The NHS spends around £3 billion a year on potentially avoidable treatment for people with diabetes, experts say.
On average, people with Type 2 diabetes – which is linked to obesity – need care costing over twice as much (£1,291 per person per year) as people without diabetes (£510), an analysis of hospital treatment in England for 2017/18 found.
Those with Type 1 diabetes, which usually develops in childhood, require six times more hospital treatment (at £3,035 per person per year).
The findings are being presented at the European Association for the Study of Diabetes (EASD) annual meeting in Barcelona.
Researchers analysed data on planned care as well as A&E visits, emergency hospital admissions and outpatient visits for 58 million people including 2.9 million with Type 2 diabetes and 243,000 with Type 1.
Overall, the NHS in England spent around £5.5 billion on hospital care for people with diabetes, of which an estimated £3 billion could potentially have been avoided, the team said.
They argued this represents almost 10% of the NHS hospital budget.
Compared to people without diabetes, the average annual cost of planned care was over twice as high for those with Type 2 diabetes and the average cost of emergency care was three times higher, once age was taken into account.
Study author, Dr Adrian Heald from Salford Royal Hospital, said: “People with diabetes are admitted to hospital more often, especially as emergencies, and stay on average longer as inpatients.
“These increased hospital costs, 40% of which come from non-elective and emergency care, are three times higher than the current costs of diabetes medication.
“Improved management of diabetes by GPs and diabetes specialist care teams could improve the health of people with diabetes and substantially reduce the level of hospital care and costs.”
Emma Elvin, senior clinical adviser at Diabetes UK, said more needed to be known about the reasons why diabetes patients were admitted to hospital before firm conclusions could be drawn.
She added: “What we do know, is that more than a million people with diabetes were admitted to hospital in England in 2017 – meaning around 18% of hospital beds were occupied by someone with diabetes – but it is incredibly important to stress that only 8% were admitted because of their condition.
“The fact is, everyone – regardless of whether they have diabetes or not – can experience health conditions or accidents that put them in hospital.
“The focus needs to be on improving the support people with diabetes receive across the whole health system to help them manage their condition.
“This will help people with diabetes live longer, healthier lives and could also save money for our already stretched NHS.”
An NHS spokesman said: “The rising number of people with Type 2 diabetes is worrying for the nation’s overall health, as well as putting avoidable pressure on the NHS with a heavy cost for taxpayers.
“The NHS Long Term Plan is playing its part by expanding the Diabetes Prevention Programme so 200,000 people a year who are at risk are helped to prevent it, as well as significant investment to care for with those with Type 1, including providing life-changing tech to measure sugar levels, which can free up NHS time and resources.”