with nonsevere hypoglycemia, received lower doses of prandial insulin and higher doses of basal insulin, in addition to reporting less frequent use of long-acting basal insulin analogs. The percentage of SH episodes was evenly distributed across all ranges of HbA1c levels, and there were no correlations between the mean number of nonsevere or severe hypoglycemic events and HbA1c values. Higher alcohol consumption and more frequent hospitalizations were independently associated with SH.

Conclusion

Although individuals presenting with hypoglycemia had lower HbA1c values than those not presenting hypoglycemia, there were no correlations between the number of nonsevere hypoglycemia or SH and HbA1c values. Also, the frequency of SH was evenly distributed across all ranges of HbA1c values. Better adherence to SMBG and higher education level were associated with hypoglycemia, while alcohol consumption, higher doses of basal insulin, and more frequent hospitalizations in the previous year were associated with SH.

Association between hypoglycaemic glucose variability and autonomic function in type1 diabetes with impaired hypoglycaemia awareness

Cardiovascular autonomic neuropathy (CAN) is suggested to underlie hypoglycaemic risk in impaired awareness of hypoglycaemia (IAH). We assessed the prevalence of CAN and the association between glucose variability (GV) and cardiovascular autonomic function in patients with type 1 diabetes (T1DM) and IAH. This study is a post-hoc-analysis of results obtained with the IN-CONTROL-trial, designed to assess the effects of continuous glucose monitoring (CGM) on glycaemia. Forty participants (aged 46.4 ± 11.4 years, diabetes duration 29.1 ± 13.5 years, HbA1c 7.5 ± 0.8%(58.2 ± 8.8 mmol/mol)) underwent 2-week blinded CGM measurements to obtain GV indices. Standardized cardiovascular reflex tests were used to determine the presence of CAN. Cardiovascular autonomic function was assessed with heart rate variability (HRV) measures. 14(35%) participants were classified as having CAN. Participants with CAN had lower percentage time spent in hypoglycaemic range and low blood glucose index(LBGI). After correction for confounders, a significant positive association was found between the coefficient of variation (CV) or time spent in hypoglycaemic range and HRV measures SDRR or RMSSD, and between LBGI and RMSSD. In patients with T1DM and IAH, hypoglycaemic parameters were associated with better cardiovascular autonomic function and lower prevalence of CAN. This suggests that autonomic neuropathy does not seem to further deteriorate hypoglycaemic risk in patients with IAH.

Design of a Sandwich Hierarchically Porous Membrane with Oxygen Supplement Function for Implantable Glucose Sensor

This study aims to develop an oxygen regeneration layer sandwiched between multiple porous polyurethanes (PU) to improve the performance of implantable glucose sensors. Sensors were prepared by coating electrodes with platinum nanoparticles, Nafion, glucose oxidase and sandwich hierarchically porous membrane with an oxygen supplement function (SHPM-OS). The SHPM-OS consisted of a hierarchically porous structure synthesized by polyethylene glycol and PU and a catalase (Cat) layer that was coated between hierarchical membranes and used to balance the sensitivity and linearity of glucose sensors, as well as reduce the influence of oxygen deficiency during monitoring. Compared with the sensitivity and linearity of traditional non-porous (NO-P) sensors (35.95 nA/mM, 0.9987, respectively) and single porous (SGL-P) sensors (45.3 nA /mM, 0.9610, respectively), the sensitivity and linearity of the SHPM-OS sensor was 98.45 nA/mM and 0.9989, respectively, which was more sensitive with higher linearity. The sensor showed a response speed of five seconds and a relative sensitivity of 90% in the first 10 days and remained 78% on day 20. This sensor coated with SHPM-OS achieved rapid responses to changes of glucose concentration while maintaining high linearity for long monitoring times. Thus, it may reduce the difficulty of back-end hardware module development and assist with effective glucose self-management for people with diabetes.

Design of a Real-time Self-adjusting Calibration Algorithm to Improve the Accuracy of Continuous Blood Glucose Monitoring

The aim of this study is to establish a real-time self-adjusting calibration algorithm to compensate for signal drift and sensitivity attenuation of subcutaneous implantable glucose sensors. A real-time self-adjusting in vivo calibration method was designed based on the one-point calibration model. The current signal was compensated in real-time and the sensitivity was calibrated regularly. The least squares method was used to fit the initial parameters of the model, and then, the in vivo monitored current data was calibrated. Comparing with the mean absolute relative difference (MARD) of the blood glucose concentration by the traditional one-point calibration model (22.85 ± 5.76%), the MARD of the blood glucose concentration calibrated by the real-time self-adjusting in vivo calibration method was 6.28 ± 2.31%. The accuracy of the dynamic blood glucose monitoring was effectively improved. This calibration algorithm could compensate the signal drift in real time and correct sensitivity regularly to improve the accuracy of dynamic glucose monitoring, thus significantly enhancing diabetic self-management.

Rotavirus Infection Enhances Levels of Autoantibodies Against Islet Cell Antigens GAD65 and IA-2 in Children with Type 1 Diabetes

BACKGROUND

Some studies implicate rotavirus infection as a trigger for the development of type 1 diabetes mellitus (T1DM) in children, however findings are controversial.

OBJECTIVES

We investigated the link between rotavirus infection and autoantibodies against islet antigens and T1DM in children.

METHODS

Serum samples from 80 new-onset diabetic and 80 nondiabetic children were screened for anti-rotavirus IgG, anti-GAD65 and anti-IA-2 autoantibodies using ELISA kits.

RESULTS

Positivity percentages of anti-rotavirus IgG detection in diabetic and nondiabetic children were 51.3% and 35.0%, respectively (p = 0.03). The mean anti-GAD65 and anti-IA-2 antibody titers in anti-rotavirus IgG positive samples were statistically higher than that the anti-rotavirus IgG negative samples. A positive correlation was found between anti-rotavirus IgG and anti-GAD65 antibody levels (p = 0.004; r = 0.22).

CONCLUSIONS

Our findings support the hypothesis that rotovirus infection may induce T1DM in children.

The relation between HbA1c and hypoglycemia revisited; a secondary analysis from an intervention trial in patients with type 1 diabetes and impaired awareness of hypoglycemia

AIMS

We aimed to re-assess the previously shown but recently disputed association between HbA1c and severe hypoglycemia.

METHODS

52 Patients with T1D and IAH participated in an earlier reported randomized, crossover trial with two 16-week intervention periods comparing continuous glucose monitoring (CGM) with self-monitoring of blood glucose (SMBG). In this previous study, time spent in normoglycemia (the primary outcome), was improved by 9.6% (p<0.0001). We performed post-hoc analyses using a zero-inflated Poisson regression model to assess the relationship between severe hypoglycemia and HbA1c, glucose variability and duration of diabetes.

RESULTS

During SMBG use, HbA1c and the number of severe hypoglycemic events were negatively associated (OR 0.20 [95% CI 0.09 to 0.44]). During CGM use, this relationship showed an odds ratio of 0.65 (95% CI 0.42 to 1.01). There was no significant relationship between glucose variability or duration of diabetes and severe hypoglycemia.

CONCLUSIONS

In patients with T1D and IAH, treated with standard SMBG, a negative association exists between HbA1c and the number of severe hypoglycemic events. Thus, reaching target HbA1c values still comes with a higher risk of severe hypoglycemia. CGM weakens this association, suggesting CGM enables patients to reach their target HbA1c more safely.

Continuous Glucose Monitoring in Patients with Type 1 Diabetes and Impaired Awareness of Hypoglycemia: Also Effective in Patients with Psychological Distress?

The aim of this study was to evaluate whether psychological distress modifies the effect of continuous glucose monitoring (CGM) in patients with type 1 diabetes (T1D) and impaired awareness of hypoglycemia. Fifty-two patients with T1D and impaired awareness of hypoglycemia participated in an earlier reported randomized crossover trial with two 16-week intervention periods comparing CGM with self-monitoring of blood glucose (SMBG). During the CGM phase, time spent in euglycemia (4-10 mmol/L), the primary outcome, was 9.6% higher compared with the SMBG phase (P < 0.0001). Psychological distress was operationalized as low emotional well-being (World Health Organization Well-being Index 5 [WHO-5] < 50), high diabetes-related distress (Problem Areas in Diabetes 5 [PAID-5] ≥ 8), and/or high fear of hypoglycemia (Hypoglycemia Fear Survey [HFS] Worry > mean HFS Worry score +1 standard deviation). Modifying effects were assessed by analyzing psychological distress score × intervention-interaction effects. Results showed that both the low emotional well-being group and normal emotional well-being group had equal glycemic outcomes during the CGM phase. High diabetes distress and elevated fear of hypoglycemia did not result in significant interaction effects for glycemic outcomes. This study demonstrated that CGM is equally effective in terms of glycemic improvements in high versus low distressed patients with T1D and impaired awareness of hypoglycemia.

Continuous Glucose Monitoring: Impact on Hypoglycemia

The necessity of strict glycemic control is unquestionable. However, hypoglycemia remains a major limiting factor in achieving satisfactory glucose control, and evidence is mounting to show that hypoglycemia is not benign. Over the past decade, evidence has consistently shown that real-time continuous glucose monitoring improves glycemic control in terms of lowering glycated hemoglobin levels. However, real-time continuous glucose monitoring has not met the expectations of the diabetes community with regard to hypoglycemia prevention. The earlier trials did not demonstrate any effect on either mild or severe hypoglycemia and the effect of real-time continuous glucose monitoring on nocturnal hypoglycemia was often not reported. However, trials specifically designed to reduce hypoglycemia in patients with a high hypoglycemia risk have demonstrated a reduction in hypoglycemia, suggesting that real-time continuous glucose monitoring can prevent hypoglycemia when it is specifically used for that purpose. Moreover, the newest generation of diabetes technology currently available commercially, namely sensor-augmented pump therapy with a (predictive) low glucose suspend feature, has provided more convincing evidence for hypoglycemia prevention. This article provides an overview of the hypoglycemia outcomes of randomized controlled trials that investigate the effect of real-time continuous glucose monitoring alone or sensor-augmented pump therapy with a (predictive) low glucose suspend feature. Furthermore, several possible explanations are provided why trials have not shown a reduction in severe hypoglycemia. In addition, existing evidence is presented of real-time continuous glucose monitoring in patients with impaired awareness of hypoglycemia who have the highest risk of severe hypoglycemia.

Continuous glucose monitoring for patients with type 1 diabetes and impaired awareness of hypoglycaemia (IN CONTROL): a randomised, open-label, crossover trial

BACKGROUND

Patients with type 1 diabetes who have impaired awareness of hypoglycaemia have a three to six times increased risk of severe hypoglycaemia. We aimed to assess whether continuous glucose monitoring (CGM) improves glycaemia and prevents severe hypoglycaemia compared with self-monitoring of blood glucose (SMBG) in this high-risk population.

METHODS

We did a randomised, open-label, crossover trial (IN CONTROL) at two medical centres in the Netherlands. Eligible participants were patients diagnosed with type 1 diabetes according to American Diabetes Association criteria, aged 18-75 years, with impaired awareness of hypoglycaemia as confirmed by a Gold score of at least 4, and treated with either continuous subcutaneous insulin infusion or multiple daily insulin injections and doing at least three SMBG measurements per day. After screening, re-education about diabetes management, and a 6-week run-in phase (to obtain baseline CGM data), we randomly assigned patients (1:1) with a computer-generated allocation sequence (block size of four) to either 16 weeks of CGM followed by 12 weeks of washout and 16 weeks of SMBG, or 16 weeks of SMBG followed by 12 weeks of washout and 16 weeks of CGM (where the SMBG phase was the control). During the CGM phase, patients used a real-time CGM system consisting of a Paradigm Veo system with a MiniLink transmitter and an Enlite glucose sensor (Medtronic, CA, USA). During the SMBG phase, patients were equipped with a masked CGM device, consisting of an iPro 2 continuous glucose monitor and an Enlite glucose sensor, which does not display real-time glucose values. The number of SMBG measurements per day and SMBG systems were not standardised between patients, to mimic real-life conditions. During both intervention periods, patients attended follow-up visits at the centres each month and had telephone consultations 2 weeks after each visit inquiring about adverse events, episodes of hypoglycaemia, etc. The primary endpoint was the mean difference in percentage of time spent in normoglycaemia (4-10 mmol/L) over the total intervention periods, analysed on an intention-to-treat basis. Severe hypoglycaemia (requiring third party assistance) was a secondary endpoint. This trial is registered with ClinicalTrials.gov, number NCT01787903.

FINDINGS

Between March 4, 2013, and Feb 9, 2015, we recruited and randomly assigned 52 patients to either the CGM-SMBG sequence (n=26) or the SMBG-CGM sequence (n=26). The last patient visit was on March 21, 2016. Time spent in normoglycaemia was higher during CGM than during SMBG: 65·0% (95% CI 62·8-67·3) versus 55·4% (53·1-57·7; mean difference 9·6%, 95% CI 8·0-11·2; p<0·0001), with reductions in both time spent in hypoglycaemia (ie, blood glucose ≤3·9 mmol/L [6·8% vs 11·4%, mean difference 4·7%, 3·4-5·9; p<0·0001]) and time spent in hyperglycaemia (ie, blood glucose >10 mmol/L [28·2% vs 33·2%, mean difference 5·0%, 3·1-6·9; p<0·0001]). During CGM, the number of severe hypoglycaemic events was lower (14 events vs 34 events, p=0·033). Five serious adverse events other than severe hypoglycaemia occurred during the trial, but all were deemed unrelated to the trial intervention. Additionally, no mild to moderate adverse events were related to the trial intervention.

INTERPRETATION

CGM increased time spent in normoglycaemia and reduced severe hypoglycaemia in patients with type 1 diabetes and impaired awareness of hypoglycaemia, compared with SMBG. Our results support the concept of using CGM in this high-risk population.

FUNDING

Eli Lilly and Sanofi.