The Artificial Pancreas: How Closed-Loop Control Is Revolutionizing Diabetes

To examine the overall state of metabolic control and current use of advanced diabetes technologies in the U.S., we report recent data collected on individuals with type 1 diabetes participating in the T1D Exchange clinic registry. Data from 16,061 participants updated between 1 September 2013 and 1 December 2014 were compared with registry enrollment data collected from 1 September 2010 to 1 August 2012. Mean hemoglobin A1c (HbA1c) was assessed by year of age from 75 years. The overall average HbA1c was 8.2% (66 mmol/mol) at enrollment and 8.4% (68 mmol/mol) at the most recent update. During childhood, mean HbA1c decreased from 8.3% (67 mmol/mol) in 2-4-year-olds to 8.1% (65 mmol/mol) at 7 years of age, followed by an increase to 9.2% (77 mmol/mol) in 19-year-olds. Subsequently, mean HbA1c values decline gradually until ∼30 years of age, plateauing at 7.5-7.8% (58-62 mmol/mol) beyond age 30 until a modest drop in HbA1c below 7.5% (58 mmol/mol) in those 65 years of age. Severe hypoglycemia (SH) and diabetic ketoacidosis (DKA) remain all too common complications of treatment, especially in older (SH) and younger patients (DKA). Insulin pump use increased slightly from enrollment (58-62%), and use of continuous glucose monitoring (CGM) did not change (7%). Although the T1D Exchange registry findings are not population based and could be biased, it is clear that there remains considerable room for improving outcomes of treatment of type 1 diabetes across all age-groups. Barriers to more effective use of current treatments need to be addressed and new therapies are needed to achieve optimal metabolic control in people with type 1 diabetes.

The Diabetes Control and Complications Trial (DCCT) demonstrated the benefits of intensive treatment of diabetes in reducing glycemic levels and slowing the progression of diabetic nephropathy. The DCCT cohort has been examined annually for another 8 years as part of the follow-up Epidemiology of Diabetes Interventions and Complications (EDIC) study. During the EDIC study, glycemic levels no longer differed substantially between the 2 original treatment groups. To determine the long-term effects of intensive vs conventional diabetes treatment during the DCCT on kidney function during the EDIC study. Observational study begun in 1993 (following DCCT closeout) in 28 medical centers in the United States and Canada. Participants were 1349 (of 1375) EDIC volunteers who had kidney evaluation at years 7 or 8. Development of microalbuminuria, clinical-grade albuminuria, hypertension, or increase in serum creatinine level. Results were analyzed by intention-to-treat analyses, comparing the 2 original DCCT treatment groups. New cases of microalbuminuria occurred during the EDIC study in 39 (6.8%) of the participants originally assigned to the intensive-treatment group vs 87 (15.8%) of those assigned to the conventional-treatment group, for a 59% (95% confidence interval [CI], 39%-73%) reduction in odds, adjusted for baseline values, compared with a 59% (95% CI, 36%-74%) reduction at the end of the DCCT (P<.001 for both comparisons). New cases of clinical albuminuria occurred in 9 (1.4%) of the participants in the original intensive-treatment group vs 59 (9.4%) of those in the original conventional-treatment group, representing an 84% reduction in odds (95% CI, 67%-92%), compared with a reduction of 57% (95% CI, -1% to +81%) at the end of the DCCT. Fewer cases of hypertension (prevalence at year 8, 29.9% vs 40.3%; P<.001) developed in the original intensive-treatment group. Significantly fewer participants reached a serum creatinine level of 2 mg/dL or greater in the intensive-treatment vs the conventional-treatment group (5 vs 19, P =.004), but there were no differences in mean log clearance values. Although small numbers of patients required dialysis and/or transplantation, fewer patients experienced either of these outcomes in the intensive group (4 vs 7, P =.36). The persistent beneficial effects on albumin excretion and the reduced incidence of hypertension 7 to 8 years after the end of the DCCT suggest that previous intensive treatment of diabetes with near-normal glycemia during the DCCT has an extended benefit in delaying progression of diabetic nephropathy.

The safety and effectiveness of automated glycemic management have not been tested in multiday studies under unrestricted outpatient conditions.