Diabetes Special Issue: Advances in Treatments, Still Hoping for a Cure

While a century ago, a diagnosis of type 1 diabetes was uniformly fatal, the discovery of insulin in 1921 offered hope for this disease, transforming it into a chronic condition – albeit one that still requires onerous lifelong treatment. In this special issue of Science, a Policy Forum and four Reviews discuss the scientific advances that have expanded researchers’ grasp of this disease in the last century, as well as expanding available therapeutic options. But these experts don’t shy away from challenges that remain. “[More] work is needed to overcome these challenges as we move into our second century of treating this common—and increasingly prevalent—disease, with the eventual goal of prevention or a cure,” writes Science Senior Editor Yevgeniya Nusinovich, in a special issue introduction.

Insulin remains inaccessible to nearly 50 million people who need it worldwide due to limited availability and poor affordability. In a Policy Forum, Abhishek Sharma and Warren Kaplan present an analysis of global insulin availability and need using real-world global insulin trade data and epidemiological estimates of diabetes. Sharma and Kaplan show that some countries with no domestic insulin production appear to have a surplus of insulin relative to need. Others, particularly those in Africa and Asia, continue to show deficits in insulin imports relative to their estimated need. According to the authors, the divide between a country’s imported insulin surplus and the population’s estimated need is due to a lack of market competition, suboptimal procurement and dysfunctional healthcare financing and delivery. To improve insulin availability for the patients who need it, coordinated on-the-ground efforts are required from multiple stakeholders. “Access to insulin needs to be framed within the wider health system and all the elements – the public sector, private sector, manufacturers, regulatory bodies, and academics and clinicians – must align for appropriate diabetes care for patients,” the authors write.

One hundred years after the discovery of insulin as a therapy for type 1 diabetes (T1D), and despite major advances in insulin delivery over the past two decades, only a minority of children and adults with T1D can achieve optimal levels of glycemic control. As well, the lengthened survival of people with T1D has revealed the problem of long-term complications such as blindness that occur despite insulin therapy. Today, an alternative therapy – avoiding the need for insulin altogether – has become possible: by either interrupting the autoimmune disease process at an early (preclinical) stage or preventing the onset of autoimmunity in the first place. In a Review, Colin Dayan and colleagues discuss how this alternative might be achieved, particularly in children. In a separate Review, Jeffrey Bluestone and colleagues focus on T1D as an autoimmune disorder; although the discovery and use of insulin has transformed T1D treatment, they say, it does not change the underlying autoimmune disease. Bluestone et al. review research in the last two decades that has identified immune cell types that destroy insulin-producing cells and discuss the current state of the immunological therapies, as well as their advantages for the treatment of T1D. In a separate Review focused on the promise of cellular therapy for T1D – where the implanted cells can inherently sense, respond to, and manage blood glucose concentrations – Todd M. Brusko and colleagues highlight advances in stem cell biology and graft site design. In a final Review, Bruce Perkins and colleagues consider the challenges of managing their disease, for T1D patients. They say the greatest future impact for improving outcomes will come from combining new pharmacological solutions with existing automated insulin delivery methods. They note that further innovation will be necessary to increase the acceptability of technologies to all people with diabetes.