Treatment for diabetic patients is a postcode lottery with a massive variation in quality of care from one region to another, a report has revealed.
In some regions, only 6% of sufferers received the recommended levels of care compared to 69% in the highest-achieving primary care trusts (PCTs), a National Audit Office (NAO) report found.
Across England only half of people with diabetes received the recommended standards of care in 2009 to 2010. And not a single PCT delivered the nine basic care processes that reduce the risk of diabetes-related complications such as blindness, amputation or kidney disease.
The report also claims the NHS does not "clearly understand" the costs of diabetes at a local level and is therefore finding it difficult to deliver diabetes services in the most effective way.
The review into the management of adult diabetes services in the NHS in England states that up to 24,000 people die each year from avoidable causes relating to diabetes.
It said that there is poor performance in expected levels of care, low achievement of treatment standards and high numbers of avoidable deaths.
It concludes that the NHS diabetes services in England are not delivering value for money.
While the DH estimates it spent £1.3 billion on diabetes services in 2009 to 2010, the NAO claimed the figure was a "substantial underestimate" and was more likely to be in the region of £3.9 billion.
The authors of the report recommend that services for the growing number of people suffering from the disease are "adequate" to help minimise additional costs that are generated by diabetes-related complications.
Barbara Young, chief executive of Diabetes UK, said the results are a "national disgrace".
She said: "The fact that the Government's own value-for-money watchdog has found that poor diabetes healthcare is resulting in avoidable complications and a high number of preventable deaths is a damning indictment of the current approach to the condition.
"By using the money we already spend on diabetes more wisely, we could stop 24,000 people dying unnecessarily every year.
"It has been clear for the last 10 years what needs to happen to fix the problem, but the plan the Government published on this has never been implemented.
"Action is needed now and escalating diabetes costs threaten to wreck the NHS budget so this is an issue that affects all of us, not just people with diabetes."
The worst offenders were Mid Essex and Swindon PCTs where less than 9% of patients were given the nine basic tests recommended by the Department of Health (DH).
The report said that the DH is not holding poorly performing PCTs to account.
The authors say: "The Department holds information to assess performance but there is a lack of accountability for PCTs who fail to ensure that the recommended standards of care are met."
Amyas Morse, head of the NAO, said: "The DH has failed to deliver diabetes care to the standard it set out as long ago as 2001.
"This has resulted in people with diabetes developing avoidable complications, in a high number of preventable deaths and in increased costs for the NHS.
"The expected 23% increase by 2020 in the number of people in England with diabetes will have a major impact on NHS recourses unless the efficiency and effectiveness of existing services are substantially improved."
Care Services Minister Paul Burstow said: "There is no excuse for delivering anything but the best diabetes care.
"Nice (National Institute for Health and Clinical Excellence) guidance and Quality Standards set out what good care looks like. By exposing poor practice and shining a light on best practice, we are determined to drive up standards for everyone.
"We are already working on a new outcomes strategy covering long-term health conditions and are committed to publishing a companion document on diabetes later this year."