Background:

The amount of insulin needed to effectively treat type 2 diabetes worldwide is unknown. It also remains unclear how alternative treatment algorithms would affect insulin use and disability-adjusted life-years (DALYs) averted by insulin use, given that current access to insulin (availability and affordability) in many areas is low. The aim of this study was to compare alternative projections for and consequences of insulin use worldwide under varying treatment algorithms and degrees of insulin access.

Methods:

We developed a microsimulation of type 2 diabetes burden from 2018 to 2030 across 221 countries using data from the International Diabetes Federation for prevalence projections and from 14 cohort studies representing more than 60% of the global type 2 diabetes population for HbA1c, treatment, and bodyweight data. We estimated the number of people with type 2 diabetes expected to use insulin, international units (IU) required, and DALYs averted per year under alternative treatment algorithms targeting HbA1c from 6·5% to 8%, lower microvascular risk, or higher HbA1c for those aged 75 years and older.

Findings:

The number of people with type 2 diabetes worldwide was estimated to increase from 405·6 million (95% CI 315·3 million–533·7 million) in 2018 to 510·8 million (395·9 million–674·3 million) in 2030. On this basis, insulin use is estimated to increase from 516·1 million 1000 IU vials (95% CI 409·0 million–658·6 million) per year in 2018 to 633·7 million (500·5 million–806·7 million) per year in 2030. Without improved insulin access, 7·4% (95% CI 5·8–9·4) of people with type 2 diabetes in 2030 would use insulin, increasing to 15·5% (12·0–20·3) if insulin were widely accessible and prescribed to achieve an HbA1c of 7% (53 mmol/mol) or lower. If HbA1c of 7% or lower was universally achieved, insulin would avert 331 101 DALYs per year by 2030 (95% CI 256 601–437 053). DALYs averted would increase by 14·9% with access to newer oral antihyperglycaemic drugs. DALYs averted would increase by 44·2% if an HbA1c of 8% (64 mmol/mol) were used as a target among people aged 75 years and older because of reduced hypoglycaemia.

Interpretation:

The insulin required to treat type 2 diabetes is expected to increase by more than 20% from 2018 to 2030. More DALYs might be averted if HbA1c targets are higher for older adults.

Funding:

The Leona M and Harry B Helmsley Charitable Trust