The need for insulin is expected to rise by 20% between 2018 and 2030 predicts research that provides direct projections of insulin use and disease outcomes among people with type 2 diabetes worldwide.
In fact, without major improvements in access, half of the 79 million adults with type 2 diabetes who will need insulin by 2030 will go without.
The investigators developed a mathematical model to predict future insulin use for type 2 diabetes, and the projected effects of different treatment availability scenarios on insulin need and burden of diabetes complications.
The study, by Sanjay Basu, PhD, of the Center for Primary Care and Outcomes Research and Center for Population Health Sciences, Departments of Medicine and Health Research and Policy, Stanford University, Palo Alto, California, was published online November 20 in The Lancet Diabetes & Endocrinology.
In addition to the predicted rise in insulin requirements, the model shows that improved access to insulin in low- and middle-income countries is badly needed, in particular in Africa and Asia.
“Despite the UN’s commitment to treat noncommunicable diseases and ensure universal access to drugs for diabetes, across much of the world insulin is scarce and unnecessarily difficult for patients to access,” remarked Basu in a Lancet press release.
He added that because of the expected rise in diabetes prevalence, “unless governments begin initiatives to make insulin available and affordable, then its use is always going to be far from optimal.”
The researchers also predict that the disability-adjusted life-years (DALYs) averted through insulin therapy will be highest if HbA1c targets of 7% are used for adults younger than 75 years and 8% are used for adults 75 years and older, as opposed to a universal target of 7%. These targets would require less insulin and provide the optimal balance between risk of hypoglycemia and benefit of longer-term reduced microvascular complications, they say.
“The incremental reduction in microvascular risk by further lowering the HbA1c target from 8% to 7% among those aged 75 years or older was outweighed by the increase in serious hypoglycemia risk,” they explain.
In an accompanying editorial, Hertzel Gerstein, MD, an endocrinologist from McMaster University and Hamilton Health Sciences, Ontario, Canada, remarks that “insulin is likely to maintain its place as a crucial therapy for type 2 diabetes and, as such, a sufficient global supply needs to be estimated and ensured.”
“Conclusions regarding the best glucose targets, however, might be more fragile,” he cautions.
Rigorous Model to Predict Diabetes Prevalence, Insulin Required
Using data that represent more than 60% of the world’s type 2 diabetes population, Basu and colleagues generated conservative projections of diabetes prevalence in adults over the next 12 years. These were then used to develop a model that estimates the number of insulin users in 221 countries and territories, as well as the worldwide insulin need by 2030 according to HbA1c treatment targets from 6.5% to 8%.
They also use various assumptions, including for example, that new insulin preparations being developed will have the same risk of hypoglycemia as those that are currently available, and that no changes will occur in the concomitant use of other drugs known to mitigate hypoglycemia risk for a particular HbA1c target when combined with insulin.
The model also assumes that type 2 diabetes prevalence will continue to increase linearly and roughly 15.5% of all people with type 2 diabetes will use insulin in 2030.
The authors point out limitations, including the fact that dietary habits and physical activity levels that might reasonably affect incidence of type 2 diabetes could change positively or negatively over time, and as such, the International Diabetes Federation prevalence projections might be unpredictable.
Underlying demographics (age, sex), biomarkers (blood pressure, HbA1c), and complications might also deviate from those assumptions used in the model, they note.
Prevalence and Insulin Need Will Rise, Use Will Depend on Access
Worldwide, the model projects that the prevalence of type 2 diabetes in adults is expected to rise from 406 million to 511 million between 2018 and 2030, with over half of these people living in just three countries: China (130 million), India (98 million), and the United States (32 million).
Based on these projected figures, insulin use is estimated to rise from 516.1 million 1000 IU vials/year in 2018 to 633.7 million 1000 IU vials/year in 2030.
Levels of insulin use would vary according to access. If insulin access remains at existing levels, 7.4% of patients with type 2 diabetes in 2030 would use insulin, increasing to 15.5% if insulin was widely accessible and prescribed for patients to reach a target HbA1c of 7% or less.
The projected HbA1c target was found to determine the number of DALYs averted. If the target is 7% or less, then insulin would avert 331,101 DALYs per year by 2030, but with access to newer antihyperglycemic drugs, DALYs averted would increase by 15%.
However, if the HbA1c target became 8% in the over-75s, the model predicted that DALYs averted would increase by 44.2% because of reduced hypoglycemia.
“Most guidelines recommend glucose targets of less than 6.5% or 7%. Targeting a more moderate threshold for control [in older patients] is likely to improve overall health by balancing the risks of hypoglycemia with longer-term microvascular disease benefit,” observed Basu.
In his editorial, Gerstein notes that the model is based on reasonable assumptions about future drug use; for example, no change over the next 12 years in treatments to reduce to diabetic kidney disease independently of insulin or therapies to reduce eye and nerve damage.
But he also cautions that “the rapid pace of diabetes-related research suggests that one or more of the foregoing assumptions will prove to be wrong.”
Regarding the value of the model in predicting future trends in insulin-related diabetes care, Gerstein concludes that “ongoing updates to models such as these, incorporating new data and trends as they accrue, might be the most reliable way of assuring their reliability and relevance to evidence-based care.”
Basu has reported no relevant financial relationships. Gerstein is the McMaster-Sanofi Population Health Institute Chair in Diabetes Research and Care. He has received research grant support from AstraZeneca, Eli Lilly, Merck, and Sanofi, speaker honoraria from AstraZeneca, Boehringer Ingelheim, Eli Lilly, Novo Nordisk, and Sanofi, and consulting fees from Abbott, Amgen, AstraZeneca, Boehringer Ingelheim, Eli Lilly, Merck, Novo Nordisk, Janssen, and Sanofi.