Opportunities and challenges in closed-loop systems in type 1 diabetes

Abstract

Commercial automated insulin delivery therapy can improve glucose outcomes by increasing glucose time-in-range (3·9–10·0 mmol/L; 70–180 mg/dL) and reducing hypoglycaemia (<3·9 mmol/L; <70 mg/dL) in people with type 1 diabetes. Commercial closed-loop systems have shown modest improvement in percentage time-in-range, with an increase of 5 percentage points for MiniMed 670G 1 Bergenstal RM Garg S Weinzimer SA et al. Safety of a hybrid closed-loop insulin delivery system in patients with type 1 diabetes. JAMA. 2016; 316: 1407-1408 Crossref PubMed Scopus (377) Google Scholar and of 10 percentage points for Control-IQ 2 Brown SA Kovatchev BP Raghinaru D et al. Six-month randomized, multicenter trial of closed-loop control in type 1 diabetes. N Engl J Med. 2019; 381: 1707-1717 Crossref PubMed Scopus (266) Google Scholar compared with open-loop therapy. New developments with closed-loop systems are likely to enable further improvements in glucose outcomes while reducing user burden for individuals able to access closed-loop systems. These developments are focused on addressing deficiencies with current closed-loop systems by, for example, reducing or eliminating the requirement of prandial insulin dosing, overcoming the slow kinetics of subcutaneous insulin compared with endogenous insulin production, and improving the handling of insulin before, during, and after exercise. These advances will ideally lead to improved performance and reduced patient burden, and enable more widespread usage.