Bridget Turner, director of policy and care improvement at Diabetes UK, said that "even a single" case of ketoacidosis developing in hospital is "unacceptable" as it suggests insulin "has been withheld from that person for some time".
The fact that this is regularly happening raises serious questions about the ability of hospitals to provide even the most basic level of diabetes care.
In every aspect of hospital diabetes care that this report shines a light on, the picture that emerges is profoundly disturbing.
Medication errors are being made with alarming regularity, large numbers of people are not getting foot checks that we know can help prevent amputation, while one in 10 people's blood glucose level is dropping dangerously low during their hospital stay.
Put together, this adds up to a situation where in too many cases hospitals are doing people with diabetes more harm than good.
There are thought to be 850,000 people who don not know they have type 2 diabetes.
A record breaking three million people have now been diagnosed with the disease, and experts are warning unless more is done to prevent the condition, the NHS could become burdened with unsustainable costs.
Diabetes sufferer Lynda Marks said dealing with the condition is much easier once you start talking about it.
We are hugely concerned that the number of people diagnosed with diabetes has reached three million for the first time and there is no reason to think this will mark the end of what has been a rapid rise in the condition.
Instead, all the projections suggest that the three million figure will be a grim staging post on the road towards a public health emergency and this unfolding tragedy is already putting huge pressure on the NHS and will have potentially devastating consequences for those people who develop the condition. But this is not inevitable.
Three million Britons have been diagnosed with diabetes, research has shown.
It is the equivalent to 4.6 per cent of the population, and experts say the figure is growing, warning it was a "grim staging post towards a public health emergency".
Research by Diabetes UK and Tesco has found that more than 130,000 people were diagnosed with the disease over the last year, with an estimated 850,000 people thought to have undiagnosed Type 2 diabetes.
Health experts say that the NHS could be burdened with unsustainable costs, unless more is done to prevent it.
The National Institute for Health and Clinical Excellence (Nice) has also recommended that people aged 25 and above of South Asian, Chinese, African-Caribbean or Black African descent, who are at a higher risk, should also perform a test.
People can be assessed at their GP surgery or community pharmacy but they can also perform self assessments online.
We are taking wide-ranging action to tackle diabetes. First through prevention - by encouraging healthier lifestyles and identifying those at risk and supporting them to take the necessary action to prevent diabetes. Secondly, by better management of the condition, both in hospital and in the community.
We hope to help prevent people getting diabetes in the first place, but by investing in the NHS and modernising it, we will also drive up the quality of care for those who have the disease.