The artificial pancreas: evaluating risk of hypoglycaemia following errors that can be expected with prolonged at-home use.

AIMS: Artificial pancreas systems show benefit in closely monitored at-home studies, but may not have sufficient power to assess safety during infrequent, but expected, system or user errors. The aim of this study was to assess the safety of an artificial pancreas system emulating the ß-cell when the glucose value used for control is improperly calibrated and participants forget to administer pre-meal insulin boluses. METHODS: Artificial pancreas control was performed in a clinic research centre on three separate occasions each lasting from 10 p.m. to 2 p.m. Sensor glucose values normally used for artificial pancreas control were replaced with scaled blood glucose values calculated to be 20% lower than, equal to or 33% higher than the true blood glucose. Safe control was defined as blood glucose between 3.9 and 8.3 mmol/l. RESULTS: Artificial pancreas control resulted in fasting scaled blood glucose values not different from target (6.67 mmol/l) at any scaling factor. Meal control with scaled blood glucose 33% higher than blood glucose resulted in supplemental carbohydrate to prevent hypoglycaemia in four of six participants during breakfast, and one participant during the night. In all instances, scaled blood glucose reported blood glucose as safe. CONCLUSIONS: Outpatient trials evaluating artificial pancreas performance based on sensor glucose may not detect hypoglycaemia when sensor glucose reads higher than blood glucose. Because these errors are expected to occur, in-hospital artificial pancreas studies using supplemental carbohydrate in anticipation of hypoglycaemia, which allow safety to be assessed in a controlled non-significant environment should be considered as an alternative. Inpatient studies provide a definitive alternative to model-based computer simulations and can be conducted in parallel with closely monitored outpatient artificial pancreas studies used to assess benefit.

Impact of continuous glucose monitoring on diabetes management and marital relationships of adults with Type 1 diabetes and their spouses: a qualitative study.

AIMS: To examine the impact of continuous glucose monitoring on diabetes management and marital relationships of adults with Type 1 diabetes and their spouses. METHODS: Nine younger (30-49 years) and 11 older (50-70 years) patients with Type 1 diabetes and 14 spouses participated in eight focus groups specific to age and role (patient or spouse). Audio-recorded data were transcribed, coded and analysed using thematic analysis and aided by NVivo software. RESULTS: Qualitative analysis revealed participants perceived continuous glucose monitoring as positively influencing hypoglycaemia management by decreasing spouses' anxiety, vigilance and negative experiences. Participants also described continuous glucose monitoring as promoting collaborative diabetes management and increasing spousal understanding of diabetes, especially when planning and managing pregnancy. Couples' conflicts occurred when (1) patients assumed sole responsibility for continuous glucose monitoring and/or did not respond to night-time glucose alarms and (2) spouses did not understand alarms and felt frustrated and helpless to assist patients. CONCLUSIONS: Our findings suggest that continuous glucose monitoring may positively impact collaborative diabetes management and marital relationships of patients with Type 1 diabetes and their spouses. However, reluctance to collaborate and lack of understanding may contribute to couples' conflicts around continuous glucose monitoring. Our findings have important implications for clinical care and point to the need for interventions that include spouses in continuous glucose monitoring training to increase their understanding of continuous glucose monitoring, minimize risk for spousal conflict and enhance collaborative diabetes management. Further studies are needed to explore these issues in more detail and depth with larger and more diverse populations.

Psychosocial factors associated with use of continuous glucose monitoring.

AIMS: To identify psychosocial factors associated with the use of continuous glucose monitoring by adults with Type 1 diabetes. METHODS: Twenty adult patients (aged 45 +/- 15 years, diabetes duration 25 +/- 19 years, 50% female) followed at our site in the multi-centre Juvenile Diabetes Research Foundation continuous glucose monitoring trial were divided into three groups: Glycated haemoglobin (HbA(1c)) Responders who demonstrated an improvement in glycaemic control with continuous glucose monitoring (baseline HbA(1c)> or = 7.0%, HbA(1c) reduction greater than or equal to 0.5%), Hypoglycaemia Responders (baseline HbA(1c) < 7.0%) who demonstrated decreased time < 3.9 mmol/l while remaining within target HbA(1c), and HbA(1c) Non-Responders (baseline HbA(1c)> or = 7.0%, HbA(1c) reduction less than 0.5%). Subjects participated in semi-structured interviews focusing on their psychosocial experiences with continuous glucose monitoring. RESULTS: Three major themes were identified that differentiated Responders (including both the HbA(1c) and Hypoglycaemia groups) from Non-Responders: (i) coping with frustrations-Responders used self-controlled rather than emotions-based coping when faced with continuous glucose monitoring frustrations; (ii) use of information-Responders used retrospective pattern analysis, not just minute-by-minute data analysis, in glycaemic management; (iii) 'significant other'/spousal involvement-Responders endorsed interest, encouragement and participation by their loved ones. Both Responders and Non-Responders expressed body image concerns when wearing continuous glucose monitoring devices. CONCLUSIONS: This qualitative study points to the importance of coping skills, retrospective review of data, and 'significant other' involvement in the effective use of continuous glucose monitoring. These findings will inform clinical initiatives to improve patient selection and training in the use of this new technology and have served as the basis for development of quantitative surveys to be used in clinical practice.