Assessing rates of hypoglycemia as an end point in clinical trials

An Owner-Independent Investigation of Diabetes Alert Dog Performance

Objective: To quantify Diabetes Alert Dog (DAD) performance by using owner-independent measures.

Research Design and Methods: Eight owners of accredited DADs used a FreeStyle Libre Flash Glucose Monitoring System (FGMS). Concurrent Closed Circuit Television (CCTV) footage was collected for between 5 and 14 days in each owner's home or workplace. The footage was blind-coded for dogs' alerting behaviors. The sensitivity, False Positive Rate and Positive Predictive Values (PPV) of dogs' alerts to out-of-range (OOR) episodes were calculated. Ratings for 11 attributes describing participant's lifestyle and compliance (taken from each dog's instructor) and the percentage of DAD alerts responded to by the owner as per training protocol (taken from CCTV footage) were assessed for association with dog performance.

Results: Dogs alerted more often when their owners' glucose levels were outside vs. inside target range (hypoglycaemic 2.80-fold, p = 0.001; hyperglycaemic 2.29-fold, p = 0.005). Sensitivity to hypoglycaemic episodes ranged from 33.3 to 91.7%, the mean was 55.9%. Mean PPV for OOR episodes was 69.7%. Sensitivity and PPV were associated with aspects of the dog and owner's behavior, and the owner's adherence to training protocol.

Conclusions: Owner-independent methods support that some dogs alert to hypo- and hyperglycaemic events accurately, but performance varies between dogs. We find that DAD performance is affected by traits and behaviors of both the dog and owner. Combined with existing research showing the perceived psychosocial value and reduced critical health care needs of DAD users, this study supports the value of a DAD as part of a diabetes care plan. It also highlights the importance of ongoing training and continued monitoring to ensure optimal performance.

Hypoglycemia evaluation and reporting in diabetes: Importance for the development of new therapies

Hypoglycemia complicating diabetes therapy is well recognized to be an ever-present threat to patients, their families, providers, payers, and regulators. Despite this being widely acknowledged, the regulatory stance on hypoglycemia as an endpoint in clinical trials to support new product registration has not evolved in any meaningful way since the publication of a position paper by an American Diabetes Association (ADA) Workgroup in 2005. As the impact of hypoglycemia on persons affected by diabetes is of major importance when assessing new treatments, the historical position of regulatory agencies on hypoglycemia is reviewed with respect to product approvals. The purpose of this article is to present proposals for facilitating development of therapies that reduce hypoglycemia risk through (1) development of composite measures of benefit for regulatory endpoints and (2) facilitation of the fulfillment of an unmet clinical need for reducing hypoglycemia. In view of greater comprehension of the effects of hypoglycemia, coupled with improved methodology to assess its frequency, the authors recommend: (1) a numerical cut point of <54 mg/dl (<3.0 mmol/L) as a clinically relevant level with which to define meaningful hypoglycemia for trials of diabetes therapies; (2) utilization in clinical trials of mature glucose monitoring technologies for purposes of regulatory evaluation and clinical decision-making; and (3) development of primary efficacy endpoint composites that include hypoglycemia rates and glycemic control.

Reliability of Trained Dogs to Alert to Hypoglycemia in Patients With Type 1 Diabetes

BACKGROUND

We examined the reliability of trained dogs to alert to hypoglycemia in individuals with type 1 diabetes.

METHODS

Patients with type 1 diabetes who currently used diabetes alert dogs participated in this exploratory study. Subjects reported satisfaction, perceived dog glucose sensing ability and reasons for obtaining a trained dog. Reliability of dog alerts was assessed using capillary blood glucose (CBG) and blinded continuous glucose monitoring (CGM) as comparators in 8 subjects (age 4-48). Hypoglycemia was defined as CBG or CGM <70 mg/dL.

RESULTS

Dog users were very satisfied (8.9/10 on a Likert-type scale) and largely confident (7.9/10) in their dog's ability to detect hypoglycemia. Detection of hypoglycemia was the primary reason for obtaining a trained dog. During hypoglycemia, spontaneous dog alerts occurred at a rate 3.2 (2.0-5.2, 95% CI) times higher than during euglycemia (70-179 mg/dL). Dogs provided timely alerts in 36% (sensitivity) of all hypoglycemia events (n = 45). Due to inappropriate alerts, the PPV of a dog alert for hypoglycemia was 12%. When there was concurrence of a hypoglycemic event between the dog alert and CGM (n = 30), CGM would have alerted prior to the dog in 73% of events (median 22-minute difference).

CONCLUSIONS

This is the first study evaluating reliability of trained dogs to alert to hypoglycemia under real-life conditions. Trained dogs often alert a human companion to otherwise unknown hypoglycemia; however due to high false-positive rate, a dog alert alone is unlikely to be helpful in differentiating hypo-/hyper-/euglycemia. CGM often detects hypoglycemia before a trained dog by a clinically significant margin.

A Multinational, Randomized, Open-label, Treat-to-Target Trial Comparing Insulin Degludec and Insulin Glargine in Insulin-Naïve Patients with Type 2 Diabetes Mellitus

Introduction

To lower the barrier for initiating insulin treatment and obtain adequate glycemic control in type 2 diabetes mellitus (T2DM), new basal insulin preparations with improved pharmacological properties and consequently a lower risk of hypoglycemia are needed. The objective of this trial was to confirm the efficacy and compare the safety of insulin degludec (IDeg) with insulin glargine (IGlar) in a multinational setting with two thirds of subjects enrolled in China.

Methods

This was a 26-week, randomized, open-label, parallel-group, treat-to-target, non-inferiority trial in 833 subjects with T2DM (48 % were female, mean age 56 years, diabetes duration 8 years), inadequately controlled on oral antidiabetic drugs (OADs). Subjects were randomized 2:1 to once-daily IDeg (555 subjects) or IGlar (278 subjects), both with metformin. The primary endpoint was the change from baseline in glycosylated hemoglobin (HbA_1c) after 26 weeks.

Results

The completion rate was high (IDeg 94.2 %; IGlar 91.4 %). Mean HbA_1c decreased from 8.3 to 7.0 % in both groups. Estimated treatment difference (ETD) [95 % confidence interval (CI)] IDeg-IGlar in change from baseline was −0.05 % points [−0.18 to 0.08], confirming the non-inferiority of IDeg to IGlar. The proportion of subjects achieving HbA_1c <7.0 % was 54.2 and 51.4 % with IDeg and IGlar, respectively (estimated odds ratio [95 % CI] IDeg/IGlar: 1.14 [0.84 to 1.54]). The mean decrease in fasting plasma glucose, self-measured plasma glucose profiles, and insulin dose were similar between groups. Numerically lower rates of overall (estimated rate ratio [95 % CI] IDeg/IGlar: 0.80 [0.59 to 1.10]) and nocturnal (0.77 [0.43 to 1.37]) confirmed hypoglycemia were observed with IDeg compared with IGlar. No treatment differences in other safety parameters were found. Subjects were more satisfied with the IDeg device compared with the IGlar device as reflected by the total Treatment Related Impact Measures-Diabetes Device score (ETD [95 % CI] IDeg-IGlar: 2.2 [0.2 to 4.3]).

Conclusion

IDeg provided adequate glycemic control non-inferior to IGlar and a tendency for a lower hypoglycemia rate. IDeg is considered suitable for initiating insulin therapy in T2DM patients on OADs requiring intensified treatment.

Trial Registration

Clinicaltrials.gov NCT01849289.

Electronic supplementary material

The online version of this article (doi:10.1007/s40268-016-0134-z) contains supplementary material, which is available to authorized users.

Glucose: archetypal biomarker in diabetes diagnosis, clinical management and research

The clinical utility of diabetes biomarkers can be considered in terms of diagnosis, management and prediction of long-term vascular complications. Glucose satisfies all of these requirements. Thresholds of hyperglycemia diagnostic of diabetes reflect inflections that confer a risk of developing long-term microvascular complications. Degrees of hyperglycemia (impaired fasting glucose, impaired glucose tolerance) that lie below the diagnostic threshold for diabetes identify individuals at risk of progression to diabetes and/or development of atherothrombotic cardiovascular disease. Self-measured glucose levels usefully complement hemoglobin A1c levels to guide daily management decisions. Continuous glucose monitoring provides detailed real-time data that is of value in clinical decision making, assessing response to new diabetes drugs and the development of closed-loop artificial pancreas technology.