The condition is caused by the pancreas not producing enough of the hormone insulin, or the body not reacting to insulin.
Insulin treatment is crucial for all type 1 diabetes patients, and some people with type 2 diabetes.
But around half of all patients may be without the treatment by the year 2030, a study has revealed.
The amount of insulin needed to effectively treat type 2 diabetes patients will rise by more than 20 per cent of the next 12 years, according to scientists.
But without significant improvements to access, insulin won’t be made available to almost 40 million adults with the condition, they found.
Those most at risk of insulin shortages are countries in Africa, Asia and Oceania, they added.
“The number of adults with type 2 diabetes is expected to rise over the next 12 years due to ageing, urbanization, and associated changes in diet and physical activity,” said Stanford University’s Dr Sanjay Basu.
“Unless governments begin initiatives to make insulin available and affordable, then its use is always going to be far from optimal.”
McMaster University’s Dr Hertzel Gerstein added: “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.”
The number of adults with type 2 diabetes is expected to rise by more than 20 per cent by 2030.
Basu said: “These estimates suggest that current levels of insulin access are highly inadequate compared to projected need, particularly in Africa and Asia, and more efforts should be devoted to overcoming this looming health challenge.”
As the number of people with diabetes rises, and patients’ life expectancy increases, a comprehensive picture of global insulin need is required, the scientists added.
Insulin is crucial for patients as it lowers the risk of some deadly diabetes complications, including kidney failure and strokes.
The hormone helps the body to convert sugar in the blood into useable energy.
Most people need medication to control their type 2 diabetes, said the NHS.
It’s also crucial make some diet and lifestyle changes to keep your blood sugar at a healthy level.
There aren’t any foods that patients should actively avoid, but it’s important to limit the amount of fat and salt in their diet.
Exercise also lowers blood sugar levels. Some of the best activities for patients are fast walking, climbing stairs, and doing strenuous housework.
Everyone should aim for at least 150 minutes of moderate-intensity activity every week.