The NHS may be facing a "diabetes time bomb" involving the future care of hundreds of thousands of younger patients, according to the biggest-ever audit of diabetes in England and Wales.

Nearly 300,000 children and younger adults with diabetes have high-risk - and 144,000 have dangerously high-risk - blood sugar levels that will lead to high levels of severe and disabling complications like kidney failure, limb amputation and stroke, according to the National Diabetes Audit 2010.

While high-risk blood sugar levels are more common in younger people and the socially deprived, over 800,000 people with diagnosed diabetes have high-risk levels and are at risk of complications, the research finds.

Also, children and younger adults (aged 0-54) are also less likely than people aged 55-69 and the elderly (70 and over) to receive all the basic care checks required to monitor their condition, leading to concerns that a large cohort of a whole generation with diabetes will require substantial hospital care in a matter of years.

Fewer younger adults (age 24 to 54) compared to other age groups receive all nine recommended basic care processes annually, such as blood pressure, blood sugar and foot checks. Overall, the percentage of patients receiving every process is improving each year, but two-thirds of patients with Type 1 diabetes and almost half of those with Type 2 still do not receive all nine.

The Audit also reveals that obesity is more prevalent among children and younger adults with diabetes than older adults and the elderly. Among younger adults with Type 2 diabetes, nine out of 10 are overweight or obese - the highest prevalence within any age group.

The prevalence of diabetes, especially Type 2, is rising each year, particularly in deprived communities, and there are substantial regional variations in both the prevalence and treatment of complications such as kidney failure and dialysis, it adds.

Commenting on the Audit’s findings, the National Clinical Director for Diabetes, Rowan Hillson, said he was "very concerned" that there is still a long way to go in delivering basic standards of diabetes care for everyone, and, in particular, that young and middle-aged people with the condition are not getting the regular checks they need to manage their diabetes and improve outcomes; these checks are vital to reducing serious but avoidable complications.

"All health care professionals should follow [the National Institute for Health and Clinical Excellence's] clear recommendations - there is no excuse for not doing the basics well," said Dr Hillson.

• The National Diabetes Audit is the largest of its kind in the world. Commissioned by the Healthcare Quality Improvement Partnership (HQIP) and managed by The NHS Information Centre, it includes data from more than 80% of the estimated 2.34 million people aged 17 and over with diagnosed diabetes in England. The Audit also includes data from all seven Local Health Boards in Wales.